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alexia/dyslexia, acquired
Loss or impairment of ability to read caused by cerebral injury. Usually manifestations of aphasia, but pure alexia may occur.
alexia with agraphia
Loss of ability to read and write, often assoc. w/ left parietal lobe (angular gyrus) lesions.
alexia w/o agraphia (aka pure alexia, Dejerine’s syndrome)
Acquired inability to read w/o corresponding deficit in writing. Pts. unable to read their own words. Usu. assoc. w/ large ischemic lesions in posterior cerebral artery territory of lang. dominant hemisphere that affects left visual cortex and posterior corpus callosum. Visual info cannot be received by damaged left occipital cortex. B/c of the corpus callosum lesion, visual input to right posterior cortex cannot be transmitted to left perisylvian lang. areas involved in decoding written language.
aphasic alexia
reading d/o assoc. w/ aphasia; reading comp. and oral reading are both impaired
attentional dyslexia
reading d/o characterized by gross disturbance in reading multiple words or text; single word reading relatively preserved; assoc. with disturbances of visual attention
central dyslexias
acquired reading d/o’s that affect processes by which word forms activate meaning or speech production mechanisms (i.e. “higher language processes”). These include deep, phonologic, and surface dyslexias, and alexia with agraphia. Contrasts with peripheral dyslexia.
deep dyslexia
rdg. d/o affecting both lexical (whole-word) and non-lexical (reading by letter-to-sound correspondences) reading routes. Characterized by semantic paralexias (e.g., reading “liberty”for “freedom”), and effect of word class (content words read better than function words), frequency (high-frequency words read better than lowfrequency words), and imagery (high-imagery words read better than low-imagery words). Nonword reading is severely impaired.
literal alexia
a reading d/o characterized by inability to recognize written letters
neglect dyslexia
a reading d/o characterized by failure to identify the initial or left-most portion of a string of letters or words in a text. Common errors: omissions and substitutions that preserve the overall length of the target. Seen most commonly in pts. with left-sided neglect.
peripheral dyslexia
rdg. d/o caused by visual processing deficits in which visual inputs cannot be assoc. w/ the stored representations of written words. Includes attentional and neglect dyslexias, and alexia w/o agraphia. Contrast with central dyslexias.
phonological alexia
rdg. d/o resulting from a selective impairment in the decoding of print to sound. B/c words can’t be sounded out, they must be read as whole units. Thus, unfamiliar or nonsense words cannot be read, but recog. and pronunciation of familiar words is more or less intact. Errors tend to involve visually similar words. Can be either an isolated lang. impairment or assoc. w/ fluent aphasia. Usu. lesions include damage to superior temporal corext and angular gyrus of the left hem. Contrast with surface dyslexia.
pure alexia
Same thing as alexia without agraphia. Acquired inability to read w/o corresponding deficit in writing. Pts. unable to read their own words. Usu. assoc. w/ large ischemic lesions in posterior cerebral artery territory of lang. dominant hemisphere that affects left visual cortex and posterior corpus callosum. Visual info cannot be received by damaged left occipital cortex. B/c of the corpus callosum lesion, visual input to right posterior cortex cannot be transmitted to left perisylvian lang. areas involved in decoding written language.
semantic alexia
Term describing surface alexia when it develops in dementia. Semantic alexia is used b/c stored representations of unusually pronounced words that reflect semantic knowledge are presumed lost.
surface alexia
rdg. d/o in which words are read and understood only inasmuch as they can be “sounded out”. Opposite pattern to phonological dyslexia: nonsense words are read accurately as are words with phonologically regular spelling. Irregularly spelled words are misread as reg. words (e.g. “busy” is read as “bussy”). Lesions usually include injury to left temporal-parietal cortex.
alexithymia
Difficulty recognizing and describing one’s emotions.
alien hand syndrome
Condition in which one hand, usually the left, either acts under its own volition or is perceived by the patient to be “foreign”, “alien”, or “uncooperative”. May result from large medial frontal lobe lesions, commissurotomy (though additional cerebral involvement must exist), or coricobasal ganglionic degeneration.
allethesia
Condition in which the sensation of touch contralateral to the lesion is referred to the analogous location on the ipsilateral side. Usually assoc. w/ right hemisphere lesions as part of the neglect syndrome. More accurately termed allochiria.
allochiria
sensation of touch contralateral to the lesion that is referred to the analogous location on the ipsilateral side.
allokinesia
limb movement that occurs contralateral to the lesion that is referred to the analogous location on the (opposite) side ipsilateral to the lesion.
alpha
1. The probability of making a type one error; i.e., incorrectly rejecting the null hypothesis. 2. The frequency band of 8-13 Hz that occurs maximally over posterior brain regions. 3. A measure of a test’s reliability (coefficient alpha) that reflects internal consistency of an item.
Alzheimer’s disease (AD)
A primary degenerative dementia w/ characteristic pathology of neurfibrillary tangles and senile plaques. Affects approx 1-5% of pop. that is 65+ y.o; 30% by age 80-90. Dx requires mem. impairment; loss of cog. ability that affects social fx; other decline e.g. naming, visual-spatial fx; r/o of other types of dementia. In absence of pathological analysis, called “probable AD” or dementia of the Alzheimer type (DAT). Pts. w/ no family hx of AD have ca. 15% lifetime risk.
Alzheimer’s Disease Assessment Scale (ADAS)
combined MSE and dementia rating scale for AD. 2 parts, one for cog (e.g. mem., lang., and praxis) and one for non-cog. fx. (e.g. mood & bx changes). Used in pharmaceutical research.
