The relative insensitivity of traditional IQ tests to
mild cognitive deficits has led investigators to develop
a version of the widely used Wechsler intelligence scales
that allows quantitative analysis of underlying qualitative
responses. This instrument, the Wechsler Adult Intelligence
Scale–Revised as a Neuropsychological Instrument
(WAIS–R NI) was administered to 16 Parkinson's
disease (PD) patients and 30 normal controls (NC). The
2 groups did not differ significantly in mean age or education,
or on their mean Mattis Dementia Rating Scale score. Relative
to NC participants, PD patients showed decreased visual
attention span, longer response latencies, slower visuomotor
processing, and more stimulus-bound errors. Many of the
WAIS–R NI measures were able to detect cognitive
impairment in a greater percentage of patients than the
traditional WAIS–R measures, making it easier to
identify deficits that could affect quality of life early
in the course of the disease. (JINS, 2001, 7,
535–543.)