Teaching Video NeuroImages: Intracerebral Recording of Rhythmic Ictal Nonclonic Hand Motions of Prefrontal Origin

We report a 37-year-old right-handed man undergoing stereoelectroencephalography (SEEG) for exploration of non-lesional focal drug-resistant epilepsy.Seizures featured right upper limb elevation, left hemiballistic movements, bilateral lip-corner contraction ("chapeau de gendarme"), lower limbs flexion, and rhythmic ictal nonclonic hand (RINCH) motions of the right hand, occurring 3-13 seconds after onset.RINCHs were present in half of the seizures and could be the only motor sign (Video 1).The patient sometimes reported a subjective feeling of "warning" or "stress," without specifying whether it occurred before or during the seizure.SEEG (Figure 1) revealed seizure-onset in the left caudal prefrontal cortex (left middle frontal gyrus and sulcus).RINCH motions, usually contralateral in temporal lobe epilepsy (TLE) and distinct from manual automatisms, 1 have also been associated with frontal or fronto-temporal epilepsy.Their correlation with prefrontal ictal discharges has been described in a small series of patients with TLE. 2 Early onset RINCH movements, whether isolated or part of broader motor semiology, can indicate a prefrontal organization of the seizures.