What is the role of imaging studies in the workup of West Nile virus (WNV) infection and encephalitis (WNE)?

Updated: Apr 05, 2021
  • Author: David J Cennimo, MD, FAAP, FACP, AAHIVS; Chief Editor: Michael Stuart Bronze, MD  more...
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Answer

Imaging studies may be helpful, especially during the early phases of an evaluation. It may facilitate exclusion of other causes of encephalopathy.

Imaging findings in patients with WNE vary wildly and, when present, are nonspecific. Imaging results may be normal even in severe WNE. [28, 29] No particular MRI or CT findings are specific for WNE. [28, 29]

Patients with MRI abnormalities of the nerve roots or spinal cord were found to be more likely to have residual neurological deficits upon resolution of acute illness, and those with normal findings were found to be more likely to have a favorable prognosis. [29]

EEG may be used as an adjunctive study but is not likely sufficient for confirmation. EEG may show generalized continuous slowing, particularly in the anterior (frontal, temporal) regions, consistent with a nonspecific encephalopathy. [28] However, not all patients with WNE have generalized slowing, and generalized slowing is not specific to WNE.


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