Hypertrophy and Transformation of Muscle Fibers in Paraplegic Patients

Abstract: Transcutaneous electrical stimulation of the quadriceps femoris muscle was applied in 14 paraplegic patients (10 spastic patients with spinal cord lesions and 4 patients with conus-cauda lesions with denervation atrophy). In both the spastic and the denervated group, the vastus lateralis muscle was biopsied and computed tomography (CT) images of the entire upper leg were made both at the onset and termination of the 8-month training period. The stimulation was carried out twice a day for 20 min. The increase in muscle tissue was significant in the CT images. The biopsies showed that the fiber diameter of both fiber types increased during the training period in the spastic group from 47 to 67 μm and in the denervated group from 22 to 38 μm. In both groups, the differences were significant between the first and second biopsies. Both groups showed a marked Type 2 fiber predominance. The histological and CT findings correlated with the clinical improvement of muscle function.