['Cell-free DNA (cf-DNA) is a marker of inflammation and cell death. The purpose of the present study was to analyze the role of cf-DNA as a putative biomarker in refractory epilepsy.', 'Baseline concentration of cf-DNA was measured in the serum of 51 carefully evaluated refractory epilepsy patients undergoing video-EEG monitoring. Epilepsy was classified based on seizure semiology, patient history, and imaging findings. Majority of the patients (47) had focal epilepsy. The association of the concentration cf-DNA with different clinical determinants was analyzed. 250 healthy individuals served as control subjects.', 'The mean baseline concentration of cf-DNA was lower in patients with extra temporal lobe epilepsy (XTLE) compared to control subjects (0.72\xa0μg/ml vs. 0.80\xa0μg/ml; p\xa0=\xa00.001). The difference in concentration of cf-DNA between patients with temporal lobe epilepsy (TLE) and control subjects was not significant. The maximum concentration of cf-DNA after baseline measurement was significantly lower in patients with duration of epilepsy\xa0≥\xa018\xa0years compared to those with duration of epilepsy\xa0<\xa018\xa0years (0.022\xa0μg/ml vs. 0.031\xa0μg/ml; p\xa0=\xa00.044). The maximum concentration of cf-DNA was higher in patients with body mass index (BMI) ≥ 25 compared to those with BMI\xa0<\xa025 (0.004\xa0μg/ml vs. 0.041\xa0μg/ml; p\xa0=\xa00.006).'] Is the concentration of cell-free DNA in video-EEG patients dependent on the epilepsy syndrome and duration of epilepsy?