title: Early-onset vs. Late-onset Parkinson's disease: A Clinical-pathological Study.
abstract: BACKGROUND
  Several studies have compared early-onset Parkinson disease (EOPD) and late-onset Parkinson disease (LOPD) but most are not based on autopsy confirmed cases.
  
  
  METHODS
  We compared clinical and pharmacological profiles, time to reach irreversible Hoehn and Yahr (H&Y) Stage 3 and levodopa motor complications in autopsy confirmed EOPD and LOPD cases.
  
  
  RESULTS
  At first clinic visit EOPD cases were younger but had longer disease duration and they died at a younger age (all p<0.0001). Anti-Parkinsonian drug use, including levodopa, was significantly delayed in EOPD. Lifetime use of amantadine (p<0.05) and dopamine agonists (p<0.01) were higher in EOPD. While lifetime use of levodopa was similar in the two groups, levodopa was used for a significantly longer period by EOPD (p< 0.0001). EOPD had a higher cumulative incidence of dyskinesias (p<0.01), wearing-off (p<0.01), and on-off (p<0.01). However, the time to dyskinesia onset was similar in the two groups. The threshold to wearing-off was much longer in EOPD (p<0.01). H&Y stage profile at first visit was similar in the two groups. The duration from disease onset to reach irreversible H&Y stage 3 was significantly longer in EOPD.
  
  
  CONCLUSIONS
  Our observations indicate that progression of PD is slower in EOPD and suggest that the pre-clinical interval in this group is longer. These findings can be used for case selection for drug trials and studies of the pathogenesis of PD.
authors.affiliation: Division of Neurology,University of Saskatchewan,Saskatoon,Saskatchewan,Canada.
authors.forename: Leslie Wayne
authors.initials: LW
authors.lastname: Ferguson
authors.affiliation: Division of Neurology,University of Saskatchewan,Saskatoon,Saskatchewan,Canada.
authors.forename: Ali H
authors.initials: AH
authors.lastname: Rajput
authors.affiliation: Division of Neurology,University of Saskatchewan,Saskatoon,Saskatchewan,Canada.
authors.forename: Alexander
authors.initials: A
authors.lastname: Rajput
mesh_terms: D000328:Adult; D000367:Age Factors; D017668:Age of Onset; D000368:Aged; D000369:Aged, 80 and over; D000978:Antiparkinson Agents; D018450:Disease Progression; D020820:Dyskinesias / Q000188:drug therapy / Q000453:epidemiology / Q000209:etiology / Q000503:physiopathology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010300:Parkinson Disease / Q000150:complications / Q000188:drug therapy / Q000453:epidemiology / Q000503:physiopathology*; D012720:Severity of Illness Index
chemical_list: D000978:Antiparkinson Agents
keywords: Age of Onset; Early-onset; Late-Onset; Parkinson disease