title: Pectoral nerve conduction studies: technique in healthy subjects and evaluation of brachial plexopathy.
abstract: OBJECTIVE
  To define the optimal nerve conduction study (NCS) technique of the pectoral nerves and evaluate its clinical utility.
  
  
  METHODS
  Prospective electrophysiologic study with healthy controls.
  
  
  METHODS
  Electrophysiologic laboratory in a large general hospital.
  
  
  METHODS
  Thirty healthy controls and 10 patients with cervical root or brachial plexus pathologies.
  
  
  METHODS
  Not applicable.
  
  
  METHODS
  Correlation of pectoral NCS with electromyography and magnetic resonance imaging.
  
  
  RESULTS
  For pectoral NCS, the mean values +/- standard deviation of onset latency, amplitude, and interside amplitude ratio (ratio of smaller over larger amplitude) were 2.01+/-0.22 ms, 11.75+/-2.21 mV, and .95+/-.04 mV, respectively. Subject age correlated significantly with both onset latency (r=.46, P<.001) and amplitude (r=-.34, P<.008). All 5 patients with brachial plexopathy had amplitude ratios below the normal limit of controls (.87). However, this was not seen for all 5 patients with cervical spondylotic radiculopathy.
  
  
  CONCLUSIONS
  The pectoral NCS technique is feasible in healthy subjects. It is useful when differentiating brachial plexopathy from cervical root lesions.
authors.affiliation: Department of Neurology, National Neuroscience Institute, Singapore General Hospital, Singapore. gnrlyl@sgh.com.sg
authors.forename: Yew-Long
authors.initials: YL
authors.lastname: Lo
authors.forename: Kumar M
authors.initials: KM
authors.lastname: Prakash
authors.forename: Teng-Hee
authors.initials: TH
authors.lastname: Leoh
authors.forename: Yam-Eng
authors.initials: YE
authors.lastname: Tan
authors.forename: Yan-Fang
authors.initials: YF
authors.lastname: Dan
authors.forename: Pavanni
authors.initials: P
authors.lastname: Ratnagopal
mesh_terms: D000328:Adult; D020516:Brachial Plexus Neuropathies / Q000175:diagnosis / Q000503:physiopathology*; D004576:Electromyography; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009431:Neural Conduction / Q000502:physiology*; D011446:Prospective Studies; D013900:Thoracic Nerves