Case of the Week
Section Editors: Matylda Machnowska1 and Anvita Pauranik2
1University of Toronto, Toronto, Ontario, Canada
2BC Children's Hospital, University of British Columbia, Vancouver, British Columbia, Canada
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October 29, 2012
"Polio-like" Myelitis
- "Polio-like" myelitis are lesions mimimicking the typical anterior horn (AH) cell hyperintensity on T2WI seen in the acute phase of poliovirus infection.
- Key Diagnostic Features: Abnormal signal intensity lesions involving predominantly the anterior horn cells appearing hypo/isointense on T1WI, hyperintense on T2WI, and demonstrating subtle enhancement are seen.
- Etiologies: Polio infection and vaccination; non-polio enteroviruses (Coxsackie EV 70 and EV 71); West Nile virus; and other vaccinations. Spinal cord infarction should be excluded before considering this diagnosis.
- In the current case, the patient had a normal CSF cytology and biochemistry. PCR was positive for adenovirus.
- Rx: Symptomatic pain and muscle spasm Rx, hemodynamic and ventilatory support.
- The actual mortality associated with spinal poliomyelitis is about 5%. Prognosis is variable (ranging from no recovery and lifelong sequelae to complete recovery), being somewhat better for non-polio enterovirus infections when compared to actual poliomyelitis. The greatest recovery is seen during the first 6 months.