It starts with everyday cold or flu-like symptoms that appear to go away. Soon after, however, harsher symptoms of acute flaccid myelitis show up with a vengeance. Right now, the seasonal illness is more prevalent than in previous years.
AFM causes severe muscle weakness or paralysis, primarily in the arms and legs. Other muscle groups can be affected as well, with some patients requiring ventilators as their breathing muscles fail. Although some kids recover completely, most face many months of therapy to hopefully overcome disabilities.
In acute flaccid myelitis, acute refers to the sudden onset of dramatic symptoms. Flaccid describes a complete loss of muscle tone and a reduced or total lack of reflexes in the limbs. Myelitis means inflammation of the spinal cord.
In 2018 so far, 62 confirmed cases of acute flaccid myelitis have occurred in 22 states, according to the latest Centers for Disease Control and Prevention figures released Monday. Overall, the CDC has received 155 reports of patients under investigation for possible AFM.
The average age for AFM patients is about 4 years old, with more than 90 percent of cases among children ages 18 or younger, according to a Tuesday, Oct. 16, press briefing with Dr. Nancy Messonnier, director of CDC’s National Center for Immunization and Respiratory Diseases. However, adults can also acquire AFM. The one known death, involving a child, occurred in 2017.
“CDC recently received increased reports for patients suspected to have AFM with an onset of symptoms in August and September,” Messonnier said. By using “enhanced efforts” in working with state and local health departments and hospitals, the CDC was able to confirm some cases more quickly, she said.
Aodhan O’Connor has been through a lot in his 3 1/2 years. “My son was 17 months and 2 days old when he woke unable to sit or walk,” says Amy O’Connor, his mother. “He had been walking since he was 10 months old.”
The O’Connors live in Bishop’s Stortford, England, although Amy comes from Maine. They first encountered acute flaccid myelitis on Oct. 14, 2016.
“He had had a cold and was quite testy,” with a low-grade fever, Amy says. However, Aodhan seemed to have recovered, so she and her husband, Jerry, took him to visit friends. “We got out of the car and put him down, and he had trouble walking,” she recalls. When his parents asked Aodhan if his leg was asleep, he said his foot hurt.
Initially, his doctor dismissed their concerns as first-time parents overreacting. But clearly, something wasn’t right. “He was waking up at night screaming,” Amy says. “He couldn’t move his legs and there were tingles. He was trying to roll over in his cot but his legs were staying where they were.”
When they next dropped Aodhan off at his day care, they received a text message image from his care provider showing his face with cheeks flushed bright red. They immediately tried but weren’t able to get a doctor’s appointment.
That night, Aodhan uncharacteristically asked to go to bed. He walked upstairs and climbed in the bathtub, while his parents read him stories. “That was the last time he walked normally,” Amy says.
The next morning, their son couldn’t even stand or hold his weight. “His legs were just jelly,” Amy says. “Every time we tried to put him down, he just kept falling. His legs kept collapsing.”
Jerry insisted that Aodhan be seen at the children’s ward at the local hospital, where he was admitted. After blood tests, an X-ray and further monitoring, Aodhan was discharged home. He didn’t get better.
A new round of testing included an MRI and a spinal tap. Aodhan’s spinal fluid was filled mostly with virus plus some bacteria, Amy says. He was moved to a private room and given stronger antibiotics. Further testing finally confirmed acute flaccid myelitis.
Rare but Scary
Less than one in a million U.S. kids is diagnosed with the infectious condition. It’s not the same as polio, which an effective vaccine eliminated in the U.S. several decades ago. Different viruses are suspected, with scientists working to identify precise causes.
Although it’s a rare condition, parents are understandably concerned.
Dr. Keith Van Haren, an assistant professor and child neurologist at the Stanford University School of Medicine, led a study of AFM cases in California, which linked acute flaccid myelitis with enterovirus D68. However, other viruses have also been implicated.
