Herpes Simplex Encephalitis: Understanding the Clinical Manifestations and Treatment Approaches

Herpes simplex encephalitis (HSE) is the most common form of sporadic and life-threatening encephalitis, with an annual incidence ranging from 1 in 500,000 to 1 in 250,000 individuals. It affects both genders equally and occurs without seasonal preference. The condition is associated with a high mortality rate of up to 30%, and survivors often face significant neurological complications, making it a critical medical concern.

Clinical Features of Herpes Simplex Encephalitis

HSE presents with a wide range of non-specific clinical symptoms and neurological signs. Common manifestations include headache, fever, neck stiffness, focal neurological deficits, altered consciousness, psychiatric and behavioral disturbances, seizures, and cognitive impairments. These symptoms can vary in severity and progression, making early diagnosis challenging.

Importance of Early Diagnosis and Intervention

One of the hallmark complications of HSE is hemorrhagic involvement of the temporal lobes. Given the high risk of long-term neurological deficits, prompt diagnosis and treatment are crucial. Clinicians should initiate therapy immediately upon suspicion of HSE, even before confirmatory test results are available. Diagnostic tools such as lumbar puncture, neuroimaging, serological testing, and molecular assays like PCR should be used concurrently to guide and refine treatment strategies.

Current Treatment Guidelines

Acyclovir remains the first-line treatment for HSE. As a guanine analog, it works by inhibiting viral DNA replication within infected cells. The standard recommended treatment duration is between 14 to 21 days. However, extended therapy beyond 21 days is advised for specific patient groups, including immunocompromised individuals, children under 12 years of age, and those with severe clinical presentations.

Monitoring for Relapse and Autoimmune Complications

Recent studies indicate that approximately 28% of patients who initially recover from HSE may later develop autoimmune encephalitis. This post-infectious complication can lead to recurrent psychiatric or behavioral changes. Therefore, any reappearance of neuropsychiatric symptoms following initial recovery should prompt immediate medical evaluation and appropriate diagnostic investigations.