May 18, 2017
An 18-year-old man with a history of high-grade fever and rigors for 3 days, along with drowsiness and decreased level of consciousness
Dengue Encephalitis
- Background:
- Dengue encephalitis is rare and occurs as a result of direct infection of the neurons by the dengue virus.
- Dengue encephalitis is thought to be benign, but can be fatal at times.
- The role of an antiviral in such cases needs to be further defined because of the extensive parenchymal involvement and possible unfavorable outcome.
- Clinical Presentation:
- Diminished level of consciousness, headache, seizure, disorientation, and behavioral symptoms
- Key Diagnostic Features:
- Imaging features alone are not diagnostic.
- Bilateral thalamic involvement with positive IgG/IgM in CSF for dengue virus is diagnostic.
- Polymerase chain reaction (PCR) for confirming the viral RNA is required, as antibodies are not seen in all cases.
- Differential Diagnoses:
- Japanese encephalitis: bilateral thalamic involvement with hemorrhagic foci, with involvement of temporal lobe and brain stem, is usually seen and is very uncommon with dengue.
- Chikungunya encephalitis: MRI shows T2W hyperintense white matter lesions with restricted diffusion. No hemorrhage or basal ganglia involvement has been reported.
- Herpetic encephalitis: involvement is bilateral but asymmetrical. Basal ganglia and thalami are typically spared.
- Treatment:
- It is mostly supportive. Ribavarin is a newer, promising agent that acts to inhibit viral replication; however, it needs further validation in the management of the virus.
