Abstract
The evoked potential (EP) elicited by electrical stimulation of the tongue was recorded in order to quantify objectively trigeminal paralysis and chronic pain due to a traffic accident. The subject was a female patient with paralysis and unstable pain in the lingual nerve, which had appeared on the left of the dorsum linguae. The differences of sensation between then ormal (right) and paralyzed (left) sides were investigated by EP.
The following results were obtained.
1) In the EP, four-phase waves showing components at N 1, P 1, N 2 and P 2 were seen during the post-stimulation periods, from 25 to 300msec.
2) In the EP of the first measurement, the N 2-P 2 amplitude involved in algesthesia was seen to be reduced in the paralyzed area, but the appearance of artifacts in the EP waves was observed.
3) In the EP of the second measurement, comparison of the EP waves of the normal and paralyzed areas was made difficult by the artifacts.
4) The generator of these artifacts was considered to be the action potential of the lingual muscles.
The results of this study suggest it is difficult to evaluate disturbances of sensation in the area dominated by the lingual nerve objectively in patients with oral psychosomatic disorder by EP measurement of the tongue.
