[The effect of anticholinergic drugs on 123I-IMP SPECT in Parkinson's disease].

Several reports have suggested that anticholinergics have some associations with mental deterioration in Parkinson's disease (PD). We investigated the effect of anticholinergics on regional cerebral uptake of tracer in PD patients using N-isopropyl p-[I-123] iodoamphetamine SPECT. Sixteen pairs of region of interest (ROI) were located in the cortex, a pair in the basal ganglia, thalamus, and cerebellum. The size of each ROI was about 16 mm x 16 mm. Regional cerebral uptake ratio (rCUR) was calculated by the next equation: rCUR = (total count in an ORI)/(mean of total count in the cerebellar ROIs). The comparison consisted of two parts; (1) 7 PD patients (age 59-76 (65.4 +/- 6.7 mean +/- S.D.)) who had been on chronic anticholinergic therapy underwent SPECT and Wechsler Adult Intelligence Scale (WAIS) twice, for the first time when they were on anticholinergics and second a month after discontinuation of anticholinergics. All but two patients performed significantly better on WAIS after discontinuation than when they were on anticholinergics. The improvement was about 10 points in total IQ. (2) 11 PD patients (age 52-79 (64.5 +/- 8.6 mean +/- S.D.)) on chronic anticholinergic therapy including all but two patients mentioned above (group A) and 25 PD patients (age 52-88 (66.7 +/- 9.8 mean +/- S.D.)) not receiving anticholinergics (group B) also underwent SEPCT. In the comparison (1), at all but two ROIs was the mean rCUR higher after discontinuation than when they were on anticholinergics and the difference was significant at 10 ROIs out of 32 ROIs in the cortex.(ABSTRACT TRUNCATED AT 250 WORDS)