Early and long-term outcomes of surgical treatment of patients with drug-resistant epilepsy

Abstract

Epilepsy surgery is effective in 30–85% of patients with drug-resistant epilepsy. However, risk factors associated with favorable and unfavorable outcomes of epilepsy surgery need to be further evaluated. We present the outcome of the large epilepsy surgery cohort in Russian Federation.Purpose: evaluation of risk factors of favorable and unfavorable long-term outcomes in the Russian cohort of drugresistant patients with epilepsy.Material and methods. Three hundred and eight patients with structural drug-resistant epilepsy were operated by the neurosurgery team of Moscow State University of Medicine and Dentistry. Presurgical investigations and surgeries were performed by this team between 01.01.2014 and 31.12.2020. All patients underwent neurological and neuropsychological evaluation, seizure semiology assessment, neuroimaging and neurophysiological examination. Histological analysis of resected tissues was performed. Results of surgery were assessed according to J. Engel (1993) at 6, 12, 24, 48 and 60 months after surgery. Risk factors, associated with favorable (Engel I–II) and unfavorable (Engel III–IV) outcomes were evaluated.Results. Underwent 308 primary resection procedures, placement of a vagus nerve stimulator were in 41 patients, 9 patients have been repeated by resection procedures and 8 — underwent radiosurgical treatment. 256 (83%) patients were MR-positive, 53 (17%) — MR-negative. Temporal lesions were revealed in 186 (60%) patients, extratemporal — in 8 (3%), bilateral temporal — in 15 (5%), combination of temporal and extra-temporal — in 81 (26%), multifocal — in 16 (5%), generalized form in 2 (1%). In 12 months after surgery there were favorable outcomes (Engel I + II) in 85% of patients (n = 148), in 24 months — 70% (n = 127). In patients with MRI positive and negative lesions the result of surgery after 12 months was comparable. Postoperative complications were diagnosed in 6 (1.9%) patients, there were no mortality. Temporal plus epilepsy (p = 0.009), multifocal (p = 0.008) and bilateral lesions (p = 0.006) were the most significant risk factors of unfavorable surgery outcomes.Conclusion. The presented results confirm the efficiency of surgical treatment of drug-resistant epilepsy. Temporal plus form epilepsy, multifocal and bilateral lesions were the most significant risk factors of unfavorable surgery outcomes.