Epilepsy etiology with special emphasis on immune dysfunction and neurovirology

The etiology of epilepsy remains in most cases an enigma. Based on the finding of a genetically dependent immune dysfunction in focal epilepsies, brain specimens from 16 patients, ranging in age from 6 to 39 years and operated on for therapy-resistant focal, mainly temporal lobe epilepsy were analyzed for the presence of viral DNA. The PCR technique was used for detection of viral DNA from the herpes virus group. HSV-1 was found in 44%, CMV in 50%, and HHV-6 in 25%. Three patients were positive for more than one of these viruses. The control material, consisting of only 4 brain tissue samples, showed DNA from HSV-1 in one case. Until more brain samples from controls have been examined, caution must be taken before a viral etiology is applied to focal epilepsy.