title: Course in Parkinson disease subtypes: A 39-year clinicopathologic study.
abstract: BACKGROUND
  Individual variations in the course of Lewy body Parkinson disease (PD) are well known. Patients have been classified into different clinical subtypes to identify differences in the course among the subgroups. Several studies indicate that the outcome is more favorable in tremor dominant (TD) cases but others report no difference. A majority of progression studies are based on cross-sectional single point data or short-term clinical observations. The lack of longitudinally followed autopsy-confirmed PD cohort remains a major weakness in the literature. Biochemical studies of brain indicate most pronounced abnormalities in akinetic/rigid (AR) and the least in TD cases. We postulate that PD course in these subtypes is concordant with the biochemical findings.
  
  
  OBJECTIVE
  To compare the course in TD, mixed (MX), and AR subtypes of PD.
  
  
  METHODS
  Longitudinal clinical follow-up and autopsy studies were performed on 166 patients with PD over 39 years (1968-2006). Patients were classified into TD, AR, and MX based on the entire clinical course. Only the pathologically confirmed PD cases were included.
  
  
  RESULTS
  Sixty-six percent of cases had MX, 26% AR, and 8% TD profile. The age at onset was younger (p < 0.001) and progression to Hoehn & Yahr stage 4 was slower (p = 0.016) in the TD cases. Dementia was most common in AR (p = 0.039) and the least common in TD. In general, the course was most favorable in TD, followed by MX and AR subgroups.
  
  
  CONCLUSIONS
  The three subtypes of Parkinson disease have different courses which are concordant with the differences in brain biochemical abnormalities.
authors.affiliation: Division of Neurology, Department of Pathology, Saskatoon Health Region/University of Saskatchewan, Canada.
authors.forename: A H
authors.initials: AH
authors.lastname: Rajput
authors.forename: A
authors.initials: A
authors.lastname: Voll
authors.forename: M L
authors.initials: ML
authors.lastname: Rajput
authors.forename: C A
authors.initials: CA
authors.lastname: Robinson
authors.forename: A
authors.initials: A
authors.lastname: Rajput
mesh_terms: D017668:Age of Onset; D000368:Aged; D000369:Aged, 80 and over; D000405:Akinetic Mutism / Q000453:epidemiology; D001344:Autopsy; D001921:Brain / Q000378:metabolism / Q000473:pathology* / Q000503:physiopathology*; D001923:Brain Chemistry / Q000502:physiology; D015331:Cohort Studies; D015897:Comorbidity; D003704:Dementia / Q000453:epidemiology; D018450:Disease Progression; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D009127:Muscle Rigidity / Q000453:epidemiology; D010300:Parkinson Disease / Q000145:classification / Q000453:epidemiology* / Q000473:pathology*; D013997:Time Factors; D014202:Tremor / Q000453:epidemiology