Subjectively reported sleep quality and excessive daytime somnolence in Parkinson's disease with and without dementia, dementia with Lewy Bodies and Alzheimer's disease

Objective We compared subjective sleep quality and excessive daytime somnolence (EDS) in controls, Parkinson's disease with (PDD) and without dementia (PD), dementia with Lewy bodies (DLB) and Alzheimer's disease (AD). We investigated whether sleep dysfunction and EDS associate with motor phenotype in PD, PDD and DLB. Method Assessments included the Epworth Sleepiness Scale (ESS) and Pittsburgh Sleep Quality Index (PSQI). Results EDS was more frequent in PD, DLB and PDD patients than in AD. PDD, PD and DLB patients also had worse sleep quality when compared with AD and controls. Baseline postural instability-gait difficulty (PIGD) motor phenotype in PDD was associated with a higher ESS score and frequency of EDS, but this association was lost at two years. PSQI scores did not differ between PIGD dominant and non-dominant PD, PDD and DLB patients. Conclusion EDS and poor sleep quality are greater in PD, PDD and DLB, compared with AD. The dissociation of EDS and motor phenotype suggests their pathophysiology is anatomically and/or temporally distinct. Copyright (c) 2006 John Wiley & Sons, Ltd.