As more and more patients are receiving immunosuppressive therapy, human herpesvirus infections are becoming more common. Historically, human herpesvirus infections were described as temporal lobe encephalitis caused by herpes simplex virus type 1 or type 2. However, more recently, other pathogens, such as varicella-zoster virus, Epstein-Barr virus, cytomegalovirus, and human herpesvirus 6, have been identified as causing severe neurological infections.