Rare Magnetic Resonance Imaging findings in dengue encephalitis

Dengue encephalitis is caused by a nonneurotropic virus of Flaviviridae group. It is a very rare manifestation of dengue fever caused by direct invasion of neural tissue into brain parenchyma. It causes a spectrum of neurologic manifestations such as meningitis, encephalitis, myelitis, and stroke. Here, we discuss a 20-year-old antenatal woman who presented with acute-onset fever and altered sensorium for 1 day. Blood investigations showed mild thrombocytopenia. Magnetic resonance imaging showed characteristic hemorrhagic encephalitis involving bilateral thalami and pons with diffusion restriction. Cerebrospinal fluid for the meningoencephalitic panel was negative. Serology for dengue NS1 antigen and immunoglobulin M antibody were positive. Although considered as a nonneurotropic virus, acute clinical presentation of fever, and altered sensorium apart from herpes and Japanese encephalitis, dengue encephalitis should also be regarded as one of the differentials.