抄録
Fifteen patients with cervical spondylotic myelopathy(CSM) were studied retrospectively. They were selected out of 33 patients with CSM who were operated during the last 3 years. Selection criteria was the patients who demonstrated both a high signal intensity area(HIA) on T2-weighted MR image and a distinct change in the waveform of spilal cord evoked potentials (SCEPs) suggesting a spinal conduction block. Those changes were highly correlated with a location in the spinal cord.
In all but one patient, the intervertebral level of the conduction block coincided with that of HIA. The HIA within the cord was, therefore, considered to reflect the level of the myelopathic condition in most patients with CSM. In only one exceptional patient, conduction block was revealed at the C4-C5 level, whereas the HIA on MRI was seen at the C5-6 level. The discrepancy can be explained that the HIA in this patient was localized in the gray matter of the spinal cord, which was suggested by the "snake-eyes" appearance on the additional axial T2-weighted MR images of the C5-6 level, while the nervous systems tested by the SCEP were the posterior and posterolateral funiculi of the spinal cord.
