Neurological Dictionary

A

acalcula:

difficulties with arithmetic; may be the result of damage to the angular gyrus in the hemisphere dominant for speech and language

 

acceleration-deceleration trauma:

According to Love and Webb (1992) the most predominant injury type is acceleration-deceleration trauma. Acceleration-deceleration trauma causes discrete lesions which affect only certain areas of the brain, occurs when the head is accelerated and then stopped suddenly, as in a car accident, and causes discrete, focal lesions to two areas of the brain, The prefrontal areas and the anterior portion of the temporal lobes. The brain will suffer contusions at the point of direct impact and at the site directly opposite the point of impact due to the oscillation of the brain within the skull.

It should be noted that brain injuries may occur as a result of acceleration-deceleration trauma unaccompanied by impact.

 

acetylcholine:

a neurotransmitter for motor neurons that is involved in the inhibitory function (as is dopamine) of the basal ganglia

 

afferent fibers:

nerve fibers that take messages from the periphery to the brain; afferent fibers are almost always sensory fibers

 

alexia:

acquired disturbance of reading due to brain injury (Love and Webb, 1996, p. 314)

 

agnosia:

lack of sensory recognition as the result of a lesion in the sensory association areas or association pathways of the brain. An example is looking at a common object but not recognizing it, or associating meaning with the image.

 

agraphia:

acquired disturbance of writing due to brain injury (Love and Webb, 1996, p. 314)

 

alexia with agraphia:

difficulties with reading and writing; may be the result of damage to the angular gyrus in the hemisphere dominant for speech and language

 

alpha cells:

the principle lower motor neurons of the spinal cord (they are located on the ventral aspect of the cord); they form the main part of the final common pathway and conduct rapid motor impulses; each alpha cell innervates approximately 200 muscle fibers

 

alternating hemiplegia:

paralysis of different structures on each side of the body; this condition may be the result of a lesion in the brain stem that damages both the nucleus of a cranial nerve and one side of the upper motor neurons of the pyramidal tract

 

amygdala:

a structure which is attached to the tail of the caudate nucleus; it is considered to be a part of the limbic system and is involved in emotion

 

anastomosis:

communication or connection between the separate components of a branching system; as in the Circle of Willis, anastomosis allows blood carried by different arterial branches to come together and be redistributed

 

angular gyrus:

the gyrus that lies near the superior edge of the temporal lobe, and immediately posterior to the supramarginal gyrus; it is involved in the recognition of visual symbols (Geschwind referred to it as the "association cortex for association cortices" and "the most important cortical areas of speech and language"). Lesions in this area can result in alexia and agraphia.

 

anomia:

difficulty with word-finding or naming; anomia may be the result of damage to the angular gyrus in the hemisphere dominant for speech and language. According to Goodglass and Kaplan (1983), anomia can be localized with the least reliability of any of the aphasic syndromes. Also, according to Keenan (1975) all patients with Aphasia experience some problems with word finding.

 

anosmia:

a loss of the sense of smell; may be a result of a lesion on the olfactory pathway

 

anterior:

toward the front (opposed to posterior)

anterior cerebral artery:

a branch of the internal carotid artery; the anterior cerebral artery supplies blood to the medial cortex, some areas of the frontal lobe, and the corpus striatum

 

anterior commissure:

one of the three major groups of commissural fibers; part of the Circle of Willis, the anterior commissure connects the temporal lobes, as well as connecting the temporal lobe to the amygdala and to the opposite occipital lobe; it is also connected to the corpus callosum

 

anterior communicating artery:

an artery which arises from the internal carotids; it joins together the anterior cerebral arteries of each hemisphere

 

aorta:

the main artery supplying blood to the body (with the exception of the lungs); it ascends from the heart then forms an arch, from which two subclavian arteries arise

 

aphasia:

a disturbance of the skills, associations, and habits of language due to injury to certain brain areas that are specialized for these functions. Disturbances of language usage that are due to paralysis or incoordination of the musculature of speech or writing or poor vision or hearing are not, of themselves, aphasic." Thus, aphasia can affect auditory comprehension, oral expression, reading and writing. (Goodglass and Kaplan, 1983)

 

apraxia:

comes from the Greek word "praxis," which means action. According to Halperin (1986 in Chapey, 1986, p.422), "apraxia of speech is an articulation disorder that results from impairment due to brain damage, of the capacity to order the positioning of speech musculature and the sequencing of muscle movements for volitional production of phonemes and sequences of phonemes; but it is not accompanied by significant weakness, slowness, or incoordination of these same muscles in reflex and automatic acts."

 

Apraxia of speech is a disruption of the capacity to program the skilled oral movements necessary for speech. The problem is with the programming associated with incorrect neural commands at higher, more central levels. In the past, apraxia was often classified as a type of articulation disorder and was in fact called central dysarthria by some. Now, it is considered a motor planning/programming deficit. According to Wertz (1984), apraxia of speech "is a neurogenic phonological disorder, resulting from the sensorimotor impairment of the capacity to select, program and execute coordinated movements of the speech musculature for the production of voluntary speech." In other words, the part of the brain that generates the motor programs for speech/phonology is damaged. Kearns and Simmons (1989, in Northern, 1989) reported that research using spectographic analysis of voice onset time (VOT) supports the programming position. Includes limb apraxia, oral apraxia, apraxia of gait, and apraxia of the swallow.

 

apraxia of gait:

difficulty with programming the motor movements involved in walking

 

apraxia of the swallow :

inability to swallow volitionally.

 

apical dendrites:

a type of dendrite which has a stalk that is filled with cytoplasm, these appear to be part of the soma of the neuron to which they are attached; the majority of apical dendrites are found in the cerebral cortex

 

Aqueduct of Sylvius (cerebral aqueduct):

a channel which connects the third and fourth ventricles

 

arachnoid mater:

the middle layer of the meninges; in some areas it has projections (arachnoid granulations or villi) into the sinuses formed by the dura mater

 

arachnoid villi (arachnoid granulations):

projections of the arachnoid mater into the sinuses formed by the dura mater that transfer cerebrospinal fluid back into the bloodstream

 

arcuate fasciculus:

the groups of fibers that connect Broca's area with Wernicke's area (these fibers connect to the angular gyrus) and are located below the supramarginal gyrus. According to Geschwind, damage to this area results in Conduction Aphasia.

 

arteriosclerosis:

formation of "plaque" consisting of muscle cells and fats on arterial walls making the flow of blood through  arteries more difficult. Informally, "hardening of the arteries"

 

arteries of stroke:

striata arteries, which are branches of the middle cerebral arteries

 

ascending reticular formation (reticular activating system):

the component of the reticular formation that is responsible for the sleep-wake cycle; it mediates various levels of alertness

 

aspiration:

occurs whenever food enters the airway below the true vocal folds. Aspiration can occur before, during, or after the swallow.

 

association fibers:

nerve fibers that connect areas within the same lobe or between lobes, within the same hemisphere; the most prevalent type of neuroal tracts found in the cortex

 

ataxia:

an incoordination of motor movement; ataxia results from cerebellar lesions; the term may also be used to describe the unsteady walk and unusual postures seen in patients who have suffered injury to the cerebellum

 

ataxic dysarthria (cerebellar dysarthria):

a disorder that results in jerky, uncoordinated movements of the speech musculature; it is caused by lesions in the cerebellum

 

athetosis:

disorder that causes slow writhing movements of the entire body but especially of the arms, face and tongue.

auditory association areas:

Brodmann's areas 21 and 22

 

auditory comprehension:

the ability to understand spoken language

 

autonomic nervous system:

one of the three main divisions of the nervous system; it innervates the involuntary structures of the body (e.g., heart, smooth muscles, glands) and is involved in control of automatic and glandular functions; it is divided into two parts, the sympathetic and parasypathetic

 

axon:

the part of the neuron that allows it to send messages to other nerve cells; although each neuron can have only one axon, the axon itself can have many branches which connects it to many others  

 

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Barium:

contrast material, not radioactive, used during barium and modified barium studies

 

basal ganglia:

the largest subcortical structure of the brain; it is made up of the caudate nucleus and the lenticular nucleus; it is located at the level of the thalamus

 

basilar artery (vertebral basilar artery):

the artery that is formed when the two vertebral arteries join together at the lower border of the pons; the basilar artery again divides at the superior border of the pons to form the posterior cerebral arteries (other arteries that arise from the basilar prior to this division include the anterior cerebellar arteries, inferior cerebellar arteries, posterior cerebellar arteries, and the pontine branches)

 

basilar dendrites:

a type of dendrite that does not have a stalk; these are more numerous than apical dendrites

 

BDAE: Boston Diagnostic Aphasia Examination

developed by Goodglass and Kaplan in 1972, is currently being revised. (I was asked by the publishing company to critique/review the upcoming edition. It promises to be quite good.) At the moment it consists of twenty-seven subtests divided into the following sections: conversational and expository speech, auditory comprehension, oral expression, understanding written language, and writing. The severity of a patient's aphasia can be rated on a scale from one to seven based on speech and language characteristics as well as auditory comprehension. The Boston Naming Test, a test for anomia which was developed to be used along with the BDAE, is the supplementary instrument most often used in the evaluation of aphasia (Chapey, 1994).

 

bilateral innervation:

both left and right nuclei of a pair of cranial nerves receive innervation from both the left and the right motor pyramidal tracts, provides both ipsilateral and contralateral innervation

 

biological intelligence:

the complex cognitive processes (such as reasoning and judgment) that are mediated by the most anterior part of the frontal lobe

 

BDAE: Boston Diagnostic Aphasia Examination

 

bradycardia:

slowed heart rate

 

Bradykinesia:

the "reduced speed of movement of a muscle through its range" (Love & Webb, 1992, p. 146).

 

brain stem:

the midbrain, pons, and medulla oblongata

 

bradycardia:

slow heart rate

 

broad-based gait:

a term used to describe the way in which some patients compensate for problems related to cerebellar injury by walking with their feet far apart

 

Broca's aphasia:

affects the third frontal convolution (both the gyrus and the sulcus) of the left frontal lobe. ( Broca's area, Brodmann's area #44)

 

Characteristics are telegraphic speech, affected syntax, as well as labored and slow speech, Melodic Contour is flat and Articulatory Agility is impaired. Potential problems include: simplification of consonant clusters (e.g. t/st, p/spl) and distortion of phonemes, substitutions are infrequent. A few paraphasias may occur. They will usually be literal. Repetition is typically impaired, as is Word finding. Auditory Comprehension is superior to expressive language. The patient's ability to understand grammatical morphemes will be affected. So, while it can be said that auditory comprehension is good in comparison to that of Wernicke's aphasics, it is not normal.

The Token Test (DeRenzi & Vignolo, 1966), which assesses subtle receptive language dysfunction, can be used to evaluate the auditory comprehension of Broca's aphasics and to help distinguish between Broca's aphasia and verbal apraxia.  Also, limb apraxia may not allow the patient to carry out the instructions, even though he/she understands them.

