[Auditory disturbance induced by carbamazepine administration in a patient with secondary generalized seizure].

We report on an 18-year-old woman with secondary generalized seizure, who developed an auditory disturbance (flat a tone) after carbamazepine (CBZ) administration. She used to have brief episodes of conjugate deviation of the eyes to the right, head heaviness, teleopsia, and visual hallucination since 16 years of age. At the age of 18 years, she developed a tonic-clonic seizures during sleep, and was placed on CBZ 400 mg/day. Immediately after taking the medication, she developed auditory disturbance while she played the musical instruments: she felt as if she played the musical note almost a half tone lower. On admission, neurological examinations and magnetic resonance images of the brain were normal. Electroencephalogram at rest was normal. However, intravenous diphenhydramine injection induced spikes in the left temporo-occipital region, followed by diffuse spike and wave complex. Although the serum CBZ level was reduced to the therapeutic level by lowering CBZ administration from 200 to 150 mg/day, she continued to have the same auditory disturbance. When CBZ administration was discontinued, the symptoms also disappeared. It remains unknown whether such a subtle side effect of CBZ is a common thing, or it can be recognized only by persons who are well trained in music.