Hemiplegic amyotrophy. Muscle and motor point biopsy study

Abstract

Thirty hemiplegic patients had simple muscle atrophy with reduced mean muscle cross sectional areas (predominantly type II fiber atrophy) and complex, multiple, or enlarged subneural apparatuses, many of which resembled subhuman endplates. Ultrastructural observations in a few patients revealed nonspecific responses of damage to sarcolemma and myofibrils. There was no correlation between structural changes and alteration of tone, sensory impairment, or site of lesion. We propose that hemiplegic amyotrophy results from a combination of disuse, loss of central "trophic" influence, and transsynaptic degeneration.