Review Lateralizing signs during seizures in focal epilepsy Tobias Loddenkemper a,b , Prakash Kotagal a, * a Department of Neurology, The Cleveland Clinic Foundation, Cleveland, OH, USA b Department of Pediatrics, The Cleveland Clinic Foundation, Cleveland, OH, USA Received 8 April 2005; accepted 14 April 2005 Available online 21 June 2005 Abstract This article reviews lateralizing semiological signs during epileptic seizures with respect to prediction of the side of the epilepto- genic zone and, therefore, presurgical diagnostic value. The lateralizing significance of semiological signs and symptoms can fre- quently be concluded from knowledge of the cortical representation. Visual, auditory, painful, and autonomic auras, as well as ictal motor manifestations, e.g., version, clonic and tonic activity, unilateral epileptic spasms, dystonic posturing and unilateral automatisms, automatisms with preserved responsiveness, ictal spitting and vomiting, emotional facial asymmetry, unilateral eye blinking, ictal nystagmus, and akinesia, have been shown to have lateralizing value. Furthermore, ictal language manifestations and postictal features, such as ToddÕs palsy, postictal aphasia, postictal nosewiping, postictal memory dysfunction, as well as peri-ictal water drinking, peri-ictal headache, and ipsilateral tongue biting, are reviewed. Knowledge and recognition of semiological lateralizing signs during seizures is an important component of the presurgical evaluation of epilepsy surgery candidates and adds further information to video/EEG monitoring, neuroimaging, functional mapping, and neuropsychological evaluation. Ó 2005 Elsevier Inc. All rights reserved. Keywords: Focal epilepsy; Lateralizing signs; Epilepsy surgery; Seizure semiology 1. Introduction Resective epilepsy surgery aims at the complete resec- tion of the epileptogenic zone, i.e., the area of cortex that is necessary to produce clinical seizures, while spar- ing eloquent cortical areas [1]. Diagnostic elements that help in the presurgical estimation of the epileptogenic zone and tailoring of surgical intervention are seizure semiology, electrophysiological recordings, neuroimag- ing, functional testing, and neuropsychological assess- ment. Ictal semiology improves lateralization and localization of the epileptogenic zone and adds addition- al information to the ictal EEG [2]. Additionally, pa- tients with lateralizing auras during seizures have a significantly better outcome after epilepsy surgery than those without lateralizing features [3]. Lateralizing semiological signs during seizures, how- ever, cannot lateralize a seizure focus with absolute cer- tainty, and always have to be considered in the context of a complete presurgical diagnostic epilepsy evaluation, including video/EEG monitoring, imaging studies, lan- guage lateralization, and neuropsychological assess- ment, if clinically indicated. Semiology can reflect only the symptomatogenic zone and, therefore, can give only indirect information about the seizure onset zone or the epileptogenic zone, as the epileptic activity may have spread from a ‘‘silent’’ cortical area into a different cor- tical area that actually produces symptoms. Determination of the lateralizing significance of semiological manifestations remains difficult and fre- quently has to rely on case series and retrospective anal- ysis. Findings are usually descriptive and statistics are frequently not calculated or difficult to calculate because of the small numbers of patients. Only a few series confirmed the laterizing sign by several observers, and 1525-5050/$ - see front matter Ó 2005 Elsevier Inc. All rights reserved. doi:10.1016/j.yebeh.2005.04.004 * Corresponding author. Fax: +1 216 445 6813. E-mail address: kotagap@ccf.org (P. Kotagal). www.elsevier.com/locate/yebeh Epilepsy & Behavior 7 (2005) 1–17