Acute hemorrhagic encephalitis: An unusual presentation of dengue viral infection

Abstract

Dengue is a common viral infection worldwide with presentation varying from clinically silent infection to dengue fever, dengue hemorrhagic fever, and severe fulminant dengue shock syndrome. Neurological manifestation usually results from multisystem dysfunction secondary to vascular leak. Presentation as hemorrhagic encephalitis is very rare. Here we present the case of a 13-year-old female admitted with generalized tonic clonic seizures. Plain computed tomography (CT) scan of head revealed hypodensities in bilateral deep gray matter nuclei and right posterior parietal lobe without any hemorrhage. Cerebrospinal fluid (CSF) and serology were positive for IgM and IgG antibodies to dengue viral antigen. Contrast-enhanced magnetic resonance imaging (MRI) revealed multifocal T2 and fluid attenuated inversion recovery (FLAIR) hyperintensities in bilateral cerebral parenchyma including basal ganglia. No hemorrhage was seen. She was managed with steroids. As her clinical condition deteriorated, after being stable for 2 days, repeat MRI was done which revealed development of hemorrhage within the lesions, and diagnosis of acute hemorrhagic encephalitis of dengue viral etiology was made.

Keywords: Cerebral hemorrhage; Dengue hemorrhagic encephalopathy, encephalitis; dengue; diffusion-weighted images.

Figure 1(A and B)

(A) Axial FLAIR and (B) gradient echo (GRE) MR images at the level of basal ganglia show multifocal FLAIR hyperintense lesions at gray-white matter junction and in bilateral basal ganglia. None of the lesions shows evidence of hemorrhage (B)

Figure 2(A and B)

(A) Axial DWI MR image at the level of basal ganglia shows restricted diffusion within these lesions. (B) Contrast-enhanced T1W MR image shows peripheral rim enhancement of the lesions

Figure 3

Follow-up GRE MR image, done after 72 h, shows multifocal areas of blooming within the lesions, suggestive of hemorrhage