The Role of Microglial Activation in the Pathogenesis of Drug-Resistant Epilepsy: A Systematic Review of Clinical Studies

Background: Microglial cells are the resident immune cells in the central nervous system (CNS) and constitute the brain’s innate immune system. They are the smallest of the glial cells and are derived from phagocytic white blood cells, fetal monocytes, which migrate from the blood into the brain during development. On the other hand, epilepsy is a chronic condition defined as recurrent unprovoked seizures, with at least two seizures occurring over 24 h apart. Methods: To determine the role of microglial activation in the pathogenesis of drug-resistant epilepsy, we systematically searched published data for biomarkers of microglial activation from main databases including PubMed, PubMed Central, Scopus, Embase, Google Scholar, and Medline. Two research registries were also searched: the Cochrane Registry and clinicaltrial.gov. Data was collected after applying inclusion and exclusion criteria and studies were appraised critically. Both Medical Subject Headings (MeSH) and regular keyword search strategies were employed. Results: Our systematic review shows significant elevation of biomarkers of microglial activation in patients with drug-resistant epilepsy, suggesting its role in the disease’s pathogenesis. Conclusions: Microglia cells are therefore considered as a special type of mononuclear phagocytes found in the CNS that plays important roles in both the brain’s immunity and homeostatic functions. The role of microglial activation in the pathogenesis of drug-resistant epilepsy is an active area of study, with potential therapies for drug-resistant epilepsy that target microglia currently being investigated.