Electromyography in Paralysis Of the Facial Nerve: General Aspects

MY task is to present some general aspects of electromyographical procedures applied in affections of the facial nerve. Up to now the action potential of the facial nerve has not been studied in facial palsies. With the muscle action potentials as indicator of possible nerve involvement, we can study the response or absence of response during voluntary effort and the response to electrical stimulation of the nerve. One might ask what advantage it is to record action potentials because the facial muscles are situated so superficially that contraction can easily be seen; cannot clinical observation give sufficient information? However, clinical observation is often deceptive. Firstly, there might be activity in only few motor units, so few that it cannot be discerned clinically. This is important to establish because the chances for recovery are consistently better when there is continuity than when there is total disruption. Secondly, clinical observation might indicate