A Rare Case of Dengue Fever Presenting With Acute Disseminated Encephalomyelitis.

Dengue fever is a viral infection transmitted by mosquitoes with a clinical spectrum that ranges from asymptomatic infection to dengue shock syndrome. Neurologic manifestations are rare. We report a case of dengue fever presented with acute disseminated encephalomyelitis. An 18-year-old boy presented with high-grade fever, generalized headache for three days, intermittent altered sensorium, nausea, and vomiting for one day. Dengue-IgG and Dengue-IgM were positive. Magnetic resonance imaging (MRI) showed abnormal signal intensity areas in the bilateral deep white matter at centrum semiovale more on the right side, which seemed hypointense on T1 and hyperintense on T2 and fluid-attenuated inversion recovery (FLAIR) images, with open ring enhancement on contrast-enhanced T1 image, and peripheral diffusion restriction on diffusion-weighted 1 (DW1) image. These features were suggestive of acute disseminated encephalomyelitis. He improved within a week of taking IV methylprednisolone 1 g once daily for five days and supportive care. Follow up MRI after three weeks showed the resolution of all abnormalities. Thus we conclude that patients with acute disseminated encephalomyelitis should be checked for dengue fever, especially in areas of high prevalence, for early diagnosis and appropriate treatment and to prevent excessively aggressive surgery and/or treatment for such abnormal MRI findings.