MedGen

An infection that is caused by herpes simplex virus. [from NCI]

An inflammatory process affecting the brain parenchyma. Causes include viral infections and less frequently bacterial infections, toxins, and immune-mediated processes. [from NCI]

Infection of the brain parenchyma with herpes simplex virus, resulting in inflammation of the brain parenchyma with neurologic dysfunction. [from HPO]

Any disease caused by a virus. [from NCI]

An inflammation of brain parenchyma due to infection with a virus. Viral encephalitis can occur as a rare complication of common infections (eg, herpes virus infections) or can occur as a characteristic presentation of rare viruses (eg, rabies virus infection). Encephalitis may be the only neurologic manifestation of infection, or may occur in association with meningitis, myelitis, radiculitis, or neuritis. Viral encephalitis is associated with neurological dysfunction. [from HPO]

A disorder of the brain caused by an infectious agent that presents with fever, headache, and an altered level of consciousness. There may also be focal or multifocal neurologic deficits, and focal or generalized seizure activity. [from HPO]

Viral infections of the brain, spinal cord, meninges, or perimeningeal spaces. [from MeSH]

A Mendelian susceptibility or predisposition to herpes simplex infection induced encephalitis in which the cause of the diseas is a mutation in the TRAF3 gene. [from MONDO]

Herpes simplex virus (HSV)-1 is most often associated with infection of the oral mucosa. Primary infection is most commonly asymptomatic, but it may lead to symptoms usually involving the mucosa and skin. Following replication at the infection site, HSV-1 enters the epithelial endings of sensory neurons and travels up the trigeminal cranial nerves to the trigeminal ganglia, where latent infection is established. Reactivation of HSV-1, usually in the form of herpes labialis (cold sores), may occur in 20 to 40% of the population. HSV-1 seroprevalence is high, with over 85% of adults between the ages of 20 and 40 years infected. HSV-1 rarely infects the central nervous system (CNS), resulting in herpes simplex encephalitis (HSE), with an incidence of 2 to 4 per 1,000,000 people per year. In HSE, HSV-1 invades and replicates in neurons and glial cells, where focal necrotizing infections occur, primarily affecting the temporal and subfrontal regions of the brain. Untreated, HSE is fatal in at least 70% of cases, although the mortality and morbidity have been drastically reduced with antiviral therapy. Approximately one-third of all HSE cases are due to primary infections, and 30% of all HSE cases occur in children under the age of 20 years. Among children, HSE peaks between 3 months and 3 years of age, coinciding with the time of primary infection. In a subset of children, HSE results from a series of monogenic primary immunodeficiencies that impair UNC93B1- and TLR3 (603029)-dependent production of IFNA (147660)/IFNB (147640) and IFNG (147570) in the CNS (summary by Sancho-Shimizu et al., 2007). Genetic Heterogeneity of Susceptibility to Acute Infection-Induced Encephalopathy, including Herpes Simplex Encephalitis (HSE) For other forms of susceptibility to acute infection-induced encephalopathy, see herpes-specific IIAE2 (613002), caused by mutation in the TLR3 gene (603029) on chromosome 4q35; IIAE3 (608033), caused by mutation in the RANBP2 gene (601181) on chromosome 2q12; IIAE4 (614212), caused by mutation in the CPT2 gene (600650) on chromosome 1p32; herpes-specific IIAE5 (614849), caused by mutation in the TRAF3 gene (601896) on chromosome 14q32; herpes-specific IIAE6 (614850), caused by mutation in the TICAM1 gene (607601) on chromosome 19p13; herpes-specific IIAE7 (616532), caused by mutation in the IRF3 gene (603734) on chromosome 19q13; herpes-specific IIAE8 (617900), caused by mutation in the TBK1 gene (604834) on chromosome 12q14; IIAE9 (618426), caused by mutation in the NUP214 gene (114350) on chromosome 9q34; herpes-specific IIAE10 (619396), caused by mutation in the SNORA31 (619378) on chromosome 13q14; IIAE11 (619441), caused by mutation in the DBR1 gene (607024) on chromosome 3q22; and IIAE12 (620461), caused by mutation in the RNH1 gene (173320) on chromosome 11p15. [from OMIM]