Real-World Application of the ILAE 2025 Semiology-Integrated Seizure Classification Framework in a Tertiary Care Epilepsy Cohort: Experience from Eastern India

Background: The recently proposed International League Against Epilepsy (ILAE) 2025 seizure classification framework emphasizes multidimensional seizure characterization incorporating responsiveness, awareness, and detailed semiologic descriptors. However, real-world clinical validation from resource-limited settings remains scarce. Objectives: To evaluate the clinical applicability of the ILAE 2025 seizure classification system and compare it with the ILAE 2017 framework in a tertiary care epilepsy cohort. Methods: This prospective observational study included 200 consecutive epilepsy patients attending the Department of Neurology, Medical College, Kolkata, West Bengal, India. Demographic, seizure semiology, electroencephalography (EEG), magnetic resonance imaging (MRI), and etiologic data were analyzed. Seizures were classified using both ILAE 2017 and ILAE 2025 frameworks. Agreement between the systems was assessed using Cohen’s kappa coefficient. Results: Focal seizures constituted the predominant seizure type (76.5%), followed by generalized seizures (20%). Impaired awareness and responsiveness were observed in 93.5 and 94% of patients, respectively. Detailed seizure descriptors were documented in 97% of cases, including adversive movements, automatisms, autonomic manifestations, and experiential auras. EEG abnormalities were identified in 29.8% of patients, with focal spike-wave discharges being the most common abnormality. MRI abnormalities were present in 58% of patients, predominantly gliotic changes (36%). Structural etiologies accounted for the majority of epilepsies, with hypoxic ischemic encephalopathy sequelae (22.5%) being the most common identifiable cause. The ILAE 2025 framework demonstrated substantial agreement with the ILAE 2017 classification ( κ = 0.78), while reducing diagnostic ambiguity through improved integration of semiologic descriptors. Detailed observable and nonobservable seizure manifestations showed significant electroclinical correlation with focal EEG abnormalities and structural MRI lesions. Conclusion: The ILAE 2025 framework demonstrated superior semiologic granularity and improved electroclinical integration compared with the ILAE 2017 system. Incorporation of detailed seizure descriptors enhanced localization-oriented interpretation and reduced unclassified seizures, highlighting its clinical utility in routine epilepsy practice, particularly in resource-constrained settings. Publication History Article published online: 15 July 2026 © 2026. The Author(s). This is an open access article published by Thieme under the terms of the Creative Commons Attribution License, permitting unrestricted use, distribution, and reproduction so long as the original work is properly cited. (https://creativecommons.org/licenses/by/4.0/) Thieme Medical and Scientific Publishers Private Limited A-13A, Graphix Tower 1, 6th floor, Sector 62, Noida 201309, Uttar Pradesh, India