2451 Diagnostic challenge – Japanese encephalitis masquerading as post SARS-CoV-2 encephalitis

Objectives and MethodsPara or post-infectious encephalitis is a neurological syndrome associated with a concomitant or antecedent infection, usually viral. The damage to the nervous system might be caused directly by the virus or by the host immune response to the infection. We report a case of encephalitis in a 68-year-old male who presented with a 4-day history of progressive paraparesis, bilateral cerebellar ataxia, and unilateral lower motor neuron pattern facial nerve palsy, 1 week after resolution of mild SARS-CoV-2 infection.ResultsNon-contrast CT of brain was unremarkable. MRI showed T2/FLAIR hyperintensities in the brainstem at bilateral cerebellar peduncles, left thalamus, left midbrain, and periventricular regions. There was no evidence of transverse myelitis. CSF analysis revealed pleocytosis and increased protein with negative BioFire viral PCR. High dose corticosteroid therapy was commenced due to clinical suspicion of post-SARS-CoV-2 encephalitis and significant clinical improvement followed. Due to increasing Japanese Encephalitis Virus (JEV) cases in the region, additional JEV tests were performed and returned positive CSF JEV PCR.ConclusionPost-SARS-CoV-2 and Japanese encephalitis are both rare and debilitating neurological conditions in Australasian setting. Diagnosis of post-SARS-CoV-2 relies on exclusion of geographically common infective aetiologies and may be akin to acute disseminated encephalomyelitis in pathophysiology. This case underscores importance of remaining vigilant on emerging infections such as JEV in Australasia. There are limited high quality evidence-based therapies for both conditions and further studies are urgently required to guide the diagnosis and choice of therapies.