Assessment of intellectual functioning of patients with Parkinson's disease using the Satz-Mogel (1962) short form of the Wechsler Adult Intelligence Scale.

The purpose of the present study was to compare the Satz-Mogel (S-M) short form of the Wechsler Adult Intelligence Scale--Revised (WAIS-R) with the full-scale WAIS-R to establish its utility in the assessment of intellectual functioning in patients with Parkinson's disease (PD). PD patients and elderly control subjects were administered a neuropsychological test battery that included the complete WAIS-R or the S-M. Results indicated that the S-M was a reliable measure of IQ. The PD subjects' Verbal, Performance, and Full-Scale IQ scores were inferior to that of controls, regardless of test form. Adjustments for depression and age did not alter these results. PD patients with more severe disease scored lower on some visual-spatial measures. Verbal decrements among PD patients may relate to problems in verbal fluency, categorical thinking, and impaired retrieval of verbal material. PD patients may experience patterns of subtle cognitive changes that include deterioration of some specific abilities as the disease progresses.