Pearls and Oy-sters: The chapeau de gendarme sign and other localizing gems in frontal lobe epilepsy

Focal seizures associated with the chapeau de gendarme sign or ictal pouting of insular origin

“…The ictal semiology and scalp EEG in our patient suggested the right frontal lobe as the symptomatogenic zone [9]. These findings were consistent with previous publications referring to the CdG as a localizing sign arising from the frontal lobe [[3], [4], [5],10]. However, in our case, SEEG recording revealed epilepti form discharges and electrographic seizure onset in the anterior insular cortex prior to the ictal semiology and activation of the frontal lobe, demonstrating that seizures associated with the CdG sign do not always localize the SOZ to the frontal lobe.…”

“…Prior reports of patients undergoing epilepsy surgery have found resection of the SOZ in the frontal lobes involving seizures with the the CdG sign have generally resulted in positive outcomes [3,4,10]. Focal seizures involving the CdG sign may arise from the insula as identified in our case or involve the insula [3], or not involve the frontal lobe at all [13].…”

“…One localizing sign that has been purported for frontal lobe epilepsy (FLE) is a characteristic down turning of the mouth into a deep frown, known as ictal pouting or ‘chapeau de gendarme’ (CdG) sign. While the CdG sign is not frequently seen, researchers and clinicians have used it to localize the seizure onset zone (SOZ) to the frontal lobe [[3], [4], [5]]. Due to the complexity of connections with the frontal lobe, however, other regions may initiate epileptogenic networks with complex propagations to the frontal lobe thereby resulting in false localizations for this unique semiological finding.…”

Localization of ictal pouting in frontal lobe epilepsy: A case report

“…Despite remaining conscious, our patient could not speak during seizures. This may be explained because her lesion was in the right hemisphere, while the other patient's was on the left side [5]. Leitinger et al reported a patient with ictal pouting as an early component of seizure without ictal EEG changes in the intracranial frontomesial electrodes.…”

Localisation in focal epilepsy: a practical guide

“…The 'chapeau de gendarme' or ictal pout sign is characterized by a downturned mouth from bilateral lip and chin contraction [38]. If seen early in the seizure it is highly localising to frontal lobe onset, in particular anterior cingulate, orbitofrontal region or mesio-prefrontal or premotor cortex (Video case 6), [39].…”