Brain lesion locations associated with secondary seizure generalization in tumors and strokes

• Published in: Human brain mapping Vol. 44; no. 8; pp. 3136 - 3146
• Main Authors: Nordberg, Janne, Schaper, Frederic L. W. V. J., Bucci, Marco, Nummenmaa, Lauri, Joutsa, Juho
• Format: Journal Article
• Language: English
• Published: Hoboken, USA John Wiley & Sons, Inc 01.06.2023
• Subjects: Adult; Age; astrocytoma; Brain; Brain - diagnostic imaging; Brain tumors; Cerebral cortex; Cerebral Cortex - diagnostic imaging; Convulsions & seizures; Cortex (frontal); Electroencephalography; Epilepsy; Epilepsy - diagnostic imaging; Epilepsy - etiology; Etiology; Hemispheric laterality; Hospitals; Humans; infarction; Ischemia; Lesions; Localization; Magnetic resonance imaging; Medicin och hälsovetenskap; Neoplasms; Neuroimaging; Patients; Registration; Risk; seizure generalization; Seizures; Seizures - diagnostic imaging; Seizures - etiology; Stroke; Stroke - complications; Stroke - diagnostic imaging; Tumors; Finland; epilepsy; infarction; seizures; astrocytoma; seizure generalization
• ISSN: 1065-9471; 1097-0193; 1097-0193
• DOI: 10.1002/hbm.26268

Structural brain lesions are the most common cause of adult‐onset epilepsy. The lesion location may contribute to the risk for epileptogenesis, but whether specific lesion locations are associated with a risk for secondary seizure generalization from focal to bilateral tonic–clonic seizures, is unknown. We identified patients with a diagnosis of adult‐onset epilepsy caused by an ischemic stroke or a tumor diagnosed at the Turku University Hospital in 2004–2017. Lesion locations were segmented on patient‐specific MR imaging and transformed to a common brain atlas (MNI space). Both region‐of‐interest analyses (intersection with the cortex, hemisphere, and lobes) and voxel‐wise analyses were conducted to identify the lesion locations associated with focal to bilateral tonic–clonic compared to focal seizures. We included 170 patients with lesion‐induced epilepsy (94 tumors, 76 strokes). Lesions predominantly localized in the cerebral cortex (OR 2.50, 95% C.I. 1.21–5.15, p = .01) and right hemisphere (OR 2.22, 95% C.I. 1.17–4.20, p = .01) were independently associated with focal to bilateral tonic–clonic seizures. At the lobar‐level, focal to bilateral tonic–clonic seizures were associated with lesions in the right frontal cortex (OR 4.41, 95% C.I. 1.44–13.5, p = .009). No single voxels were significantly associated with seizure type. These effects were independent of lesion etiology. Our results demonstrate that lesion location is associated with the risk for secondary generalization of epileptic seizures. These findings may contribute to identifying patients at risk for focal to bilateral tonic–clonic seizures. Structural brain lesions are the most common cause of adult‐onset epilepsy. The lesion location may contribute to the risk for epileptogenesis, but whether specific lesion locations are associated with a risk for secondary seizure generalization from focal to bilateral tonic‐clonic seizures, is unknown. Our results demonstrate that lesion location is associated with the risk for secondary generalization of epileptic seizures independent of lesion etiology.