Progressive sleep 'destructuring' in Parkinson's disease. A polysomnographic study in 46 patients.

BACKGROUND: Sleep abnormalities in Parkinson's disease (PD) are frequent, but it is unknown whether or not there is progressive loss of physiological sleep architecture or what the causes could be. METHODS: Retrospective review of medical records and polysomnographic data from 46 non-demented PD patients. RESULTS: Sleep latency was correlated with disease duration (F1,44=4.87, P=0.03). Total sleep time (F1,44=8.54, P=0.005), deep sleep time (F1,44=4.06, P=0.05), REM sleep time (F1,44=9.15, P=0.004) and sleep efficiency (SE) (F1,44=10.20, P=0.003) were inversely correlated with disease duration. The same sleep parameters were independent from the degree of motor impairment, dosage of the dopaminergic medications, and age. Subjective sleep complaints could only partially predict abnormalities in polysomnographic (PSG) studies. CONCLUSION: In PD nocturnal sleep 'destructuring' is linked to disease duration and evolves independently from other major disease parameters.