Dengue-Associated Acute Necrotizing Encephalopathy: A Case Report and Review of the Literature

Dengue virus infection is increasingly recognized as a cause of neurological complications, though severe parenchymal involvement such as acute necrotizing encephalitis remains exceptionally rare in adults. We report a 35-year-old woman presenting with fever, seizures, and altered consciousness. Laboratory tests confirmed dengue virus infection, while cerebrospinal fluid analysis revealed normal protein and glucose, no pleocytosis, and positive dengue IgM. Brain MRI demonstrated bilateral thalamic hyperintensities with central hypointense cores, the characteristic “double-doughnut” sign, along with additional involvement of the brainstem, cerebellum, and occipital lobe, consistent with ANE. Despite prompt initiation of high-dose intravenous methylprednisolone, the patient developed persistent akinetic mutism, highlighting the poor prognosis in adult-onset cases. This case underscores the dissociation between severe radiological findings and relatively unremarkable CSF, emphasizes the diagnostic utility of MRI, and illustrates the therapeutic challenges in resource-limited settings. Early recognition and context-appropriate management are critical to improving outcomes.