AMA
against medical advice; used in pt’s discharge summary, e.g, if discharge was not ordered/approved by attending physician
amaurosis fugax
Transient monocular blindness fr. transient ischemic attack (TIA) of ophthalmic artery. Descr. by pts. as a blanket of gray coming down slowly over one eye. Episodes indicate underlying atherosclerotic disease w/ incr. risk for stroke and MI (myocardial infarction).
ambidextrous
able to use either lt or rt hand for manual tasks
Amer-Ind.
American Indian Sign Language. Often used as compensatory communication technique in aphasic pts.
amimia
inability to express ideas through gestures. occas. used to describe the loss of facial expressiveness assoc. w/ parkinsonism.
ammon’s horn
Portion of the hippocampus that is a common site for scar tissue formation (i.e., sclerosis or gliosis), which often gives rise to temporal lobe seizures. Named after an Egyptian god depicted as a ram; area lks like a ram’s horn.
amnestic/amnesic syndrome
Severe impairment in ability to acquire/retain new info, w/ otherwise preserved cog. fxs. Common lesion sites incl. the hippocampus, hippocampal projections to the fornix and septum, and medial thalamic nuclei. Conditions assoc. with amnesia include Korsakoff’s syndrome, herpes simplex encephalitis, posterior cerebral artery stroke, anoxia, trauma, and transient global amnesia (TGA). Memories encoded well before onset of amnestic syndrome rel. well preserved. Contrasts with psychiatric dx of “functional amnesia”, which involves failure to recall autobiographical material, such as one’s name; in the latter, abil. to learn new info. gen. unaffected.
amobarbital
intermediate-acting barbiturate used as sedative or to control seizures. most common agent used in Wada Test to induce hemispheric anesthesia.
Amorphognosia
Inability to i.d. an object by proprioception due to poor perception of its physical attributes that cannot be explained on the basis of concurrent hypesthesia.
amorphosynthesis
Impairment of sensory integration that involves not only tactile agnosia but also visual-spatial difficulties, neglect, and dressing apraxia. Old heuristic term, not currently used.
amusia
Acquired deficit in music processing. With RH lesions, may have impairment of melody recog. or diff. in ident. musical elements such as rhythm. With LH lesions, music reading and music performance may be poor w/o impairment of music recog. or ability to judge music quality.
amygdala
almond-shaped nucleus in mesial anterior temporal lobe that plays a role in memory and emotional control
Amyotrophic lateral sclerosis (ALS)
Progressive motor neuron disease that affects neurons in the cerebral cortex, brainstem, and spinal cord. Gen. only see onset ages 45+. Fatal due to respiratory complications, usu. 2-4 yrs. post onset. Aka Lou Gehrig’s disease, motor neuron disease.
ANA
antinuclear antibody. A positive ANA suggests collagen vascular disease such as systemic lupus erythematosus.
anagram letters
individual movable letters that are used to test spelling or orthographic competence w/o need for writing ability.
analogy theory
theory proposing that the pronunciation of new words and nonwords is based on analogies with known words. See Rule-based reading.
anaplasia
loss of cell differentiation that is characteristic of most malignant tumors.
anarthria
Speech impairment, often used to describe impaired speech from bulbar paralysis.
anastomosis
the anatomical connection of one set of blood vessels to another
anenchephaly
Congenital malformation resulting from failure of neural tube formation that involves degeneration of forebrain germinal cells. Often results in spontaneous abortion. Cerebral and cerebellar hemispheres often completely absent and may be only rudimentary brainstem and basal ganglia.
anesthesia
impaired tactile stimulus detection that may result from damage to the anterior parietal lobe, spinal injury, or peripheral causes. Anesthesia induced by pharmacological depression of neural fx used to minimize/eliminate pain assoc. w/ medical/surgical procedures.
aneurysm
An arterial bulge resulting from a weakened vessel wall. Most are located in the subarachnoid space and pose a risk of hemorrhage. A dissecting aneurysm consists of layers of the artery separating.
aneurysm, berry
Sac-like or berry-like aneurysm that grows outward from an arterial wall. Those that are intracranial are commonly seen at bifurcations of cerebral vessels. Ruptured berry aneurysms are the most common cause of nontraumatic subarachnoid hemorrhage. Usu. treated surgically. Aka saccular aneurysm.
aneurysm, fusiform
A long segment of arterial dilation. Typically develop 2ary atherosclerosis and pose v. low risk of bleeding.
aneurysm, giant
aneurysm that has expanded to >25mm in diameter. Often present with mass effect rather than rupture.
aneurysm, mycotic
Dilation of artery 2ary to any infectious process. “Mycotic” refers to fungal infection; term is retained for historic continuity.
angiography
Radiological technique for imaging cerebral vessels that involves the intro of a contrast medium. An invasive procedure that carries risk of stroke or rx to contrast medium. Aka arteriography. See magnetic resonance angiography.
angioma
A congenital vascular malformation involving blood vessel proliferation that resembles a tumor. Most angiomas are asymptomatic, and when present, symptoms are usually due to arteriovenous ventricular malformations (AVMs) or cavernous angiomas.
angular gyrus
Brodman’s area 39. Convolution of inferior parietal lobe, arching over the posterior end of the superior temporal sulcus and continuous within the middle temporal gyrus. Lesions of the angular gyrus in dominant hemisphere may produce various combinations of Gerstmann syndrome signs, which include agraphia, acalculia, finger agnosis, and R/L disorientation. Alexia may also result from angular gyrus lesions.
