Context The neurologic manifestations, laboratory findings, and outcome of patients
with West Nile virus (WNV) infection have not been prospectively characterized.
Objective 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.
Results 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.
Conclusions Movement disorders, including tremor, myoclonus, and parkinsonism, may
be present during acute illness with WNV infection. Some patients with WNV
infection and meningitis or encephalitis ultimately may have good long-term
outcome, although an irreversible poliomyelitis-like syndrome may result.