Mystery Paralysis in Kids
More than a hundred children in the US -- and at least six in Canada -- have developed a mysterious form of paralysis. Health officials are trying to determine if it could be related to Enterovirus D68 which has hospitalized hundreds of kids in North America.
Experts call the condition acute flaccid myelitis because the onset is sudden (usually over one to three days) and because the limbs affected become markedly weak or flaccid. The paralysis can be full or partial. Some have lost the use of an arm, a leg, or more. Others have had paralysis of the breathing muscles and have required a ventilator to help them breathe. The kids range in age between one year and eighteen years of age. Imagine being a child or the parent of a child affected. Most of the kids have abnormal MRI scans of the spine showing inflammation of the grey matter of the spinal cord. That's the place where the nerve cells that allow us to use our muscles reside.
Late last month, the US Centers for Disease Control reported 51 confirmed cases of this polio-like syndrome. The reports date back to August, and have occurred in nineteen states. That number is undoubtedly an underestimate. According to an article in The Atlantic, the moderator of a special session of the Child Neurology Society asked the 250 or so child neurologists in the audience how many had seen a recent case. One third of them raised their hands, and several dozen said they had seen two to five cases or more. By that rough estimate, the more than a hundred actual cases is likely an underestimate.
We're talking about at least six cases here in Canada. A pediatric neurologist at McMaster Children's Hospital in Hamilton told a reporter he saw four kids with paralysis over a two week period. Two cases have also been reported in British Columbia, four in Calgary and three at Toronto's Hospital for Sick Children. The pediatric neurologist at McMaster told the Globe and Mail that the hospital usually sees four to six cases of sudden muscle weakness in a year (not two weeks). But those cases are usually due to a different neurological condition called Guillain-Barré Syndrome which is a disorder in which the body's immune system attacks not the spinal cord but the nerves that connect to the spinal cord. It causes weakness or tingling sensations in the legs, and is also known as ascending paralysis because of its predilection to start in the legs and work its way upward.
The cause is unknown. In the last month or so, the CDC began asking doctors and health officials to compile detailed reports of children affected. Some but not all doctors believe the paralysis is a complication of Enterovirus D68 - the virus identified as the cause of a respiratory illness that affects mainly kids - one that has caused outbreaks in forty-seven states. The number of laboratory confirmed cases in the US is more than a thousand, and in Canada one hundred and fifty. Those are cases that meet strict definitions; the actual number is likely to be considerably higher. But the link is inconsistent. In BC, both of the two kids with acute flaccid paralysis tested positive for the enterovirus but not so all of the kids affected in Hamilton. And, there are lots of children infected with EV-D68 who do not develop paralysis.
As one doctor who attended the meeting of the Child Neurology Society said, "The bottom line is that right now we don't have an effective treatment." That's why the doctors met and are working with CDC researchers: to develop treatment guidelines. For a neurological disease that causes paralysis, it's too soon to give an exact prognosis. So far, some kids have had mild to moderate recovery of muscle strength. Very few doctors have seen a complete recovery. Because there is no effective treatment, doctors at the CDC recommend taking precautions to prevent the spread of EV-D68 -- things like washing hands before touching food and after going to the bathroom, blowing your nose, changing a baby's diaper and before and after taking care of a sick person or dressing a cut or a wound.
The best thing they can say about the condition is that it remains very rare.