A rare "polio-like syndrome" has caused paralysis in about 20 children from across California, according to a report released Sunday by physicians in the San Francisco Bay Area.
The children, who are between the ages of 3 and 12, developed what is called acute, or sudden, flaccid paralysis -- weakness or loss of muscle tone resulting from injury or disease of the nerves that stimulate muscles to move.
Although polio has been wiped out across most of the globe, other viruses can injure the spine, causing paralysis, said Dr. Keith Van Haren, author of the case report and a pediatric neurologist at Lucile Packard Children's Hospital, at Stanford University. The children who have been affected seem to have been permanently paralyzed, he said.
Van Haren said these cases suggest there is a possibility of a new infectious polio-like syndrome in California.
The illness is not polio. All the victims had been immunized against polio and tested negative for the presence of the disease, Van Haren explained. And the disease is rare. "It's not an epidemic," he said. "But it is something that is concerning."
The culprit could be a virus strain called enterovirus-68 that has been linked to polio-like outbreaks in children in Asia and Australia, Van Haren said. But not all of the victims tested positive for that virus, so the cause of the disease is still unclear.
Some of the children had respiratory or other illnesses before developing muscle paralysis, but for others muscle weakness was the first symptom.
Van Haren said some victims suddenly developed weakness of one or more limbs within about 48 hours of becoming sick. MRI scans showed worrisome changes in the gray matter of the spinal cord.
To help them more effectively fight the disease, the children were given steroids, intravenous immunoglobulin and or blood plasma exchange -- without improvement, according to the authors of the case report.