State health officials alerted doctors after six Minnesota children were diagnosed with a rare, polio-like disorder that resulted in reduced mobility or paralysis of the arms and legs.

The six cases of acute flaccid myelitis (AM) have been reported since September 20, prompting the Minnesota Department of Health to ask doctors to monitor the disorder, which has serious but mysterious consequences.

"It's very rare and it's certainly something we take very seriously," said Kris Ehresmann, who heads the infectious diseases section of the Ministry of Health. "It's a very devastating situation" for children and their families, she said.

The disease attacks the nervous system via the spinal cord and can be transmitted by a virus. Symptoms usually include sudden weakness of the arms or legs and loss of muscle reflexes, but may also include droopy eyelids, slurred speech and difficulty swallowing. Treatment and therapy restore lost mobility in some children over time, but the syndrome can be fatal in those who lose muscle function to breathe.

James Hill, of Lakeville, said his son, Quinton, was suffering from cold symptoms early in the school week last month. At the end of the week, he vomited and stayed home. At the end of the week, his left arm and neck were stiff.

Because the disorder is rare – affecting less than a child in a million – the children's hospital doctors did not consider it initially, Hill said. They performed blood tests, imaging tests and lumbar puncture to reach a diagnosis.

"Super scary for us," he said. "We had never heard of it, no one had ever heard of it."

The AFM drew the attention of the US Centers for Disease Control and Prevention (CDC) in 2014 after the discovery of case groups in Colorado and California, related to the spread of a type of virus called EV- D68.

Since then, states have reported 362 cases, some of which were devoid of viruses and others that appeared to be linked to other West Nile viruses.

All six children in Minnesota, aged 10 and under, were hospitalized because of their conditions. They come from the twin cities of central Minnesota and northeastern Minnesota. Several parents have contacted the Star Tribune directly, hoping that media coverage would prompt parents to take precautions, as well as doctors and hospitals should identify the problem quickly when they encounter it.

Ms. Ehresmann said she hoped that further study of the children – and any other cases revealed by the latest alert to doctors – could reveal the causes.

"We are looking for something in common, but for now … we have nothing to conclude," she said.

The cases are not even verified by the results of the laboratory tests. Ehresmman said it was the "constellation of symptoms" that united them.

Mario Bros.

Orville, the son of 4-year-old Elaine Young, was perhaps the first case in the Minnesota cluster. Last July, he suffered from typical cold symptoms, which quickly gave way to leg immobility and paralysis of the upper right arm. Limited muscle activity in his diaphragm also limited his breathing, which may be a fatal complication of AFM.

Ms. Young said the doctors had diagnosed her fairly quickly – after initially dismissing a stroke – when she had taken Orville to the Masonic Children's Hospital of the University of Minnesota, where a neurologist had written an article on the AFM. But faced with one of the first cases in the Minnesota case, she had to know what to do by herself, she said, before going to Gillette Children's Specialty Services in St. Paul.

Physical rehabilitation, combined with electrical muscle stimulation over the past two months, has allowed Orville to regain 90% of the function of his legs. The upper half of his right arm remains motionless.

"It definitely affected me and his father a lot more, emotionally, at least, because we can see in his future," said Young. "When you're four years old … every time you wake up, it's a big change." So, losing the use of your arm? He said: "I can not do it anymore." very good hugs, but I do all my exercises! "

Orville still plays video games Donkey Kong and Mario Bros., his favorites because he uses his right wrist and his lower arm.

Hill found a cure for his son, even a week after hospitalization, with Gillette therapy. Unable to move the top of his left arm, Quinton trains him to reach Legos and build with both hands. The muscles on the left side of his face remain weak, making it difficult to smile, blink and swallow.

Both children risk a complication called subluxation or dislocation of their arms in sleep if they do not move them.

"Keep the left-handed involved with the right-hander," the therapists say to Quinton.

Three cases in 2014

Although it is the largest cluster to have been reported in Minnesota, this is not the first in the state. Minnesota had three cases in 2014 and only one case in recent years. Nationally, most cases were reported each year in September.

In addition to viruses, health officials suspect that the syndrome is linked to unknown genetic and environmental factors. Treatments include steroid-based drugs and immunoglobulin infusions to strengthen the child's immune system.

Most cases start with cold symptoms followed by loss of movement from one side of the body, and can be checked by imaging scans detecting the inflammation of a central part of the spinal cord, said Dr. Anu Kalaskar, infectious disease specialist at Children's. But the treatment varies from case to case and involves respiratory assistance for children who have trouble breathing.

The risk of transmission is low and can be further reduced by routine cold-prevention practices such as hand washing and coughing, she said.

The CDC is working with researchers to understand the AFM, to estimate the number of cases occurring before 2014 and to determine why the number of cases has increased significantly from this year.

Sophia, the daughter of 5-year-old Mehdi Ayouche, is still hospitalized at the Children's in Minneapolis. Chanhassen fears that the loss of mobility in her neck and right arm does not prevent her from doing the things she likes – from swimming and drawing to Tae Kwon Do. He hopes the therapy will help, and relieved that Sophia's twin brother and elder sister did not contract the syndrome, despite cold symptoms.

"We want to raise awareness," he said. "It's a rare condition. [When it occurs], people might not know what to do next. "