anhedonia
Inability to experience pleasure from events typically considered enjoyable.
anomia (dysnomia)
Impaired ability to name objects or retrieve words. Word-finding difficulties must exist to a pathological degree, rather than being WNL or 2ary vocabulary limitations. Hx assoc. with lesions of temporal-parietal junction. However, present to some degree with all forms of aphasia, is common in mod. severity dementia, and by itself usu. has little localizing significance. Often assessed through visual object confrontation, though the term “anomia” is also used to characterized w-f difficulties in spontaneous speech. However, the these two types of w-f diffs. are dissociable (i.e. confrontation and spontaneous). Dysnomia implies a milder naming impairment than anomia.
anosmia
Impairment in the ability to smell. Assoc. w/ facial bone injuries, olfactory nerve degeneration, head trauma, or frontal lobe tumors [also poss. prodromal sign with AD].
anosodiaphoria
Lack of concern for serious neurological impairments, w/o denying their existence. La bell indifference, which also describes absence of concern for sensory or motor deficits, is commonly used in the context of psychogenic impairment (e.g., conversion symptomatology).
anosognosia
Orig. used to describe unawareness of hemiplegia following nondom. (rt) hem. injury as part of acute neglect syndrome, anosognosia is now used more broadly for commonly occurring unawareness of cog., linguistic, sensory and motor deficits after focal injuries (e.g., Wernicke’s aphasia) or conditions affecting the CNS more diffusely (e.g. TBI, dementia). Anosognosia consisting of denial of blindness is a cardinal symptom of Anton’s syndrome.
anoxia
Complete or near complete lack of O2 supply to tissue. Cardiac arrest is most common cause of cerebral anoxia. Greatest effect is on hippocampus (Sommer sector), resulting in anterograde memory impairment. Also may affect the primary visual/visual assoc. cortices, resulting in central visual disturbances (e.g. cortical blindness, visual agnosia). “Hypoxia” refers to less complete lack of 02.
anterior commissure
interhemispheric fiber bundle near the most anterior portion of the third ventricle that connects olfactory structures and lateral parts of the temporal lobe to each other. Commissurotomy as a treatment for intractable epilepsy may, but does not always, include transection of the anterior commissure in addition to the corpus callosum.
anterior communicating artery syndrome
A syndrome of dense anterograde amnesia, disorientation, and confabulation combined with disturbances of attention and behavior including distractibility, perseveration, and utilization behavior. Motor, sensory, and linguistic fxs remain intact. Assoc. w/ rupture of anterior communicating artery aneurysms.
anterior fossa
The cranial vault in which the frontal lobes rest.
anterograde amnesia
The inability to acquire and retain new information regardless of the type of material presented (ie verbal or nonverbal) or the sensory modality in which it is presented (ie auditory, visual). See amnestic syndrome.
antianxiety drugs
Meds. to reduce anxiety, aka anxiolytics or minor tranquilizers. Benzodiazepines are most commonly prescribed class.
anticoagulation therapy
Drug tx that decreases blood viscosity/coagulation; often initiated following ischemic (i.e. non-hemorrhagic) stroke or transient ischemic attacks. Aims to prevent thrombogenesis and recurrent embolism, though diff. agents used for the two modes.
anticonvulsant drugs
Older term for antiepileptic drugs. Still used, but has lost favor b/c some seizure types include no convulsions (e.g. absence szs, simple complex szs). See Antiepileptic drugs.
antidepressant drugs
Meds. used to treat deprs; 2 most common classes include SSRIs and tricyclics. Also MAOIs.
antiepileptic drugs (AEDs)
Meds used to control szs. AEDs may have cognitive side f/x, 1arily on rate of psychomotor speed and rate of info. processing. Risk of cog. impairment increases with polydrug tx.
antihistamines
Class of drugs that reduces histamine action. Have anticholinergic effects, which may cause sedation, though newer ones less so. In pts. w/ dementia, the anticholinergic f/x may exacerbate recent memory difficulty or confusion.
antipsychotic drugs
Meds. used to manage psychotic d/o’s. Aka neuroleptic drugs. Chemical classes vary widely in potency and side f/x (phenothiazines, thioxanthines, dibenzapines, butyrophenones, indolones).
Anton’s syndrome
Denial of blindness, usu. seen with bilateral occipital lobe lesions causing cortical blindness. Confabulations may be present. Anton’s syndrome is a specialized form of anosognosia.
Apgar score
A measure of neonatal status usu. assessed at 1, 5, and 10 mins. after birth. Based on heart rate, respiratory effort, muscle tone, skin color, and response to stimulation. Lower scores reflect poorer status and prognosis.
aphagia
Decreased eating, typically assoc. w/ hypothalamic lesions. Aphagia may also refer to swallowing diff., which in turn leads to decreased eating.
aphasia
Acquired d/o of symbolic lang. processing. Aphasia is characterized by a combination of naming, fluency, comprehension, and repetition deficits that are accompanied by reading and writing deficits. Characteristics of the lang. impairment include paraphasias, circumlocution, anomia, or conduite d’approche. Does not include disorders of articulation such as dysarthria. Most pts. more accurately described by term dysphasia, but aphasia usu. used. Classic aphasia subtypes usu. occur 2ary acute injury, usu. vascular in origin. Slow-growth tumors may lead to aphasia, but usu. much less impairment since more focal. Also seen sometimes in TBI and other conditions. Usu. not static; rather, degree changes according to disease progression (or recovery).
