[Etiologic factors of cervical spondylotic myelopathy in aged patients--clinical and radiological studies].

Thirty-seven aged patients with cervical spondylotic myelopathy were investigated clinically and radiologically, and their findings were compared with those of younger patients. Dynamic canal stenosis in addition to developmental canal stenosis had a significant role in the occurrence of myelopathy in the aged patients. This dynamic canal stenosis was commonly encountered in the upper disc levels of C3-4 and C4-5. Myelography and CT-metrizamide myelography represented multisegmental lesions which resulted in variable clinical features. Spinal cord compression was correlated with severity of symptoms (p less than 0.05) and was more extensive in the elderly than in the younger patients. Furthermore, morphological changes of spinal cord were classified into four types: central, lateral, diffuse and additionally atrophic types. The high prevalence of diffuse type (51.4%) and atrophic type (21.6%) in the aged patients suggested that the prognosis despite treatment might be poor.