Acute hemorrhagic leukoencephalitis following the first dose of BNT162b2 vaccine against SARS-CoV-2: A case report.

Acute hemorrhagic leukoencephalitis (AHLE), is a rare inflammatory demyelinating disorder, variant of acute disseminated encephalomyelitis. The diagnosis of AHLE remains challenging due to the rarity of the disease and the lack of a reliable biomarker. We report here a case of a 73-year-old male patient with a progressive, low-grade febrile confusional syndrome 20 days after receiving the first dose of BNT162b2 vaccine against SARS-CoV-2. Evidence indicative of the underlying condition by an extensive panel of imaging (brain magnetic resonance imaging, computed tomography and digital subtraction angiography), laboratory (complete blood count, biochemistry, coagulation, tests for autoimmune or infectious disorders, tumor markers, hormonal levels, cerebrospinal fluid analysis) and electrodiagnostic tests were scarce, and mainly non-specific. Sequential neuroimaging revealed the appearance of extensive T2 lesions (signs of gliosis) along with multiple hemorrhagic lesions at various cortical sites. The patient was treated with corticosteroids, discontinued due to severe adverse effects, and subsequently with sessions of plasmapheresis and monthly intravenous administration of cyclophosphamide. Considering the rapid aggravation of the patient's neurological status, the MRI findings of cortical lesions and the lack of response to any treatment, a biopsy of a frontal lobe lesion was conducted, confirming the presence of confluent, inflammatory-edematous lesions with scattered areas of necrosis and hemorrhage, and ultimately areas of demyelination, thus confirming the diagnosis of AHLE. After more than 5 months of hospitalization the patient was transferred in a primary care facility and remained in a permanent vegetative state until his death, more than 2 years later.