Hemiplegia/Hemiparesis of the right side is common in left hemisphere lesions causing Broca's aphasia (remember, the language center is in the left hemisphere for more than 90% of the population) The face and arm are most likely to be affected due to the organization of the motor strip.Apraxia frequently accompanies this type of aphasia as it is also caused by lesions to area 44. Broca's aphasics typically have low frustration tolerance. They are aware of their errors and may respond to them with a catastrophic reaction which might include crying, screaming and yelling, etc.

 

Broca's area:

the area of the brain involved in the programming of motor movements for the production of speech sounds; it is also involved in syntax; Broca's area is located on the inferior third frontal gyrus in the hemisphere dominant for language; injuries here may result in apraxia or Broca's aphasia

 

Brodmann's Classification System:

a map of the cortex developed by neurologist Korbinian Brodmann that classifies the different areas of the brain by number

 

buccinator muscle (oral cavity):

holds food in contact with the teeth. with the obicularis oris and zygomaticus all three are  innervated by the facial nerve (CN. VII).

 

bulbar lesions:

injuries to the nuclei of the cranial nerves located in the brain stem; they are considered to be lesions of the final common pathway: usually bilateral, they produce bulbar palsy

 

bulbar palsy:

paralysis produced by bulbar lesions  

 

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catastrophic reaction:

crying, screaming and yelling, etc. by  a person with Broca's aphasia as an expression of low frustration tolerance/awareness of their errors

 

cauda equina:

The continuation of nerve fibers in the part of the vertebral column that lies below the spinal cord; cauda equina is Latin for "horse's tail"

 

caudal:

"toward the tail," may mean the same as inferior; an antonym is rostral

 

caudate nucleus:

one of the two structures that make up the basal ganglia; it is divided into a head, body, and tail and is bounded on one side by the lateral ventricle

 

central canal:

the space in the middle of the grey matter of the spinal cord; it contains cerebrospinal fluid

 

central sulcus (fissure of Rolando):

the deep sulcus that separates the frontal and parietal lobes

 

cephalic:

a synonym of superior; refers to the upper parts of the nervous system

 

cerebellar peduncles:

three pairs of fiber bundles (the superior cerebellar peduncle, the middle cerebellar peduncle, and the inferior cerebellar peduncle) which connect the cerebellum to the brain stem; information passes on these tracts in both directions, every message that is sent or received by the cerebellum travels on the cerebellar peduncles

 

cerebellar dysarthria (ataxic dysarthria):

a disorder that results in jerky, uncoordinated movements of the speech musculature; it is caused by lesions in the cerebellum

 

cerebellum:

It is involved in the coordination and production of speech, the organization of muscle movement, coordination of fine motor movement, and balance; it is the center of a feedback loop involving motor and sensory information; "cerebellum" means "little brain" in Latin

 

cerebral dementia:

may result from anterior cerebral artery blockages. Confused language, or a language indicative of cognitive impairment, may also occur.

 

cerebral peduncles:

fiber bundles that are located in the brain stem; the cerebral peduncles connect the pons to the cerebrum

 

cerebral vascular accident:

is a temporary or permanent loss of functioning of brain tissue caused by an interruption in the cerebral blood supply

 

cerebrospinal fluid:

a clear liquid produced and found in the ventricles. It flows through the subarachnoid space (surrounding the brain and spinal cord), and inside the central canal of the spinal cord; it functions as a protective cushion for, brings nutrients to, and removes waste from, the neuraxis

 

cerebrovascular resistance:

makes it more difficult for blood to flow from one area to another. It can be caused by arterial spasm, a high level of tri-glycerides in the blood which increases its viscosity, or by elevated levels of cerebral spinal fluid.

 

cholesterol:

HDLs or high density lipoproteins are the "good" cholesterol. LDLs or low density lipoproteins are the "bad" cholesterol. It is all right to have high levels of HDLs, but a high concentration of LDLs is a health risk. Overall cholesterol levels should be under 200.

 

choroid plexes:

structures that produce cerebrospinal fluid by allowing certain components of blood to enter the ventricles; formed by a fusing of the pia mater and the ependyma

 

cingulate gyrus:

a cortical area (a gyrus) considered to be a part of the limbic system; it is located immediately superior to the corpus callosum

 

Circle of Willis (Circulus Arteriosus):

the main arterial anastomatic trunk of the brain; the Circle of Willis is a point where the blood carried by the two internal carotids and the basilar system comes together and is subsequently redistributed by the anterior, middle, and posterior cerebral arteries

 

circumlocutions:

wordy and circuitous description of unrecalled terms. For example the patient may say "have one of them up there" when trying to explain he's had brain surgery.

 

claustrum:

a structure considered by some anatomists to be a part of the basal ganglia

 

Closed Head Injury (CHI):

brain injury resulting from coup-contra coup, acceleration or deceleration injury. Classified as severe, moderate, or mild based on the degree to which consciousness is impaired immediately after injury. According to Clifton (1989), severe head injury has been defined as coma for longer than six hours. Concussion defines mild head injury.

Secondary damage in CHI includes widespread or localized edema as well as slowly developing hemorrhages (Ylvisaker and Szekeres, 1994, in Chapey, 1994).

 

cocktail hour speech:

often seen in a person with Wernicke's Aphasia

 

cognitive approach:

introduced by Schuell with the use of auditory stimuli, evolved through Duffy to use a multi-modality approach and by Chapey (1994) to use divergent thinking

 

collateral circulation:

a safety mechanism of the arterial system of the brain; collateral circulation involves the redirecting of blood through a route that is different than normal; it can be crucial when blockages occur

 

commissural fibers:

nerve fibers that connect the hemispheres of the brain; the corpus callosum, anterior commissure, and the posterior commissure are composed of commissural fibers

 

commissurectomy:

an operation that severs the corpus callosum; commissurectomies have been used as a treatment for severe epileptic seizures

 

completed stroke:

type most commonly seen, the infarction of brain tissue has ceased to occur

 

conduction aphasia:

a type of aphasia that may be the result of a lesion to the arcuate fasciculus

may result from anterior cerebral artery blockages

 

conduit d'approche:

(Goodglass and Kaplan, 1983) patient is aware of his/her paraphrasitic errors and will produce repeated approximations of the intended word, as if he is trying to untangle it

 

confrontation naming:

one way of testing one's word finding ability

 

confused language:

a language indicative of cognitive impairment that may occur as a result of anterior cerebral artery blockages and may accompanied by cerebral dementia, seems to be the result of cognitive problems with right hemisphere lesions.

 

contralateral hyposthesia:

lack of sensation on side of body opposite to site of lesion

 

contralateral innervation:

when a cranial nerve, or a portion of it, receives information only from fibers on the opposite side of the brain

 

conus medularis:

the point at which the spinal cord ends, just above the small of the back

 

convolution:

the corrogated appearance of the cortex, includes both gyri and sulci

 

coronal cut:

a cut that separates the brain into front and back portions; a cut that runs from ear to ear

 

corpora quadrigemina:

consists of the tectum and the four colliculi which are bumps on the tectum (two superior colliculi and two inferior colliculi); the corpora quadrigemina is located on the posterior surface of the midbrain

 

corpus callosum:

Latin for "large body," the corpus callosum is the major group of commissural fibers; it is located some distance down inside the longitudinal cerebral fissure; it connects the hemispheres and mainly connects mirror image sites

 

corpus striatum:

the group of structures that includes the basal ganglia and internal capsule; it is called the "striped body" because the internal capsule runs between the caudate nucleus and lenticular nucleus of the basal ganglia, creating a striped appearance

 

cortex:

the layer of cells that cover the two hemispheres of the brain; its surface is composed of gyri and sulci

 

cortical blindness:

caused by damage to occipital lobes, often when blood is cut off in the posterior cerebral arteries.

 

corticobulbar tract:

the fibers of the pyramidal tract that synapse with the cranial nerves located in the brain stem

 

corticopontine tract:

fibers from the motor strip of the cortex

 

corticopontocerebellar tract:

a fiber tract that brings a copy of the motor information (including information about the nature, destination, strength, and speed of the motor impulse being sent by the precentral gyrus) to the cerebellum from the frontal lobe; the information travels on this tract from the precentral gyrus, descending in the internal capsule, then synapsing with cells in the pons;  pontine nuclei then send second order neurons to the cerebellum on the middle cerebellar peduncle

 

corticospinal tract:

the fibers of the pyramidal tract that synapse with spinal nerves; these fibers carry information about voluntary movement to the skeletal muscles; as they descend they form part of the posterior limb of the internal capsule

 

coup contre-coup:

usually due to a fall or a blow to the head. The coup is the damage to the braim just beneath the site of impact. Contra-coup is the damage to the opposite side of the brain as the brain bounces against the skull.

 

cranial:

a synonym of superior; cranial refers to the upper parts of the nervous system

 

cricopharyngus m. or pharyngeal-esophageal (P.E) segment:

separates the pharynx from the esophagus. At the end of the pharyngeal stage of the swallow, it must relax to allow the bolus to enter the esophagus. (It is normally closed to prevent the reflux of food and to keep air out of the digestive system.) 

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deep nuclei of the cerebellum:

four different nuclei (the dentate nucleus, the emboliform nucleus, the globose nucleus, and the fastigial nucleus) located deep within each cerebellar hemisphere that have axons to the brain stem and thus send messages out to be conveyed to other parts of the central nervous system; these nuclei are regulated by Purkinje cells which perform an inhibitory function.

 

Dementia:

Between 30 and 40 percent of Parkinson's patients suffer from dementia; loss of mental acuity

 

dendrite:

the part of the neuron that receives messages from the axons of other nerve cells; the two types of dendrites are apical dendrites and basilar dendrites

 

descending reticular formation:

the component of the reticular formation that is involved in autonomic nervous system activity; it receives information from the thalamus; the descending reticular formation also plays a role in motor movement

 

diabetes insipidus:

the most serious type of diabetes; diabetes insipidus is caused by lesions in the hypothalamus or between the pituitary gland and the hypothalamus

 

diachisis:

is a kind of post-lesional cerebral shock resulting in sudden inhibition of function diminishment and possibly a complete loss of functioning in brain areas distal to the site of lesion, may be far away from the point of original damage,   usually connected to the infarcted area by nerve pathways (Steadman, 1997). Cause of diachisis in unknown; it may be the result of edema, reduced cerebral blood flow, the release of neurochemicals or other factors which have not yet been identified. Diachisis can occur after CHI as well as after stroke.

 

diencephalon:

the thalamus and hypothalamus

 

Diffuse Brain Injury:

wide spread injury, it can impair attention and perception causing problems like neglect and prosopagnosia. An inability to analyze and synthesize information and a reduction in the rate of information processing may also result from wide-spread brain damage. In addition, long term memory and problem solving may be impaired. Reasoning, both inductive and deductive, may be involved. Convergent and divergent thinking are the two main parameters of reasoning. Convergent thinking often produces single conclusions while divergent thinking is open ended e.g. how many things can you do with a toothbrush? Pragmatic problems like impaired social judgment, reduced inhibition, and poor comprehension of abstraction may occur as well.