aphasia rel. to clinical pt. characteristics: crossed aphasia
Aphasia resulting fr. RH injury in right-handed indivs. RH (or bilateral) lang. representation is inferred, and may be assoc. w/ complexly reversed cerebral lateralization in which the LH is dom. for vis-spat. fx (situs inversus).
aphasia rel. to clinical pt. characteristics: ictal aphasia
Transient lang. impairment assoc. w/ sz. discharges from language areas of cortex. Suggests sz focus in LH.
aphasia rel. to clinical pt. characteristics: optic aphasia
Inability to name items despite preserved optic acuity and ability to demonstrate their fxs. Tactile examination of the same items results in correct naming. Rare; assoc. w/ parietal-occipital or occipital lesions.
aphasia rel. to clinical pt. characteristics: post-traumatic aphasia
Impaired language following brain injury.
aphasia rel. to clinical pt. characteristics: primary progressive aphasia (PPA)
Focal progressive decline in which aphasia develops and worsens w/o impairment of other higher cog. fxs. Varied lesions involving inferior frontal gyrus and temporal lobe have been described.
aphasia rel. to clinical pt. characteristics: subcortical aphasia
Aphasia resulting fr. subcortical lesion, as in the thalamus, basal ganglia, or afferent tracts to the auditory speech areas. Left thalamic hemorrhage is the most common cause of subcortical aphasia, which is associated w/: fluctuating language performance in which naming is impaired; fluent speech w/ many paraphasias; normal repetition. Left basal ganglia lesions, if large, may produce language impairment that resembles global aphasia.
aphasia syndromes: amnesic aphasia
Aphasia subtype used in early classification, characterized by diff. remembering words and names; synonymous w/ nominal (anomic) aphasia. Seen w/ small left temporal lesions. “Amnesic” aphasia implies word-finding diff. results from words being “forgotten”.
aphasia syndromes: anomic aphasia
Aphasia subtype char. by impaired naming ability w/ circumlocutions, few paraphasia, good comp. fluent speech, & normal repetition. Not synonymous w/ anomia, though anomia is one feature of anomic aphasia. Aka nominal or amnesic aphasia, but anomic aphasia may be observed following lesions throughout the LH.
anterior aphasia
Nonfluent aphasia; aka Broca’s aphasia. Contrast with posterior aphasia. Name is derived from characteristic lesions anterior to the central sulcus.
Broca’s aphasia
Nonfluent aphasia char. by effortful, often agrammatic speech production w/ poor repetition and rel. preserved comp. of single words/short phrases (though comp. of syntax may be impaired—e.g. Token Test). Cueing with context or initial phoneme may facilitate naming, otherwise gen. impaired. Language lacks grammatical complexity; reading comp. poor if grammatical words must be processed. Rt. hemiplegia a common neighborhood neurological sign due to char. lesion of posterior inferior frontal lobe. The lesion usu. results fr. infarction of upper division of middle cerebral artery involving upper and lower frontal operculum, insula, and adjacent regions surrounding Sylvian fissure. Global aphasia following stroke often resolves into Broca’s aphasia.
conduction aphasia
Fluent aphasia w/ rep. that is severely impaired but rel. preserved lang. comp. Prominent phonemic (literal) paraphasias & w-f difficulty.Assoc. w/ lesions of posterior perisylvian lang. areas. May represent a partially resolved Wernicke's aphasia.
dynamic aphasia
equivalent to transcortical motor aphasia. non-fluent output w/ preserved repetition and comp.; diff. w/ speech initiation.
expressive aphasia
nonfluent output most prominent; lesions gen. anterior; not commonly used b/c most aphasias incl. expressive diff. to some degree.
fluent aphasia
char. by rel. normal prosodic variation and artic. w/ freq. paraphasias. category includes W's a., conduction a., anomic a., and transcortical sensory a; contrasts w/ nonfluent a.
global aphasia
nearly complete loss of all core linguistic fxs incl. fluency, comp., rep., reading, and writing. lesions gen. involve both B's and W's area, as well as other perisylvian lang. areas.
jargon aphasia
char. by fluent paraphasic speech that may be incomprehensible and filled w/ neologisms. an acute expression of W's aphasia. numerous semantic (verbal) and phonemic (literal) paraphasias.
mixed transcortical aphasia
rare; rep. rel. intacat despite signif. aphasia. nonfluent spontaneous speech, unable too name, read, write. normal rep. up to standard span length, may be echolalic. pathology spares the perisylvian lang. areas but involves surrounding watershed zones.
nonfluent aphasia
char. by effortful speech production, lack of normal prosody. incl. B's aphasia, global a., transcort. a., and mixed transcort. a.
pure motor aphasia
nonfluent speech w/ largely preserved lang. fxs demonstrated by abil. to write. aka apraxia of speech; aphemia has the same meaning.
receptive aphasia
rel. impaired comp; more posterior; uncommon term b/c most a. involves some degr. of comp. diff.
transcortical motor aphasia
nonfluent a.; preserved rep., rel. pres. lang. comp.; similar to B's aphasia except for preserved rep. lesions typically vascular, involving area superior or anterior to B's areas or supp. motor area.
transcortical sensory aphasia
fluent aphasia; comp. severely imp. but rep. rel. preserved; speech fluent & circumlocutory, often w/ semantic jargon. like W's a., rep. largely preserved lesions involve posterior brain from occipital pole forward on both medial and lateral surfaces, often reching along medial occ. lobe in area of distr. of post. cerebral art.; neighborhood signs incl. visual agnosia, hemianopsia, sensory loss; occas. seen in late Alz. disease.
