Tactile hallucinations in Parkinson's disease.

Hallucinations occur in up to 40% of patients with Parkinson's disease (PD) and are mainly of a visual nature. We prospectively studied 8 patients with PD and tactile hallucinations (TH). TH occurred with a clear sensorium, and were long-lasting. In most cases they involved animals, were combined with other types of hallucinations occurring simultaneously (mainly formed visual hallucinations), and predominated in the evening and/or at night. Pharmacological and disease-related factors, including a disorder in rapid-eye-movement sleep mechanisms, could play a part in the pathophysiology of these hallucinations.