 

direct pyramidal tract (ventral pyramidal tract, anterior corticospinal tract):

the uncrossed (direct) fibers of the corticospinal tract that synapse with the spinal nerves on the ipsilateral side of the body; these fibers travel down the ventral aspect of the cord

 

diskinesias:

disorders of involuntary movement; may be the result of extrapyramidal tract lesions

 

divergent thinking:

a patient with aphasia is required to produce several creative responses to every stimulus. For example, the patient might be asked to think of several unusual ways to make use of an everyday object.

 

dopamine:

a neurotransmitter involved in the inhibitory function of the basal ganglia; it is produced by the substantia nigra. Lack of dopamine can result in Parkinson's disease.

 

dorsospinocerebellar tract:

one of the two main tracts that bring sensory information from the periphery to the cerebellum; proprioceptive information from the upper body travels on this fiber tract; it carries messages received by the reticular nuclei in various parts of the brain stem from the cortex, spinal cord, vestibular system and red nucleus; information from this tract enters the cerebellum on the inferior cerebellar peduncle

 

dura mater:

Latin for "hard mother," the dura mater is the most superior of the layers of the meninges; this tough, inflexible tissue forms several structures that serve to separate the cranial cavity into compartments and protect the brain from displacement, as well as forming several vein-like sinuses that carry blood back to the heart

 

dysarthria:

According to Darley, Aronson and Brown (1975), a speech disorder resulting from a weakness, paralysis, or incoordination of the speech musculature that is of neurological etiology. All types of dysarthria  result from damage to the central or peripheral nervous system that impairs the transmission of neural messages to the muscles involved in speech. In contrast to apraxia which affects the brain's capacity to produce the "programs" necessary for coordinated motor movements, dysarthria results from an inability to send the proper messages to the musculature. While apraxia affects articulation and, to some extent, prosody, dysarthria can impair all processes involved in speech production including respiration, phonation, articulation, resonance and prosody. Based on etiology, Darley, Aronson and Brown (1969), identified six different types of dysarthria. These include four forms of the disorder which are caused by damage to upper motor neurons. They include spastic, hyperkinetic, hypokinetic, and ataxic dysarthria.

 

dysphagia:

difficulty swallowing, types can include the most common type, delayed/absent initiation of the pharyngeal stage of the swallow, disorders of the pharyngeal stage of the swallow  which are the most prevalent type of dysphagia among the CVA population, and types associated with site of lesion including brain stem stroke, subcortical stroke, unilateral left hemisphere stroke, Unilateral Right Hemisphere Stroke, and multiple strokes. Therapy strategies may include Icing, Thermal Stimulation, Sensory Stimulation, Suck-Swallow technique, Chewing, Oral-motor exercises. Posture to facilitate swallow is also utilized for therapy, as is selection of food consistencies and techniques for protecting the airway

 

Dystonia:

causes slow jerky movements which are most likely to occur in the trunk, neck and proximal parts of the limbs.

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Edema:

swelling, begins two or three days after a cerebral insult. Only in the area that has been injured, however, as localized swelling can greatly increase pressure throughout the whole cranium, the functioning of the entire brain may be affected. Edema of the brain should begin to decrease by the beginning of the first week post-injury. As intracranial pressure returns to normal levels, any behavioral changes that were caused by the swelling rather than by the brain injury will disappear.

 

efferent fibers:

nerve fibers that take messages from the brain to the peripheral nervous system; motor fibers are efferent

 

Effortful Swallow:

increases the tongue driving force by causing exaggerated retraction of the tongue. This helps to get food past the valleculae. The patient is directed to squeeze hard with hi/her   throat and neck muscles during the swallow.
*** The above techniques are most often used with patients who have had brain stem lesions and so have severe dysphagia, but still have good cognitive ability.

 

endolymph:

the fluid that fills the semicircular canals of the inner ear

 

ependyma:

the membranous lining of the ventricles

 

Epidural Bleeding:

According to Stedman (1997) epidural hemorrhaging, also called extra dural, is an accumulation of blood between the skull and the dura mater. It is usually the result of acceleration-deceleration trauma. This type of bleeding results from lesions of the arteries, most commonly the middle meningeal artery.  The patient is usually unconscious immediately, then lucid briefly, then loses conscious again from a large clot in the epidural space. The clot may compress cranial nerves resulting in pupillary dilation, as well as ipsalateral weakness or paralysis (Pires,1984, in Urosovich, 1984).

 

Surgical aspiration of hematomas resulting from epidural bleeding may be used as a life-saving technique.

 

epidural space:

a potential space between the dura mater and the skull

 

esophageal stage of the swallow:

involuntary stage where the larynx returns to its normal position, and the cricopharyngus muscle contracts to prevent reflux and respiration resumes.

 

executive function:

according to Dunkla, 1996, the executive function regulates and directs cognitive processes. It organizes behavior, sets goals, and facilitates goal achievement while inhibiting behavior detrimental to goal completion.

 

expressive Aphasia:

most commonly called  Broca's Aphasia, also called Motor Aphasia

 

external carotid artery:

a division of the common carotid; the external carotid supplies blood to the face

 

external granular layer:

the second most superior layer of the cortex; it is very dense and contains small granular cells and small pyramidal cells

 

external circular layer (of the pharynx):

made up of the superior, middle, and inferior pharyngeal constrictor muscles

 

external pyramidal layer (medial pyramidal layer):

the third most superior layer of the cortex; it contains pyramidal cells in row formation and the cell bodies of some association fibers

 

extraneural factors:

factors that may include abnormal blood pressure, cerebrovascular resistance, and arteriosclerosis may impede collateral circulation

 

extrapyramidal tract:

involved in automatic motor movements, gross motor movements, posture and muscle tone (in combination with the autonomic nervous system) and facial expression; it is an indirect, multisynaptic tract; the components of the extrapyramidal system include the basal ganglia, the red nucleus, substancia nigra, the reticular formation, and the cerebellum, consists of neurons that regulate involuntary/automatic movements. Lesions in the extrapyramidal tract cause various types of diskinesias or disorders of involuntary movement. The problems mostly commonly affecting the extrapyramidal tract include degenerative diseases, encephalitis, and tumors.

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Facial Nerve (Cranial Nerve VII):

innervates the lip muscles including the obicularis oris and the zygomaticus. The muscles must contract during the oral preparatory and oral transport stages of the swallow to prevent food from dribbling out of the mouth. The facial also innervates the buccinator muscles of the cheeks. These must remain tense during the oral component of the swallowing process to prevent the pocketing of food between the teeth and the cheeks.

Sensory Component carries information about taste from the anterior 2/3 of the tongue.

 

falx cerebelli:

separates the lobes of the cerebellum; the falx cerebelli is formed by the dura mater

 

falx cerebri:

separates the lobes of the cerebrum; the falx cerebri is formed by the dura mater

 

festinating movements:

movements which become increasingly rapid and uncontrolled

 

final common pathway:

lower motor neurons traveling to the muscles of the body on the only route by which information from any of the upper motor tracts can reach the periphery. Thus, when lower motor neurons are damaged, the parts of the body that they innervate are deprived of input from the pyramidal and extrapyramidal tract as well as cerebellar pathways. Thus, voluntary, automatic and reflexive movements are all affected.

 

finger agnosia:

an inability to recognize objects through the sense of touch; may be the result of damage to the angular gyrus in the hemisphere dominant for speech and language

 

fissure:

a particularly deep sulcus

 

fissure of Rolando (central sulcus):

the sulcus that separates the frontal and parietal lobes

 

fissure of Sylvius (lateral fissure):

the fissure that separates the frontal and temporal lobes

 

flaccid (lower motor neuron) dysarthria:

the only form of dysarthria that results from damage to lower motor neurons.

 

Fluent Aphasias:

Fluent aphasias are the result of lesions affecting the post Rolandic area. Problems with meaning are associated with posterior lesions.

Phoneme selection and sequencing as well as syntax are preserved. Speech is characterized by a facility of articulation and many long runs of words combined using a variety of grammatical constructions. However, fluent speech is not equivalent to meaningful speech. Often the speech of fluent aphasics sounds like "jabberwocky." Typically, there are word-finding problems that affect nouns and picturable action words. Comprehension is typically poor with fluent/posterior lesion aphasias. (Conduction aphasia would be the exception to this). The amount and type of paraphasias, the presence of auditory receptive impairments and of impaired repetition are variable in fluent aphasias, depending upon the exact site of lesion.

 

flocculi:

the most ancient part of the cerebellum; the flocculi are part of flocculonodular lobe

 

flocculonodular lobe:

the lobe of the cerebellum that consists of the flocculi and the nodulus; the flocculonodular lobe is involved in the maintenance of equilibrium

 

focal lesions:

generally small and just in one area, focal lesions can affect the language and swallowing centers of the brain, they can cause symptoms similar to those seen as a result of a left cerebral vascular accident including apraxia, dysarthria, aphasia, dysphagia, agnosia, anomia, and dysphonia. Focal lesions can also cause more general impairments that affect language, similar to those resulting from right hemisphere damage. These include attentional, perceptual and pragmatic deficits.

 

foramina of Luschka:

two lateral openings (along with the medial foramen of Magendie) which serve to connect the fourth ventricle to the subarachnoid space

 

foramen of Magendie:

a medial opening (along with the lateral foramina of Luschka) which serves to connect the fourth ventricle to the subarachnoid space

 

foramina of Munro (interventricular foramina):

two openings which connect the lateral ventricles to the third ventricle

 

fornix:

a subcortical component of the limbic system; the fornix is a group of fibers that arise from the hippocampus and connect the rhinencephalon to the thalamus and hypothalamus; the fornix is connected to the septal nuclei and the mamillary bodies

 

fourth ventricle:

one of the four ventricles of the brain; it is filled with cerebrospinal fluid; the fourth ventricle is located between the cerebellum and the pons

 

frontal lobe:

the most anterior lobe of the brain; it is bounded posteriorly by the central sulcus and inferiorly by the lateral fissure; this lobe is associated with higher cognitive functions and is involved in the control of voluntary muscle movement

 

fusiform layer (multiform layer):

the sixth and most inferior layer of the cortex  

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GABA:

Gamma Amino Butric Acid; a neurotransmitter that is involved in the inhibitory function of the basal ganglia; it is a glutamate

 

gag reflex:

a good example of a true reflex. It is "triggered" whenever a noxious substance touches the back of the tongue, back of the pharynx, or soft palate. The swallow response, on the other hand, cannot be initiated by touching any particular area in the oral cavity. The gag reflex and the swallow response also differ in terms of neurological control. The gag reflex is completely controlled by the brain stem. The swallow, on the other hand, is only partially controlled by the brain stem. It also receives cortical input, and input from muscle spindles, including feedback from tongue movements.

(It is important to note that the gag reflex and the swallow response are not related. In the past, many physicians would determine feeding status based on the presence or absence of a patient's gag. Actually, the presence or absence of a gag reflex does not predict the status of the swallow response.)

