ObjectiveTo explore the pathogenic mechanism of human herpesvirus 6B (HHV-6B) in the intractable mesial temporal lobe epilepsy (MTLE).Methods42 cases of intractable MTLE and 17 cases of non-MTLE patients who treated in Wuhan Brain Hospital from Jan. 2012 to Dec. 2018 were enrolled in this study. Resected hippocampus, amygdala and mixed uncus samples were examined by real-time polymerase chain reaction (PCR) and reverse-transcriptase PCR to detect viral DNA and message RNA. Comparative analysis was used between the clinical characteristics and the HHV-6 detection.ResultsDetection of HHV-6 DNA was higher in MTLE patients (40.48%) than non-MTLE patients (11.7%). HHV-6B viral DNA was determined in 15/30 HHV-6 DNA-positive samples, and no HHV-6B mRNA were detected in all HHV-6 DNA negative samples. The patient’s age was the only influencing factor of HHV-6 expressing in MTLE. While the patient’s gender, onset age and possible disease cause had no effect on the HHV-6 content.ConclusionsThis study suggests that HHV-6B may play an important role in the pathogenesis of MTLE, but the mechanism needs further study.