(616) Herpes Simplex Virus Encephalitis With Intracerebral Hemorrhage in a Child

Introduction: The most common cause of nonendemic encephalitis in the United States is the Herpes Simplex Virus. Although petechial hemorrhages are reported, frank intracerebral hemorrhages (ICH) are uncommon with herpes encephalitis (HE). We describe a boy with HE who presented with an ICH.

Description: A previously healthy, 14-month-old male, born full-term, presented with a generalized tonic-clonic seizure and a 5-day history of fever, requiring intubation in the ER. A CT scan of his head revealed an ICH in the right frontal lobe measuring 11x25x8 mm, accompanied by vasogenic edema. Dexamethasone and meningitic doses of ceftriaxone, vancomycin, and acyclovir were administered. Initial examination in the PICU showed reactive pupils, preserved cough and gag reflexes, and intermittent movements of all four extremities between sedation boluses. CSF analysis revealed 6 WBCs, 3 RBCs, protein 45.8 mg/dL, glucose 78 mg/dL, positive HSV-1 PCR, and negative HSV-2 PCR. VEEG findings were consistent with mild encephalopathy (on sedation). His MRI demonstrated multiple abnormal signal areas with cortical and subarachnoid contrast enhancement, restricted diffusion, and subacute hemorrhage in the right frontal and parietal regions, suggestive of inflammatory diseases like HE. Skeletal survey and ophthalmologic examinations were normal. After 3 days, he was extubated to room air with no focal neurological deficits. Antibiotics were discontinued following negative CSF bacterial cultures. A Follow-up MRI showed the previously seen subacute hemorrhage with decreased enhancement in the right frontal and parietal regions. He was discharged to continue acyclovir for 21 days and levetiracetam for seizure prophylaxis.

Discussion: ICH in HE is more often reported in adults than in children. Our patient had no coagulopathy or trauma. The bleeding mechanism in HSV encephalitis is not well understood but may involve small vessel vasculitis. The prognostic implication of ICH in HE is unknown. In this case, the child showed a favorable short-term outcome. This report adds to the limited literature on HE and associated ICH. In children with spontaneous ICH, HE should be in the differential diagnosis. Delays in treatment could lead to adverse outcomes.