Early Empiric Treatment Prior to Diagnosis of Acute Hemorrhagic Leukoencephalitis

Abstract

INTRODUCTION: Acute Hemorrhagic Leukoencephalitis (AHLE) is a rare acute demylinating disease. The presentation can mimic viral encephalitis or tumor. Early treatment with immunosuppressants is thought to have a significant impact on outcome. CASE PRESENTATION: A 33-year-old Puerto Rican female with minimal medical history presented with a two-day history of frontal headache, nausea, and vomiting. She denied recent viral illness or vaccination. Initial exam revealed 4/5 strength in the proximal left lower extremity, inability to dorsiflex or plantarflex the left foot, and brisk left sided reflexes, which progressed to left sided flaccid paralysis. Magnetic resonance imaging revealed a right frontal lobe enhancing hemorrhagic lesion with surrounding edema. She was treated with dexamethasone for presumed vasogenic edema surrounding a primary tumor. On hospital day five, decompressive craniotomy revealed necrotic tissue with no mass lesion. Biopsy showed dense macrophage predominant inflammatory infiltrates surrounding parenchymal blood vessels, which had mural fibrinoid necrosis and luminal thrombosis. Luxol fast blue staining demonstrated perivascular cuffs of demylination with relatively preserved axons. The patient was diagnosed with AHLE and continued on dexamethasone until she developed disease progression, after which she was treated with IVIG and later plasma exchange. Her course was complicated by a pulmonary embolism and intraparenchymal hemorrhage while on anticoagulation. DISCUSSION: AHLE has a poor prognosis, but there are reports of survival with preserved neurologic function in cases treated early with glucocorticoids, plasma exchange, or IVIG. The disease is difficult to diagnose and is often initially managed as a viral encephalitis or tumor. Our patient was not formally diagnosed until nineteen days into the clinical course; however, early treatment with dexamethasone and timely decompressive craniectomy may have improved her outcome. CONCLUSION(S): We report a case of AHLE that was initially managed as a primary brain tumor before being correctly diagnosed. Intensive care unit providers should be aware of this diagnosis as prompt recognition and treatment has the potential to improve long-term outcomes.