Case Presentation: A 71 year-old man with no medical history presented in October with fevers, headache, neck stiffness, photophobia, and confusion for 3 days. Per family, patient was fully functional with no memory deficits at baseline. He never traveled outside of New York tri-state area and has had no sick contacts or insect bites. Initial exam was notable for photophobia, neck stiffness, and disorientation. However, on hospital day 3 the patient also manifested significant slowed mentation, masked facies, acute bradykinesia, a coarse right hand tremor, and cogwheel rigidity in spite of regaining orientation. Initial labs were unrevealing and head imaging was negative for acute pathology. Lumbar puncture results were inconclusive with elevated glucose, protein and neutrophil count of 70. Patient was empirically started on vancomycin, ceftriaxone, ampicillin, acyclovir, and doxycycline for meningoencephalitis. Magnetic resonance imaging head with contrast showed minimal small vessel vascular disease but no focal enhancement to suggest herpes simplex virus encephalitis. Cerebrospinal fluid (CSF) analysis with PCR for common pathogens as well as cultures were negative. Blood cultures, HIV, syphilis, Lyme, and cytomegalovirus serologies were also negative. On day 2, West Nile Virus (WNV) serologies were drawn from peripheral blood and added onto prior CSF samples, which resulted in high titers of IgM and IgG suggestive of acute infection. Antimicrobial therapy was discontinued and patient was discharged to rehabilitation facility. At his one month post-discharge follow up, the patient had resolution of Parkinsonian features, but was noted to have persistent slowed mentation with difficulty identifying common objects.
Discussion: WNV is an arbovirus now considered endemic to North America since 1999 outbreak in New York. WNV-associated neuroinvasive disease most commonly affects the elderly. The presentation can range from a mild confusion to severe encephalopathy, coma, or death. Extrapyramidal symptoms, including myoclonus, bradykinesia, coarse tremor, and rigidity, are also common in neuroinvasive WNV. Such Parkinsonian features appear to be transient and self-resolving over several days to weeks and do not require dopaminergic therapies per case reports. Neurocognitive sequelae can appear to persist up to a year per one study on initially affected population in 1999; however, there are limited longitudinal studies to assess recovery in the long run.
Conclusions: Neuroinvasive WNV can present with acute onset of extrapyramidal symptoms and cognitive impairments. Inpatient clinicians should therefore consider WNV in the differential diagnosis in the appropriate setting. WNV-related neurologic sequelae often persist after resolution of acute phase, though little is known about the long term prognosis as WNV encephalitis seems to be underreported. Notification of affected patients to Department of Health or Center for Disease Control by inpatient clinicians may open venues to follow disease course. There may be a possible role for initiating early neurocognitive rehabilitation to hasten recovery as well as mitigate deficits.