LATERALIZING VALUE AND SEMIOLOGY OF ICTAL LIMB POSTURING AND VERSION IN TEMPORAL-LOBE AND EXTRATEMPORAL EPILEPSY

Purpose: Unilateral dystonic limb posturing in partial seizures has be en shown to be an accurate lateralizing sign indicating seizure onset in the contralateral hemisphere. However, its clinical utility may be reduced by confusion with other lateralized ictal motor phenomena. In this study, the ictal phenomena of dystonic limb posturing, tonic limb posturing, unilateral immobile limb, and version were distinguished a nd examined in patients with temporal and extratemporal seizures. Meth ods: Partial seizures in 54 patients, successfully treated by surgery (34 temporal, 20 extratemporal; 14 frontal, 3 parietal, and 3 occipita l), were analyzed blindly by 3 reviewers. Interobserver agreement was tested with kappa indexes and positive predictive value (PPV) was dete rmined for each sign. Results: In patients with temporal lobe epilepsy (TLE), dystonic posturing occurred in 35.3% (kappa 0.78, positive pre dictive value (PPV) for the sign being contralateral to seizure onset 92%); tonic limb posturing occurred in 17.7% (kappa 0.36, PPV 40%); un ilateral immobile limb occurred in 11.8% (kappa 0.23, PPV 100%); and v ersion occurred in 35.3% (kappa 0.77, PPV 100%). In patients with extr atemporal epilepsy, dystonic posturing occurred in 20.0% (kappa 0.31, PPV 100%); tonic limb posturing occurred in 15.0% (kappa 0.08, PPV 67% ); and version occurred in 40.0% (kappa 0.54, PPV 100%). The higher ka ppa indexes were significant for dystonic posturing (p < 0.001) and to nic limb posturing (p = 0.032) in TLE. Dystonic posturing (p = 0.034), tonic posturing (p = 0.07), and version (p = 0.0038) occurred earlier in extratemporal seizures than in temporal seizures. Conclusions: Of the limb ictal motor phenomena, only dystonic posturing was accurate a nd had good interobserver agreement.