John Driskell Hopkins, the bassist and founding member of country music's Zac Brown Band, revealed that he was diagnosed with the neurological disease amyotrophic lateral sclerosis, or ALS.
"I've noticed some balance issues and some stiffness in my hands. After careful analysis by some of the country's top neurologists, I've been diagnosed with ALS," the 51-year-old country music star said in a YouTube video posted over the weekend.
ALS, also known as Lou Gehrig's disease, is relatively rare, affecting approximately 20,000 people each year, ABC News Medical Contributor Dr. Darien Sutton explained on "Good Morning America" Monday morning.
At the core of this diagnosis is muscle weakness, as it causes the messaging system that connects the brain and muscles to degenerate, Dr. Sutton said. Symptoms also include muscle wasting and difficulty speaking, swallowing or breathing.
Hopkins said his symptoms are progressing slowly, and it's common for ALS to worsen gradually.
"God willing, I plan to be rocking with these amazing people for many years to come," he said in the YouTube video.
Although a small percentage of people diagnosed have a genetic predisposition for developing this disease, ALS has no known risk factors for the majority of cases, Dr. Sutton said.
While there is no cure for ALS, treatments can assist with symptoms and help prolong survival. In light of his diagnosis, Hopkins created Hop On A Cure, which is "committed to supporting research to prevent, reverse and cure ALS while raising awareness."
The eight-member Zac Brown Band, one of the most popular country music bands in the U.S., began touring in 2004 and is known for hits like "Chicken Fried," "Highway 20 Ride" and "Toes." The band is touring throughout the country this summer.