Dengue encephalitis

Dengue encephalitis is a rare condition resulting from direct involvement of the central nervous system by the dengue virus.  

Dengue infection, and thus dengue encephalitis, predominately occurs in tropical and subtropical areas. 1 

Dengue encephalitis presents similar to other forms of encephalitis with non-specific symptoms such as headache, seizures and altered level of consciousness. 

Dengue virus is a mosquito-transmitted RNA virus belonging to the Flavivirus genus.  There are four serotypes, designated DENV1-DENV-4. 1 The serotypes most commonly implicated in neurologic manifestations of dengue virus infection are DENV2 and DENV-3. 2

CT

  • hyperattenuating intraparenchymal foci representing spontaneous macrohaemorrhages 1

MRI

  • T2
    • hyperintense lesions involving the basal ganglia, thalami, cortical grey matter, and subcortical and deep white matter are the classical features of dengue encephalitis, usually with associated edema
    • rarely, similar lesions are found in atypical locations such as the brainstem (particularly the substantia nigra), cerebellum, and hippocampus 1
  • DWI/ADC: affected regions demonstrate restricted diffusion in most cases 1
  • SWI: microhemorrhages are commonly seen 1
  • acute disseminated encephalomyelitis (ADEM)
    • hemorrhage is uncommon 1
    • the timing between the CNS manifestations and lesions and the febrile illness may assist in differentiating dengue encephalitis from ADEM - with dengue encephalitis manifesting during the febrile period and ADEM occurring after resolution of the acute illness 1
  • Japanese encephalitis 
    • hemorrhagic findings, although described, are less common 1
  • herpes simplex encephalitis
    • usually spares the basal ganglia 1

Article information

rID: 71866
Synonyms or Alternate Spellings:

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