Electromyographical Studies of Free Autogenous Muscle Transplants in Man

Abstract

In 26 free autogenous muscle transplants, performed in 21 patients with facial palsy, the pattern of reinnervation was studied by means of electromyography. The observation time after transplantation was 2–12 months with a mean of 8 months. Observations were made with conventional EMG and Single Fibre EMG. Signs of denervation were recorded up to 1 month after grafting in 20, out of 24 investigations, and only exceptionally after 4 months. Voluntary activity was found in 15 out of 24 investigations during the first month; and after 2-3 months, all examined grafts showed signs of reinnervation. Action potentials were generally prolonged, and 12 months after grafting, the interference pattern at maximal effort was discrete in 3, reduced in 8 and full in 2 of 13 investigated transplants. The amplitude of the potentials were generally lower than normal and the recordings made by Single Fibre EMG showed, in the first months, increased jitter and blockings. Action potential complexes became progressively more stable, but blockings could exceptionally be seen even after 12 months. There were thus conclusive evidence that free muscle transplants in man survived and became reinnervated.