Search for Human Herpesvirus-6 in Mesial Temporal Lobe Epilepsy Surgical Brain Resections

摘要

Human Herpesvirus-6 (HHV-6) causes roseola infantum and has been associated with multiple sclerosis, seizures, meningitis, and meningoencephalitis. A 2003 study isolated HHV-6 DNA in astrocyte-resembling cells of temporal lobe surgical brain tissue resections in four of eight patients with mesial temporal lobe epilepsy (MTLE). This suggests that the initial infection or reactivation of HHV-6 in astrocytes plays a role in the development of MTLE. We sought to replicate this finding in 18 patients undergoing lobectomy for medically refractory seizures with history of roseola and MTLE. We found no evidence of HHV-6 DNA in temporal lobe specimens of 18 patients with MTLE. Introduction Human herpesvirus-6 (HHV-6), a T lymphotrophic beta-herpesvirus that causes roseola infantum (exanthum subitum), is associated with neurological diseases like multiple sclerosis, seizures, meningitis, and meningoencephalitis.1 Like other herpes viruses, HHV-6 can cause latent infection of the CNS with the possibility of reactivation.2,3 HHV-6 DNA was found in the cerebrospinal fluid of immunocompromised patients with limbic encephalitis4 and in the hippocampus of children with prolonged focal febrile seizures.5 Materials and Methods Donati et al. isolated HHV-6 DNA in astrocyte-resembling cells of temporal lobe surgical brain tissue resections in four of eight patients with mesial temporal lobe epilepsy (MTLE).6 This suggests that either the initial infection or reactivation of HHV-6 in astrocytes plays a role in the development of MTLE. We sought to replicate this finding using PCR amplification of HHV-6 DNA in pathological brain tissue resected during the surgical treatment of MTLE. Utilizing a larger sample than Donati et al., we studied the relationship between HHV-6A and HHV-6B DNA detected in brain tissue and the reported history of roseola and febrile seizures in patients with MTLE.Eighteen consecutive patients undergoing temporal lobectomy for medically refractory seizures (10 male, mean age 38 years, range 19 to 66 years) participated. Mesial temporal sclerosis (11 left, 4 right, 3 without) was detected in most specimens. Table 1 shows demographics, age of seizure onset, and medication.