AUTHOR=Lourbopoulos Athanasios , Schnurbus Lea , Guenther Ricarda , Steinlein Susanne , Ruf Viktoria , Herms Jochen , Jahn Klaus , Huge Volker 

TITLE=Case report: Fatal Borna virus encephalitis manifesting with basal brain and brainstem symptoms

JOURNAL=Frontiers in Neurology

VOLUME=Volume 14 - 2023

YEAR=2024

URL=https://www.frontiersin.org/journals/neurology/articles/10.3389/fneur.2023.1305748

DOI=10.3389/fneur.2023.1305748

ISSN=1664-2295

ABSTRACT=Background: Since the first report of fatal Borna Virus-1 (BoDV-1) encephalitis in 2018 cases gradually increase. A diagnostic algorithm is lacking and there is no effective treatment so far.
Case presentation: We report an acute BoDV-1 encephalitis in a 77-year-old female with flu-like onset, rapid progression to word-finding difficulties, personality changes, global disorientation, diffuse cognitive slowness, and gait ataxia and further deterioration with fever, meningism, severe hyponatremia, epileptic seizures, cognitive decline and focal cortical and cerebellar symptoms/signs. The extensive diagnostic workup (cerebrovascular fluid, serum, MRI) for (meningo-)encephalitis was negative of known causes. Our empirical common antiviral, antimicrobial, and immunosuppressive treatment efforts failed. The patient fell into coma 5 days after admission, lost all brainstem reflexes on day 18, remained fully dependent on invasive mechanical ventilation thereafter and died on day 42. Brain and spinal cord autopsy confirmed an extensive, diffuse, and severe non-purulent, lymphocytic sclerosing panencephalomyelitis due to BoDV-1, affecting neocortical, subcortical, cerebellar, neurohypophysis and spinal cord areas. Along with our case, we critical review all reported BoDV-1 encephalitis cases. 
Conclusion: Diagnosis of acute BoDV-1 encephalitis is challenging and delayed, while it progresses fatal. We list all tried and failed treatments so far for future reference and propose a diagnostic algorithm for prompt suspicion and diagnosis.