Wernicke's aphasia
fluent a. w/ freq. semantic (verbal)paraphasias; lang. comp. and rep. severely impaired; naming impaired in contrast to B's a., and prompting helps little; lesions gen. vascular and may result fr. occlussion of posterior temporal branch, angular branch, or occas. middle temp. branch of middle cerebral art.
aphonia
loss of voice; pts. can mouth words & whisper. in contrast w/ mutism, is assoc. w/ peripheral etiology; milder = hypophonia
Apolipoprotein E (ApoE)
lipid-protein complex resp. for lipid transport in blood; the e4 allele linked to incr. risk of late-onset AD, though AD may dev. in absence of it and those w/ e4 allele may not dev. AD
apoplexy
hemorrhagic stroke, now only used to refer to pituitary apoplexy
appallic syndrome
vegetative state
apraxia
inability to perform purposeful mvts. for reasons other than impaired motor strength, sensation, coordination, or comprehension.
apraxia of eyelids often assoc. w/ what lesion?
top-of-the-basilar syndrome
buccofacial apraxia
aka oral apraxia; involves face, lips, tongue; lesion commonly includes left central operculum and anterior insula, consequently often coexists w/ Broca's aphasia
callosal apraxia
form of ideomotor apraxia assoc. w/ diff. w/ motor sequencing tasks of left hand following CC lesion; thought to result from disconnection of visuokinetic motor engrams of LH fr. motor area of RH; aka unilateral apraxia; occas. seen in indivs. w/ lesion affecting fibers passing thru anterior CC, usu. transient
conceptual apraxia
inability to perform limb mvts. on command due to impairment in linking meaning/intention of action to mvt. plan; movements well-performed but inaccurate in content.
constructional apraxia
inabil. to copy/assemble 2- or 3-D objects; differs from other apraxias b/c involves visual-constructional impairment not motor imp.; may be better descr. as visuo-contsr. impairment; common effect of RH parietal lesions; one of earliest NP findings assoc. w/ dementia; common w/ diffuse cerebral impairment
dressing apraxia may be present as part of what syndrome?
neglect syndrome
frontal apraxia
inabil. to do routine actions b/c of temporal or sequential disorganization; unimproved by verbal mediation; action becomes a series of isolated fragments, as link b/w action goal and steps that must be assembled are destabilized
gait apraxia
aka frontal gait; inabil. to walk despite capacity to execute normal walking mvts. when lying in bed; may appear glued to floor; may be caused by frontal lobe lesions, normal pressure hydroceph., and Parkinson Plus syndromes
graphomotor apraxia
inabil. to write/draw despite normal capacity to hold, manipulate instrument; mahy exist indep. of central agraphia; may accompany anterior/posterior lesions of either cerebral hemisphere; more commonly known as apraxic agraphia
ideational apraxia
inabil. to peform series of gestures due to loss of plan of action (ideation) for mvt.; common sequence tested--filling and lighting a pipe; freq. seen in pts. w/ moderately severe dementia
ideomotor apraxia
inabil. to perform transitive or instransitive gestures on command; common error is using body part as object (or tool); e.g. in pretended use of hammer, scissors, key; errors in symbolic gestures, e.g.making saluting or hitchhiking gesture; Usu. assoc. w/ LH lesions (inferior parietal lobe or supplementary motor area), or lesion of CC; freq. coexists w/ ideational apraxia
limb-kinetic apraxia
clumsiness of hand not due to weakness or tone impairment; thought related to pyramidal motor lesions; not considered d/o of learned skill mvts per se; no diff. in selected or sequencing motor programs
ocular apraxia
apraxia assoc. w/ visual scanning and volitional eye mvts; gen. assoc, w/ bilateral frontal-parietal lesions
optic apraxia/optic ataxia
apraxia of ocular searching mvts. affecting visually guided hand mvt; usu. results from bilateral posterior parietal lesions; diff. names vary in emphasis of underlying neurobehavioral deficit; aka visuomotor apraxia
aprosexia
disturbance of attn. and conc. assoc. w/ psychomotor inefficiency; common complaints include diff. remembering conversations, instructions, appointments, materials just read, etc, and keeping mind on task; assoc. complaints include insomnia and fatigue
aprosodia (dysprosodia)
impairment in prosodic or melodic component of speech; seen in either LH or RH lesions; LH produce inapprop. syllable stress; RH affects emotional content--often emotional flattening or lability; aka motor aprosodia
Aqueduct of Sylvius
canal that drains CSF fr. 3rd to 4th ventricle thru midbrain; common site of obstruction causing childhood hydrocephalus; aka cerebral aqueduct
arachnoid mater
middle of 3 meninges loc. b/w dura and pia mater; arachnoid and pia together form leptomeninges
arachnoid villi
granulations that fx as one-way valves allowing passage of substances from CSF to venous blood in the superior sagittal sinous
arcuate fasciculus
the major assoc. fiber bundle orig. in the tmeporal lobe and terminating in the prefrontal cortex; also forms part of superior longitudinal fasciculus or dorsal pathway; connects to Wernicke's area through angular gyrus to Broca's area
Argyll Robertson pupil
pupillary abnormality assoc. w/ normal pupillary convergence w/ loss of consensual pupillary reflex (i.e. the eyes can accomodate but cannot react); often accompanies tabes dorsalis and is diagnostic of teriary neurosyphilis
arhinencephaly
congenital absence of olfactory bulb and tracts; assoc. w/ fusion of cerebral hemispheres
Arnold-Chiari malformation
congenital malformation, cerebellum and medulla protrude into spinal canal thru foramen magnum; may be assoc. w/ other defects incl. spina bifida/meningomyelocele
arousal
state of general alertness; arousal may be divided into tonic arousal--general arousal state that included sleep-wake cycle--and phasic arousal, referring to sudden increase in attentiveness needed for rapid response
anterior cerebral artery (ACA)
orig. at bifurcation of internal carotid artery that supplies blood to dorsolateral and mesial frontal regions
anterior communicating artery (ACoA)
small artery connecting the 2 anterior cerebral arteries, & forming anterior portion of circle of Willis
basilar artery
formed by union of left and rt. vertebral arteries; runs from lower to upper pons, where it bifurcates into the two posterior cerebral arteries
carotid artery
major artery to brain; bifurcates to form internal and external carotid arteries (ICA and ECA)
internal carotid artery
begins at bifurcation of the common carotid artery; terminates in middle fossa where it bifurcates into anterior and middle cerebral arteries
lenticulostriate arteries
small penetrating arteries suppying lentiform nucleus and striatum
middle cerebral artery (MCA)
major artery supplying temporal lobe, thalamus, striatum, and insula. MCA distribution is involved in most strokes.
