title: Extrapyramidal type rigidity in rheumatoid arthritis.
abstract: OBJECTIVE
  We had noted cogwheel rigidity in a number of patients with rheumatoid arthritis (RA). Based on this finding, we aimed to investigate formally the presence of rigidity and cogwheeling in RA patients. Our secondary aim was to survey the co-existence of RA and Parkinson's disease (PD).
  
  
  METHODS
  A total of 87 consecutive patients with a diagnosis of RA, 78 patients with PD and 67 otherwise healthy patients attending a dedicated headache clinic participated in the study.
  
  
  RESULTS
  Rigidity was observed in 24% of RA, 60% of PD and 2% of headache patients. The frequency among the RA patients was significantly higher compared to that of patients with headache (chi 2 = 15.2; P = 0.00009). The frequency of PD among the RA patients was 2/87 (2.3%), while the frequency of RA among the PD patients was 6/78 (7.7%).
  
  
  CONCLUSIONS
  Rigidity can be observed in approximately a quarter of patients with RA.
authors.affiliation: Department of Neurology, Cerrahpaşa Medical Faculty, University of Istanbul, Turkey.
authors.forename: S
authors.initials: S
authors.lastname: Ertan
authors.forename: I
authors.initials: I
authors.lastname: Fresko
authors.forename: H
authors.initials: H
authors.lastname: Apaydin
authors.forename: S
authors.initials: S
authors.lastname: Ozekmekçi
authors.forename: H
authors.initials: H
authors.lastname: Yazici
mesh_terms: D000328:Adult; D000368:Aged; D001172:Arthritis, Rheumatoid / Q000150:complications* / Q000503:physiopathology; D001480:Basal Ganglia Diseases / Q000209:etiology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D018482:Muscle, Skeletal / Q000503:physiopathology; D010300:Parkinson Disease / Q000503:physiopathology