Sleep in patients with Parkinson's disease and normal subjects prior to and following levodopa administration

Six patients with parkinsonism and 4 spouse control subjects were studied in the sleep laboratory prior to administration of levodopa and during initial, short-term, long-term, and chronic usage. The parkinsonian patients had a significant amount of sleeping difficulty, taking much longer to fall asleep and awakening frequently for long periods during the night, as compared with spouse control subjects and a normal, elderly control group. Values for rapid eye movement (REM) sleep were similar to those of both control groups, while Stage 3 sleep was decreased. Three of the 6 patients showed a decrease in REM sleep with initial drug administration at the 1.0 Gm. per day dosage level. One had a marked increase in REM sleep for about the first 2 weeks of drug administration. However, REM sleep values for all patients with long-term and chronic drug administration were similar to base-line values. In the spouse control subjects, other than a slight increase in REM sleep with initial drug administration which was not maintained with long-term use, no changes were noted in REM sleep, even during withdrawal of the drug. In both patients and control subjects, values for sleep induction and sleep maintenance were essentially unaltered by the administration of levodopa. Biochemical implications of these data are discussed. In addition, the clinical implications in terms of evaluating and treating the moderately severe insomnia in parkinsonian patients are described.