Herpes Simplex Encephalitis: Analysis of 68 cases from a tertiary care hospital in Karachi, Pakistan

Objective: To evaluate clinical presentation, radiological and cerebrospinal fluid findings and outcome of patients with Herpes simplex encephalitis (HSE). Methods: The charts of all the patients (n=88), who were admitted to The Aga Khan University, Karachi with diagnosis of HSE, from 1990-2002, were retrospectively reviewed. Sixty eight patients were included in the study. The variables were identified (including demographic data, signs and symptoms at presentation and laboratory investigations such as CSF analysis including, PCR, serum IgM antibodies, EEG and neuroimaging). The patients were included in the study if they had any three of the five criteria positive in addition to clinical features suggestive of herpes encephalitis. Results: Sixty eight patients, that fulfilled the criteria, were included in the study. Clinical findings included fever, seizures, altered mental status, aphasia and hemiparesis. CSF, analysed in all the patients, was abnormal in 65 patients (96%) and EEG was abnormal in 82% patients. All patients underwent CT or MRI of the brain, 66% patients had abnormal scans. Temporal lobe involvement was seen in 34 patients (50%) and 11 patients had purely extra temporal lesions. All patients were treated with standard Acyclovir. Seven patients died. At the time of discharge, 17 patients showed normal neurological examination, 29 were ambulatory with assistance and 15 were bedridden. Conclusion: Our study suggests that large number of patients with HSE have extra temporal involvement on CT or MRI. Majority of patients had complete or good recovery after completion of therapy.