Favorable outcomes of epilepsy with gait-induced seizures after resection of the unilateral supplementary motor area.

Background: Gait-induced seizures are a rare manifestation of reflex epilepsy. Pathophysiology of this phenomenon has not been fully understood. Case presentation: A 28-year-old woman presented with a long history of "falls" following paroxysmal bilateral leg stiffness triggered by walking. Scalp electroencephalogram (EEG) revealed low-amplitude rhythmic beta activity, maximal at the Cz electrode, during these events. Magnetoencephalography demonstrated repetitive sharp waves source-localized to the right primary motor cortex. Multiple anti-seizure medications failed to improve her symptoms; however, the clinical manifestation was consistent with epilepsy with gait-induced seizures. Intracranial subdural EEG recording was performed and confirmed ictal activity originating from the right supplementary motor area. Resection of this area resulted in complete resolution of her symptoms. Discussion: This is the first reported case of successful resective surgery for epilepsy with gait-induced seizure. Brain networks involving cortical regions responsible for the initiation or execution of walking presumably played a key role in the generation of gait-induced seizures. Careful assessment using non-invasive neurophysiological studies facilitated accurate diagnosis, successful intracranial recordings, and effective resective surgery.