Effects of neurotomy on human skeletal muscle ultrastructure

Effects of neurotomy on human skeletal muscle ultrastructure were studied in biopsies from denervated abdominal muscles. After 35 days of denervation the alterations included fiber atrophy which varied from slight to total, swelling and disalignment of sarcotubular system, nuclear changes, mitochondrial abnormalities, and lysosomal proliferation. Capillaries were normal and no cell infiltration was evident. Cases studied several months after neurotomy showed signs of reinnervation with a partial recovery of normal structure. The differences between the histopathological pictures caused by neurotomy and by degenerative diseases which produce neurogenic atrophy are discussed. The restorative capacity of human skeletal muscle after spontaneous reinnervation is also studied.