Calgary experience with West Nile virus neurological syndrome during the late summer of 2003.
BACKGROUND
Between August 25 and September 25, 2003 seven patients with West Nile virus neurological manifestations were identified through the hospital neurology consultation services in Calgary, Alberta, Canada. Three of the seven patients were treated with interferon alpha-2b (IFN alpha-2b). In this report we document the clinical characteristics of these seven cases.


METHODS
Clinical and laboratory information was obtained from a retrospective review of patient hospital and clinic charts. Patients were included if they had serological evidence of West Nile virus infection and had clinical evidence of aseptic meningitis, encephalomyelitis, cerebellar syndrome or motor neuronopathy. Three patients received a treatment course of three million units IFN alpha-2b, administered by subcutaneous injection once per day for 14 days.


RESULTS
Four patients had cerebellar signs without change in consciousness, two had both encephalitis and neuromuscular weakness, and one patient had focal lower motor neuron arm weakness. The mean age was 52 (range 24 - 73). All patients had flu-like illness and fever as presenting symptoms and six had severe headaches. Two patients were immunocompromised prior to infection. Two patients with cerebellar signs (one with opsoclonus-myoclonus) improved spontaneously and exhibited only mild residual deficits on discharge. The other two patients with cerebellar findings developed brainstem involvement, one coinciding with and one subsequent to the cerebellar symptoms. Within one week of treatment with IFN alpha-2b these latter two patients showed marked improvement. One patient with encephalitis and neuromuscular weakness, was treated with IFN alpha-2b and subsequently recovered.


CONCLUSIONS
In this case review of seven patients, multiple neurological symptoms occurred in each patient and the neurological presentation was varied. Four patients had predominant cerebellar findings and one patient had opsoclonus-myoclonus, not previously reported. The marked improvement in three patients who received IFN alpha-2b raises preliminary optimism towards this potential treatment.
Sayao
Ana-Luiza
AL
Faculty of Medicine, University of British Columbia, Vancouver, BC, Canada.
Suchowersky
Oksana
O
Al-Khathaami
Ali
A
Klassen
Brian
B
Katz
Nili R
NR
Sevick
Robert
R
Tilley
Peter
P
Fox
Julie
J
Patry
David
D
D000328:Adult; D000368:Aged; D000416:Alberta; D000998:Antiviral Agents / Q000627:therapeutic use*; D001259:Ataxia / Q000175:diagnosis / Q000188:drug therapy / Q000821:virology; D002493:Central Nervous System Diseases / Q000175:diagnosis / Q000188:drug therapy* / Q000821:virology; D018792:Encephalitis, Viral / Q000175:diagnosis / Q000188:drug therapy / Q000821:virology; D017809:Fatal Outcome; D005260:Female; D006801:Humans; D000077190:Interferon alpha-2; D016898:Interferon-alpha / Q000627:therapeutic use*; D008297:Male; D008587:Meningitis, Viral / Q000175:diagnosis / Q000188:drug therapy / Q000821:virology; D008875:Middle Aged; D018908:Muscle Weakness / Q000175:diagnosis / Q000188:drug therapy* / Q000821:virology; D020361:Paraneoplastic Syndromes, Nervous System / Q000175:diagnosis / Q000188:drug therapy / Q000821:virology; D011994:Recombinant Proteins; D012189:Retrospective Studies; D016896:Treatment Outcome; D014901:West Nile Fever / Q000150:complications / Q000175:diagnosis* / Q000188:drug therapy*; D014902:West Nile virus / Q000302:isolation & purification
D000998:Antiviral Agents; D000077190:Interferon alpha-2; D016898:Interferon-alpha; D011994:Recombinant Proteins