Focal neurological injury caused by West Nile virus infection may occur independent of patient age and premorbid health.
BACKGROUND
Limited evidence suggests that focal neurological injury (e.g., acute flaccid paralysis) caused by infection with the West Nile virus (WNV) is more common in older patients. We re-evaluate this association in a series of patients who were infected with the WNV during the 2002 epidemic.


METHODS
We performed a retrospective chart review of 34 patients who were hospitalized for treatment of serologically confirmed WNV infection. Measurements included the patient's demographic characteristics, baseline medical diagnoses, the occurrence of symptoms and exam findings, the results of various diagnostic tests, and the patient's clinical outcome.


RESULTS
Patients infected with the WNV who developed focal neurological injury were found to be comparable to patients who did not develop focal neurological injury both in terms of patient age and the number of medical conditions the patient had prior to infection. This is in contrast to WNV-infected patients who developed an encephalitis-like clinical course, or who died or were institutionalized after their hospitalization; such patients tended to be older and-in cases with a poor outcome-have more medical conditions prior to WNV infection.


CONCLUSIONS
In our patient group, focal neurological injury caused by WNV infection was not related to advanced patient age or to the number of medical conditions the patient had prior to infection. Our findings bring into question commonly held views about the development of focal neurological injury caused by WNV infection, and they raise concerns about the management of future WNV epidemics and the testing and use of potential antiviral treatments against this infection.
Bhangoo
Sandeep
S
Department of Neurology, Northwestern Memorial Hospital, Chicago, IL 60611, USA.
Chua
Rowena
R
Hammond
Chris
C
Kimmel
Zebadiah
Z
Semenov
Irene
I
Videnovic
Aleksandar
A
Kessler
John
J
Borsody
Mark
M
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000375:Aging; D003710:Demography; D005260:Female; D006304:Health Status; D006801:Humans; D008297:Male; D008875:Middle Aged; D009422:Nervous System Diseases / Q000134:cerebrospinal fluid / Q000209:etiology* / Q000821:virology; D012189:Retrospective Studies; D014901:West Nile Fever / Q000134:cerebrospinal fluid / Q000150:complications* / Q000821:virology; D014902:West Nile virus / Q000302:isolation & purification