Hallucinations in Parkinson's disease--a study of forty three patients.

Objective: To see the prevalence of hallucinations in patients with Parkinson's disease and to compare the various parameters between hallucinators and non-hallucinators.

Methods: Forty-three patients of Parkinson's disease were included. Detailed motor assessment was done with UPDRS scales. Assessment was done for the presence of depression and sleep disturbances. The patients were enquired for the presence of depression and sleep disturbance. The patients were enquired for the presence of hallucinations. Hallucination types and associated emotional experience were probed into. Comparative analysis was subsequently done between hallucinators and non-hallucinators.

Results: The mean age of the patients was 61.47 years while mean duration of symptoms of PD was 4.30 years. The mean UPDRS II and III scores were 15.18 and 38, respectively. Fifteen patients (34.9%) had experienced hallucinations. The hallucinations described were visual as well as auditory in nature. Majority of these patients (12 out of 15, 80%) had not volunteered about their hallucinations on their own. On analysis of various parameters between the hallucinators and non-hallucinators, it was observed that hallucinators were older and had a higher mean duration of symptoms of PD. The patients with hallucinations had a higher severity of motor symptoms and signs. Hallucinators more commonly had depression and sleep disturbances. Mean dosage of L-dopa equivalent dose was higher in patients with hallucinations as compared to those without hallucinations. On statistical analysis, however, only two parameters were found to be different in a statistically significant manner. These were the duration of illness and the Hoen and Yahr scale (p < 0.05). Also, hallucinations occurred independent of dopaminergic drugs.

Conclusion: Hallucinations are common source of distress but are often neglected. One should always probe actively into the presence of hallucinations.