Peripheral nerve morphometry in stroke patients.

Sural nerve biopsy specimens from affected and non-affected limbs of stroke patients were examined morphometrically. Two principle abnormalities of peripheral nerve were found in hemiparetic and hemiplegic limbs. First, the frequency of abnormal teased nerve fibers was significantly increased with abnormal internodes frequently "clustered" and showing a 50% or more reduction in myelin thickness. Second, the mean diameter of myelinated nerve fibers was reduced. These results suggest a primary atrophy of peripheral nerve fibers in the affected limbs of stroke patients with secondary demyelination. Possible aetiological factors include disuse, transynaptic degeneration, ischemia, pressure effect, and decreased axoplasmic flow. It would seem that the structural integrity of peripheral nerve is frequently compromised following a cerebral lesion.