Sensory evoked response to electrical stimulation of the trigeminal nerve in humans.

Electrical stimulation of the upper and lower lips of normal subjects evoked a consistent response recorded from over the face area of the ipsi- and contralateral hemispheres. This response consisted of seven discrete waves. Peak latencies ranged from as early as 8 msec to 115 msec. Stimulation of the lower lip evoked a response of lower amplitude and reversed polarity, as compared to te upper lip stimulation response. The data support the validity of the trigeminal sensory evoked response in the evaluation of the trigeminal pathways. Previously reported methods are reviewed and compared.