Lateralizing Value of Ictal Behaviors in Temporal Lobe Epilepsy

ABSTRACT

To find out whether the commonly observed ictal behaviors in temporal lobe epilepsy (TLE) contribute to the lateralization of epileptogenic focus, 116 seizures in 19 unilateral TLE patients were reviewed and analyzed carefully by two epileptologists. Unilateral motor manifestations such as dystonia, tonic posturing, clonic jerking, head version, head turning, eye deviation, unilateral eye blinking and unilateral automatism were observed in ipsilateral or contralateral side of EEG seizure focus. Ictal language was classified as normal speech, speech arrest, dysphasia and nonidentifiable speech. They were evaluated for their significance in determining dominant (DHS) or nondominant hemisphere onset (NHS) based on the results of Wada test. Other categories of automatisms were analyzed to investigate whether they indicate right or left TLE. Dystonia(in 34 seizures), tonic posture(17), clonic jerking(24) and head version (14) were observed only in contralateral side of EEG seizure focus in 89 seizures. The direction of head turning was ipsilateral to seizure focus in 15 seizures (46.9%) and contralateral to seizure focus in 17 seizures (53.1%), Eye deviation direction inclined to suggest contralateral hemisphere seizure origin without statistical significance [contralateral in 13 seizures (65%) and ipsilateral in 7 seizures (35%)]. Unilateral eye blinking and unilateral automatism were seen in 35 seizures and occurred exclusively in ipsilateral side to ictal EEG onset (12,85.7% ;23,88.5%) compared with contralateral side(2,14.3% ;3,11.5%). Ictal normal speech was observed in 9 seizures of 2 patients who had NHS, wheares dysphasia occurred in 4 DHS of 3 patients. Deglutition, sexual automatism and sniffing were observed in both right and left TLE, and not valuable in seizure lateralization. These results show unilateral dystonia, tonic posture, clonic jerking and head version suggest strongly contralateral hemisphere seizure origin. Unilateral eye blinking and unilateral automatism indicate ipsilateral hemisphere seizure focus. Among ictal speech manifestations, ictal normal speech and dysphasia suggested NHS and DHS respectively.