• STUDY DESIGN
    • Correlation between compressed spinal cords on magnetic resonance imaging (MRI) and electrophysiological findings in cervical spondylotic myelopathy patients.
  • OBJECTIVE
    • To clarify the correlation between spinal-cord-evoked potentials and MRI measurements of compressed spinal cords in patients with cervical spondylotic myelopathy.
  • SUMMARY OF BACKGROUND DATA
    • Compression of the spinal cord does not always cause clinical symptoms and it is difficult to infer the degree of dysfunction of the spinal cord from MRI findings.
  • METHODS
    • Seventeen patients with cervical spondylotic myelopathy were examined with MRI and spinal-cord-evoked potentials before surgery. Using abnormality in spinal-cord-evoked potentials as indicators of spinal cord morphology, spinal-cord transverse area and compression ratios (central and 1/4-lateral) were measured on T1-weighted axial imaging. The correlations between these dimensions and electrophysiological findings were investigated.
  • RESULTS
    • The mean preoperative transverse area of the spinal cord was 47.13 mm2. The mean preoperative central compression ratio of the spinal cord was 34.4%. The mean preoperative 1/4-lateral compression ratio of the spinal cord was 27.5%. A correlation (Spearman r=0.65, P < 0.01) was observed between the 1/4-lateral compression ratio of the spinal cord and the amplitude ratio of spinal-cord-evoked potentials after electric stimulation of the brain (Br(E)-SCEPs).
  • CONCLUSIONS
    • The preoperative 1/4-lateral compression ratio of the spinal cord was found to reflect the degree of dysfunction of the corticospinal tracts.