Differences in sleep in patients with Parkinson's disease.

Twenty-three Parkinson patients were recorded during 2 or 3 consecutive nights. Their treatment, if any, was withdrawn for at least 15 days before the first recording session. Some qualitative abnormalities were noticed during each night in 13 of these patients. They consisted in: 1. Repetitive blinking at the beginning of the night when the lights were turned off, persistence of the electromyographic activity of the chin muscles during paradoxical sleep, occurrence of rapid eye movements and blepharospasms during slow wave sleep before the onset of paradoxical sleep episodes, and alpha rhythm during paradoxical sleep. 2. The study of these signs showed that association between blinking and persistence of the activity of the chin muscles during paradoxical sleep is never encountered. 3. The patients with chin muscle activity during paradoxical sleep had a 50% decrease in paradoxical sleep as compared with the group of patients with repetitive blinking. 4. The possibility that lesions of the locus coeruleus are responsible for this decrease in paradoxical sleep is discussed.