Acute Transverse Myelitis (Ascending Myelitis) as the Initial Manifestation of Japanese Encephalitis: A Rare Presentation

Japanese encephalitis, an inflammatory brain disease prevalent in Southeast Asia, usually presented with fever, headache, convulsions, brain stem signs with pyramidal and extrapyramidal features, and altered sensorium. Acute transverse myelitis, as the initial manifestation of Japanese encephalitis, is an unusual manifestation and is seldom reported. We hereby report a case of 13-year-old adolescent boy who presented to us with fever and acute onset paraparesis with urinary retention initially, progressing to quadriparesis and then followed by headache and altered sensorium. Brain MRI revealed bilateral basal ganglia that were grossly swollen with vasogenic edema tracking along internal capsule and midbrain. Adjacent ventrolateral thalamus and internal capsule also showed mild abnormal intensities. Spinal screening showed abnormal cord intensities in entire cord with gross edema in cervical and conus regions. He had elevated IgM titres against JE virus in cerebrospinal fluid. The patient was treated conservatively along with intravenous methyl prednisolone for 5 days. He regained near normal power at 3 months in followup, but hesitancy, dysarthria, and slowness of movement still persisted. To conclude, a young boy presenting with ATM in an endemic region of JE, then a possibility of Japanese encephalitis, should be sought by clinicians as early use of immunomodulator shows survival benefit. 1. Introduction Japanese encephalitis is the commonest endemic encephalitis in Southeast Asia causing significant morbidity and mortality [1]. It is caused by the JE virus belonging to family Flaviviridae, transmitted by mosquito Culex, and has an incubation period of 5 to 15 days. Mostly infections are asymptomatic and only 1 in 250 infections develops into encephalitis. The diagnosis is commonly based on demonstrating a rising titre of antibodies against JE virus in acute and convalescent sera [2]. The course of the disease can be divided into three stages: a prodromal stage, an encephalitic stage, and a late stage characterized by recovery or persistence of signs of CNS injury. Apart from the classical presentation other atypical presentations of JE have been reported. Among them, acute transverse myelitis had been recently reported, and this is distinctly rare. Here we describe a 13-year-old adolescent boy who presented with fever, acute transverse myelitis, and altered sensorium that was diagnosed as Japanese encephalitis. 2. Case Report A 13-year-old male presented to us with fever (acute in onset, mild to moderate grade and associated with mild chills) since