Type:
Educational Exhibit
Keywords:
Performed at one institution, Observational, Retrospective, Infection, Education, MR, Neuroradiology brain, CNS, Neuro
Authors:
S. KALE1, D. P. kumar1, N. Panchal2, S. Agrawal3; 1Bengaluru+/IN, 2Mumbai/IN, 3Bangalore/IN
DOI:
10.26044/ecr2020/C-05937
Findings and procedure details
Dengue encephalitis: What is it ?
Dengue virus was considered non-neurotropic [1] of Flaviviridae group.
Dengue virus and anti-dengue IgM has been isolated from CSF of dengue serology positive patients with neurological manifestations.
DEN2 and DEN 3 have relatively greater likelihood of neurological manifestation.
Dengue encephalitis is a very rare manifestation with a prevalence of ~4-21% [2]
characterized by direct invasion of virus into brain parenchyma.
The reported incidence of neurological complications of dengue has been found to vary between 0.5% and 6.2% [3],
Encephalitis V/s Encephalopathy:
encephalitis is primarily a histologic diagnosis of inflammation of the brain parenchyma, commonly due to viral infection.
It usually presents with fever (if infective), reduced consciousness, headache, seizures, and focal neurologic signs.
When to suspect
Typical MRI features suggestive of hemorrhagic encephalitis in a patient of endemic areas, presenting with fever and encephalopathy :
Clinical Presentation:
Fever
Headache
Reduced consciousness
Generalised / focal seizures
Other features identified include meningism, [4],extensor plantars, [4] frontal release signs, [4] abnormal posturing, [4]
Rarely may present with facial nerve palsy, [45] and tetraparesis. [6]
Serological positive
In contrast, encephalopathy most common neurological manifestation, is a clinical picture of reduced consciousness, caused commonly by other infections, metabolic derangements, alcohol, or drugs and rarely by encephalitis.
However, it’s occasionally possible to differentiate two clinically.