 

gamma neurons:

neurons of the final common pathway (located on the ventral aspect of the spinal cord); these cells conduct slow motor impulses and their main function is to stretch muscle spindles; gamma cells are only half as numerous as alpha cells

 

ganglionic cells:

neurons of the autonomic system that originate within the ganglia of the autonomic nervous system and project to post-ganglionic neurons

 

ganglionic layer:

the fifth layer of the cortex; it contains small granular cells, large pyramidal cells, and the cell bodies of some association fibers (the association fibers that originate here form the Bands of Baillerger and Kaes Bechterew, which are two large fiber tracts)

 

Glasgow Coma Scale:

developed by Jennett and Teasdale (1989), instrument most frequently used to quantify levels of consciousness, consists of three categories: eye opening, verbal responses and motor responses.

 

Global Aphasia:

third most common aphasic syndrome after Broca's and Wernicke's, occurs when there are both anterior and posterior lesions. All aspects of language are so severely impaired that there is no longer a distinctive pattern of preserved vs. impaired components. Articulation may be adequate in the context of stereotypical utterances. Prognosis is poor.

 

globus pallidus:

the more medial part of the lenticular nucleus

 

Glossopharyngeal Nerve (Craninial Nerve IX):

considered the major nerve for the swallowing center, Motor Component innervates the 3 salivary glands in the mouth. The saliva from these glands mixes with the chewed up food to form a bolus. Has motor, sensory, and autonomic nervous system nerve fibers. It, along with the vagus (CN. X), provides some innervation to the upper pharyngeal constrictor muscles (Zemlin, 1997). Innervates the stylopharyngeus muscle which elevates the larynx and pulls it forward during the pharyngeal stage of the swallow. This action also aids in the relaxation and opening of the cricopharyngeus muscle. Sensory components mediate all sensation, including taste, from the posterior 1/3 of the tongue. Also carries sensation from the velum and the superior portion of the pharynx. A lesion may impair the gag reflex unilaterally (Zemlin, 1997).

 

graduated stick:

may be used instead of a pacing board. Graduated sticks have bumps on them at regular intervals and the patient must touch one bump for every syllable. Metronomes can also be used to slow speech rate. Patients are taught to produce one syllable per "tick" on the metronome.

 

gyrus:

a raised fold of brain tissue  

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hemianopsia:

loss of sight in one half of the visual field. damage to either middle cerebral artery can cause This blindness affects the contralateral aspect of both visual fields. For example, a blockage in the right middle cerebral artery will cause left hemianopsia or blindness in the left visual field of both eyes.

 

hyposthesia:

lack or sensation

 

hemiplegia:

complete paralysis on one side

 

hemiparesis:

partial paralysis on one side

 

hematomas:

or pools of congealed blood, in the parenchyma, the subarachnoid space, or the subdural space, bleeding due to stroke, hemmorrhage or traumatic brain injury, tissue is irritated rather than infarcted

 

Hemophilia:

is a thinning of the blood which prevents it from coagulating.

 

hemorrhagic strokes

Hemorrhagic stroke occurs when a cerebral artery ruptures, causing bleeding within the cranium. Such ruptures may be caused by aneurysms, weak spots in arterial walls. (Aneurysms can balloon out rather than bursting. The excess pressure resulting from this swelling can also damage brain tissue.) 

 

Heschl's Gyrus (anterior transverse temporal gyrus):

the primary auditory area; it is located in the temporal lobe

 

hippocampus:

a cortical area classified as part of the limbic system; it is a gyrus located on the medial edge of the temporal lobe, it is involved with memory

 

homunculus:

"little man"; a pedagogical device that is used to explain and demonstrate the functioning of the motor strip

 

horizontal cut (transverse cut):

a cut that divides the brain into upper and lower sections; perpendicular to coronal, medial, and sagittal cuts

 

hydrocephalus:

a condition that occurs when too much cerebrospinal fluid is produced and the ventricles swell, resulting in pressure being exerted on the tissue of the brain; it may be caused by tumors

 

hydroencephali:

a rare birth defect in which the cerebrum is absent and the space where it should be is filled with cerebrospinal fluid; the term literally means "water brain"

 

hyperkinetic dysarthria:

occur when the extrapyramidal tract is damaged, specifically the basal ganglia

 

hypertension:

blood pressure that is elevated regardless of activity level; may be a factor in stroke

 

Hypokinesia :

"the reduced amplitude of muscle movement" (Love & Webb, 1992, p. 146).

 

Hypoglossal Nerve (Cranial Nerve XII)

Information about motor movement is received from the muscle spindles in the tongue via this nerve, serves as part of the swallowing center that initiates the swallow. The hypoglossal innervates all extrinsic and intrinsic tongue muscles. (It is strictly a motor nerve.)

 

hypopharynx (of the Pharynx):

lower portion of the pharynx. It is also known as the laryngopharynx

 

hypothalamus:

a subcortical structure located immediately below the thalamus, part of it is also anterior to the thalamus and it forms the floor and part of the lateral walls of the third ventricle; by controlling the functioning of the pituitary gland it regulates basic biological functions (e.g., appetite, body temperature, sex drive)

 

hypokinetic dysarthria:

occur when the extrapyramidal tract is damaged, specifically the substantia nigra

 

Hyperuricemia:

a risk factor for CVA, involves an elevation of the level of uric acid in the blood. (This is the cause of gout.)

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infarction:

death of tissue

 

inferior:

refers to the lower parts of the nervous system

 

inferior cerebellar peduncles (restiform bodies):

one of the three fiber bundles called cerebellar peduncles that connect the cerebellum to the brain stem; the inferior cerebellar peduncle connects the cerebellum with the vestibular nuclei located in the lower pons and medulla, and with the reticular formation; proprioceptive information from the upper body (information that travels along the dorsospinocerebellar tract) enters the cerebellum on the inferior cerebellar peduncle

 

inferior colliculi:

structures of the midbrain that relay auditory information to the medial geniculate bodies of the thalamus

 

insula (the Island of Reil):

the cortical area that lies below the fissure of Sylvius; it is considered by some anatomists as the fifth lobe of the brain; it may be associated with the viscera

 

interconnecting fibers:

nerve fibers that connect structures within the brain; the two types of interconnecting fibers are commisural fibers and association fibers

 

internal capsule:

a group of myelinated ascending and descending fiber tracts that connect the cortex to other parts of the central nervous system; although the axons that pass through it descend to the brain stem and spinal cord, the capsule itself ends within the cerebrum; the internal capsule is located between the lenticular nucleus and the caudate nucleus

 

internal carotid artery:

a division of the common carotid; the internal carotid arteries supply blood to the brain; the two main branches of this artery are the anterior cerebral artery and the middle cerebral artery,  The internal carotids and basilar arteries are connected via the Circle of Willis, which allows blood to pass from one system to another in the event of blockage.

 

internal granular layer:

the fourth layer of the cortex; it is very thin; it contains pyramidal cells in row formation

 

interneurons:

association neurons of the spinal cord; interneurons connect the anterior and posterior horns of grey matter and are involved in the reflex arc (they function within the same segment of the spinal cord)

 

internuncial neurons:

association neurons of the spinal cord; internuncial neurons project (ascend) to the brain stem and cerebellum

 

intraparnchymal bleeding:

can occur at a very slow rate within structure such as the thalamus, the spontaneous recovery period following a stroke caused by this type of bleeding may be especially lengthy. For this reason, it is justifiable to continue therapy for a longer period of time with patients who have had parenchymal bleeding than with those who have had other types of hemorrhages.

 

intraparynchemal hemorrhaging:

Due to Penetrating Brain Injury Bleeding within the structures of the brain is usually the consequence of penetrating head wounds rather than CHI. This kind of hemorrhaging can occur in the cortex as well as in subcortical areas. When it is the result of closed head injury, rather than CVA, it most commonly affects the frontal and temporal lobes. Most penetrating brain injuries result from high velocity missiles such as bullets. Low velocity focal injuries (blows to the head-head hitting windshield) can result in bone fragments penetrating the brain. There is a high rate of mortality following penetrating brain injury especially to the brain stem (Brookshire, 1997).

 

ischemic:

refers to a lack of blood-bourne oxygen. Ischemic strokes are more common than hemorrhagic strokes and may be caused by stenosis or thrombosis of the arteries, as well as by the presence of thrombo-emboli in the arteries. Almost always contralateral and therefore unilateral

 

Island of Reil (the Insula):

the cortical area that lies below the fissure of Sylvius; it is considered by some anatomists as the fifth lobe of the brain; it may be associated with the viscera. It has recently been associated with programming for muscle movement involved in speech. 

 

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kinesthesia:

feedback from muscle spindles (a more specific term than proprioception)  

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lateral:

toward the sides

 

lateral aspect:

the part of the motor strip that is located on the lateral surface of the hemisphere; it is responsible for motor control of the upper body (including the larynx, face, hands, shoulders, and trunk)

 

lateral corticospinal tract (lateral pyramidal tract):

the fibers of the corticospinal tract that decussate at the pyramids

 

lateral fissure (fissure of Sylvius):

the fissure that separates the frontal and temporal lobes

 

lateral geniculate bodies:

the thalamic nuclei that receive visual information from the superior colliculi of the midbrain, process, and then transmit this information to the cortex

 

lateral pterygoid muscle of the oral cavity:

depresses, opens, and protrudes the mandible, as well as moving it laterally

 

lateral ventricles:

the two large ventricles (filled with cerebrospinal fluid) that have anterior horns located in the frontal lobes, inferior horns located in the temporal lobes, and which also extend posteriorly into the parietal lobes

 

left middle cerebral artery:

supplies blood to Broca's area, Wernicke's area, Heschl's gyrus, angular gyrus and also the  areas of the motor and sensory strips from the head to the hips.

 

left-right disorientation:

an inability to distinguish the left from the right; may be the result of damage to the angular gyrus in the hemisphere dominant for speech and language

 

left side neglect:

an impairment in the ability to recognize and respond to stimuli on the left side of the body

 

lenticular nucleus (lentiform nucleus):

one of the two structures that make up the basal ganglia; it is composed of the globus pallidus and the putamen; the lenticular nucleus is located between the caudate nucleus and the Island of Reil with its anterior aspect attached to the head of the caudate nucleus

 

levator veli palatini (oral cavity):

with the palatoglossal both raise the velum. They are innervated by the vagus nerve (CN. X).

 

limbic system (rhinencephalon):

the most ancient and primitive part of the brain; it is composed of both cortical and subcortical structures located on the medial, inferior surfaces of the cerebral hemispheres; the limbic system is involved in the processing of olfactory stimuli, emotions, motivation, and memory, and may be involved in cortical speech and language behavior

 

literal/phonological paraphasia:

More than half of the intended word is produced correctly. For example, a patient may say /pun/ instead of /spun/. In addition, transpositions of sounds can occur, e.g tevilision for television. (Brookshire, 1997).

 

long association fibers:

association fibers that connect areas that are located in different lobes of the brain (e.g., the arcuate fasciculus)

 

longitudinal fissure (interhemispheric fissure):

the split or gap between the right and left cerebral hemispheres that is lined with cortex

 

lower motor neurons:

second order neurons; the cranial and spinal nerves; the cell bodies of the lower motor neurons are located in the neuraxis, but their axons synapse with the muscles of the body, sometimes called the final common pathway

 

lumbar puncture (spinal tap):

a diagnostic procedure in which a needle is inserted in the lower lumbar section of the vertebral canal to obtain a sample of cerebrospinal fluid

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magnum foramen:

the large opening in the base of the skull

 

mamillary bodies (mamillary nucleus):

subcortical component of the limbic system (rhinencephalon); the mamillary bodies are connected to the hippocampus, the thalamus, and the fornix

 

masked facies:

Parkinson's patients usually display little facial expression, so their faces are described as "mask-like."

