[Clinical and pathological study of myelopathy accompanied with cervical spinal canal stenosis--with special reference to complication of mental retardation or cerebral palsy].

We studied 3 cases with myelopathy caused by cervical spinal canal stenosis (developmental), who had been suffering from walking difficulty followed by tetraplegia, clinically and pathologically. In all 3 cases, mental retardation and/or cerebral palsy was diagnosed. We hypothesized that the brain damage in the developmental stage might also cause developmental disturbance in the cervical spine. In all cases, pathological investigation showed decreased antero-posterior diameter and degeneration in the gray matter and in the lateral and posterior column in the involved cervical spinal cord. The findings, such as relative preservation of the anterior column and cyst formation in the gray matter, were thought to be in common with cervical spondylotic myelopathy or ossification of the occipital longitudinal ligament (OPLL) which had been reported before. In one case we found aberrant peripheral nerve bundles and peripheral type remyelination in the transverse spinal cord lesion. Compared to the pathological change in the OPLL, our cases showed more severe degenerative change in the spinal segments with a relatively preserved antero-posterior diameter of the spinal cord, which supports the theory that the dynamic factor plays a more important role than the static compression factor. We concluded that the aging process and/or dystonic neck movement added spondylotic change to the narrow canal, and excess movement of the neck and/or falls caused dynamic injury to the spinal cord and secondary circulatory disturbance further worsened spinal lesions. When elderly patients with cerebral palsy develop motor symptoms, we should consider cervical spinal stenosis as a possible cause.