Abstracts

We observed distinctive non-clonic unilateral rhythmic hand motions during seizures in several patients with temporal lobe epilepsy undergoing seizure monitoring. We initially considered these rhythmic hand movements to be automatisms, but noted they were contralateral to the seizure focus. Automatisms usually have no lateralizing value in temporal lobe epilepsy, but will be ipsilateral to the seizure focus if there is contralateral hand dystonic posturing. We studied these RINCH motions systematically in a consecutive series of patients. We identified thirteen patients with epilepsy who demonstrated RINCH motions and reviewed video-EEG recordings of all their seizures. We recorded time of clinical and EEG onset, time and duration of the rhythmic motions, specific character and laterality of these motions, association with other ictal signs, proportion of seizures that involved this activity, and laterality of the seizure focus. RINCH motions were unilateral, rhythmic, non-clonic hand motions. The description of the movements varied between patients, but was consistent in each patient. They were either low amplitude milking, grasping, fist clenching, pill-rolling, or large amplitude opening-closing motions. The mean duration of the motions was 24 seconds with a range of 6-128 seconds. RINCH motions occurred 0-72 (mean 17.5) seconds following the onset of the electrographic seizure and 0-50 (mean 13) seconds following the onset of the clinical seizure.
In the thirteen patients studied, RINCH motions were noted in 28 of 91 seizures analyzed. All patients with RINCH motions had temporal lobe epilepsy (TLE). RINCH motions were followed or accompanied by posturing (dystonic or tonic) in every patient (though not in every seizure). They involved the hand contralateral to the temporal lobe of seizure onset in 12/13 patients. Only one patient demonstrated rhythmic hand movements ipsilateral to the seizure onset, and that patient had bilateral dystonic posturing consistent with contralateral seizure spread. Interestingly, RINCH motions affected the right hand in 89% (25/28) of the seizures and 10/13 patients. For each individual, the proportion of seizures with these rhythmic hand movements ranged from 6% to 100%. Based on a limited survey, we estimated that RINCH motions occur in [sim] 10% of patients with TLE. RINCH motions are a distinct ictal sign associated with posturing. They appear to be a lateralizing contralateral sign in temporal lobe epilepsy, unless bilateral dystonic posturing is present. RINCH motions are to be distinguished from automatisms, which are more likely to be ipsilateral to the seizure focus, involving the arm not affected by dystonic posturing. The mechanism of RINCH motions is unknown; evaluation of these motions in patients with implanted electrodes may help in understanding their mechanism.