Sleep-wake disturbances in the premotor and early stage of Parkinson's disease.

ABSTRACT

PURPOSE OF REVIEW Review of recent literature pertaining to frequency, associations, mechanisms, and overall significance of sleep--wake disturbances (SWD) in the premotor and early phase of Parkinson's disease. RECENT FINDINGS: SWD are frequent in Parkinson's disease and their prevalence increases with disease progression. Recent studies confirm previous findings that SWD can appear as initial manifestation of Parkinson's disease even decades before motor signs appear and highlight their clinical associations in these early stages. More intriguingly, new evidence underpins their role as risk factors, predictors, or even as driving force for the neurodegenerative process. As our understanding of sleep--wake neurobiology increases, new hypotheses emerge concerning the pathophysiology of SWD in early Parkinson's disease stages involving dopaminergic and nondopaminergic mechanisms. SUMMARY: SWD are predictors for the development of parkinsonian syndromes including Parkinson's disease. This may offer the opportunity of developing new preventive strategies and interventions at an early stage of this neurodegenerative disease.