title: Near-nerve versus surface electrode recordings of sensory nerve conduction in patients with carpal tunnel syndrome.
abstract: OBJECTIVE
  The aim of the study was to compare the relative sensitivity of sensory nerve conduction (SNC) recorded with near-nerve needle electrodes and SNC recorded with surface electrodes in demonstrating focal slowing of the median nerve in patients with symptoms of carpal tunnel syndrome (CTS).
  
  
  METHODS
  Eighty-two consecutive patients with clinical symptoms and signs of CTS were studied prospectively by the same clinical neurophysiologist. Orthodromic near-nerve recording from digits 1 and 3, distal motor latency, and antidromic surface recording from palm to digit 2 and wrist to digit 2 were performed in all patients. Near-nerve recording of the ulnar nerve was done in patients with abnormal median nerve conduction. Patients were compared to controls.
  
  
  RESULTS
  Near-nerve SNC was abnormal (slowed velocity or absent response) in 52% of the patients from digit 1 to wrist, in 51% from digit 3 to wrist, and 40% had a prolonged distal motor latency. Surface antidromic SNC was abnormal in 49% from wrist to palm, and in 43% from wrist to digit 2. Statistical analysis revealed no significant difference between the near-nerve method and the surface method. Absent sensory potentials were more common with the surface method.
  
  
  CONCLUSIONS
  As a routine study of CTS patients, the surface technique can be used and the near-nerve technique merely used for patients with absent surface responses.
authors.affiliation: Department of Neurology, Odense University Hospital, Denmark.
authors.forename: T
authors.initials: T
authors.lastname: Smith
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D002349:Carpal Tunnel Syndrome / Q000175:diagnosis / Q000503:physiopathology*; D004566:Electrodes; D004867:Equipment Design; D005260:Female; D006225:Hand / Q000294:innervation*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009412:Nerve Fibers / Q000502:physiology; D009431:Neural Conduction / Q000502:physiology*; D011446:Prospective Studies; D011930:Reaction Time; D012680:Sensitivity and Specificity; D012684:Sensory Thresholds / Q000502:physiology; D013499:Surface Properties; D014459:Ulnar Nerve / Q000503:physiopathology