posterior cerebral artery (PCA)
artery formed by bifurcation of basilar artery that supplies the thal. & hypothal, cerebral peduncles, choroid plexus of the lat. & 3rd ventricles, and temp. and occipital lobes
posterior communicating artery (PCoA)
arteries of internal carotid origin that connect w/ posterior cerebral arteries to form the circle of Willis
arteriosclerosis
vessel abnormalities in which "hardening of the arteries", major risk factor for stroke; artery walls become thickened and lose their elasticity; two main forms affect cebral vessels--arteriolosclerosis and atherosclerosis
arteriolosclerosis
form of arteriosclerosis affecting smaller arteries (arterioles); assoc. w/ chronic hypertension
atherosclerosis
buildup of plaques (fatty deposits) on innermost layer of arterial walls, resulting in narrowing of vessel lumen; thrombi may form over the plaques (localized atherosclerotic deposits)--these are often assoc. with myocard. infarction
articulatory loop
component of working memory involved in storage, manipulation of speech-based info; aka phonological loop
asomatognosia
denial by a pt. of own body part (only on one side); commonly seen as part of neglect syndrome, which may result from from acute rt.sided lesions
asperger's syndrome
variant of autism characterized by social isolation & eccentric bx in childhood; impaired social interaction and nonverbal comm., abnormalities in inflection, speech may be repetitive; clumsy; arithmetic deficit; impaired humor and comprehension of gestures
aspiration pneumonia
pneumonia caused by saliva, food or drink entering the lungs; commonly occurs with impaired swallowing or oral motor control & diminished gat & cough reflexes
association cortex
cortical areas other than 1ary sensory or motor regions; these areas are involved with complex fxs.
astasia-abasia
inability to stand (astasia) and to walk (abasia); when used in hyphenated form like this, typically refers to psychogenic d/o of motor coordination
astereopsis
inability to perceive objects' depth
asterixis
motor disturbance, char. by rapid & sporadic contraction of limbs followed by slow return to extension; seen in toxic-metabolic encephalopathy or confusional states (e.g. can be seen prior to hepatic coma)
astrocyte
a large glial cell
astrocytoma
1ary brain tumor arising from prolif. of brain astrocytes; in children typically rel. benign & located in posterior fossa; in adults gen. in cerebrum, become malignant, & infiltrate extensively
ataxia
abnormal mvt. including varied errors, such as rate, direction, force, etc; components include breakdown of mvts. into component parts, dysdiadochokinesia, & tremor
ateriovenous malformation (AVM)
congenital vasc. malformation involving direct connection b/w arteries and veins that bypasses normal capillaries. Typically resent as subarachnoid hemorrhage or seizures. May be associated w/ a "steal phenomenon"--blood diverted into AVM leading to lower perfusion of neural tissue.
athetosis
an invol. slow writhing movement; distal limbs usually more affected
athetosis is most commonly associated with what condition?
mental retardation, though it may be present in many basal ganglia diseases
athetosis results most commonly from what conditions?
kernicterus, hypoxia, and permaturity
atonic seizures
generalized seizures resulting in sudden loss of motor tone; aka "drop attacks"; usu. come with no warning
autism
a form of PDD that appears in childhood before 3 y.o.; char. by poor social interaction, communication deficits (eg delay, echolalia), and odd bxs (eg stereotypic, ritualistic mannerisms)
automatism
simple and repetitive actions that are not mediated by conscious intention; common ones in complex partial seizures include lip smacking or repetitive hand movements
autonomic nervous system
nervous system part of the nervous systme involved in maintaining body fxs and bx; 2 major divisions are sympathetic & parasympathetic; in general, regulates smooth muscle & organs; involved in modulation of the 4 f's: feeding, fighting, fleeing & procreating
axon
the relatively long, single process of a neuron; conducts the action potential to the presynaptic terminal from the soma and dendrites
axonal/dendritic sprouting
process in which axons that are injured regenerate or dev. new terminal connections
name 3 subtypes of ataxia
limb ataxia, optic ataxia, truncal ataxia
truncal ataxia is most commonly associated with what two disorders?
