PERSONALIZED ALGORITHM FOR PRESURGICAL STRATIFICATION OF PATIENTS WITH DRUG-RESISTANT FOCAL EPILEPSY

Abstract

Drug-resistant focal epilepsy remains one of the most challenging problems in modern epileptology and functional neurosurgery, since delayed referral for presurgical evaluation increases the duration of uncontrolled seizures, worsens quality of life, and may reduce the likelihood of a favorable surgical outcome. A prospective single-center observational study was conducted and included 86 patients examined at a specialized epileptology and neurosurgical center. All patients underwent clinical and semiological seizure analysis, brain MRI, routine EEG, long-term video-EEG monitoring, neurological assessment, and neuropsychological evaluation. The stratification criteria included the presence of a structural lesion on MRI, localized seizure onset, concordance of seizure semiology with the presumed epileptogenic zone, local epileptiform activity, MRI/EEG concordance, seizure frequency, secondary bilateral tonic-clonic generalization, progressive cognitive decline, and the functional significance of the presumed intervention zone. Based on the total clinical and diagnostic score, patients were divided into low, intermediate, and high surgical eligibility groups. High surgical eligibility was identified in 29 patients, intermediate eligibility in 36, and low eligibility in 21. The most significant factors associated with the possibility of localizing the epileptogenic zone were an MRI-positive structural lesion, local ictal or interictal onset on video-EEG, concordance of clinical semiology with the presumed anatomical zone, and MRI/EEG concordance. The proposed algorithm may be used as an accessible model for primary stratification of patients requiring standard follow-up, extended presurgical evaluation, or discussion of invasive monitoring.