Yes, CMT causes atrophy. There are three types of atrophy: physiologic, pathologic, and neurogenic. Atrophy is defined as tissue wasting caused by an external factor that acts independently of the tissue that’s wasting. Whereas dystrophy, on the other hand, is defined as tissue wasting caused by something happening within the tissue itself.
First and foremost, CMT is not a disease of muscle tissue. Yes, CMT causes muscle tissue to waste. However, muscle tissue wastes in CMT as a consequence of the disease within the nerves that control the muscles. Because the muscle tissue wastes as a result of diseased nerves, the wasting is medically defined as atrophy (the nerves are separate from the muscles that are wasting). By comparison, muscular dystrophy gets its name from muscle wasting as a direct result of the muscles themselves being diseased. For these reasons, CMT is not a type of muscular dystrophy, despite the MDA including CMT within its wheelhouse, as it does ALS and many other non-MD diseases.
What is physiologic atrophy? Physiologic atrophy is atrophy caused by not using the muscle enough. CMT can often lead to a sedentary lifestyle. In turn, this often leads to physiologic muscle atrophy. Physiologic muscle atrophy is also quite common with surgery. Muscle tissue lost from physiologic atrophy can be recovered through proper exercise, physical therapy, post-op surgery recovery, etc.
What is pathologic atrophy? Pathologic atrophy is usually seen with aging and malnutrition/starvation. Muscle tissue lost from pathologic atrophy is typically recoverable with proper diet and nutrition, proper exercise, and becoming more physically active.
What is neurogenic atrophy? Neurogenic atrophy is muscle atrophy that occurs with injury to, or disease of, the nerve that controls the atrophied muscle. This is the type of atrophy caused by CMT, and unfortunately, it is not recoverable. People who have CMT can have muscle atrophy for many reasons, and not all muscle atrophy someone may be experiencing is caused by CMT.
Somebody who has CMT can experience physiologic atrophy and pathologic atrophy. In CMT, any muscle loss not caused by neurogenic atrophy is still recoverable. For this reason, proper exercise and remaining as active as possible are essential. Should a muscle experiencing physiologic atrophy be overtaken by neurogenic atrophy, the lost muscle tissue will not be recoverable. It’s critically important in CMT to give the muscles as much of an advantage as possible. Proper exercise and remaining as active as possible together provide this needed advantage.
