September 15, 2003
By Deborah Mitchell
The first reported case of human coronavirus associated with acute disseminated encephalomyelitis (ADEM) was reported by researchers at the 43rd annual Interscience Conference on Antimicrobial Agents and Chemotherapy here on Sunday, providing further support for the hypothesis that human coronavirus plays a role in the pathogenesis in demyelinating disease in humans.
Dr. Arlene Collins and colleagues at the State University of New York at Buffalo described the case of a 15-year-old boy with presumed ADEM who had human coronavirus OC43 detected in the CSF and nasopharyngeal specimens. The boy also had a four-fold increase in antibody titer.
ADEM, a simple episode of demyelinating disease of the CNS, mostly affects children and adolescents.
The previously healthy patient presented to the Women's and Children's hospital in Buffalo in January of this year after a 5-day history of numbness, which started in the lower legs and progressed to the umbilicus. About 1 day before admission, he had difficulty walking. No visual changes, seizure, headache, mental status alterations or speech or language difficulties were noted. There was also no bowel or bladder dysfunction or history of toxin ingestion.
Approximately 1 week before the symptoms began, the patient had an upper respiratory infection. In addition, his brother had a sore throat 1 to 2 weeks earlier.
The results of MRI conducted the day after admission revealed lesions in the white matter tracts in the cerebral cortex, the left cerebellum and the spinal cord.
The boy's symptoms resolved without therapeutic intervention over the course of several weeks.
ADEM is "characterized by high signal-intensity lesions in the white matter of the brain and spinal cord on MRI," Dr. Collin's group writes in their conference summary. The lesion can be independent of clinical findings and the majority of cases have no associated infectious agent.
Coronavirus are RNA viruses, with outbreaks that tend to occur in the winter and spring and preferentially affect children, they note. The viruses are not easily cultured and therefore difficult to diagnose.
The cause of ADEM is most likely multifactorial, the researchers conclude,
with environmental and genetic factors both playing a role. However, they
speculate that human coronavirus may be an important etiologic factor in
human demyelinating disease.
Copyright © 2003, Reuters Ltd