The origin of the focal spike in musicogenic epilepsy.

To clarify the pathogenesis of a typical case of musicogenic epilepsy, we examined interictal spikes using the dipole tracing method (DTM). The patient was a 49-year-old, right-handed Japanese man. He first experienced seizures at the age of 32 years; listening to his favorite piece of music frequently triggered them. His seizure type is partial (often complex, but sometimes simple). An interictal EEG examination revealed many focal spikes in F8 and T4. We estimated equivalent current dipoles (ECDs) using DTM. We performed one-dipole analyses on the peaks of the spikes using an EEG analyzer with a three-layer head model called the scalp-skull-brain (SSB) model. We analyzed the interictal EEG because there were no spikes during the seizure. The ECDs were located in the posterior transverse temporal gyrus. The characteristics in this patient not only bolstered arguments in favor of the role of the right temporal lobe in musicogenic epilepsy, but also showed that transverse temporal gyri, which are included in the auditory area, could play an important role in musicogenic epilepsy.