Stimulation-induced ictal vocalisation of left frontal lobe origin.

Pure ictal non-speech vocalisation occurs in frontal and temporal lobe epilepsies. Electrical stimulation of supplementary motor areas is reported to evoke vocalisation in selected patients. Here, we report a patient with focal epilepsy of the left anterior insula who had isolated monotonous vocalisation elicited by electrical stimulation of the left superior frontal gyrus. Quantitative analysis of audio signals was performed and compared with a former patient with left frontal lobe epilepsy who had pure ictal vocalisation. Both patients showed a comparable reduction in frequency variation indicating a monotonous voice. [Published with video sequences on www.epilepticdisorders.com].