Evoked electromyogram as a function of facial nerve.

Compound muscle action potentials were recorded bilaterally from alae nasi muscles following stimulation of facial nerve in 45 normal subjects in the age group of 20-30 years. Latency, amplitude and total duration of the compound muscle action potential were compared on both sides. A significant positive correlation between the three parameters with the highest for the amplitude was observed. Therefore it is suggested that amplitude is a better parameter for comparison while testing for side to side facial nerve integrity.