Country music star Alan Jackson announced his farewell tour, “Last Call: One More for the Road,” and promised to “give [fans] the best show I can,” Billboard Reports. The Grammy-winning musician went public about living — and acting — with a neurological condition called Charcot-Marie-Tooth disease in 2021, about a decade after being diagnosed. “There is no cure for this, but it has been affecting me for years. And it’s becoming more and more obvious,” Jackson told Today.
Here’s what you should know about Charcot-Marie-Tooth disease, or CMT, and how it can affect those, like Jackson, who have it.
What is CMT?
Charcot-Marie-Tooth disease is a genetic neurological condition that causes damage to the peripheral nerves that connect the spine and brain to the arms and legs, according to the Mayo clinic. “It’s genetic, I got it from my father,” Jackson explained during his appearance on 2021 Today. CMT is one of the most common inherited neurological conditions and affects about 1 in 2,500 people in the U.S., according to the Hereditary Neuropathy Foundation.
The nerve damage caused by CMT can result in muscle shrinkage and weakness, especially in the ankles and feet. Some patients eventually also develop hand weakness, although this is less common. Dr John Kincaid, a neurologist at the Indiana University School of Medicine who specializes in the disease, told Yahoo Life. Although some nerve damage, or neuropathycan cause pain or loss of sensation, these problems are “very secondary” to the muscle weakness in CMT and most people do not experience them.
How do people develop CMT?
The condition is hereditary, so people are born with one or more genetic mutations that cause CMT. But symptoms may not appear until someone is over 20 years old. Some patients don’t know they have the disease until they are 50, says Kincaid. Others may begin showing symptoms during adolescence.
What are the symptoms?
Weakness is the most common symptom of CMT. Specifically, signs of ankle weakness and instability tend to appear first, along with weakness in the feet and legs. Someone with CMT may notice symptoms while “standing still, in a crowd, or in a checkout line, where the person has to maintain balance without holding on to anything,” says Kincaid. Or they could easily trip and have “curb problems,” he adds. Doctors diagnose the disease with electromyography to measure the activity of the muscles and nerves that control them. This is usually followed by a genetic test.
One possible early warning sign is an “abnormally high arched foot,” explains Kincaid. A doctor may suspect the condition if a teenager is experiencing ankle weakness and both the teenager and one of the teenager’s parents have the same abnormally high arch. But to be clear, “not every foot with a high arch is due to CMT” and a high arch does not occur in every patient who has the condition, he says.
Some people with CMT may have some loss of sensation in their hands, feet, and legs, but “most patients don’t have a major pain component,” says Kincaid. “There is no tingling, tingling or numbness in the burning, burning feet.”
Does it get worse with age?
CMT tends to progress with age. But it typically moves slowly, according to Kincaid. Most people will develop mobility difficulties such as unsteadiness when standing, he says, but it may be 10 to 30 years after onset before they will need assistive devices such as ankle braces, canes or walkers, also known as walkers.
Jackson said little about his specific symptoms. But some patients develop hand weakness, for which there aren’t many assistive devices, Kincaid notes. If the disease affected Jackson’s hands, “it’s likely he would have some problems playing the guitar, strumming frets, and plucking strings,” explains Kincaid. Even though the CMT weakness is isolated to Jackson’s ankles and feet, “just standing on stage and walking on stage — that can be a big problem,” he says.
On the positive side, Kincaid points out that it’s very rare for CMT patients to lose enough mobility to need wheelchairs; for most, ankle bracelets or perhaps a cane provide sufficient support.
Are there treatments?
There is currently no cure or treatment for the genetic disease. “But research suggests that we will soon have a potential, true genetic treatment”—that is, a gene therapy to correct the mutation that causes CMT—“for the most common type,” says Kincaid.
