The chapeau de gendarme sign can be evoked by lateral prefrontal epileptic seizures

PurposeThe ‘chapeau de gendarme’ (CDG) sign, characterised by a symmetric down-turned mouth, has been considered as semiological hallmark of focal epileptic seizures with cingulate or insular involvement. We report three cases in which the CDG sign featured habitual seizures.MethodsThe epileptogenic zones these patients were localized lateral prefrontal cortex video-stereoelectroencephalography monitoring. A sulcal resection led to seizure-free outcome each patient.ResultsIctal stereoelectroencephalography demonstrated that ictal discharges arising from cortices immediately followed low-voltage fast activity, concomitantly involving anterior insulo-cingulate cortices, and preceding onset signs. Limited seizure freedom after surgery confirmed restricted distributions cortex.ConclusionOur observations us speculate could enter emotional cortical system through prefrontal-cingulate inhibitory projections (feedforward pattern) —arising supragranular layers cortex—and proceed deeper anterior-middle cortex, trigger co-occurrence gamma bands, evoke set exaggerated behaviours, is often accompanied unique facial sign.