 

massa intermedia (thalamic adhesion):

the tissue that connects the two thalamic bodies

 

masseter muscle of the oral cavity:

elevates and closes the mandible

 

MTDDA: Minnesota Test for Differential Diagnosis

 

medial:

toward the center

 

medial muscle of the oral cavity:

which also elevates the mandible and aids in its closure

 

medial aspect:

the part of the motor strip that extends down into the longitudinal cerebral fissure; it controls the movements of the body from the hips downward

 

medial cut:

a section that divides the brain into right and left halves of equal size; it separates the hemispheres from each other; a medial cut is a type of sagittal cut

 

medial geniculate bodies:

the thalamic nuclei that receive auditory information from the inferior colliculi of the midbrain, process, and then transmit this information to the cortex

 

medulla oblongata:

the most inferior structure of the brain stem; the "bulb"; the medulla is involved in circulation and respiration

 

Melodic Intonation Therapy:

(Sparks & Holland, in Chapey, 1994)  Melodic intonation therapy, or MIT, uses music to involve the non-dominant hemisphere in language production. originally developed by Sparks and Holland for the treatment of severe non-fluent aphasia. Currently, however, it is frequently used to treat individuals with apraxia. This technique involves teaching the patient to sing words or phrases set to simple melodies. It is hypothesized that this therapy is effective because the use of music helps involve the right hemisphere in the production of speech.

 

Mendelsohn Maneuver:

helps the patient gain some voluntary control over the opening and closing of the p.e. segment. The patient is told to pay attention to the way the thyroid cartilage goes up and down during swallowing. Then he learns to use muscles to keep the larynx elevated for several seconds after the swallow. This should facilitate the opening of the cricopharyngus muscle.

 

meninges:

dura mater, arachnoid and pia mater, three layers of protective tissue that surround the neuraxis; the meninges of the brain and spinal cord are continuous and are connected through the magnum foramen

 

micrographia:

often seen with parietal lobe lesion, the "tendency for handwriting to be very small in the height of the letters and to get progressively smaller as the person continues to write" (Love and Webb, 1992, p. 146).

 

midbrain (mesencephalon):

the most superior part of the brain stem

 

middle cerebellar peduncle (middle brachium pontis):

the largest of the cerebellar peduncles; the middle cerebellar peduncle connects the cerebellum with the pons; through this connection the cerebellum receives a copy of the information for muscle movement that the pyramidal tract carries to lower motor neurons

 

middle cerebral artery:

a branch of the internal carotids; the middle cerebral artery supplies blood to the entire lateral aspect of each hemisphere (including the lateral motor strip, lateral sensory strip, Broca's area, Wernicke's area, Heschl's gyrus, angular gyrus) and to the corpus striatum

 

middle meningeal artery:

this artery sometimes ruptures after traumatic brain injury

 

Minnesota Test for Differential Diagnosis: (MTDDA)

developed by Schuell in 1965. This comprehensive test assesses the patient's strengths and weakness in all language modalities.

 

Mixed dysarthria:

occurs when both upper and lower motor neurons are injured, amyotrophic lateral sclerosis (Lou Gehrig's Disease) is the most frequent cause of mixed dysarthrias. Etiology is unknown and prognosis is poor.

 

Mixed Nonfluent Aphasia:

diagnosis given to patients who produce language that is similar to the telegraphic speech characteristic of Broca's aphasia, but cannot be categorized as actually having Broca's aphasia due to the severity of their auditory comprehension deficits.

 

modified barium swallow:

procedure used to image the swallowing process is a modified barium swallow, not a true barium swallow. the patient consumes foods of varying consistencies that have been coated with barium.A true barium swallow is used to view the esophagus

 

molecular commotion:

(Love and Webb, 1992) a disruption in the molecular structure of the brain which may cause permanent changes in both white and grey matter

 

molecular layer:

the most superior layer of the cortex; it contains the cell bodies of neuroglial cells

 

muscularis uvula (oral cavity):

shortens the velum. It is also innervated by the spinal accessory (CN XI).

 

Myasthenia Gravis:

According to Fitz Gerald (1996), it is caused by the immune system producing antibodies to the ACh receptor. This disease impairs the ability of nerve fibers to synapse with the muscles by reducing the number of acetylcholine (ACh) receptors at the neuromuscular junction. It causes weakness in muscles throughout the body, especially those involved in speech and swallowing. This weakness is progressive. In the morning or after rest, the patient's speech may sound clear. However, as he becomes fatigued, slurring of speech will increase.

 

myelin:

a fatty insulating substance that covers, at regular intervals, many of the axons in the central and peripheral nervous system; myelin serves to increase the speed of transmission of impulses, by allowing them to jump from one unmyelinated segment to the next (this is called saltatory conduction)

 

myotomy:

the procedure of cutting the cricopharygeus muscle

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neuraxis:

the brain and spinal cord; the central nervous system

 

Neuronal Unmasking:

(Bach-y-Rita, 1989) Neurons which are normally quiescent may begin working again after others have been destroyed. This means that brain processes which are normally inhibited by higher level controls will be able to function. This may help in recovery. Negative effects of unmasking are reflexes and responses like the startle reflex which are usually only seen in young children. The Babinski reflex and the patilla reflex may also be abnormal after head injury.

 

neurons:

the nerve cells of the central and peripheral nervous systems; a neuron is composed of an axon, a soma, and dendrites (while all neurons have one soma and one axon, some neurons have many dendrites and others have none)

 

neurological input for the swallow

in the initiation in the swallow comes from the trigeminal, facial, and glossopharyngeal nerves

 

neocerebellum:

the posterior lobe of the cerebellum; it is considered to be the newest part of the cerebellum; it is involved in the coordination of muscle movement through the inhibition of involuntary movement, it is also involved in fine motor coordination

 

neologistic paraphasias:

less than half of the intended word is produced correctly. In some cases the entire word is produced incorrectly. Neologisms are also common in the speech of schizophrenics.

 

NG tubes and swallowing:

naso-gastric feeding tube; According to Logemann (1989), its not necessary to wait until tubes are removed to begin therapy.

 

Nodes of Ranvier:

the segments of axons between areas of myelin, which are in direct contact with extracellular fluid

 

nodulus:

the narrowest and most inferior part of the vermis; it is part of the flocculonodular lobe of the cerebellum

 

nonfluent aphasias:

Nonfluent aphasias are the result of damage to the area of the brain anterior to the central sulcus (Broca's area)

 

The flow of speech is more or less impaired at the levels of speech initiation, the finding and sequencing of articulatory movements, and the production of grammatical sequences. Speech is choppy, interrupted, and awkwardly articulated.

 

Comprehension appears to be better than production and in a sense it is. The linguistic competence underlying both comprehension and production of language is the same, so both comprehension and production are affected by a nonfluent aphasia. However, just as it is easier to understand a second language than to produce it, it is easier for the patient to understand what is said than to speak. One can often get by with only comprehending the key words and using non-verbal cues.

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obicularis oris:

lip muscle, with the buccinator and zygomaticus  innervated by the facial nerve (CN. VII).

 

occipital lobe:

the most posterior lobe of the brain; it is associated with vision

 

olfactory pathways:

the olfactory pathways originate in the nasal area and pass posteriorly to enter the temporal lobe at the hippocampal gyrus; the olfactory tract is immediately superior to the optic tract

 

olivary nuclei:

landmarks in the medulla which lie posterior to the pyramids; the olivary nuclei are involved in the processing and relaying of auditory information

 

operant conditioning:

a form of behavior modification, used to remediate aphasia. This approach involves shaping language behavior by helping patients to progress through a series of tasks presented in fixed order, from least to most difficult.

 

oral apraxia:

an inability to make voluntary, non-speech oral movements

 

oral preparatory phase of the swallow:

voluntary,  mechanical phase that can be by-passed by dropping liquid or food into the back of the throat.In this stage, the food is chewed into smaller pieces and tasted. It is also mixed with saliva from three pairs of salivary glands, which are innervated by the glossopharyngeal nerve. The food and saliva form a bolus of material. The bolus is kept in the front of the mouth, against the hard palate by the tongue. The front of the tongue is elevated with its tip on the alveolar ridge. The back of the tongue is elevated and the soft palate is pulled anteriorly against it  (the airway is open and nasal breathing continues during this phase). Labial seal is maintained to prevent food from leaking out of the mouth. Buccal muscles are tense.  Duration of the oral-preparatory stage is variable (Logemann, 1983, 1997).

 

oral transport stage of the swallow:

voluntary stage, starts with the jaws and lips closed, and the tongue tip on the alvealor ridge. The pattern-elicited response is initiated at the end of this phase. Inspiration is reflexively inhibited at the beginning of this stage. The food is moved to the back of the mouth by the tongue via an anterior to posterior rolling motion. The anterior portion of the tongue is retracted and depressed while the posterior portion is retracted and elevated against the hard palate. When the bolus passes the anterior faucial pillars/touches the posterior wall of the pharynx, the oral stage ends and the pharyngeal stage begins as the tongue driving force or the tongue's plunger action, forces the bolus into the pharynx. Logemann (1997) describes the "pharyngeal tongue" which extends from the velum to the hyoid bone and valleculae. The "oral tongue" which extends from the tip to the back, adjacent to the velum, functions during the oral stage of the swallow while the "pharyngeal tongue" functions during the pharyngeal stage. This stage lasts one second (Logemann, 1989, 1998; Dobie, 1978).  

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pacing board

may be helpful for patients with dysarthria, divided into sections, the patient must tap one section every time he pronounces a syllable. As the fingers cannot move nearly as rapidly as the articulators, this should slow the rate of speech enough to improve intelligibility. After reduced rate has been established using the board, the client can begin to count syllables on his fingers. Eventually, he should be able to maintain the proper rate without counting syllables at all. A device called a graduated stick may be used instead of a pacing board. Graduated sticks have bumps on them at regular intervals and the patient  must touch one bump every time he says a syllable. Metronomes can also be used to slow speech rate. Patients are taught to produce one syllable per "tick" on the metronome.

 

palatoglossal muscle (oral cavity):

with the levator veli palatini both raise the velum. They are innervated by the vagus nerve (CN. X)

 

palatopharyngus muscle (oral cavity):

depresses the velum and constricts the pharynx. It is innervated by the spinal accessory (CN. XI).

 

paleocerebellum:

the anterior lobe and second oldest part of the cerebellum; the paleocerebellum receives proprioceptive input from the spinal cord and controls the anti-gravity muscles of the body, it thus regulates posture

 

Pallilalia:

the compulsive repetition of syllables sometimes present in hypokinetic dysarthria

 

paraphasia:

the production of unintended syllables, words, or phrases during the effort to speak" (Goodglass & Kaplan, 1983, p. 8). Patients with fluent forms of aphasia exhibit many more paraphasias than do those with nonfluent types. There are three types of paraphasias, literal/phonological, neologistic, and semantic/verbal.

