National news reports in 2018 were peppered with stories of young children who were seemingly fighting a cold one day, then paralyzed the next. One of a handful of centers with experience treating children with this polio-like condition, acute flaccid myelitis (AFM), is the International Center for Spinal Cord Injury (SCI) program shared by the Johns Hopkins Department of Physical Medicine and Rehabilitation and the Kennedy Krieger Institute, which specializes in pediatric developmental disabilities and disorders of the brain, spinal cord and musculoskeletal system.

“As of now, rehabilitation is the only known intervention that helps children with AFM,” says Cristina Sadowsky, clinical director of the SCI program. “Early, intensive rehabilitation is essential for day-to-day function for children to be able to get dressed, go to school and perform activities of daily living.”

AFM is a rare condition that affects motor neurons in the spinal cord, resulting in a sudden onset of limb weakness and loss of muscle tone and reflexes, explains Sadowsky.Children around age 4 are most often affected, some with symptoms such as facial weakness, difficulty swallowing or slurred speech. The cause is unknown, though it is thought to be brought on by a virus. 

Children with AFM seen on an inpatient or outpatient basis in the SCI program typically receive up to six hours of speech, physical and occupational therapy per day targeted to neurologic deficits. Therapists employ a range of modalities, including functional electrical stimulation to generate movement in paralyzed muscles, aqua therapy and walking while holding on to parallel bars. The unit has seven different methods to promote gait training, including robotic technology and an underwater treadmill. In this pediatric environment, most activities are designed to look like play.

“We know that activity helps with restoration of function in the nervous system,” says Sadowsky, who is also a clinical researcher in spinal cord injury and paralysis restoration. “Synaptic formation and connection between nerves, and new cell birth in the nervous system, are all dependent on activity.”

Unlike traditional rehabilitation in which individuals may learn compensatory motor patterns to complete motor skills such as dressing and feeding, she says, the therapy used in the SCI unit—activity-based restorative therapy for individuals with spinal cord disease-related paralysis, including AFM—involves trying to reproduce the “normal” motor patterns used before the illness. And “it can take hundreds or thousands of repetitions to relearn,” she cautions.

AFM tends to come in biennial cycles, Sadowsky says, with about 120 cases nationwide reported in 2014, 149 in 2016 and 210 in 2018. Johns Hopkins and Kennedy Krieger have seen children with AFM-like disease since 2006. Beyond providing rehabilitation, SCI program experts are performing nerve transfers in some cases to help restore muscle movement, studying genetics of the condition, and participating in a national AFM work group established in October 2018 and led by Johns Hopkins physicians.