Include recognition of the four different serotypes of DENV and their epidemiology as well as recognition of the expanded
dengue syndrome encompassing multisystem involvement in the severe form of the disease including involvement of the central nervous system (CNS). DENV is a neurotropic virus with the ability to infect the supporting cells of the CNS. Neural injury during the acute stage of the
infection results from direct neuro-invasion and/or the phenomenon of antibody-dependent enhancement, resulting in plasma leakage and coagulopathy. Immune mechanisms have been implicated in the development of the delayed neurological sequelae through molecular mimicry. A myriad of neurological syndromes has been described as a result of the involvement of the CNS, the peripheral nervous system (PNS), or both.
Neurological manifestations in DENV
infection are increasingly being recognized, some of which are potentially fatal if not treated promptly. DENV
encephalopathy and
encephalitis should be considered in the differential diagnosis of other
acute febrile encephalopathies,
autoimmune encephalitides, and in cases of
encephalopathy/
encephalitis related to SARS-CoV2
infection, especially in
dengue-endemic areas.
Acute disseminated encephalomyelitis (ADEM) may be occasionally encountered. Clinicians should be knowledgeable of the expanded
dengue syndrome characterized by the concurrent compromise of cardiac, neurological, gastrointestinal, renal, and hematopopoietic systems. Isolated
cranial nerve palsies occur rather uncommonly and are often
steroid responsive. These neuropathies may result from the direct involvement of cranial nerve nuclei or nerve involvement or may be immune-mediated. Even if the diagnosis of
dengue is confirmed, it is absolutely imperative to exclude other well-known causes of isolated
cranial nerve palsies. Ischemic and
hemorrhagic strokes may occur following
dengue fever. The pathogenesis may be beyond the commonly observed
thrombocytopenia and include
cerebral vasculitis. Involvement of ocular blood vessels may cause
maculopathy or
retinal hemorrhages.
Posterior reversible encephalopathy syndrome (PRES) is uncommon and possibly related to dysregulated
cytokine release phenomena. Lastly, any patient developing acute neuromuscular weakness during the course or within a fortnight of remission from
dengue fever must be screened for
acute inflammatory demyelinating polyneuropathy (AIDP), hypokalemic
paralysis, or acute
myositis. Rarely, a Miller-Fisher-like syndrome with negative anti-GQ1b antibody may develop.