title: Double crush syndrome: an analysis of age, gender and body mass index.
abstract: OBJECTIVE
  The aim of this study is to evaluate the role of age, gender, body mass index (BMI), wrist ratio and median sensory nerve conduction velocity as independent risk factors for double crush syndrome (DCS) and to analyze the strength of association of these factors.
  
  
  METHODS
  We have undertaken a case-control study in 142 patients (125 females) with carpal tunnel syndrome (CTS) and 109 controls. Based on clinical and electrophysiologic criteria 106 pure CTS patients and 36 DCS patients as well as 62 female and 47 male control subjects were selected from patients and their relatives referred to our tertiary referral hospital. Totally nerve conduction studies and electromyographic examination were done in 201 hands. Height, weight, BMI, wrist width, depth, circumference and ratio were measured in all patients and control group. Mean values of different risk factors for DCS group and controls were measured. A logistic regression analysis was conducted to evaluate odds ratio of different risk factors.
  
  
  RESULTS
  The mean values for age was greater in DCS patients than CTS group. Male gender and increasing age had odds ratio of 4.19 (CI 95%: 1.35-12.96) and 1.13 (CI 95%: 1.07-1.19), respectively.
  
  
  CONCLUSIONS
  Our study confirms that male gender and increased age are independent risk factors for DCS. We suggest that in elderly men presenting with CTS, electrophysiologic screening for cervical radiculopathy should be considered because the treatment of DCS differs from pure CTS.
authors.affiliation: Neurology Department, Zahedan University School of Medicine, Khatam Teaching Hospital, Zahedan, Iran. moghtaderi@zdmu.ac.ir
authors.forename: Ali
authors.initials: A
authors.lastname: Moghtaderi
authors.forename: Shahrokh
authors.initials: S
authors.lastname: Izadi
mesh_terms: D000328:Adult; D000367:Age Factors; D015992:Body Mass Index; D002349:Carpal Tunnel Syndrome / Q000209:etiology / Q000473:pathology* / Q000503:physiopathology*; D016022:Case-Control Studies; D005260:Female; D006801:Humans; D007492:Iran; D008297:Male; D008475:Median Nerve / Q000503:physiopathology; D008875:Middle Aged; D009431:Neural Conduction / Q000502:physiology; D012307:Risk Factors; D012737:Sex Factors; D014953:Wrist