title: Course and risk factors for excessive daytime sleepiness in Parkinson's disease.
abstract: BACKGROUND
  Excessive daytime sleepiness (EDS) is a common feature of Parkinson's disease (PD) that contributes to the disease burden and increases risk of harm. The aim of this study was to examine persistency, cross-sectional and longitudinal associations, and risk factors for EDS in patients with PD.
  
  
  METHODS
  Analyses were performed on data from the SCOPA-PROPARK cohort, a 5-year hospital-based longitudinal cohort of over 400 PD patients who were examined annually. Cross-sectional analyses were conducted to evaluate differences between patients with and without EDS at baseline, while linear mixed models using data of all patients were used to identify factors associated with longitudinal changes in SCOPA-SLEEP-Daytime Sleepiness (SCOPA-SLEEP-DS) scores. A survival analysis was done using data of patients without EDS at baseline to identify risk factors for future EDS.
  
  
  RESULTS
  EDS proved a non-persistent symptom, although persistency and the proportion of patients with EDS increased with longer follow-up. At baseline 43% of patients had EDS, while 46% of patients without EDS at baseline developed this symptom during follow-up. Male gender, poorer nighttime sleep, cognitive and autonomic dysfunction, hallucinations, less severe dyskinesias, dose of dopamine agonists and use of antihypertensives were associated with higher EDS scores over time, while use of benzodiazepines was associated with lower scores. Baseline SCOPA-SLEEP-DS score and PIGD phenotype were risk factors for future EDS.
  
  
  CONCLUSIONS
  With longer disease duration a large proportion of patients develop EDS. Some risk factors are modifiable and patients should be monitored to improve quality of life and reduce risk of harm.
authors: Department of Neurology, Leiden University Medical Center, Leiden, The Netherlands.
authors: Kangdi
authors: K
authors: Zhu
authors: Department of Neurology, Leiden University Medical Center, Leiden, The Netherlands.
authors: Jacobus J
authors: JJ
authors: van Hilten
authors: Department of Neurology, Leiden University Medical Center, Leiden, The Netherlands. Electronic address: j.marinus@lumc.nl.
authors: Johan
authors: J
authors: Marinus
mesh_terms: D000368:Aged; D003430:Cross-Sectional Studies; D004185:Disability Evaluation; D006970:Disorders of Excessive Somnolence / Q000209:etiology*; D005260:Female; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D010300:Parkinson Disease / Q000150:complications*; D012189:Retrospective Studies; D012307:Risk Factors; D012720:Severity of Illness Index; D018709:Statistics, Nonparametric; D011795:Surveys and Questionnaires; D016019:Survival Analysis
keywords: Excessive daytime sleepiness; Parkinson's disease; Risk factors