RT Journal Article SR Electronic T1 Adult acute hemorrhagic leukoencephalitis: role of susceptibility-weighted imaging in diagnosis and importance of aggressive early immunotherapy. (P1.2-027) JF Neurology JO Neurology FD Lippincott Williams & Wilkins SP P1.2-027 VO 92 IS 15 Supplement A1 Dana Sugar A1 Jonathan Galli A1 Stacey Clardy A1 John Greenlee YR 2019 UL http://n.neurology.org/content/92/15_Supplement/P1.2-027.abstract AB Objective: We present a case of adult acute hemorrhagic leukoencephalitis emphasizing the role of susceptibility-weighted (SWI) MRI in diagnosis and the importance of aggressive early immunotherapy.Background: Acute hemorrhagic leukoencephalitis (AHLE) is a postinfectious condition characterized by extensive demyelination and foci of intracerebral hemorrhage. Although most often a condition of childhood, AHLE can also affect adults, with high morbidity and mortality.Design/Methods: A 44 year old male with history of recent upper respiratory tract infection presented with headache and encephalopathy which progressed to coma within 24 hours. Cerebrospinal fluid analysis was notable for lymphocytic pleocytosis. MRI demonstrated multifocal white matter hyperintensities on T2 and FLAIR sequences, and rim enhancement with gadolinium. Gradient recalled echo (GRE) sequences were normal but SWI sequences showed extensive microhemorrhages. Serological studies were notable for elevated immunoglobulin G antibody titers to influenza A and B and coxsackie B virus.Results: The patient was diagnosed with AHLE and immediately treated with immunotherapy including five days of methylprednisolone and five days of plasmapheresis used concomitantly, followed by three days of intravenous immunoglobulin. He demonstrated significant clinical improvement during his immunotherapy course and was successfully discharged to inpatient rehabilitation, and later home. At follow up 3 months later, he only reported fatigue as a residual symptom and had no clinical deficits on examination. Follow-up MRI at that time demonstrated complete resolution of the T2 and FLAIR white matter hyperintensities as well as SWI microhemorrhages.Conclusions: AHLE is a potentially catastrophic condition with high morbidity and mortality. SWI imaging may detect hemorrhagic lesions not detectable by GRE. Aggressive immunotherapy begun emergently may result in substantial recovery.Disclosure: Dr. Sugar has nothing to disclose. Dr. Galli has nothing to disclose. Dr. Clardy has received personal compensation for consulting, serving on a scientific advisory board, speaking, or other activities with Adivo Associates (<$1000, to University Development account). Dr. Clardy has received personal compensation in an editorial capacity for Neurology Podcast Section Editor. Dr. Greenlee has received personal compensation for consulting, serving on a scientific advisory board, speaking, or other activities with Wheeler, Trigg, and O’Donnell. Dr. Greenlee has received personal compensation in an editorial capacity for Medlink and Merck Manual, Professional and Home.