 

parasympathetic nervous system:

a division of the autonomic nervous system; it helps to bring the body back to normal

 

parenchyma

means "specific cells of a gland or organ" (Stedman's Concise Medical Dictionary, 1997). Parenchymal bleeding refers to the flow of blood into brain tissue rather than into an existing space like the subarachnoid space or a potential space like the subdural space. Parenchymal hemorrhages occur most frequently in the putamen, thalamus, pons, and cerebellum (Coch & Metter, 1994).

 

paragrammatical:

(Goodglass and Kaplan, 1983) patients with Wernicke's Aphasia make grammatical errors but their speech cannot be considered agrammatical as it does contain complex syntactical forms

 

parietal lobe:

the lobe of the brain which is immediately posterior to the central sulcus, anterior to the occipital lobe, and superior to the posterior portion of the lateral fissure (and thus the temporal lobe); it is associated with sensation (touch, kinesthesia, perception of temperature, vibration), writing, and some aspects of reading

 

Parkinson's Disease:

a degenerative disease, is probably the most frequently occurring illness that results from extrapyramidal tract lesions. It occurs when the dopaminergic neurons of the substantia nigra are destroyed. Its symptoms include:

Tremor, Festinating movements( these movements can also affect speech), Hypokinetic dysarthria, weak voice, and mask-like facial expression. Recent research indicates that those who acquire the disease prior to age 50 may have genetic causation.

 

pattern-elicited response:

the swallow was previously classified as a reflex, most sources now disagree and label it pattern-elicited

 

perilymph:

fluid of the inner ear; it surrounds the utricle, saccule, and semicircular canal

 

peripheral lesions:

lesions to the axons of the cranial nerves; these are considered to be lesions of the final common pathway

 

peripheral nervous system:

the cranial nerves and spinal nerves

 

peristalsis:

wave-like motions of muscles that occur in the esophagus. In some of the literature, the action of the pharyngeal constrictor muscles is mistakenly called peristalsis, rather than a stripping action.

 

pharyngeal-esophageal (P.E) segment or cricopharyngus m.:

separates the pharynx from the esophagus. At the end of the pharyngeal stage of the swallow, it must relax to allow the bolus to enter the esophagus. (It is normally closed to prevent the reflux of food and to keep air out of the digestive system.)

 

pharyngeal recesses:

the valleculae is a space or depression between the base of the tongue and the epiglottis, two pyriform sinuses are located in the pharynx, beside the larynx. They are formed by the shape of muscle attachments to the pharyngeal walls.  Food boluses can lodge in these recesses.

pharyngeal stage of the swallow: (Logemann, 1989, 1997, 1998; Cherney, 1994)

involuntary, and most critical stage of the swallow; airway closure must occur to prevent the bolus from entering the respiratory system. Almost simultaneously: 1.Sensory information from receptors in the back of the mouth and in the pharynx goes to the swallowing center in the medulla via CN. IX. The palatopharyngeal folds pull together medially to form a slit in the upper pharynx. The bolus passes through this slit. 2. The velum is raised, primarily by the levator and tensor veli palatini muscles. 3. The tongue is retracted

 

Has a laryngeal substage in which three actions occur simultaneously  (Obviously, inspiration is inhibited during the pharyngeal stage of the swallow.) 1.The larynx and the hyoid bone are pulled both upward and forward.  2.The true and false vocal folds adduct. (Closure begins at the level of the true vocal folds and progresses up to the false vocal folds and then to the ari-epiglottic folds.) 3.The epiglottis drops down over the top of the larynx,   The bolus passes down on both sides of the epiglottis. If the bolus is liquid, the epiglottis acts as a ledge to slow its movement through the pharynx, giving the vocal folds time to adduct and the larynx time to elevate.

Three factors cause food to move down the pharynx during the rest of the pharyngeal stage (Cherney, et al., 1994; Logemann, 1983, 1989, 1997): The tongue driving force using the "pharyngeal tongue", the stripping action of the pharyngeal constrictors and   the presence of negative pressure in the laryngopharynx

The pharyngeal stage ends when the cricopharyngus muscle relaxes.

 

pia mater:

the innermost layer of the meninges; it adheres closely to the brain, descending into the sulci and fissures of the cortex and fuses with the ependyma to form the choroid plexes

Pill-rolling tremor:

Parkinson's  patients move their thumbs and forefingers together as if rolling a small pill between them. This movement occurs at rest, but subsides during voluntary movement and sleep.

 

pituitary gland:

an endocrine gland of the central nervous system; secretes a number of different hormones

 

plaque:

composed of cholesterol build up and smooth muscle cells

 

plunger action or or the tongue driving force:

plays a major role in this process.in the movement of food down the pharynx, according to the  latest research on swallowing disputes the action of the pharyngeal constrictor muscles as the most critical factor

 

pneumoencephalography:

a technique used prior to the introduction of CT, MRI, and PET technology, in which a small amount of cerebrospinal fluid is removed from the ventricles and replaced with an inert gas, allowing the examiner to view the ventricles in a scan and assess brain pathology

 

polycythemia:

a thickening of the blood due to an increase in the number of cells.

 

pons:

the brain stem structure located between the midbrain and medulla; fibers in it connect the brain stem to the cerebellum; pons is Latin for "bridge"

 

Porch Index of Communicative Ability: (PICA)

(Porch, 1967) samples fewer language behaviors than the MTDDA. However, it is known for its elaborate scoring system, which allows the examiner to differentiate between responses elicited with different degrees of cueing, various types of errors, and also to note the immediacy of the response.

 

postcentral gyrus (primary sensory area, sensory strip):

the area of the brain located in the parietal lobe immediately posterior to the central sulcus; this area receives sensory feedback from the muscles, joints and tendons in the body; the postcentral gyri have lateral and medial aspects

 

posterior:

toward the back (opposed to anterior)

 

posterior cerebral arteries:

arteries that arise from the basilar artery (before it divides); the posterior cerebral arteries supply blood to the posterior areas of the brain, including the medial parts of the occipital lobes, and the inferior areas of the temporal lobes, as well as supplying blood to the thalamus and other subcortical structures

 

posterior commissure:

one of the three major groups of commissural fibers

 

posterior communicating arteries:

arteries that arise from the internal carotid arteries; they join the middle cerebral arteries to the posterior cerebral arteries

posterior lesions:

problems with meaning are associated with posterior lesions

 

post-ganglionic cells:

neurons of the autonomic nervous system that are located in its target organs and muscles

 

post Rolandic area:

lesions in this area result in fluent aphasia, these are posterior lesions and result in problems with meaning

 

a gyrus in the frontal lobe which controls the voluntary movements of skeletal muscles; it is located immediately anterior to the central sulcus and has a lateral and medial aspect; the cell bodies of the pyramidal tract are found here

 

pre-ganglionic cells:

neurons of the autonomic nervous system that are located in some of the cranial nerves of the brain stem and in some spinal nerves; they project to the ganglionic chains of the autonomic nervous system

 

premotor areas (supplemental motor areas):

Brodmann's Area 6, areas located immediately anterior to the motor strip; this portion of the frontal lobe is responsible for the programming of motor movements (except speech)

 

presensory areas (secondary sensory areas or sensory association areas):

areas located posterior to the postcentral gyrus; these areas are capable of more detailed discrimination and analysis than the primary sensory areas

 

press of speech:

phenomenon characterizes Wernicke's aphasics. Patients may speak very rapidly, interrupting others. It may seem as though the patient is striving for a sense of closure or a sense that he has actually communicated what he intended to say (Goodglass and Kaplan, 1983).

 

primary auditory cortex:

Brodmann's areas 41 and 42

 

primary visual area:

an area located within the occipital lobe; it receives input from the optic tract; damage to this area may cause blind spots in the visual field or total blindness

 

pragmatic approaches:

use social interaction to improve the communicating abilities of aphasic patients.

 

programmed stimulation:

LaPointe (1990), approach to aphasia therapy combines behavioral and cognitive methods. He advocated the use of a hierarchy of therapy tasks based on level of difficulty employed by behaviorists, but uses the kinds of stimuli employed by therapists with a cognitive orientation. Several types of programmed stimulation for aphasics have been developed by other therapists. Among these are melodic intonation therapy (Sparks & Holland, in Chapey, 1994) and visual action therapy VAT (Fitzpatrick & Baresi, 1982).

 

progressive strokes:

still evolving, meaning that the patient's condition is continuing to deteriorate. Progressive strokes can last for over a week. This condition is usually the result of a severe hemorrhage.Particular caution should be used when evaluating the swallowing status of such a patient. Also, progressive strokes tend to happen to people who have very poor cerebral vascular health and are therefore at risk for having another stroke very soon.

 

promoting aphasic's communicative effectiveness (PACE):

developed by G. Albyn Davis,  based on the pragmatic rule of reciprocity; the therapist and the patient participate in a conversation as equals, each taking turns sending and receiving messages. According to Davis and Wilcox (1981)PACE is based on the following four principles, The Exchange of New Information, Free Choice of Communicative Channels, Equal Participation, Functional Feedback

 

proprioception:

sensory information about pressure, movement, vibration, position, muscle pain, and equilibrium that is received by the brain (especially the cerebellum) from the muscles, joints, and tendons

 

prosopagnosia:

inability to recognize faces

 

pseudobulbar palsy:

the paralysis that results from bilateral upper motor neuron lesions of the pyramidal tract; it produces a paralysis very similar to that seen with bulbar palsy

 

putamen:

the more lateral part of the lenticular nucleus

 

Purkinje cells:

radish-shaped cells located in the cerebellar cortex that regulate and inhibit the firing of the deep nuclei, thus controlling the output of the cerebellum

 

pyramidal tract:

a fiber tract that carries messages for voluntary motor movement to the lower motor neurons in the brain stem and spinal cord; the pyramidal tract is direct and monosynaptic, pyramidal tract, which is the most important of the upper motor neuron tracts, transmits messages directing voluntary motor movements. It is primarily facilitory  (Duffy, 1995).  

 

pyramids:

landmarks in the medulla which mark the decussation of the pyramidal tract; they lie on either side of the medial fissure  

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rami communicantes:

the rami of the autonomic nervous system are the axons of its pre-ganglionic and ganglionic cells

 

red nucleus:

a structure of the midbrain, connects the cerebellum to the thalamus and spinal cord

 

reflex arc:

a reflexive behavior that occurs when a message from sensory fibers causes a motor reaction directly, without the impulse having to first be sent to the brain (e.g., the reflex arc of the spinal nerves)

 

release phenomenon:

the rapid firing of motor neurons; the basal ganglia acts to inhibit this

 

rigidity :

If the limbs of a Parkinson's patient are moved passively, the muscles will often contract involuntarily, causing rigidity. This rigidity may be constant or intermittent. Intermittent rigidity is called cogwheel rigidity.

