Definitions WXYZ
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- Wada Test
- technique to assess language lateralization, memory fxs; mult. cog. tasks presented during period of hemispheric anesthesia (used to i.d. critical areas before brain surgery, e.g.)
- Wallerian degeneration
- atrophy of distal portion of neurons after being severed from proximal portion
- what is Wallerian degeneration typically due to? (3 types of events)
- trauma, infarction, tumor infiltration
- Watershed zones
- Border zone of anastomoses that lies b/w territories of 2 major cerebral arteries. [anastomose: To unite by contact, e.g. 2 vessels at their extremities]
- what is the main clinical significance of watershed zones?
- a significant drop in blood pressure (e.g. w/ anoxia, carbon monoxide poisoning) will lead to drop in oxygenated blood supply where 2 arterial distributions overlap-- become infarcted
- Name one type of syndrome that may result from watershed zone infarction
- transcortical aphasia--lesions of watershed zones around the Broca-Wernicke language axis may isolate the area.
- Where is Wernicke's area? What is the corresponding Brodmann's area?
- the posterior one-third of the superior temporal gyrus; aka Brodmann's area 22
- Wernicke's disease
- acute phase of Wernicke-Korsakoff syndrome; signs include nystagmus, gaze paresis, ataxia, confusion, disorientation, apathy, amnesia
- what is the etiology of Wernicke's disease/encephalopathy?
- B1 (thiamine) deficiency 2ary chronic alcoholism or malnutrition
- Wernicke-Korsakoff syndrome
- syndrome involving B1 deficiency; char. acutely by Wernicke's disease and chronically by Korsakoff's disease (anterograde amnesia, confabulation, orientation disturbance, suggestibility)
- Common findings in Wernicke-Korsakoff syndrome after acute stage include:
- normal IQ, ant.& retr. amnesia, amotivation, visual-perceptual and executive task difficulties, vulnerability to proactive interference
- lesions commonly involved in Wernicke-Korsakoff syndrome include:
- midbrain, cerebellum, mammillary bodies, thalamus; lesions in dorsomedial nucleus of the thalamus thought to play 1ary role in anterograde amnesia
- What is the name of the model describing the language-associated neural pathways with input/output fxs and interralationships with other cortical language areas, which helps to define aphasia subtypes?
- Wernicke-Lichtheim model
- West syndrome
- encephalopathy of infancy; char. by mental retardation/arrested psychomotor dev., spasms, hypsarrhythmic EEG
- white matter
- myelin sheath covering axons that leads to white appearance of brain; as cell bodies are unmyelinated, regions dense with cell bodies appear gray (gray matter)
- what subtest is often given as an indicator of premorbid level of ability?
- WRAT reading subtest, as reading is felt to be relatively resistant to the effects of diffuse brain impairment
- Williams syndrome
- metabolic d/o (genetic) that leads to characteristic "elfin" facial features, supra valvular aortic stenosis, pronounced visual-spatial deficits, freq mild to mod. mental retardation.
- Wilson's disease
- genetic d/o (autosomal recessive); results from defect in copper metabolism; leads to movement d/o & hepatic insufficiency; initially presents w/ personality/mood changes, leads to dementia
- Witzelsucht
- abnormal affect assoc. w/ frontal lobe pathology--disinhibted, facetious and inappropriately euphoric
- word attack
- a reading strategy; string of letters is broken into segments before reading
- word class effects
- describes tendency of aphasia pts. to have diffential ability depending on the type of word; e.g. Broca's aphasics skip more connecting (function) words; in addition, people w/ reading d/o's have harder time with abstract than concrete nouuns
- xanthochromia
- CSF discoloration due to presence of blood for 1+ day; assoc. w/ subarachnoid hemorrhage
- XYY syndrome
- chromosomal abormality; results from nondysjunction of sex chromosomes; leads to cerebral migrational abnormalities, maturational delays
- the _________ law holds that performance is facilitated by mild anxiety, inhibited by anxiety beyond that; represented graphically as an inverted-U function
- Yerkes-Dodson law