As a biologist, one disease has plagued my mind for so long, and that is Herpes Simplex Encephalitis. This simplified post on Herpes Simplex facts and treatment is my attempt to shed some light on the subject.
Herpes Simplex Virus Type I (HSV – 1)
HSV – 1 (labialis) produces an encephalitis that occurs in any age group but is most common in children and young adults. Only about 10% of the patients have a history of prior labial herpes. The most commonly observed clinical presenting symptoms are alterations in mood, memory, and behaviour.
HSV-1 may also cause as subacute encephalitis whose clinical manifestations (weakness, lethargy, ataxia, seizures) develop over a more protracted period (4 to 6 weeks) and that is associated with more diffuse involvement of the brain rather than being restricted to the temporal lobes.
Acyclovir has emerged as the most efficient treatment, leading to a significant reduction in the mortality rate.
The encephalitis starts in, and most severely involves, the lower and middle regions of the temporal lobes and some parts of the frontal lobes. The infection is grossly necrotizing and often hemorrhagic in the most severely affected areas.
Herpes Simplex Virus Type 2 (HSV – 2)
HSV – 2 (genitals) also affects the nervous system and is responsible for most cases of herpetic viral meningitis. Generalized and usually severe encephalitis develops in as many as 50% of neonates born by vaginal delivery to women with active primary HSV infection.
The dependence on a route of delivery indicates that the infection is probably acquired during passage through the birth canal rather than transplacentally. HSV – 1 causes similar encephalitis in neonates. In AIDs patients, HSV – 2 may rarely cause acute, hemorrhagic necrotizing encephalitis.