Absence seizures in lesion‑related epilepsy

Background In the new International League Against Epilepsy(ILAE)classification of seizure types,generalized seizures such as absence seizures(ASs)may originate from a focal point and rapidly spread to the bilaterally distributed brain network.Increasing evidence from animal and clinical studies has indicated that focal changes may occur prior to ASs;however,the relationship of ASs with epileptogenic lesions remains unclear.Methods We retrospectively collected and analyzed the clinical,imaging,and electrophysiological data of 16 patients who had ASs and structural lesions with seizure-free outcomes after lesion resection.Results In semiology analysis,nine patients displayed focal onset;only two patients showed simple ASs,and seizure types other than ASs were observed in the remaining patients.On ictal electroencephalography(EEG),four patients showed bilateral synchronous symmetric 3 Hz generalized spike-wave discharges(GSWDs),and the remaining patients showed bilateral 1.5–2.5 Hz GSWDs.Moreover,most patients(13/16,81.3%)exhibited focal features in addition to ASs,while interictal EEG was the same in 12 patients.Furthermore,on stereoelectroencephalogram(SEEG),2/5 patients showed focal discharges before bilateral burst GSWDs.Additionally,all patients had structural lesions on imaging.In four typical AS patients,the lesions were located in deep brain regions.Notably,in 9 patients(9/16,56%),the lesions were located in the posterior cortex.All patients underwent lesion resection and had seizure-free outcomes during follow-up,and intelligence quotient(IQ)also improved by 10.71±3.90 one year after surgery.Conclusions Patients with lesion-related epilepsy may present with ASs that have a focal onset and are associated with good surgical outcomes.