09 - The Wechsler Adult Intelligence Scale (WAIS)

The Wechsler Adult Intelligence Scale (WAIS)

© SPMM Course Occipital lobe lesions

C. Neuropsychological tests The Wechsler Adult Intelligence Scale (WAIS)  Most widely used intelligence test in clinical practice.  The latest revision, the WAIS-III, is designed for persons 16 to 89 years of age. Wechsler Intelligence Scale for Children-III [WISC-III] is used for <16. For ages, 4 to 61/2 years Wechsler Preschool and Primary Scale of Intelligence-Revised [WPPSI-R] is used.  The WAIS is composed of 11 subtests made up of six verbal subtests and five performance subtests, which yield a verbal IQ, a performance IQ, and a combined or full-scale IQ.  Verbal tests = similarities, arithmetic, digit span, vocabulary, information and comprehension  Performance tests = picture arrangement, block design, picture completion, digit symbol, matrix reasoning (replaces object assembly)  Certain tests are called ‘hold tests’ as they are supposed to be resistant to age-related decline; these tests may be sensitive for organic brain damage such as dementia. In WAIS, hold tests are vocabulary, information, object assembly and picture completion. Non-hold tests are block design, digit span, similarities and digit symbol. A deterioration quotient is derived from the difference between ‘don’t hold’ and ‘hold’ test scores.

Unilateral lesions Bilateral lesions Contralateral (congruent) homonymous hemianopia which may be central (splitting the macula) or peripheral; also homonymous hemiachromatopsia Cortical blindness (pupils reactive) Elementary (unformed) hallucinations—usually due to irritative lesions Anton syndrome (visual anosognosia, denial of cortical blindness) If deep white matter or splenium of corpus callosum is involved, alexia and color-naming defect Loss of perception of color (achromatopsia) Visual object agnosia Prosopagnosia (temporo-occipital), simultanagnosia (parieto-occipital) Visual illusions (metamorphopsias) and hallucinations (more frequent with right sided lesions) Balint syndrome (parieto-occipital)