Neurologic manifestations and outcome of West Nile virus infection

JAMA. 2003 Jul 23;290(4):511-5. doi: 10.1001/jama.290.4.511.


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.

Publication types

  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Activities of Daily Living
  • Antibodies, Viral / blood
  • Antibodies, Viral / cerebrospinal fluid
  • Central Nervous System / diagnostic imaging
  • Central Nervous System / pathology
  • Disease Progression
  • Electroencephalography
  • Electromyography
  • Encephalitis, Viral / diagnosis
  • Encephalitis, Viral / physiopathology
  • Glasgow Coma Scale
  • Hospitalization
  • Humans
  • Magnetic Resonance Imaging
  • Meningitis, Viral / diagnosis*
  • Meningitis, Viral / physiopathology
  • Movement Disorders / diagnosis
  • Movement Disorders / physiopathology
  • Movement Disorders / virology*
  • Muscle Hypotonia / virology
  • Myoclonus / virology
  • Neurologic Examination
  • Neuropsychological Tests
  • Paralysis / diagnosis
  • Paralysis / physiopathology
  • Paralysis / virology*
  • Tomography, X-Ray Computed
  • West Nile Fever / diagnosis*
  • West Nile Fever / physiopathology*
  • West Nile virus / isolation & purification


  • Antibodies, Viral