Herpesviral DNA in brain tissue from patients with temporal lobe epilepsy.

Presence of DNA from six herpesviruses were examined in brain tissue from patients operated for temporal lobe epilepsy.A total of 19 Canadian patients (I) with a median age of 22 years, 17 Swedish patients (II) with a median age of 14 years and a reference group comprising 12 individuals were studied. Presence of herpesviral DNA was detected by nested polymerase chain reaction.Of three children with Rasmussen's encephalitis, Cytomegalovirus (CMV) DNA was found in two, and human herpesvirus type 6 DNA in two. In six children with ganglioglioma, Epstein-Barr virus (EBV) was detected in four. CMV DNA was found significantly more in group I compared with II, while the reverse occurred with EBV DNA. Malformations of cortical development were found significantly more in group II compared with I.Detection of DNA from some herpesviruses in epileptic brain tissue may possibly be associated with distinct clinical conditions, but factors such as age and malformations of cortical development should also be considered.