title: Premotor and nonmotor features of Parkinson's disease.
abstract: OBJECTIVE
  This review highlights recent advances in premotor and nonmotor features in Parkinson's disease, focusing on these issues in the context of prodromal and early-stage Parkinson's disease.
  
  
  RESULTS
  Although Parkinson's disease patients experience a wide range of nonmotor symptoms throughout the disease course, studies demonstrate that nonmotor features are not solely a late manifestation. Indeed, disturbances of smell, sleep, mood, and gastrointestinal function may herald Parkinson's disease or related synucleinopathies and precede these neurodegenerative conditions by 5 or more years. In addition, other nonmotor symptoms such as cognitive impairment are now recognized in incident or de-novo Parkinson's disease cohorts. Many of these nonmotor features reflect disturbances in nondopaminergic systems and early involvement of peripheral and central nervous systems, including olfactory, enteric, and brainstem neurons as in Braak's proposed pathological staging of Parkinson's disease. Current research focuses on identifying potential biomarkers that may detect persons at risk for Parkinson's disease and permit early intervention with neuroprotective or disease-modifying therapeutics.
  
  
  CONCLUSIONS
  Recent studies provide new insights into the frequency, pathophysiology, and importance of nonmotor features in Parkinson's disease as well as the recognition that these nonmotor symptoms occur in premotor, early, and later phases of Parkinson's disease.
authors: aSection of Parkinson Disease and Movement Disorders, Department of Neurological Sciences, Rush University Medical Center, Chicago, Illinois, USA bDepartment of Neurology, Montreal General Hospital, McGill University, Montreal, Quebec, Canada.
authors: Jennifer G
authors: JG
authors: Goldman
authors: Ron
authors: R
authors: Postuma
mesh_terms: D001342:Autonomic Nervous System Diseases / Q000209:etiology*; D003072:Cognition Disorders / Q000209:etiology*; D006801:Humans; D009043:Motor Activity; D000857:Olfaction Disorders / Q000209:etiology; D010300:Parkinson Disease / Q000150:complications*; D012893:Sleep Wake Disorders / Q000209:etiology*