title: Prodromal symptoms and early detection of Parkinson's disease in general practice: a nested case-control study.
abstract: BACKGROUND
  Timely diagnosis of Parkinson's disease (PD), facilitating early intervention, depends largely on the GP's awareness of early symptomatology. For general practice, it is unknown which prodromal symptoms (symptoms preceding the typical motor symptoms of PD) demand the GP's alertness.
  
  
  OBJECTIVE
  To assess prodromal symptoms that should alert the GP to the possibility of PD in primary care patients.
  
  
  METHODS
  A nested case-control study was carried out in a population of approximately 12000 patients registered in the Continuous Morbidity Registration database affiliated with the University of Nijmegen in the Netherlands. The database pools subject data from four primary care practices. The subjects comprised all 86 patients diagnosed with PD between 1972 and 2007, and 78 controls, matched by sex, age, socioeconomic status and primary care practice. The primary measures of outcome were the prodromal symptoms presenting in the two years prior to the diagnosis of PD. The number (and type) of referrals and diagnostic tests were also assessed.
  
  
  RESULTS
  In the two-year period prior to diagnosis, PD patients more often presented with functional somatic symptoms, constipation, hyperhidrosis and sleep disorders than controls. Patients also more frequently experienced more than one prodromal symptom and were more often referred within the primary care team or to a medical specialist.
  
  
  CONCLUSIONS
  Prodromal symptoms of PD are encountered in general practice. GPs should be alert when patients present with multiple prodromal symptoms in a two-year period, especially considering the benefits of early intervention, and the future possibilities for disease-modifying therapy.
authors.affiliation: Department of Primary and Community Care and Annette.Plouvier@radboudumc.nl.
authors.forename: Annette O A
authors.initials: AO
authors.lastname: Plouvier
authors.affiliation: Department of Primary and Community Care and.
authors.forename: Renier J M G
authors.initials: RJ
authors.lastname: Hameleers
authors.affiliation: Department of Primary and Community Care and.
authors.forename: Eva A J
authors.initials: EA
authors.lastname: van den Heuvel
authors.affiliation: Department of Primary and Community Care and.
authors.forename: Hans H
authors.initials: HH
authors.lastname: Bor
authors.affiliation: Department of Primary and Community Care and.
authors.forename: Tim C
authors.initials: TC
authors.lastname: Olde Hartman
authors.affiliation: Department of Neurology and Parkinson Centre Nijmegen, Donders Institute for Brain, Cognition and Behaviour, Radboud university medical center, Nijmegen, the Netherlands and.
authors.forename: Bastiaan R
authors.initials: BR
authors.lastname: Bloem
authors.affiliation: Department of Primary and Community Care and Australian Primary Health Care Research Institute, Australian National University, Canberra, Australia.
authors.forename: Chris
authors.initials: C
authors.lastname: van Weel
authors.affiliation: Department of Primary and Community Care and.
authors.forename: Antoine L M
authors.initials: AL
authors.lastname: Lagro-Janssen
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D016022:Case-Control Studies; D005260:Female; D058006:General Practice; D006801:Humans; D008297:Male; D009426:Netherlands; D016017:Odds Ratio; D010300:Parkinson Disease / Q000175:diagnosis*; D062706:Prodromal Symptoms; D012042:Registries; D013001:Somatoform Disorders
keywords: Early diagnosis; Parkinson disease; general practice; prodromal symptoms; somatoform disorders.