Human Herpesvirus-6: Neurologic Implications of a Newly-Described Viral Pathogen

Abstract

Discovered only 12 years ago, human herpesvirus-6 (HHV-6) has been associated with central nervous system (CNS) ®ndings such as febrile seizures, encephalitis, meningitis, and possibly multiple sclerosis. These manifestations have been reported in both immunocompetent and immunocompromised individuals. The applications of such sophisticated laboratory tools as polymerase chain reaction, in situ hybridization, immunohistochemical staining, and representational difference analysis have expanded knowledge of the spectrum of CNS disease attributable to HHV-6 while delineating pathogenic mechanisms of both primary HHV-6 infection and reactivation from latency. This article reviews existing knowledge of the CNS manifestations of HHV-6, focusing on both clinical aspects of HHV-6 infection and its pathogenesis on neurologic diseases.

Human herpesvirus 6-associated uveitis with optic neuritis diagnosed by multiplex PCR

“…A number of studies have suggested that the central nervous system is the site of persistent HHV-6 infection [3,[6][7][8][9]. However, only 3 cases of ocular inflammation-associated HHV-6 have been reported [10][11][12].…”

Brain morphological changes associated with exposure to HSV1 in first-episode schizophrenia

“…HSV2 infection of brain usually occurs in neonates. 17 Both HSV1 18 and HHV6 19 can cause central nervous system infection in immunocompetent persons. Herpes virus infection of the central nervous system can lead to acute encephalitis but can also cause self-limited infection.…”

Association of Serum Antibodies to Herpes Simplex Virus 1 With Cognitive Deficits in Individuals With Schizophrenia

“…Herpes simplex virus 2 can cause infections of the central nervous system in neonates and is an occasional cause of central nervous system infection in adults. 29 Herpes simplex virus 1 25 and HHV-6 30 can cause infection of the central nervous system in otherwise healthy individuals who do not have any apparent immune defect. Herpesvirus infections of the central nervous system can result in varying degrees of encephalitis, which can be associated with a high degree of morbidity and mortality in the absence of antiviral therapy.…”