 

restiform bodies (inferior cerebellar peduncles):

one of the three fiber bundles called cerebellar peduncles that connect the cerebellum to the brain stem; the inferior cerebellar peduncle connects the cerebellum with the vestibular nuclei located in the lower pons and medulla, and with the reticular formation; proprioceptive information from the upper body (information that travels along the dorsospinocerebellar tract) enters the cerebellum on the inferior cerebellar peduncle

 

reticulocerebellar tract:

a fiber tract that carries information received by the reticular nuclei in the brain stem from the cortex, spinal cord, vestibular system, and red nucleus to the cerebellum

 

reticulospinal tract:

a fiber tract that runs from the reticular nuclei of the pons and medulla to the spinal nerves; it carries information related to the functioning of the autonomic nervous system (e.g., circulation of the blood, dilation of blood vessels, respiration, and visceral activity); it is also involved in somatic motor control like the rubrospinal tract and also plays an important role in the control of autonomic functions.

 

reticular activating system (ascending reticular formation):

the component of the reticular formation that is responsible for the sleep-wake cycle; it mediates various levels of alertness

 

reticular formation:

a set of interconnected nuclei that are found throughout the brain stem; the dorsal tegmental nuclei are located in the midbrain, the central tegmental nuclei are located in the pons, and the central and inferior nuclei are located in the medulla; the reticular formation has two components, the ascending reticular formation and the descending reticular formation

 

Reversible Ischemic Neurological Defect(RINDs):

RINDs are lengthy TIAs, . The term RIND is usually applied to attacks that continue for more than 12 hours without interruption, although some RINDs may last for several days. As is the case with TIAs, RINDs resolve in complete recovery, however some neurologists do not consider them temporary. (There is some evidence that RINDs do cause some subtle neurological damage, but these minor changes are nothing like the types of disabilities seen after "real" strokes.)

Sometimes, events that last for twenty-four hours are called TIAs rather than RINDs, so there is some inconsistency in the application of this terminology.

 

rhinencephalon (limbic system or limbic lobe):

the most ancient and primitive part of the brain; it is composed of both cortical and subcortical structures located on the medial, inferior surfaces of the cerebral hemispheres; the limbic system is involved in the processing of olfactory stimuli, emotions, and memory

 

right hemisphere syndrome:

blockages of the right middle cerebral artery due to right hemispher lesions whic can cause left side neglect, which is an impairment in the ability to recognize and respond to stimuli on the left side of the body, prosopagnosia or the inability to recognize faces, and various cognitive problems, including agnosia.

 

right hemianopsia:

visual field deficit due to left hemisphere lesion, the disorder of vision that most often accompanies aphasia

 

rostral:

"toward the beak," rostral can mean the same as superior, and is an antonym of caudal

 

rotational trauma:

occurs when impact causes the brain to move within the cranium at a different velocity than the skull. This results in a shearing of axons by the bones of the skull. Because this type of injury damages neural connections rather than gray matter, it can affect a wide array of cerebral functions and should therefore is likely to cause diffuse injury.

 

rubrospinal tract:

a fiber tract, the fibers of which descend from the cerebellum through the red nucleus to synapse with the spinal nerves; this tract carries information important for skeletal muscle control and the regulation of muscle tone for posture  

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sagittal cut:

a cut that runs parallel to the medial cut, but divides the brain into two unequal parts

 

salpingopharyngus muscle (of the Pharynx):

with the stylopharyngus m. makes up the internal longitudinal layer of the pharynx

 

secondary auditory areas (auditory association areas):

two areas, located in the temporal lobes, which contribute to the ability to comprehend speech

 

secondary visual areas:

areas of the occipital lobe, superior to the primary visual cortex, that integrate visual information and give meaning to what is being seen by relating it to prior experience and knowledge; damage to this area can cause visual agnosia

 

second order neurons:

there are several types, lower motor neurons; the cranial and spinal nerves; the cell bodies of second order neurons are located in the neuraxis, but their axons can synapse with the muscles of the body

 

semantic aphasia:

see Wernicke's Aphasia

 

septal region:

subcortical component of the limbic system; it includes the septal nuclei

 

septum pellucidum:

a double walled structure located between the corpus callosum and the fornix

association fibers that connect areas that are located within the same lobe

 

silent aspiration:

aspiration of food and liquids without coughing, can occur as a result of neurological damage. (If food or liquid enters the respiratory system of a normal, healthy individual, it induces coughing.) Silent aspiration can cause pneumonia, with a temperature spike being the first indication that food or liquids are entering the lungs.

 

soma:

cell body; the part of the neuron that contains the cell's nucleus and cytoplasm

 

spastic dysarthria:

results from lesions to the pyramidal tract, characterized by "Generalized hypertonicity, weakness, immobility, abnormal force physiology, and exaggerated reflexes of virtually all muscles of the speech mechanism produce obvious dysfunction of the articulation subsystem. Speech is slow-labored, and imprecise articulatory efforts, compounded by disturbances of respiration; resonation, and phonation often render speech unintelligible" Dworkin (1991, p.188).

 

spinal cord:

the part of the central nervous system that lies below the magnum foramen, and that extends downward to just above the cauda equina; it contains the cell bodies of the spinal nerves and their afferent and efferent fibers

 

Spinal Accessory Nerve (CN. XI):

Motor Component innervates the palatopharyngeus muscle which depresses the velum and constricts the pharynx, and so innervates the muscularis uvula which tenses the velum. It, along with CN.X, innervates the levator veli palatini.
(CN. XI is strictly a motor nerve.)

 

spinal nerves:

thirty-one pairs of mixed nerves (sensory and motor) that are second order lower motor neurons and form part of the final common pathway; they also form a reflex arc; their motor fibers originate on the ventral part of the spinal cord at the anterior horns of grey matter and their roots of sensory fibers are located on the dorsal side of the spinal cord in the posterior root ganglia; these join together to form the spinal nerves after they exit the spinal column; the spinal nerves receive only contralateral innervation from first order neurons

 

spinal tap (lumbar puncture):

a diagnostic procedure in which a needle is inserted in the lower lumbar section of the vertebral canal to obtain a sample of cerebrospinal fluid

 

stenosis:

a general term that means "narrowing", in this course it is used to describe arterial narrowing

 

stripping action:

pharyngeal constrictor muscles help move food down toward the esophagus via this action.(This process should not be confused with peristalsis which is the wave-like motions of muscles that occur in the esophagus. In some of the literature, the action of the pharyngeal constrictor muscles is mistakenly called peristalsis.)

 

stylopharyngus muscle (of the Pharynx):

with the salpingopharyngus m. makes up the internal longitudinal layer of the pharynx

 

striata:

the "artery of stroke"; a branch of the middle cerebral artery; the striata supplies blood to the corpus striatum

 

stroke:

or cerebral vascular accident is a temporary or permanent loss of functioning of brain tissue caused by an interruption in the cerebral blood supply. Strokes can  be divided into the categories here are two principle kinds of strokes, ischemic and hemorrhagic within which they are categorized completed or progressive.

 

Subarachnoid bleeding:

According to Love and Webb (1992), bleeding into the subarachnoid space is often the result of aneurysm. According to FitzGerald (1997), berry aneurysms bleed directly into the subarachnoid space, because they originate in the circle of Willis. Strokes in those under 40 are often the result of ruptured aneurysm (FitzGerald, 1997). TBI is less likely to cause subarachnoid bleeding

 

subarachnoid space:

a space that lies between the arachnoid mater and pia mater; it is filled with cerebrospinal fluid; all blood vessels entering the brain and cranial nerves pass through the subarachnoid space

 

subcallosal gyrus:

a cortical area (a gyrus) that is considered to be a part of the limbic system; it is located immediately inferior to the corpus callosum

 

Subcortical Aphasia:

Lesions in the anterior subcortical area involving the limb of the internal capsule and putamen are associated with sparse language output and impaired articulation. Posterior subcortical lesions are associated with fluent forms of aphasia, while lesions of the thalamus may cause a global aphasia.

 

subdural bleeding:

According to Stedman (1997), subdural hemorrhaging, or the extravasation of blood in the potential space between the dura mater and the arachnoid membrane, causes hematomas to form. Chronic hematomas may become encapsulated by neomembranes. This is often over the frontal and temporal lobes. As this type of bleeding results from damage to veins, which contain less blood than arteries, subdural bleeding is much slower than epidural bleeding. According to Pires (1984), sometimes days or weeks pass before any symptoms of hemorrhaging appear. According to Bhatnagar and Andy (1995), subdural hematoma is usually due to traumatic brain injury, with bleeding from ruptured blood vessels in the arachnoid tissue below the dura mater. If not removed the blood will compress neural tissue causing infarction.

 

subdural space:

a potential space between the dura mater and the arachnoid mater

 

substantia nigra:

a group of dark colored cell bodies in the midbrain which produce dopamine; the substantia nigra is part of the extrapyramidal system

 

sulcus:

a groove between two gyri

 

superior:

refers to the upper parts of the nervous system

 

superior brachium conjunctivum (superior cerebellar peduncle):

the fiber tract that connects the cerebellum to the midbrain; it contains efferent fibers from the dentate, emboliform, and globose nuclei that send feedback to the motor cortex, and afferent fibers that carry proprioceptive information to the cerebellum from the lower body (information that is carried upward along the spinal cord on the ventrospinocerebellar tract)

 

superior colliculi:

structures of the midbrain that relay visual information to the lateral geniculate bodies of the thalamus

 

superior sagittal sinus:

a vein-like sinus that runs across the top of the brain in an anterior-posterior direction, it is from dura mater

 

supraglottic swallow:

patient is told to take a breath and hold it while swallowing and then cough after the swallow. This results in the voluntary closure of the vocal folds before, during and after the swallow.

 

supra supra-glottic swallow:

This technique closes the entrance to the airway at the level of the arytenoid cartilages. The patient follows the same procedure as with the supra-glottic swallow, but "bears down while holding his breath."

 

supramarginal gyrus:

Brodmann's area 40

 

swallowing center:

believed to be located in the medulla within the nuclei of the reticular formation; specifically the nucleus ambiguous When the swallow response is initiated, this center causes messages to be sent to the glossopharyngeal, the vagus, and the hypoglossal nerves. The glossopharyngeal is considered the major nerve for the swallowing center.

 

sympathetic nervous system:

a division of the autonomic nervous system; it prepares the body for fight or flight  

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Tardive Dyskinesia:

a condition which results from long-term use of anti-psychotic drugs called phenothiazines

 

TBI: seeTraumatic Brain Injury

 

tectum:

the roof of the brain stem

 

telegraphic speech:

function words or grammatical morphemes, morphological inflections (e.g. plurals,past tense),articles, conjunctions and prepositions are omitted. In addition, nouns, verbs, adjectives and adverbs may be produced. Output can be restricted to noun-verb combinations. Sentence length is short. Average utterance length (MLU) is typically about 2. In extreme cases, the patient may only be able to produce single word utterances.

