Cervical spondylotic myelopathy : Clinicopathologic study of the progression pattern and thin myelinated fibers of the lesions of seven patients examined during complete autopsy

This study was designed to reveal the progression pattern and essential histological findings of the lesions in the spinal cord affected by cervical spondylotic myelopathy. The purpose of this study was to gain new information about symptom progression and recovery in cervical spondylotic myelopathy. The characteristics of the distribution and the progression pattern of the lesions and whether demyelination and remyelination processes actually occur in cervical spondylotic myelopathy remain unclear. Tissues from seven patients with cervical spondylotic myelopathy were taken during autopsy and examined macroscopically and microscopically. An ultrastructural examination of spinal cord from two patients was also performed. The anterior horn and intermediate zone of the gray matter in the compressed segments showed atrophy in all the cases and in one, atrophy was limited to these areas. Atrophy and myelin pallor in the lateral and posterior funiculi were observed in six patients, and the lateral funiculi of two were severely affected. Many thin myelinated fibers and denuded axons were demonstrated ultrastructurally in the damaged white matter of two patients. There appears to be a common pattern of lesion progression in cervical spondylotic myelopathy: atrophy and neuronal loss in the anterior horn and intermediate zone develop first, followed by degeneration of the lateral and posterior funiculi. Eventually, marked atrophy develops throughout the entire gray matter and severe degeneration occurs in the lateral funiculus. Furthermore, the existence of thin myelinated fibers in the white matter suggests focal demyelinating and remyelinating processes occur in cervical spondylotic myelopathy.