Changes due to age in internodal length in the sural nerve in man.

Abstract

Internodal length of fibers in the Sural nerve was studied in specimens from 14 patients ranging in age from 18 to 80 years of age. In nerves from subjects under 65 years of age the internodal length correlated closely with fiber diameter. The relationship was approximately linear. In nerves from those subjects over the age of 65 irregularities of internodal length were common and appeared to be the result both of segmental demyelination and remyelinatlon and regeneration after complete dengeneration of fibers. Segmental demyelination and remyelination was the more common cause. Degenerative changes which occur in peripheral nerves in later life at present lack explanation. Ischemia, related to occlusive disease of the vasa nervorum is a possible cause. A study of internodal length in peripheral nerve specimens from patients with occhisive vascular disease in the legs would be of interest. In addition the cumulative effects of repeated minor trauma throughout life must be considered.