title: Preoperative diagnosis of the responsible level in CCM using CMAPs: comparison with SCEPs.
abstract: METHODS
  A retrospective study.
  
  
  OBJECTIVE
  To elucidate the correlation between compound muscle action potentials (CMAPs) amplitudes and responsible level of compressive cervical myelopathy (CCM), and the accuracy of level diagnosis by using CMAPs.
  
  
  METHODS
  This study was conducted at the Department of Orthopedic surgery, Yamaguchi University Graduate School of Medicine, Japan.
  
  
  METHODS
  A total of 28 patients with CCM were investigated in this study. Erb's point-stimulated CMAPs were measured from deltoid, biceps, triceps in all patients as compared with 88 healthy subjects. We performed a level diagnosis on the basis of CMAPs amplitudes. We performed a level diagnosis on the basis of CMAPs amplitudes and using an index that measures the deviation of CMAPs amplitudes between triceps and deltoid or biceps.
  
  
  RESULTS
  Significant correlations between the mean CMAPs amplitudes and responsible level were showed for deltoid (6.82±2.33 mV) at C3/4 (P<0.01) and biceps (8.75±4.42 mV) at C4/5 (P=0.015). Despite considerable individual variability in CMAP amplitudes, there were correlations among CMAPs amplitudes for deltoid, biceps and triceps in the same individual. The sensitivity was 75.0%, specificity 75.0% in the index for diagnosis of C3/4. The sensitivity was 75.0%, specificity 66.7% in the index for diagnosis of C4/5.
  
  
  CONCLUSIONS
  This study showed small CMAPs amplitudes in the deltoid indicated a C3/4 level of myelopathy and in biceps at the C4/5 level and could help exclude clinically silent cord compression and determine the surgical procedure to the suitable level of concern.
authors: Department of Orthopedic Surgery, Yamaguchi University Graduate School of Medicine, Yamaguchi, Japan.
authors: M
authors: M
authors: Funaba
authors: Department of Orthopedic Surgery, Yamaguchi University Graduate School of Medicine, Yamaguchi, Japan.
authors: T
authors: T
authors: Kanchiku
authors: Department of Orthopedic Surgery, Yamaguchi University Graduate School of Medicine, Yamaguchi, Japan.
authors: Y
authors: Y
authors: Imajo
authors: Department of Orthopedic Surgery, Yamaguchi University Graduate School of Medicine, Yamaguchi, Japan.
authors: H
authors: H
authors: Suzuki
authors: Department of Orthopedic Surgery, Yamaguchi University Graduate School of Medicine, Yamaguchi, Japan.
authors: Y
authors: Y
authors: Yoshida
authors: Department of Orthopedic Surgery, Yamaguchi University Graduate School of Medicine, Yamaguchi, Japan.
authors: T
authors: T
authors: Taguchi
mesh_terms: D000200:Action Potentials / Q000502:physiology*; D000368:Aged; D000369:Aged, 80 and over; D002574:Cervical Vertebrae / Q000473:pathology / Q000503:physiopathology* / Q000601:surgery; D004558:Electric Stimulation / Q000379:methods; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods; D008297:Male; D008875:Middle Aged; D018482:Muscle, Skeletal / Q000503:physiopathology* / Q000601:surgery; D009431:Neural Conduction / Q000502:physiology; D012189:Retrospective Studies; D013117:Spinal Cord Compression / Q000175:diagnosis* / Q000503:physiopathology*; D013126:Spinal Nerve Roots / Q000503:physiopathology / Q000601:surgery