Lateralizing value of unilateral motor and somatosensory manifestations infrontal lobe seizures

Purpose: To evaluate the lateralizing value of unilateral somatosensory aur a, unilateral tonic posturing, head version, non-forced head turning, ictal cloni, dystonic posturing, and postictal nose wiping in seizures originati ng in the frontal lobe. Methods: We included patients who had consecutively undergone presurgical evaluation with ictal video-EEG monitoring at our in stitution, had had resective epilepsy surgery involving the frontal lobe, a nd had remained seizure-free > 1 year after operation. Twenty-seven patient s aged 1-42 years (mean 18) met the inclusion criteria. Fifteen patients ha d right-sided, 12 patients had left-sided epileptogenic regions. Seizures r ecorded during EEG-video monitoring were re-evaluated by two investigators in order to identify lateralization signs in frontal lobe seizures. One of the investigators was blind to patients' clinical data. Results: We analyze d 153 seizures of 27 patients. The most common unilateral phenomenon was th e unilateral tonic posturing occurring in 48% of all the patients and in 25 % of all seizures. Somatosensory aura and head version appeared exclusively contralateral whereas clonus occurred in 92% and unilateral tonic posturin g in 89% of seizures contralateral to the epileptogenic region. Ictal non-f orced head turning and postictal nose wiping showed no lateralizing signifi cance. Dystonic posturing did not occur. Conclusions: Somatosensory aura, h ead version, ictal cloni, and tonic posturing are reliable lateralizing sig ns in frontal seizures. These signs may help in identifying the epileptogen ic region during presurgical evaluation of patients suffering from frontal lobe epilepsy. (C) 2001 Elsevier Science B.V. All rights reserved.