initial sx of a neurologic event that "warns" of imminent presentation; often present w/ migraines or seizures
ABA design/reversal design
A--baseline target bxs measured; B--same bxs assessed while intervention is applied; A--bxs assessed once more w/ intervention withdrawn
abasia
inability to walk
ABCs
refers to "airway, breathing, and circulation" (ie pulse)w
abiotrophy
programmed loss of neurons resulting from genetic abnormality; manifests in neurodegenerative diseases
ablation
surgical destruction/removal of tissue--e.g. in intractible epilepsy, might have lobectomy of ant. temp. lobe
abulia
lack of initiative/drive; manifests in lack of spontaneity in speech/thought/action; may occur w/ psychosis or neurologic disease
abulia may be assoc. w/ lesions in what regions?
bilat. frontal or orbital frontal l. (2ary tumor, severe TBI, degen. illness such as Pick's disease, etc)
acalculia
acquired or developmental disturbance of computational ability; freq assoc w/ both agraphia and alexia for numbers
name the two subtypes of acalculia:
primary acalculia (anarithmetria)and spatial acalculia
milder forms of acalculia may affect ___ and ___ more than ___ and ___
mult. and div., addition and subtraction
what lesion is classically associated with acalculia? (name of regions and corresponding Brodmann's areas)
left angular gyrus; areas 39 and 40
computational impairment may also be assoc. w/ any lesion in the _________ that results in _______.
perisylvian area; aphasia
define primary acalculia
acquired or dev.impairment in calc.; cannot be explained by alexia/agraphia for numbers, or by spatial disorganization for numbers
define spatial acalculia
impaired abil. to perform written calculations due to diff. in processing spatial aspects of written problems
what hemisphere is associated with: primary acalculia/anarithmetria? spatial acalculia?
LH; RH
acceleration-deceleration injury
impairment caused by rotational forces assoc. w/ rapid deceleration
acceleration-deceleration injury is commonly associate with what phenomenon?
diffuse axonal injury
acetylcholine (ACh)is a(n)[excitatory or inhibitory]neurotransmitter; ACh plays an important role in _____ _______.
excitatory; memory formation
diminished ACh is seen in ______; ACh also plays a role in_____ _____, which are managed by _______ ACh in the _______
AD; movement disorders; decreasing, caudate
What may be a side effect of anticholinergic drugs used in movement disorders?
anterograde memory impairment
achromatopsia, defined as ______________, results from damage to the _____-_____ lobe
loss of color vision, temporal-occipital lobe
in left occipital-temporal lobe lesions, ____ and ____ may occur in addition to achromatopsia
alexia, hemianopsia (loss of vision in one half of visual field)
acoustic neuroma: a benign tumor, arises from _____ ______ that surround the vestibular portion of the ___th (acoustic) cranial nerve
Schwann cells; 8th
acoustic neuromas may obstruct ______ _____ by compressing the _____ and lateral ______
CSF circulation; pons, medulla
sxs of acoustic neuromas include disturbances of _____ and ____, _______, tinnitus, and ________of gait
hearing, balance; headache; unsteadiness
name some of the phenomena that may affect the nervous system in AIDS
dementia, cerebral lymphoma, intracranial infections processes (eg cytomegalovirus), encephalitis, toxoplasmosis, meningitis, peripheral neuropathy
action tremor: a rhythmic postural or _____ tremor that is often worse at the ____ of motor activity
intention; end
action tremors occur with _____ motor movements
fine
patients with Parkinson's often have __________ tremors
both action and resting
Define and give a few examples of ADLs
actities of daily living (ADLs) are skills nec. for indep. living, such as using telephone, shopping, preparing food, etc
adenomas: benign or malignant? where are they most likely to arise in the CNS?
benign tumor; most likely to arise within the CNS in the pituitary; cells arise from glandular strucutures; epithelial (covering surface such as an organ)
adiadochokinesia (or dysdiadochokinesia)
deficit in ability to perform rapid alternating movements
adiadochokinesia may arise from lesions in which area(s)?
cerebellum; also poss. w/ frontal lobe, basal ganglia
adipsia--definition, lesion location?
absence of thirst; assoc. w/ lesion in lateral hypothalamus
adrenal glands are stimulated by what brain structure? what functions are regulated by the adrenal cortex?
stimulated by the pituitary; regulated metabolism, blood pressure, sexual bx
what is secreted by the adrenal medulla secretes what hormones?
epinephrine and norepinephrine
adrenergic system
component of the ANS that consists of cells containing catecholamines (ie epinephrine, norepinephrine, dopamine)
adrenocorticotropic hormone (ACTH)is secreted by the ____, it is a major regulator of ______
pituitary; adrenal activity
ACTH (aka corticotropin) is increased in a number of conditions/circumstances, including among others:
stress, hypoglycemia, Addison's disease
ACTH is diminished in these two conditions:
panhypopituitarism, adrenal cancer
adrenoleukodystrophy
genetic disease of childhood; marked by diffuse abnormality of cerebral white matter & adrenal atrophy
adrenoleukodystrophy is marked by cognitive impairment that leads to _______, and is characterized additionally by _____,_____,_____ and impaired vision
dementia; aphasia, apraxia, dysarthria
afferent
neural impulses that are conducted towards the CNS
agenesis of the corpus callosum (ACC); typical presentation
congenital; failure of CC to develop; MR and epilepsy typical, though occurs in some heathy indivs.
ageusia--definition
loss of taste sense
ageusia is common in _______ palsy; may be associated with TBI if the _____ cranial nerve (the _th/_st nerve) is severed
Bell's; olfactory/1st
agnosia: impaired recognition of prev. meaningful stimuli; not attributable to _____ defects, a _____ disorder, or disturbance in _____
sensory, naming, attention. agnosia has been described as a "normal percept stripped of its meaning" (Teuber)
agnosias can be present in any sensory modality, but the most common are ____ and ____.
