Spatio-temporal dynamics of interictal activity in musicogenic epilepsy: Two case reports and a systematic review of the literature

Objective: To explore neurophysiological features of musicogenic epilepsy (ME), discussing experimental findings in the framework of a systematic review on ME. Methods: Two patients with ME underwent high-density-electroencephalography (hd-EEG) while listening to ictogenic songs. In one case, musicogenic seizures were elicited. Independent component analysis (ICA) was applied to hd-EEG, and components hosting interictal and ictal elements were identified and localized. Finally, the temporal dynamics of spike-density was studied relative to seizures. All findings were compared against the results of a systematic review on ME, collecting 131 cases. Results: Interictal spikes appeared isolated in specific fronto-temporal independent components, whose cortical generators were located in the anterior temporal and inferior frontal lobe. In the patient undergoing seizure, ictal discharge relied in the same component, with the interictal spike-density decreasing before the seizure onset. Conclusion: Our study shows how ICA can isolate neurophysiological features of ictal and interictal discharges in ME, highlighting a fronto-temporal localization and a suppression of spike-density preceding the seizure onset. Significance: While the localization of ME activity could indicate which aspect within the musical stimulus might trigger musicogenic seizures for each patient, the study of ME dynamics could contribute to the development of models for seizure-prediction and their validation.