Lateralizing value of ictal dorsiflexion of the great toe in refractory partial epilepsy

Abstract

IntroductionA case of ictal dorsiflexion of the great toe was reported two years ago in a patient with insular cortex seizures. Since that publication, series of patients with the sign have not been reported. ObjectivesThe aims of the present study were to describe the frequency of the ictal sign and to evaluate positive predictive value (PPV) to lateralize the epileptogenic zone. MethodsWe retrospectively analyzed archived seizures of all patients who were consecutively evaluated at two tertiary centers for epilepsy surgery. All patients underwent a standard presurgical evaluation. We evaluated the dorsiflexion latency and, also, examined whether dorsiflexion of the great toe appeared when ictal electrographic activity remained focal or generalized. ResultsIctal dorsiflexion of the great toe was seen in only 15 (9.1%) out of 165 patients and in 25 (9.2%) of 272 seizures. The seizure localized to the temporal lobe in 22 (88%) out of 25 seizures. More than 50% of these seizures were associated with hippocampal sclerosis. Ictal dorsiflexion of the great toe was contralateral to the epileptogenic zone in 72% of the patients. In 7 out of 25, the seizures had a short latency period. In 6 out of these 7 seizures, the sign was contralateral to the epileptogenic zone (VPP=85.7). ConclusionThis ictal motor sign is not infrequent in refractory partial epilepsy and has a high positive predictive value.