Muscle fiber type morphology and distribution in paraplegic patients with traumatic cord lesion

Abstract

Biopsies of the rectus femoris muscle of 22 paraplegic patients with complete acute spinal cord transection due to trauma were taken for enzyme-histochemical and electron-microscopic studies in successive stages starting from occurrence of the accident (1-17 months). Ingravescent muscular atrophy was demonstrated with a progressive decrease in the fiber diameter and changes in the fiber type distribution with predominant type II atrophy in the first stage and type I atrophy in the later stage of the cord transection. Muscular "neurogenic" changes, such as angular dark atropic fibers, targetoid fibers, and type predominance are frequently observed. Myopathic alterations are observed in a low percentage in the later stages of the lesion. The ultrastructural findings are characterized by myofibrillar alterations and by dilatation and proliferative phenomena of the sarcoplasmic reticulum and T-system. There are ingravescent accumulation of lipid, interstitial fibrosis and microcirculatory alterations. The possible mechanism of "central" muscle atrophy is reviewed and discussed with reference to the morphological findings.

Comparison of muscular and articular factors in the progression of contractures after spinal cord injury in rats

“…In immobilized joints, intact muscles are allowed voluntary isometric contraction and reach equilibrium rapidly, as explained by an adaptive shortening through the loss of sarcomeres. 6 Following SCI, it is well documented in humans [28][29][30][31] and animals 24,32,33 that skeletal muscles below the level of an upper motor neuron lesion undergo marked changes in their morphological, metabolic, and contractile properties. 34 Changes in spastic skeletal muscle generally include atrophy, loss of elasticity and relative increase in the connective tissue within the muscles, ingravescent accumulation of lipid, interstitial fibrosis and microcirculatory alteration.…”

Morphometric and neurophysiological analysis of skeletal muscle in paraplegic patients with traumatic cord lesion

“…In fact, whereas patterns of denervation were frequently reported by some authors (Scelsi et al, 1982), the subsequent steps of fibre alteration or transformation in skeletal muscle are not unequivocal (Grimby et al, 1976;Khoubesserian et aI., 1983). The purpose of the present study was to determine the morphometric modifications of soleus muscle, composed almost exclusively of slow-twitch fibres and medial gastrocnemius muscle, composed of a mixed fibre type population, in paraplegic patients with complete spinal cord transection.…”

Skeletal muscle changes following myelotomy in paraplegic patients

“…The major ultrastructural changes were myofibrillary disorganisation and dilatation and proliferative phenomena of the sarcoplasmic reticulum and T -system. These changes are considered to be done to various causes, from disuse and derangement of upper motor neuron control on the lower motor neuron (Ochs, 1974;Scarlato et al, 1976;Scelsi et al, 1982).…”

“…Alterations of muscle fibre morphology and distribution were recently described in patients with traumatic cord lesions at intervals starting from the time of occurrence of the accident (Scelsi et al, 1982). Three of these patients who had excessive spasticity and pain, underwent a dorsal longitudinal myelotomy.…”