Lateralizing signs in intractable partial epilepsy

Abstract

We evaluated the accuracy and interobserver variability of selected ictal and postictal behavioral changes. Three observers, blinded to clinical history, EEG, and side of surgical resection, analyzed videotapes of 166 seizures in 38 patients, looking for lateralizing signs. Twenty-seven patients with temporal lobe resections were seizure-free for > or = 1 year postoperatively, and 11 with extratemporal resections had at least 90% reduction in seizures > or = 1 year postsurgery. The epileptogenic region (ER) was lateralized by analyzing lateralizing signs in 78% of patients; positive predictive value (PPV) was 94% (90% CI = 87% to 100%). Overall kappa was 0.68. Signs were considered present if seen by two or more observers. Forty-five percent had version, ie, forced and sustained head deviation (kappa = 0.76, PPV = 94%); 37% had dystonic posturing of the upper extremity (kappa = 0.47, PPV = 93%); and 34% had unilateral mouth deviation (kappa = 0.83, PPV = 92%). These signs indicated a contralateral ER. Twenty-one percent had unilateral upper extremity automatisms, all ipsilateral to the ER (kappa = 0.65, PPV = 100%); 21% had postictal dysnomia, indicating a dominant-hemisphere ER (kappa = 0.89, PPV = 100%); and 16% had ictal speech, usually indicating a nondominant-hemisphere ER (kappa = 0.75, PPV = 83%). Dystonic posturing, postictal dysnomia, ictal speech, and unilateral upper extremity automatisms may indicate a higher probability of temporal lobe epilepsy. Analysis of lateralizing signs shows good interobserver agreement and provides useful clinical information.

Clinical and eeg analysis of mesial and lateral temporal lobe seizures

“…The predominance of unilateral upper limb automatisms in group 1 seizures was also found by Saygi et al 16 , who also reported, as in our study, a larger incidence of leg automatisms after the first five seconds of ictal onset in group 2 patients. UDP occurred in 16% of the seizures, a less expressive result to that observed in other studies 6,8,9,26 . This feature was always contralateral to the EA matching with other reports 6,8,28,29 and confirming its lateralizatory value.…”

“…Ictal speech occurred mainly during right temporal seizures as reported by others 18,34 suggesting nondominant temporal EA 18,26,35,36 . It seems to result of functional nondominant temporal lobe impairment by epileptic discharges and consequent hyperfunction of the dominant hemisphere for language 35 .…”

“…Mimic automatism of smile occurred predominantly in neocortical seizures, a fact reported by Hiyoshi et al 25 . Unilateral motor automatisms were predominantly ipsilateral to the EA, as occurred in other casuistics 26,27 . The predominance of unilateral upper limb automatisms in group 1 seizures was also found by Saygi et al 16 , who also reported, as in our study, a larger incidence of leg automatisms after the first five seconds of ictal onset in group 2 patients.…”

“…The greatest percentage of postictal language preservation in the right temporal EA patients was also observed in other studies 7,18 . Postictal aphasia occurred mainly in the left temporal seizures as in other casuistics 7,18,26,35 . It seems to result of functional impairment of the dominant basal temporal lobe language area 36 .…”

Lateralizing Value and Semiology of Ictal Limb Posturing and Version in Temporal Lobe and Extratemporal Epilepsy

“…A subsequent study showed that although dystonic posturing had good positive predictive value for the side of seizure onset there was not good agreement between different observers as to its presence or absence in individual patients (4). Such a lack of agreement limits the clinical utility of a lateralizing sign.…”