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Background: Visual hallucinations in Parkinson disease (PD) occur in approximately one third of patients treated long-term with dopaminergic medications. In Alzheimer disease, hallucinations and psychosis have been linked to increased representations of B2/B2 homozyogotes for the dopamine receptor gene DRD1 and 1/1 or 2/2 homozygotes for DRD3. In addition, a previous study of PD patients with and without hallucinations did not show differences in D2 and D3 polymorphisms, although careful case-control matching was not performed. Another study linked the apolipoprotein E4 (APOE4) allele to hallucinations in PD., Objective: To determine whether the frequency of dopamine receptor genetic variants and APOE alleles in patients with PD with and without chronic visual hallucinations resembles the pattern previously documented in patients with Alzheimer disease., Methods: We conducted a case-control study of 44 patients with PD and chronic hallucinations and 44 patients with PD who had never hallucinated. Cases and controls were matched for current age and medications. DNA was isolated from blood samples and assayed for DRD1, DRD2, DRD3, DRD4, and APOE polymorphisms. Receptor polymorphisms were genotyped by polymerase chain reaction. Genotypes in hallucinators and nonhallucinators were compared using Mantel-Haenszel tests stratified by pair, and allele frequencies were compared using Wilcoxon signed rank tests within pairs., Results: Neither D1 receptor genotypes (P =.37) nor allele frequencies (P =.38) differed, and there was no predominance of B2/B2 homozygotes in the hallucinators. For D3, there was a higher frequency of allele 2 (P =.047), but there was no significant difference between frequencies of homozygotes vs heterozygotes (P =.39) as reported in Alzheimer disease. D4 receptor distribution of long and short alleles did not differ between the 2 patient groups, and there were too few C alleles (3 of 86) to compare D2 allele genotypes or frequencies. For APOE, 12 cases and 12 controls carried E4 alleles (P>.99)., Conclusions: With careful case-control matching, visual hallucinations in PD are not associated with the pattern seen for patients with Alzheimer disease and visual hallucinations. Furthermore, there was no association between hallucinations and APOE. Similar methods using larger sample sizes might be adapted to test whether specific dopaminergic receptor genetic variants are associated with visual hallucinations in PD. Based on our data, the DRD3 allele 2 may merit further study.

Patient on-off diaries are used in clinical trials, but a method to assure agreement between patient and examiner has never been developed. We tested whether a patient-teaching tape increased the rate of agreement between patient diary ratings and simultaneous neurologic assessment by a trained professional. A total of 32 consecutive patients who had Parkinson's disease with motor fluctuations independently completed a 4-h on-off diary (nine ratings) at the same time as an examiner. Those with < 80% agreement with the examiner (n = 20) were randomized to view either a training tape that showed motor fluctuations (experimental group) or-another videotape of general patient educational material (control group). All patients then underwent the same 4-h assessment of motor fluctuations. To test for long-term retention, they returned 1 month later and, without reviewing the videotape, underwent a final 4-h correlation assessment. After the training tape, the experimental group showed significant improvement, whereas the control group showed no improvement. Furthermore, another month later, the improvement in the experimental group was retained. Based on these findings, we suggest that future clinical trials assessing motor fluctuations incorporate this tape into their basic methodology.