Performance on the Benton Visual Retention Test was compared between those with Parkinson's disease (PD) and age-equivalent controls. The major difference between groups was that those with PD showed an increase in figural reproduction errors between test periods spaced six months apart, while controls showed little increase in errors over this time and made fewer errors at each time of testing. Age and IQ accounted for major proportions of variance in performance for both groups (about 50%), far more than that attributable to group membership. Within the PD group, however, age and disease onset were confounded (r = .92), indicating that age as a variable is quite when disease onset is considered. The results support the notion that PD is associated with change in visual-spatial memory, beyond that predicted by age per se.

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.

No abstract