Value and Limitations of Seizure Semiology in Localizing Seizure Onset

Abstract

Seizure semiology has been the foundation of clinical diagnosis of seizure disorders. This article discusses the value and the limitations of behavioral features of seizure episodes in localizing seizure onset. Studies have shown that some semiologic features of seizures are highly accurate in the hemispheric lateralization and lobar localization of seizures. There is good agreement between blinded reviewers in lateralizing video-recorded seizures in temporal lobe and extratemporal lobe epilepsies. However, seizure semiology alone should not be used to determine the site of seizure onset. Each semiologic feature may falsely localize seizure onset. Seizure semiology in some patients may signify the site of seizure propagation rather than origination. Moreover, seizure semiology may not be as reliable in multifocal epilepsies as it is in unifocal epilepsies. Many semiologic features of seizures of adults are often missing in seizures of children. Seizure semiology should be analyzed and integrated with EEG and neuroimaging data to localize the seizure focus. A sample of the recorded seizures should be shown to the patient's relatives or friends to verify that it is representative of habitual seizures.

The seizure semiology consistent with frontal lobe symptomatogenic zone in children

“…In adults with frontal lobe epilepsy who became seizure free after the surgery, 14-35% of the patients experienced focal clonic seizures, lateralizing to the contralateral hemisphere in 85-90% of the seizures [25][26][27] . In children, 14-30% of seizures showed focal clonic semiology, lateralizing to the contralateral hemisphere in 90-100% of the seizures 1,12,18 .…”

“…It is often difficult to achieve communication with children during postictal period. Postictal motor deficits is a diagnosis that has a robust lateralizing value; it indicates seizure focus in the contralateral side with 100% rate 27,36,37 . In a study of postictal motor deficit in adults (44 patients with a mean age of 31 years) with focal epilepsies 13.4% of the seizures were identified as Todd's paresis 36 .…”

Diagnostic challenge in neuropsychiatry: two case reports

“…In addition, knowledge of the hallucinatory symptoms of epilepsy and their relationship to neuro-physiological cerebral processes has taken a long time to emerge [1]. This knowledge has developed in line with the increasing knowledge about the brain itself, ranging from the nature of neuronal activity to localization of brain functions [2].…”

The cultivation of epilepsy neurosurgeons: requirements and challenges

“…Seizure semiology can provide elementary information for clinical diagnosis and valuable topical diagnosis information [8]. Several auxiliary examinations could be applied during the presurgical evaluation process accordingly.…”

“…Due to the expression limitations, many semiologic features of seizures in adults are often absent in children. Under these circumstances, epilepsy neurosurgeons should assess the clinical semiology of recorded seizures together with clinical history, EEG, neuroimaging and neuropsychological information [8].…”