Impact of Intravenous Immunoglobulin on Neuroinflammation Markers in Patients With Electrical Status Epilepticus During Slow Sleep

<h3>Background/Aim:</h3> Electrical status epilepticus during slow sleep (ESES) is a rare syndrome that often presents with refractory seizures and cognitive impairment. Immune modulatory drugs may show higher efficacy than anti-seizure drugs (ASD) in ESES. Our study aimed to determine the immune-modulatory treatment-responsive subgroups through assessment of neuroinflammatory mediators. <h3>Patients and Methods:</h3> The study included thirty-five consecutively diagnosed patients with treatment-resistant ESES, all under ASD treatment and the control group comprised 25 individuals diagnosed with primary headache disorders. Serum, peripheral blood and cerebrospinal fluid (CSF) samples were collected before commencement and after the 12-month follow-up of monthly intravenous immunoglobulin (IVIg)+ASD regimen. Serum and/or CSF levels of YKL-40, CXCL13, HMGB1, GFAP and NFL and <i>NLRP3</i> and <i>IL1β</i> gene expression levels in peripheral blood mononuclear cells (PBMC) were measured using ELISA and real time quantitative PCR, respectively. <h3>Results:</h3> Seizures and ESES activity ceased in 20 (57.1%) patients with ESES. Under IVIg+ASD, CSF levels of YKL-40, CXCL13, HMGB1 and GFAP and serum levels of YKL-40 and HMGB1 were significantly reduced, whereas serum CXCL13, CSF NFL, PBMC <i>NLRP3</i> and <i>IL1β</i> levels remained comparable among groups. Enhanced baseline CSF CXCL13, CSF HMGB1 and PBMC <i>IL1β</i> levels were associated with treatment resistance (n=15, 42.9%) in ESES. Levels of neuroinflammation markers were comparable among etiology subgroups (rolandic epilepsy, genetic abnormalities, cerebral palsy). <h3>Conclusion:</h3> IVIg treatment dampens the neuroinflammatory response and thus immune-modulatory treatment in combination with ASD may contribute to the improvement of ESES symptoms. CXCL13, HMGB1 and IL-1β may serve as markers of immune-modulatory treatment response in ESES.