Introduction:

Herpes Simplex Virus (HSV) encephalitis remains one of the most common causes of fatal sporadic viral encephalitis(1, 2). The causative agent in beyond the neonatal period is usually HSV-1 but HSV-2 and HSV-1 both can cause HSV encephalitis (HSE) in neonatal period. The mortality rate is high in non-treated patients compared to treated ones. The mortality rate of HSE has been reduced to 28% from 70% with development of anti viral therapy.(3). HSV- encephalitis accounts approximately 10-20 percent of the 20,000 annual viral encephalitis in US(4). Incidence of HSV encephalitis varies worldwide with incidence reported around 0.7 to 13.8 per 100,000 for all ages. (0.7-12.6 /100000 for adults and 10.5-13.8/100000 for children )(2, 5). Patients with HSV-1 encephalitis usually presents with altered mentation and consciousness for more than 24 hours, fever, new onset of seizures or focal neurological deficits. Focal neurological deficits may include any focal cranial nerve deficits, paraparesis, dysphasia, aphasia or ataxia(6). The diagnosis of herpes simplex encephalitis is confirmed by positive polymerase reactions (PCR) results for HSV DNA in the cerebrospinal fluid(CSF)(7). HSV encephalitis causes perivascular edema and hemorrhagic necrosis of the brain parenchyma, frequently in orbitofrontal and temporal region. Magnetic resonance imaging (MRI) performed in the acute course of the disease helps to get best visualisation of cerebral edema and hemorragic necrosis(8). However, the occurrence of a frank intracerebral hematoma in the setting of HSE is rare. We report a case of delayed temporal lobe hemorrhage managed conservatively in an immunocompetent patient with HSE.