About 20 cases of a polio-like syndrome have been found in California children since 2012, causing severe weakness or paralysis in one or more limbs—and physicians and public health officials are still scratching their heads trying to determine what exactly is ailing them.

Dr. Keith Van Haren, a pediatric neurologist at Stanford University's Lucile Packard Children's Hospital, is part of the team investigating the illness. He says it’s not polio, as those affected had been vaccinated against the disease. He will present the cases of five impacted children at the American Academy of Neurology's upcoming annual meeting.

Scans of patients spinal cords showed damage patterns similar to those found in polio sufferers.  Several of the children have tested positive for enterovirus-68, a virus that is usually associated with respiratory illness but has also been linked to polio-like illnesses. The children, whose average age is 12, have not recovered mobility of their paralyzed limbs.

Polio is a vaccine-preventable illness that has disappeared from much of the world—including the United States—but it continues to affect people living in developing countries. The 18 cases of polio reported so far this year were in southeastern Afghanistan and northwestern Pakistan, according to the Council on Foreign Relations.

Those investigating the California illness are urging physicians to report new cases of acute paralysis as they work to determine a cause.

For more resources and contact information you can visit the Los Angeles County Department of Public Health website.

Guest: 
Dr. Keith Van Haren, a pediatric neurologist at Stanford University. He and his fellow researchers will present findings of these infections at the American Academy of Neurology’s annual meeting in Philadelphia next month.

Dr. Thomas Mack, Professor of Preventive Medicine and Pathology at the Keck School of Medicine, USC