Neurologic Manifestations and Outcome of West Nile Virus Infection

To describe prospectively the clinical and laboratory features and long-term outcome of patients with neurologic manifestations of WNV infection. DESIGN, SETTING, AND PARTICIPANTS: From August 1 to September 2, 2002, a community-based, prospective case series was conducted in St Tammany Parish, La. Standardized clinical data were collected on patients with suspected WNV infection. Confirmed WNV-seropositive patients were reassessed at 8 months. MAIN OUTCOME MEASURES: Clinical, neurologic, and laboratory features at initial presentation, and long-term neurologic outcome.

Sixteen (37%) of 39 suspected cases had antibodies against WNV; 5 had meningitis, 8 had encephalitis, and 3 had poliomyelitis-like acute flaccid paralysis. Movement disorders, including tremor (15 [94%]), myoclonus (5 [31%]), and parkinsonism (11 [69%]), were common among WNV-seropositive patients. One patient died. At 8-month follow-up, fatigue, headache, and myalgias were persistent symptoms; gait and movement disorders persisted in 6 patients. Patients with WNV meningitis or encephalitis had favorable outcomes, although patients with acute flaccid paralysis did not recover limb strength.