Comparison of Quantified Ipsilateral and Contralateral Head Movements in Patients with Frontal and Temporal Lobe Epilepsies

We have attempted to compare the lateralizing significance of ipsilateral and contralateral head movements during seizures in patients with frontal (FLE) and temporal lobe epilepsy (TLE). We inlcuded only EEG and video recorded seizures (n=45) of patients with temporal lobe (n=18) and frontal lobe epilepsies (n=16) considered for resective epilepsy surgery, in whom the camera position was perpendicular to the head facing the camera in an upright position. FLE and TLE were diagnosed based on neuroimaging (MRI, PET, ictal SPECT), and interictal and ictal EEG. Head turning in a reaction to outside stimuli was excluded. Ipsi- and contralateral head versions were defined according to the side of ictal EEG seizure patterns. Head movements were quantified for speed analysis on the videos by selecting the movement of the nose in relation to a defined point on the trunk (25/s) in the inner 90° angle facing the camera. The analysis of the duration was independent of the camera angle. The angular speed, the duration of the movements, and the duration from seizure onset to occurrence of the ipsilateral and contralateral head movements were computed (Mann-Whitney test). Ipsilateral head movement was always preceding contralateral head movement in FLE and TLE. Contralateral head movement occurred significantly earlier in FLE (median 5s±7.4) than in TLE (median 20s±16.3) (p<0.001), whereas ipsilateral head movement occurred similarly early in the seizure evolution in FLE (2s±5.8) and TLE (3.5s±14.2). The duration of the contralateral head movement was significantly longer in TLE (7s±3.1) than in FLE (4s±2.3) (p<0.01). The angular speed of the ipsilateral (7.9 deg/s±8.3 vs. 10.3deg/s±11.5) and contralateral (9.9deg/s±6.6 vs. 11.8deg/s±9.1) head movements was similar in TLE and FLE. The quantitative analysis of ipsilateral and contralateral head movements shows differences in the movement characteristics and seizure evolution, which provide helpful information for the differentiation of patients with frontal and temporal lobe epilepsies considered for resective epilepsy surgery.