A Washington University surgeon has pioneered a technique to attempt to restore some function in the legs of children paralyzed by a virus that attacks their spinal cord.
Dr. Amy Moore is the first to perform nerve transfer surgeries on the legs of children with acute flaccid myelitis, a rare polio-like condition that causes muscle weakness and paralysis, and has captured the attention of federal health investigators and the media.
Since June 2017, 10 children have traveled from out-of-state to St. Louis for the procedure. The oldest was 11.
“This is a devastating disease process where these children are normal, healthy, running around and then get a virus and it knocks out their spinal cord,” Moore said.
A handful of surgeons across the country have tried nerve transfers on children’s paralyzed arms, but Moore is the first to apply the same principles to the lower body. The surgeon has extensive conversations with families before they make the trip. She tells them she has little evidence that the procedure will work, but the theories are solid.
“It just takes one person to think, ‘Is this possible?’ and take the risk with the families,” Moore said of her work.
There have been 155 confirmed and suspected cases of acute flaccid myelitis in U.S. children this year, including at least two in the St. Louis area. Cases of AFM first spiked in 2014, when there were 120 cases. There were 22 cases in 2015, 149 in 2016 and 33 last year.
Researchers have not found a common cause for AFM, but the most likely culprit is a type of enterovirus, a cousin to the polio virus that in most people only causes mild cold symptoms.
Children with AFM experience weakness in their arms or legs, and some require ventilators to breathe. Most can improve over time with physical therapy, but doctors are still searching for more effective treatments.
Moore has been performing nerve transfers on people with traumatic injuries for years by taking a working nerve from another part of the body and rewiring it to activate a paralyzed muscle.
For children with AFM, Moore typically transfers working nerves from the child’s toes to the damaged hip, hamstring or quadriceps muscles to stimulate the muscle again to stabilize the hip, bend the knee or strengthen the leg.
Nerves grow at a millimeter a day, so progress is slow, but Moore said the first children to undergo the surgeries are “recovering function that they didn’t have preoperatively. They are able to stand or bend their leg where before they were completely paralyzed. It’s very subtle and we don’t expect them to be normal . but it gives them more than they would otherwise have.”
Sophia Gary of Orlando, Florida, was diagnosed with AFM in 2016 when she was 2.
“She started out with a cold, and then she just woke up and said ‘Mommy, I can’t walk,’ “ said her mother, Amanda Gary.
When physical therapy failed to garner much improvement in her weakened right leg, Sophia’s parents searched for other options.
“We came across this surgeon in St. Louis. She was taking a leap of faith and trying these nerve transfers in the legs,” Gary said.
In January, Moore transferred nerves from Sophia’s abdomen to two of her quadricep muscles and grafted another nerve like an “extension cord” to the muscles. Since the surgery in January, Sophia, now 4, has muscle twitches but still can’t bear weight on her leg or walk without a brace, her mother said.
Moore said she expects to see continued improvement in Sophia for two years after the surgery.