 

temporal lobe:

the lobe of the brain that is inferior to the lateral sulcus and anterior to the occipital lobe; it is associated with auditory processing and olfaction

 

temporal parietal lobe:

often a site of lesion for Wernicke's Aphasia (the angular gyrus may also be affected)

 

temporalis muscle of the oral cavity:

elevates, retracts, and assists in closing the mandible

 

TBI: Traumatic Brain Injury:

According to Adamovich, Henderson, and Auerbach (1984), as many as 400,000 head injuries occur in the United States each year. The severity of head injury has generally been classified as mild, moderate and severe. Mild head injury has been defined as concussion, while severe head injury means being in a coma for at least six hours. There does not appear to be a consensus for a definition of moderate head injury. Jennett and Teasdale developed the Glasgow Coma Scale in 1974 (Bach-y-Rita, 1989). It is a numerical scale that quantifies level of consciousness in response to three categories: response to pain, ability to open eyes, and ability to speak. 

 

tensor veli palitini (oral cavity):

tenses the velum. It receives innervation from the trigeminal (CN. V).

 

tentorium cerebelli:

formed by the dura mater, the tentorium cerebelli separates the cerebrum from the cerebellum

 

Tentorial Herniation

Due to the edema that follows CHI, brain matter can be forced through the tentorial notch. The notch is a cavity formed by the the tentorium cerebelli. The tentorium is a sheath of hard tissue, formed by the dura mater. According to FitzGerald (1997), it forms a tent above the posterior fossa. It separates the cerebrum and brain stem from the cerebellum. Tentorial herniation may cause decortication or removal of cortical tissue from the underlying white matter. It may also put excessive pressure on the brain stem and thus affect cranial nerves involved in vital functions including respiration and circulation. Symptoms indicating that the brain stem is under too much pressure include sleepiness, bradycardia (slow heart rate), confusion, respiratory difficulties, and pupil dilation (due to pressure on the nuclei of CN III) (Bach-y-Rita, 1989).After CHI, barbiturate induced coma may be used to manage intracranial pressure.

 

thalamic adhesion (massa intermedia):

the tissue that connects the two thalamic bodies of the thalamus

 

thalamus:

a subcortical structure that receives and integrates sensory information from the periphery (with the exception of smell), and sends the information to the cortex for further processing; the thalamus is composed of two thalamic bodies and the massa intermedia; it is located inferior to the caudate nucleus and the fornix and medial to the lenticular nucleus

 

third ventricle:

one of the four ventricles, it contains cerebrospinal fluid; it lies between the two thalamic bodies, with the massa intermedia passing through it and the hypothalamus forming its floor and part of its lateral walls

 

Thrombosis:

total blockage of an artery due to plaque build-up or emboli

 

TIA: see transient ischemic attack

 

Token Test (DeRenzi & Vignolo, 1966):

assesses subtle receptive language dysfunction. Can be used to evaluate the auditory comprehension of Broca's aphasics and helps to distinguish between Broca's aphasia and verbal apraxia. The test has five parts involving the manipulation of objects of different colors, shapes, and sizes and becomes progressively more difficult. It tests receptive language by by requiring the patient to follow instructions like "Put the red square on the yellow circle." However you must be aware that words like "before" which are grammatical morphemes may be missed due to conceptual or semantic problems. Also, limb apraxia may not allow the patient to carry out the instructions, even though he/she understands them.

 

topical disorientation:

the inability to know location and strategy to move about in an environment

 

transcortical aphasia:

a type of aphasia that may occur as the result of blockages in the water shed areas of the brain. Lesions are typically smaller than those that cause Broca's aphasia and are superior to and often anterior to Broca's area. Broca's area itself is not affected, but the damage may extend down into the white matter including the white matter below Broca's area. Luria (1966) referred to this syndrome as dynamic aphasia.

Communication between Broca's area and the pre-motor or supplementary motor area (Brodmann's Area 6) is cut off. Because Wernicke's area and the arcuate fasciculus are spared these patients have good repetition (Brookshire, 1997). This type of lesion may also sever links between Broca's area and basal ganglia and/or the thalamus, which may affect motor and pre-motor function.  In addition, the damage could cause symptoms by affecting the link between Broca's area and the limbic system which also seems to be involved in memory and speech and language.

 

Characteristics are: Repetition is much better than other types of speech. In repetition, grammar and articulation are normal. Articulation in general is fair to good. Little or no paraphasia is present. Confrontational naming is well-preserved. The patient will respond well to prompting with phonemic cues. Auditory comprehension is fair to excellent. According to Goodglass and Kaplan (1983) the fluent/nonfluent distinction is not especially applicable to this syndrome. Sometimes the patient will produce a grammatically correct, well-articulated sentence.

 

Transient Ischemic Attacks (TIAs):

transient disturbances of the blood supply to a localized part of the brain, which produce a temporary, focal lesion. Unlike strokes they resolve in spontaneous and complete recovery. Symptoms of TIAs mimic those of stroke.and severe TIAs cannot be differentiated from a stroke until recovery occurs. TIAs typically last between 2 and 15 minutes, although such an event could conceivably last as long as 24 hrs. It is also possible to have a series of many brief TIAs during one day. For example, a patient might have 10 or more transient ischemic attacks within a 24 hr. period.

 

transverse cut:

a cut that divides the brain into upper and lower sections; perpendicular to coronal, medial, and sagittal cuts

 

Trigeminal Nerve (Cranial Nerve V):

both a motor and sensory nerve, efferent  innervates the muscles involved in chewing. These include the temporalis, the masseter, the medial, and the lateral pterygoid, also innervates the tensor veli palatine muscle, which tenses the velum, in addition, the trigeminal assists the glossopharyngeal nerve in raising the larynx and pulling it forward during the laryngeal substage of the pharyngeal swallow. Sensory component sensation, except taste to the anterior 2/3 of the tongue and information from the face, mouth and mandible

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uncinate fit:

an epileptic seizure that is preceded by an olfactory hallucination

 

upper motor neurons:

a type of first order neuron that carries motor impulses; the upper motor neurons remain inside the neuraxis', they synapse with lower motor neurons  

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Vagus Nerve (Cranial Nerve X):

Motor Components include responsibility for raising the velum as it innervates the glossopalatine and the levator veli palatine muscles, along with CN. IX innervates the pharyngeal constrictor muscles, along with CN. XI innervates the intrinsic musculature of the larynx. It is responsible for vocal fold adduction during the swallow.

 

Also innervates the cricopharyngeus muscle. The vagus controls the muscles involved in the esophageal stage of the swallow as well as those that control respiration. (This is the only cranial nerve that influences structures inferior to the neck.)

 

Sensory Components include carrying information from the velum and posterior and inferior portions of the pharynx and mediation of sensation in the larynx.

 

valleculae:

space between the epiglottis and base of the tongue

 

velum:

five muscles which control the movements of the velum are :  palatoglossal and the levator veli palatini both raise the velum. They are innervated by the vagus nerve (CN. X). The tensor veli palatini tenses the velum. It receives innervation from the trigeminal (CN. V). The palatopharyngus depresses the velum and constricts the pharynx. It is innervated by the spinal accessory (CN. XI). The muscularis uvula shortens the velum. It is also innervated by the spinal accessory. Poor velopharyngeal closure will affect speech but is not a matter of great concern in regard to swallowing. Patients may be concerned about it and believe that it is very important. While the entrance of food into the nasopharynx may be unpleasant, it is certainly not life-threatening.

 

ventral:

toward the belly

 

ventricles:

four spaces within the brain that are filled with cerebrospinal fluid, they protect the brain by cushioning it and supporting its weight; they include the two lateral ventricles, the third ventricle, and the fourth ventricle

 

ventrospinocerebellar tract:

one of the two main tracts that bring sensory information from the periphery to the cerebellum; it is a fiber tract that contains proprioceptive fibers from the lower body; its axons decussate and travel upward on the contralateral side of the spinal cord, then cross again and continue upward ipsilaterally, the fibers then enter the cerebellum on the superior cerebellar peduncle

 

Verbal paraphasias:

paraphasias in which a word is substituted for the target word. (The substitution must be a real word. If it is not, the paraphasia is classified as neologistic.) Two types of verbal paraphasias: within category/semantic paraphasias and remote paraphasias. Within category errors involve the substitution of a word that is closely related to the target word, as in cat/dog. Remote errors involve the substitutions of a word that is only distantly related to the target word, as in sink/dog. Remote paraphasias are, of course, indicative of more severe language problems than are within category substitutions.

 

vermis:

"worm," a thin structure that separates the hemispheres of the cerebellum from one another

 

vertebral arteries:

one of the two main branches of the subclavian arteries; the two vertebral arteries ascend through the spinal column, entering the brain through the magnum foramen, at the lower border of the pons the two vertebral arteries join together to form the basilar artery (vertebral basilar artery)

 

vestibulocerebellar tract:

a fiber tract that brings information from the semi-circular canals of the inner ear via the vestibular nucleus of the lower pons and medulla to the cerebellum; these fibers travel to the flocculi on the inferior cerebellar peduncle

 

vestibulospinal tract:

a fiber tract which brings information about the body's position in space to the antigravity muscles; the fastigial nucleus of the cerebellum sends messages to the vestibular nuclei in the lower pons and midbrain, from here the information is sent to lower motor neurons in the brain stem and spinal cord, runs from the vestibular nuclei located in the lower pons and medulla to the spinal nerves. It is involved in balance.

 

visual agnosia:

a condition in which an individual can see a visual stimuli, but is unable to associate it with meaning or identify its function; it represents a problem with meaning and may be a result of damage to the secondary visual areas  

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watershed areas:

areas of the brain that are located beyond the ends of the vascular systems; these areas are particularly vulnerable to problems with blood supply

 

Wernicke's Aphasia:

also termed semantic aphasia

 

lesion is located in the posterior region of the left superior temporal gyrus or the first gyrus of the temporal lobe. Brodmann's areas 21 and 42 correspond to Wernicke's area (FitzGerald, 1997). The damage often extends into the parietal lobe, affecting the angular gyrus (Brodmann's area 39). The major impairment is semantic. With severe Wernicke's aphasia there is usually a severe impairment in auditory comprehension. Speech, while fluent, is semantically inappropriate and paraphasic. The speech of Wernicke's patients is sometime called cocktail hour speech. Comprehension and expression tend to be equally impaired. Patients with moderate Wernicke's can get the point in conversations but miss many specifics (Brookshire, 1997). Articulation is normal, Melodic Line is unaffected. If one ignores the content, the form of the patient's speech may sound normal. They have long, grammatically well formed utterances that contain almost no meaning, speech is paragrammatical, paraphasias are common (FitzGerald, 1997). Repetition is typically poor. Patients may use augmentation. Also due to auditory comprehension deficits, the patient may repeat the examiner's words without understanding them. Word finding problems are very common. Confrontational naming is typically impaired. Auditory comprehension is impaired.
Alexia with agraphia may be present, and press of speech also characterizes Wernicke's aphasics

 

Wernicke's area:

an area of the brain, located in the temporal lobe on the posterior portion of the superior temporal gyrus, that is associated with the ability to understand and produce meaningful speech; a lesion in this area will cause Wernicke's aphasia

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zygomaticus (oral cavity):

lip muscle of the oral cavity with the obicularis oris and buccinator all three are innervated by the facial nerve (CN. VII).