Optimizing of electroneuronography of the facial nerve

The amplitude ratio between the paretic and the normal side as determined by electroneuronography is used as a basis for estimating the prognosis of facial palsy. Several methods have been described of placing the surface electrodes and of finding the supramaximal impulse strength. We investigated 16 normal test persons with the aim (1) of optimizing the procedure of neuronography with regard to the possible variations of electrode placement and stimulus intensity and (2) of finding out the right/left difference in normal test subjects. Following our results, the best positions of the recording electrodes are the nasal alae. Even under these most favorable test conditions we found an average side difference of the bilaterally recorded electroneurograms of normal test persons of 22%.