title: Diagnosing neurogenic thoracic outlet syndrome with the triple stimulation technique.
abstract: OBJECTIVE
  We assessed the diagnostic value of triple stimulation technique (TST) in eight patients with neurogenic thoracic outlet syndrome (TOS) by revealing the conduction block of the proximal lower trunk of the brachial plexus and locating the compression site.
  
  
  METHODS
  Eight patients fulfilling the conventional criteria of the lower-trunk neurogenic TOS were enrolled in our study. TST along with the central motor-conduction time was evaluated. The parameters including the TST amplitude ratio and the TST area ratio were compared between patients and controls.
  
  
  RESULTS
  The amplitude ratio was significantly lower in the patient group than in the control group (patients: 0.518 ± 0.113; control: 0.954 ± 0.020, P<0.01), so was the area ratio (patients: 0.453 ± 0.194; control group: 0.955 ± 0.192, P<0.01). No significant difference of central motor-conduction time (CMCT) was seen between the patient group and the control group (patients: 6.62 ± 0.36 ms; control: 6.54 ± 0.36 ms; P=0.528). Surgical procedures proved the compression of the lower trunk in all patients.
  
  
  CONCLUSIONS
  Our results indicated that there was conduction block besides axon loss in neurogenic TOS patients, and the conduction block was located between the nerve root emerging site and the supraclavicular stimulation site.
  
  
  CONCLUSIONS
  We first applied TST in diagnosing neurogenic TOS, and we showed that the patient's TST ratio was significantly lower than normal. Combined with clinical manifestations, TOS can be more precisely diagnosed.
authors.affiliation: Department of Hand Surgery, Huashan Hospital, Shanghai Medical College, Fudan University, Shanghai, China.
authors.forename: Jun-Tao
authors.initials: JT
authors.lastname: Feng
authors.affiliation: Department of Hand Surgery, Huashan Hospital, Shanghai Medical College, Fudan University, Shanghai, China.
authors.forename: Yi
authors.initials: Y
authors.lastname: Zhu
authors.affiliation: Department of Hand Surgery, Huashan Hospital, Shanghai Medical College, Fudan University, Shanghai, China.
authors.forename: Xu-Yun
authors.initials: XY
authors.lastname: Hua
authors.affiliation: Department of Hand Surgery, Huashan Hospital, Shanghai Medical College, Fudan University, Shanghai, China.
authors.forename: Yu
authors.initials: Y
authors.lastname: Zhu
authors.affiliation: Department of Hand Surgery, Huashan Hospital, Shanghai Medical College, Fudan University, Shanghai, China.
authors.forename: Yu-Dong
authors.initials: YD
authors.lastname: Gu
authors.affiliation: Department of Hand Surgery, Huashan Hospital, Shanghai Medical College, Fudan University, Shanghai, China.
authors.forename: Jian-Guang
authors.initials: JG
authors.lastname: Xu
authors.affiliation: Department of Hand Surgery, Huashan Hospital, Shanghai Medical College, Fudan University, Shanghai, China; Department of Hand and Upper Extremity Surgery, Jing'an District Central Hospital, Shanghai, China; State Key Laboratory of Medical Neurobiology, Fudan University, Shanghai, China. Electronic address: wendongxu@fudan.edu.cn.
authors.forename: Wen-Dong
authors.initials: WD
authors.lastname: Xu
mesh_terms: D000328:Adult; D004558:Electric Stimulation / Q000379:methods; D004576:Electromyography / Q000379:methods; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008875:Middle Aged; D009431:Neural Conduction / Q000502:physiology; D011446:Prospective Studies; D013901:Thoracic Outlet Syndrome / Q000175:diagnosis* / Q000503:physiopathology*; D050781:Transcranial Magnetic Stimulation / Q000379:methods*
keywords: Central motor-conduction time; Conduction block; Neurogenic thoracic outlet syndrome; Triple stimulation technique