Efficacy of neurosurgical interventions for epilepsy in polymicrogyria: A systematic review

Polymicrogyria (PMG) is a rare malformation of cortical development (MCD) characterized by abnormal neuronal architecture, often associated with epilepsy. Neurosurgical interventions have been explored, but their effectiveness remains a subject of ongoing research and debate. This systematic literature review aims to provide a comprehensive analysis of surgical interventions for epilepsy in PMG individuals, their outcomes, complications, and factors influencing surgical decision-making. This systematic review, conducted according to PRISMA guidelines and registered on PROSPERO (CRD420251010221), analyzed studies on individuals with PMG and epilepsy undergoing neurosurgical treatment. A structured search across five databases was performed. Two reviewers independently selected and extracted data on clinical characteristics, surgical techniques, and outcomes, with seizure control assessed through Engel and ILAE classifications. Statistical analyses included Chi-square and Mann-Whitney U tests. Study quality was evaluated. A total of 47 studies involving 225 patients were included, mostly consisting of case reports or series. The majority of patients underwent resective surgery or hemispherotomy. Postsurgical outcomes were evaluated using Engel or ILAE classifications in 178 cases: 64.61% achieved seizure freedom (Engel/ILAE I). A shorter epilepsy duration was significantly associated with better outcomes. Only a minority received neuropsychological assessments, with cognitive improvements observed mainly in patients operated at a younger age. Postoperative complications were discussed. This review highlights the potential effectiveness of neurosurgical interventions in selected patients with PMG and drug-resistant epilepsy. Despite the overall encouraging seizure outcomes, the limited and heterogeneous reporting of cognitive and quality-of-life measures underscores the need for more comprehensive and standardized pre- and postsurgical assessments to better inform clinical decision-making and long-term management. PLAIN LANGUAGE SUMMARY: This study looked at the effects of brain surgery in people with epilepsy caused by polymicrogyria, a condition where the brain does not form properly before birth and develops an unusual surface. Many patients became seizure-free or had fewer seizures after surgery, especially when performed at an earlier stage. More research is needed to understand how surgery affects mental functions (e.g., memory, attention) and quality of life of these patients.