Herpes simplex encephalitis (HE) is one of the most common causes of fatal sporadic encephalitis. Psychiatric symptoms and sudden behavioral changes often occur during the initial phase of disease, presumably from inflammation of the inferomedial temporal lobe or limbic system. However, the treatment for HE is not clearly established and scarce literature suggest benefit with acyclovir and possibly with corticoids.
Methods: Case report of HE with prominent behavioral and manic-like symptoms responsive to pharmacotherapy which is first line choice for acute mood stabilization. Neurological exam, clinical psychiatric interview according to DSM-IV, lumbar puncture, tomography, MRI with gadolinium, laboratory tests and cognitive/mood scales were used for diagnosis and follow-up.
Results: A 20-year old woman was admitted to psychiatric ward after 16 days of acyclovir treatment for HE. At admission, she showed impaired executive function and memory, mental confusion, inappropriate laugh, incongruity of emotional responses, elevated mood, hipersexuality, uninhibited behavior. The Young Mania Rating Scale and Hamilton Depression Rating Scale scores were 14 and 2 points, respectively. Tomography showed bilateral frontal-temporal hipodensity. Behavioral symptoms persisted after acyclovir treatment was completed and after lumbar puncture was negative. Patient received valproate 1000mg and an atypical antipsychotic, olanzapine 10mg, showing a marked response within 7 days. Symptoms improved despite persistent inflammation suggested by bilateral increase in signal intensity in frontal-temporal lobes in the follow-up MRI with gadolinium.
Conclusion: Commonly used medication for mood stabilization may be useful in improving neuropsychiatric symptoms and preventing further damage in HE. Future clinical trials and prospective reports are needed.