Sleep disorders in Parkinson's disease: the contribution of the MPTP non-human primate model.

To replicate the sleep-wake disorders of Parkinson's disease (PD) and to understand the temporal relationship between these sleep disturbances and the occurrence of parkinsonism, we performed long-term continuous electroencephalographic monitoring of vigilance states in unrestrained rhesus monkeys using an implanted miniaturized telemetry device and tested the effect of MPTP intoxication on their sleep-wake organization. MPTP injection yielded a dramatic disruption of sleep-wake architecture with reduced sleep efficacy that persisted years after MPTP administration. Primary deregulation of REM sleep and increased daytime sleepiness occurring before the emergence of motor symptoms were a striking feature of the MPTP effect.