Definitions A
Terms
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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 processesâ€). 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 “libertyâ€for “freedomâ€), 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 outâ€. 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 “bussyâ€). 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 “foreignâ€, “alienâ€, or “uncooperativeâ€. 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 amnesiaâ€, 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 “forgottenâ€.
- 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