Guillain-Barre syndrome had 3-year-old son of Dodgers’ Freddie Freeman 'in full-body paralysis.' How does that happen?

Freddie Freeman's toddler Max Freeman is back home after spending eight days in the pediatric intensive care unit battling Guillain-Barre syndrome, a rare life-threatening form of paralysis. “Max still has a long road ahead of him to regain his strength and relearn how to walk. But we are so thankful to have our family back together,” Freddie, first baseman for the Los Angeles Dodgers, and his wife, Chelsea, posted on Instagram Sunday.

Max developed a limp on July 22 and by the end of the day he was unable to walk, Freddie told the Los Angeles Times. Several doctors believed Max had transient synovitis, a more common condition involving inflammation that can affect the hip and ability to walk following a viral infection. The Freemans were told to give him Tylenol and sent home. But within two days, Max could no longer sit up and had stopped eating and drinking. On July 26, Chelsea took Max to a pediatrician, who told her she needed to take her son to the hospital immediately. The paralysis had progressed to Max's diaphragm and "they didn’t think he was going to be able to breathe that long," Freddie told the Los Angeles Times.

Max “rapidly declined and went into full-body paralysis,” wrote Chelsea in an Aug. 2 post. The 3-year-old spent several days on a ventilator to support his lung function. The hardest part for Freddie was "my 3-year-old son needing help to breathe, when five days earlier, he was doing front flips,” the veteran Dodger told the L.A. Times. “You just wish you could switch." After eight days in the ICU, Max's condition improved enough to have his breathing tube removed, "and within six minutes, he was sitting on me," Freddie added. On Saturday, Max was cleared to go home, but he will need to "relearn how to do pretty much everything," said Freddie.

Guillain-Barre is rare, especially among children, but it can afflict anyone. The good news is that in most cases — including Max’s — people recover. So how can someone become suddenly paralyzed by this disorder and then regain their function? Here’s what to know.

What is Guillain-Barre syndrome?

Guillain-Barre is an autoimmune disease, meaning that it occurs when the immune system attacks healthy tissues, according to the Centers for Disease Control and Prevention. In the case of Guillain-Barre syndrome (GBS), these attacks are waged on peripheral nerves (those found outside the brain and spinal column), damaging the protective coating around them which in turn confuses or blocks the signals between the brain and the body. Interference with this communication causes muscle weakness and paralysis.

What causes GBS?

There isn’t a single cause, but scientists believe that the majority of cases happen after people have been sick with viral or bacterial infections which, scientists believe, trigger GBS. “The body delivers antibodies to that infection, but the antibodies can't distinguish the virus [or bacteria] and start attacking part of the nervous system,” Dr. Aarti Sarwal, chief of neurocritical care at Virginia Commonwealth University, tells Yahoo Life.

The illness most closely linked to GBS is a campylobacter infection, a gastrointestinal illness that’s typically acquired from undercooked poultry, according to the Mayo Clinic. But “any sort of infectious process can trigger an abnormal immune response,” Dr. Kunal Desai, a specialist in neuromuscular medicine at Yale University tells Yahoo Life. That includes the flu, COVID-19 and hepatitis A, B, C or E. Symptoms usually appear between two and four weeks after an illness.

Who gets GBS?

Only one or two out of every 100,000 people in the U.S. develop Guillain-Barre syndrome in a given year, according to the CDC. The primary risk factor is a recent bacterial or viral infection, regardless of someone’s age, sex, race or ethnicity. Apart from campylobacter, one illness is not more likely to trigger BGS than another, although, Sarwal notes, patterns vary regionally based on what types of infections are most common in a given place.

The disorder more frequently affects adult males than females, with risks rising as people age, according to the World Health Organization. But the disorder can strike anyone, including toddlers like Max Freeman.

What are the first warning signs?

Paralysis from GBS can progress quickly, experts warn, but it usually begins with numbness, weakness or tingling in the furthest extremities. “It’s almost like a glove,” explains Sarwal. “It progresses from the tips of the fingertips to the arms and shoulders and marches toward the body,” or from the toes up the legs, she says. Muscle weakness gives way to paralysis, which tends to progress symmetrically, throughout both sides of the body. However, there are many different subtypes of GBS, so symptoms can vary; for some, the first signs are vision changes or trouble keeping their balance.

How is GBS treated?

Because the disorder can cause the lungs to stop functioning, it’s critical to get to a doctor immediately if you notice progressively worsening weakness or tingling — whether or not you remember having been sick recently (you can be asymptomatic during many infections, as became abundantly clear amid the COVID pandemic).

Most of the care GBS patients get is supportive, but infusions of immunoglobulin, a type of immunotherapy, are often used to help normalize the immune system’s behavior, Sarwal explains. If that doesn’t help, patients may choose to undergo a procedure called plasmapheresis, in which the “blood is cleaned of the [off-target] antibodies,” Sarwal says. These treatments are done in hospitals, where — importantly — ventilators like the one Max Freeman was put on are available to support the respiratory during recovery, if the lungs or throat should become paralyzed.

Is the disorder life-threatening or permanent?

Guillain-Barr can certainly be life-threatening, although most people make a full or nearly full recovery, according to the Mayo Clinic. The condition becomes dangerous if the paralysis spreads to the lungs and muscles that control swallowing. Between 20% and 30% of all patients diagnosed with Guillain-Barre syndrome reach this precarious stage and have to be put on mechanical ventilators in an ICU to ensure they continue to get enough oxygen.

Severe cases can result in permanent paralysis, the WHO says, but they’re by far in the minority. The American Brain Foundation estimates that about 30% of people will still experience some weakness after three years from their initial diagnosis, and 15% have long-term weakness.

The good news, per ABF, is that 70% of people make a full recovery. But, as the Freemans put it, it’s a long road. Depending on what muscles were affected, patients may need physical therapy to recover their strength, and may require occupational or speech therapy, if their hand or foot dexterity, or facial or throat muscles, are affected, Desai says. “Recovery can take weeks to months, including up to 12 or 24 months in rare cases,” he adds.

Vaccines and GBS

There’s some debate about whether the immune response that vaccines are designed to prompt can trigger GBS. According to the CDC, people are more likely to develop Guillain-Barre after having influenza than after the vaccine against it, suggesting that a flu shot can reduce risks of both getting an infection and GBS. Sarwal — an expert in Guillain-Barre — calls the suggested link between the syndrome and vaccines an “urban myth." Desai, who has also published multiple papers on GBS, says that “anything that can trigger the immune system can trigger this abnormal response, [but] it’s exceedingly rare," but emphasizes that it's critical for everyone to get their recommended shots, as the risks posed by infections outweigh the risk of GBS, which is more likely to be triggered by viral illness than immunization.