Here we describe unique neuroradiologic findings in a case of cerebrospinal fluid-confirmed West Nile virus neuroinvasive disease.

West Nile virus neuroinvasive disease (WNND) most commonly presents as meningitis, encephalitis, or acute flaccid paralysis, with variable neuroimaging findings. While MRI abnormalities classically involve deep gray matter and brainstem structures, hemorrhagic manifestations are rarely reported.

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We report a 77-year-old woman who presented with rapidly progressive altered mental status following a brief febrile prodrome. Cerebrospinal fluid studies demonstrated a lymphocytic pleocytosis consistent with aseptic meningitis. Brain MRI revealed an acute lacunar infarct and diffuse cerebral microhemorrhages initially concerning for cerebral amyloid angiopathy. During hospitalization, she developed livedo-like peripheral skin changes prompting evaluation for autoimmune or vasculitic etiologies. Extensive infectious and autoimmune testing was ultimately notable for positive serum and CSF West Nile virus serologies, confirming neuroinvasive WNV infection. Despite transient neurologic improvement, her clinical course deteriorated, and she died following transition to comfort-focused care.

This case highlights petechial cerebral microhemorrhages as a potential, previously underrecognized manifestation of WNND. These findings may reflect underlying neurovascular inflammatory injury and can mimic other small-vessel or autoimmune pathologies, complicating early diagnostic evaluation. Recognition of this expanded radiographic and clinical spectrum may aid timely diagnosis of WNND in patients with atypical presentations.