Herpes simplex encephalitis (HSE) and its outcome in the patients who were admitted to a tertiary care hospital in Mashhad, Iran, over a 10-year period

Introduction: The effective cure rate of acyclovir emphasizes the importance of an early diagnosis and treatment in reducing the considerable mortality and the morbidity in patients with Herpes Simplex Encephalitis (HSE). Methods: The demographic as well as clinical features, the lab data and the neuroimaging findings of the patients with HSE, which were confirmed by Cerebrospinal Fluid (CSF) PCR and/ or brain MRI, were reviewed and analyzed statistically over a 10-year period. Results: Over a 10-year period, the characteristics of 45 patients with HSE were reviewed. 34 (76%) out of the 45 patients showed positive CSF HSV-1 PCR results. 8 (18%) had a normal CSF analysis and a CSF/blood glucose ratio of less than 0.5 was observed in 13 (29%) patients, while 14% had PMN-dominant pleocytosis. 68% of the patients for whom brain MRI was performed, had temporal lobe involvement. While 37 (83%) patients recovered completely, 6 (13%) survived with sequelae, and 2 (4%) died. Conclusion: Because of the increasing number of atypical forms of HSE and the great impact of an early diagnosis and treatment on a favourable outcome, the acyclovir therapy should be administrated for any type of febrile encephalopathy of unknown aetiology, until HSE can be excluded.