“The enterovirus species in the U.S. seem to circulate in the late summer, early fall,” Van Haren says. “Why they seem to peak only some years and not others is mysterious to everyone.” The available data suggest that mutations in enteroviruses are making them more dangerous, he says. “What we don’t have right now is an obviously effective treatment or even preventive strategy.”
With these sporadic outbreaks, it isn’t clear whether certain kids are at higher risk, says Dr. Gail Harrison, a pediatric infectious disease doctor, clinical virologist and professor of pediatrics at Baylor College of Medicine and Texas Children’s Hospital.
“Acute flaccid myelitis can attack children who have altered immune systems, children with normal immune systems and children who are fully vaccinated,” Harrison says. “So it’s sort of an equal-opportunity disease in that regard.”
Doctors are currently using treatments such as intravenous immunoglobulin and steroids to calm the immune system. Supportive care in the hospital includes careful monitoring, Harrison says, not only for limb paralysis but also for whether the patient’s diaphragm is involved. Patients who could stop breathing are placed on a ventilator and watched in the intensive care unit. Once the acute crisis is over, the long rehabilitation journey begins.
In Aodhan’s case, the exact viral cause was never determined. He was sent home on steroid treatments, from which he was gradually weaned.
A few months later, Aodhan showed signs of progress, first sitting and eventually crawling. Next, he began kneeling and rising from his knees. “He started pulling up so we gave him things to pull up on,” Amy says. “At one point, he was in the doorframe bouncy chairs.” Although he tried to walk, he had trouble planting his feet.
By March 2017, Aodhan was taking steps again. “They weren’t pretty, but he was doing it,” Amy says. Last year, the family flew to the U.S. and took Aodhan to the Kennedy Krieger Institute in Baltimore for further evaluation.
No single, unifying cause has been identified for the majority of AFM cases. Viruses, environmental toxins and conditions all contribute, Messonnier said. For an AFM diagnosis, cases meet several criteria. Illness with acute flaccid limb weakness is the first. Confirming laboratory evidence consists of an MRI showing a spinal cord lesion, mostly restricted to the gray matter and spanning one or more spinal segments. For probable cases, spinal tap fluid with an elevated white blood cell count is supportive lab evidence, according to CDC case definitions.
Enterovirus has been detected in several individual cases, Messonnier said, as has rhinovirus. “There’s sort of a long list of other agents that we have found in one or two (cases),” she added. Enteroviruses are commonly found in the digestive and upper respiratory tracts. Rhinoviruses cause the common cold, sinus infections and other illnesses.
Perspective for Parents
Acute flaccid myelitis is extremely rare, experts emphasize, even with the current uptick. “Overall, since we have started detecting the increases in 2014, there have been 386 cases,” Messonnier told reporters.
“We recommend seeking medical care right away if you or your child develop sudden weakness of the arms or legs,” Messonnier added. “As we work better to understand what is causing AFM, parents can help protect their children from serious diseases by following prevention steps like washing their hands, staying up to date on recommended immunizations and using insect repellent.”
As Harrison explains, “There’s not a cause for alarm, but parents should be aware. It’s a rare complication of a probably viral infection. As with any time your child is ill, if they don’t recover as expected — or if they recover and start to get sick again — that’s a red flag that something might be going on, and parents should of course call their pediatrician.”
Staying on the Move
Now, Aodhan attends preschool and will start regular school next September. He continues to have right-sided foot drop and wears braces to help him walk.
Aodhan receives physical therapy and regularly does fun activities like going to the pool and pony riding. He is using a scooter and learning to ride a bike. “Anything we can do to keep him moving,” Amy says.
Challenges continue. “The first couple of times we went to the playground that first summer, we were seeing kids go the other way, or parents taking their kids the other way from him,” Amy said. “He’s not fragile. He’s curious; he’s a child. It’s so much better to ask than to avoid. It’s about inclusion and treating them as children. It’s giving them the opportunity to be involved and engaged.
Amy encourages families in similar situations to maintain hope and insist on exploring new treatments. Her message is this: “Persevere. Keep going — keep advocating.”
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