Electromyographic Patterns in Reinnervated Muscle

EXTENSIVE reports are available concerning the action potentials occurring in normal and denervated muscles.1A few investigators have reported the electromyographic changes during the process of reinnervation following section and suture of peripheral nerves. However, these reports have been confined to a relatively short period following the suture. Weddell, Feinstein and Pattle2described the changes during this period: (a) Fibrillation action potentials decrease in number; (b) motor unit action potentials, small in amplitude and highly polyphasic, are the earliest to make their appearance, first close to the motor point and then spreading rapidly throughout the muscle; (c) with what the authors term "functional recovery," a few polyphasic units and fibrillation potentials are still present, and the range of amplitude and duration of motor unit responses are greater than in normal muscle. In the cases which they reported in detail, nerve sections were not all complete; the patients