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

Abstract

Introduction: A 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.

Objectives: The 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.

Methods: We 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.

Results: Ictal 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).

Conclusion: This ictal motor sign is not infrequent in refractory partial epilepsy and has a high positive predictive value.