Abstracts

Rationale: Music is an essential part of everyday life, social and culture; and is believed to be inductive of increased body metabolism, acceleration of respiration and heart rate and enhancement of the special senses. The ideas it carried and the emotions it expressed can further arouse the innermost feeling of sadness, happiness and like or dislike. Music can be categorized into instrumental or vocal music. Song can be viewed as rhythm and melody added to our speech and both music and speaking are two high cortical functions exclusively to humankind. The right hemisphere has been traditionally viewed as the “musical hemisphere”, and the left hemisphere plays a major role in language functions. We studied patients with musicogenic epilepsy (ME) who specifically can be triggered by listening to pop songs. By manipulate different instruments, human voice, and languages, patients with ME give insight into functional neuroanatomy of music processing in human brain. Methods: We recruited three patients with ME from a single tertiary epilepsy center. Musicogenic seizures were triggered by various musical stimuli including different types of music, instruments, and languages under video-EEG monitoring. The study protocol and stimulating music were summarized in Table 1. Results: Two men and a woman, all right handed, aged between 35 and 55 years were enrolled. Patient 1 seizure can only be triggered by “Moonlight by Cyndi Wang” when listening through biauricular earphones, but was ineffective by loudspeakers. Piano solo, male vocal and Japanese language were changes made to the same stimulating song but were unsuccessful in triggering seizure for patient 1. Patient 2 has seizure triggered by “You Exist in My Song” irrespective of female or male vocal. In addition, “Let it go by Frozen” was accidentally found to cause seizure for patient 2 that she did not know prior to the study and denied any emotional linkage. Musicogenic seizure for the third patient was provoked by “Grandma's Words by Ricky Hsiao”, a song in Taiwanese language which he was familiar, but was not provoked by piano solo of the same song.These three patients have acoustic stimulus of ME to human singing pop songs with lyrics only and not response to neither instrumental, classical music nor non-vocal instrumental music of the same song. Sentimental content of love song, high-pitch singing and specificity are the most important triggering factors for patient 1 and 2. Familiarity and singing in native language are elements that easily induce ME for patient 3. There were no effect when listening to dance music and emotionally sad content of allegro tempo pop songs. Recognition of human voice singing is one thing in common among our three patients, and the video-EEG revealed that all the musicogenic seizures initiated from left temporal lobe. The results of Ictal EEGs are presented in Figure 1.  Conclusions: Earphone provides more intense, greater projection of musical stimulus to the epileptic brain and it was more easily able to provoke a seizure than loudspeaker. Process of human voice despite in musical condition is functionally organized in left temporal lobe. Recognition of human singing song with lyrics is a left temporal function manifested by hyperexcitable neurons in ME patients. ME can be a distinct seizure pathway different from the spontaneous seizure network (different ictal initiation area for patient 2 in Figure 1), especially noteworthy when managing such patients in epileptic surgery. Funding: No funds received.