title: Gender differences in Parkinson's disease.
abstract: OBJECTIVE
  To investigate gender differences in basic disease characteristics, motor deterioration and nigrostriatal degeneration in Parkinson's disease (PD).
  
  
  METHODS
  We studied 253 consecutive PD patients who were not receiving levodopa or dopamine agonists (disease duration < or = 10 years). We investigated the influence of gender and oestrogen status on: (1) age at onset, (2) presenting symptom, (3) severity and progression of motor symptoms (Unified Parkinson's Disease Rating Scale III (UPDRS-III) scores) and (4) amount and progression of nigrostriatal degeneration ([123I]FP-CIT single photon emission computed tomography measurements).
  
  
  RESULTS
  Age at onset was 2.1 years later in women (53.4 years) than in men (51.3 years). In women, age at onset correlated positively with parity, age at menopause and fertile life span. Women more often presented with tremor (67%) than men (48%). Overall, patients presenting with tremor had a 3.6 year higher age at onset and a 38% slower UPDRS-III deterioration. Mean UPDRS-III scores at disease onset were equal for both genders, as was the rate of deterioration. Women had a 16% higher striatal [123I]FP-CIT binding than men at symptom onset and throughout the course of PD.
  
  
  CONCLUSIONS
  Our results suggest that, in women, the development of symptomatic PD may be delayed by higher physiological striatal dopamine levels, possibly due to the activity of oestrogens. This could explain the epidemiological observations of a lower incidence and higher age at onset in women. Women also presented more often with tremor which, in turn, is associated with milder motor deterioration and striatal degeneration. Taken together, these findings suggest a more benign phenotype in women with PD.
authors.affiliation: Department of Neurology, Radboud University Nijmegen Medical Centre, 6500 HB, Nijmegen, The Netherlands.
authors.forename: Charlotte A
authors.initials: CA
authors.lastname: Haaxma
authors.forename: Bastiaan R
authors.initials: BR
authors.lastname: Bloem
authors.forename: George F
authors.initials: GF
authors.lastname: Borm
authors.forename: Wim J G
authors.initials: WJ
authors.lastname: Oyen
authors.forename: Klaus L
authors.initials: KL
authors.lastname: Leenders
authors.forename: Silvia
authors.initials: S
authors.lastname: Eshuis
authors.forename: Jan
authors.initials: J
authors.lastname: Booij
authors.forename: Dean E
authors.initials: DE
authors.lastname: Dluzen
authors.forename: Martin W I M
authors.initials: MW
authors.lastname: Horstink
mesh_terms: D000328:Adult; D017668:Age of Onset; D000368:Aged; D001921:Brain / Q000000981:diagnostic imaging / Q000473:pathology; D018450:Disease Progression; D005260:Female; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D019957:Motor Skills Disorders / Q000209:etiology; D010300:Parkinson Disease / Q000150:complications* / Q000453:epidemiology / Q000473:pathology*; D010641:Phenotype; D012720:Severity of Illness Index; D012737:Sex Factors; D015899:Tomography, Emission-Computed, Single-Photon