title: Parkinson disease and cognitive impairment: Five new things.
abstract: OBJECTIVE
  While the distinctive motor symptoms of Parkinson disease (PD) have been described for centuries, cognitive impairment has only recently been recognized as a central feature. Studies have yielded clues to the etiology and natural history of cognitive impairment in PD, but much remains unclear and effective therapies are needed.
  
  
  RESULTS
  Longitudinal cohort studies demonstrate that almost all patients with PD will develop dementia if they live long enough. New CSF biomarker and genetic studies suggest that it may soon be possible to forecast and track the progression of dementia in PD. Sleep and sleep disturbance appear to be intrinsically linked with PD, although the implications for individual outcomes and opportunities for intervention are unclear. Multidisciplinary treatment approaches incorporating cognitive training may help to improve outcomes.
  
  
  CONCLUSIONS
  We review several recent advances in understanding the pathophysiology, genetics, and management of cognitive impairment in PD.
authors.affiliation: Department of Neurology (AAD, BR), Washington University School of Medicine, St. Louis, MO; and School of Public Health (BR), University of the Witwatersrand, Johannesburg, South Africa.
authors.forename: Albert A
authors.initials: AA
authors.lastname: Davis
authors.affiliation: Department of Neurology (AAD, BR), Washington University School of Medicine, St. Louis, MO; and School of Public Health (BR), University of the Witwatersrand, Johannesburg, South Africa.
authors.forename: Brad
authors.initials: B
authors.lastname: Racette