visual, auditory
apperceptive agnosia: while basic visual functions including acuity are fairly intact, there is impairment in...
recognition of a particular shape or object
associative agnosia results from disruption at the post_____ level of visual processing, in the stage at which _____ is usually attributed
perceptual, meaning
in associative agnosia a pt. can accurately ____ an object, but cannot associate it with ____ information for identification. Lesions are typically (acute or diffuse?)
draw, semantic, diffuse
astereognosis: impaired ability to i.d. objects based on ______characteristics
physical (e.g. size, shape, texture)
astereognosis is typically associated with (pre or post)central lesions
post
astereognosis is typically __lateral, and differs in this way from ____agnosia, which is a higher order deficit that is ____lateral
unilateral, tacticle, bilateral
two types of auditory agnosia are ____ ____ agnosia and ____ ____ ____ (described later)
auditory sound agnosia, pure word deafness
auditory sound agnosia is the inability to recognize meaningful ______ auditory information (e.g. [give example])
nonspeech, such as an ambulance siren
autotopagnosia: disturbance in ____ ____, involving an inability to identify the ___ of one's ____
body schema; parts, body
limited forms of autotopagnosia include _____ agnsosia and impaired _____ _______
finger, left/right discrimination
color agnosia (inability to ____colors despite intact color discrimination) differs from color ____ (can't name colors) and _____ (impaired color perception)
recognize, anomia, achromatopsia
color agnosia localization:
usually left or bilateral occipital-temporal
finger agnosia: ____lateral loss of ability to name/i.d. fingers. May be part of ____ ____ (name condition).
bilateral, Gerstmann's syndrome
finger agnosia is postulated to occur with lesions in the ___ hemisphere in the ___ lobe, and are located in the inferior region of this lobe. Specifically, they may be located at the _____ gyrus.
left, parietal, angular gyrus
prosopagnosia: inability to recognize familiar ___, unrelated to a primary visual disturbance
faces
prosopagnosia may also include difficulty recognizing familiar things such as...
building, cars, landscapes
prosopagnosia: lesions are typically bilateral infarctions in _____ artery in the ____ area; if unilateral, usually involves the ___ hemisphere
posterior cerebral artery (PCA), occipital-temporal or parietal occipital; right
pure word deafness
loss of comprehension of aural language; occurs in absence of other lang. impairments; comp. of nonverbal sounds rel. intact
pure word deafness is thought to occur due to disconnection of ______ ____ from ____ input.
Wernicke's area, auditory
lesions in pure word deafness usually involve cortical/subcortical areas of the superior _____ gyri
temporal
simultagnosia: impaired recognition of the meaning of _____, with preserved ability to describe its ______
a whole picture or object; parts
simultanagnosia may be due to a defect in ______ ______
ocular scanning
tactile agnosia involves inability to recognize objects by touch that is not due to deficit in tactile sense (hypesthesia). it is __lateral, and lesions are generally in the inferior ____ lobe (Brodmann's areas __ and ____). The posterior ___ may be incl
unilateral, parietal, 39 and 40; insula
agrammatism (disturbance in production/comprehension of grammatical structures) is also known as _______ ______; substantive words such as nouns and verbs are generally preserved, though function words are ommitted
telegraphic speech
agraphia is an acquired difficulty in writing or spelling. it is commonly associated with ___ and ___
aphasia, alexia
typical location of lesions in agraphia: superior ___ lobe or the 2nd ____ gyrus of the language dominant hemisphere.
parietal, frontal
the following are all agraphia ______ disorders: deep agraphia, jargon agraphia, lexical agraphia , phonological agraphia , semantic agraphia , surface agraphia , and verbal agraphia .
spelling
the following are types of agraphia _______ disorders: afferent a., allographic a., apraxic a., peripheral a., and spatial a.
writing
akathisia
inner restlessness & continual leg movement
akathisia is sometimes associated with ______, and may sometimes follow medication reduction in the treatment of this condition; it is also associated with ____ therapy
Parkinsonism; neuroleptic
akinesia
decreased movement occurring in the absence of paralysis
apraxia involves poor motor ____, whereas akinesia involves poor motor _____; that is, akinesia is a disorder of motor _____
sequencing, initiation, intention
in parkinsonism, one form of akinesia is ______ face; aka amimia or reptilian stare
masked
akinesia may be seen with lesions of the bilateral _______ motor area and ______ ______ gyrus lesions
supplementary, cingulate gyrus
akinetic mutism involves _____ limb movments and _____ speech
decreased, absent
akinetic mutism is associated with large medial _____ lobe tumors, or ruptured aneurysms of the _____ cerebral artery; it can also occur after injury to the ______
frontal, anterior, thalamus
in contrast to "locked-in syndrome" in which eye movements can be used for communication, cognition can be difficult to demonstrate in akinetic mutism b/c pts will typically ____ ____ to requests
not respond
alcohol withdrawal syndrome involves ____, _____, and ___ following alcohol withdrawal in alcoholics. it may progress to autonomic _____, delirium t______, ______ and death
agitation, disorientation, hallucination; hyperactivity, delirium tremens, seizures
alcoholic cerebellar degeneration results in a ____-____ stance and gait, instability of the _____, and ____ of the legs. It typically (resolves vs. remains unchanged).
wide-based, trunk, ataxia; remains unchanged

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