Yes, CMT can cause breathing problems. When it does, it’s a specific kind of respiratory impairment called CMT-induced neuromuscular respiratory muscle weakness. This type of impairment, which is not a disease of lung tissue, is caused by a weakening of the muscles used for breathing.
The muscles used for breathing, therefore, can become weakened as a consequence of CMT much in the same way as do the muscles of the lower legs. The question becomes focused on to what extent are these affects.
When CMT causes breathing problems, the cause is from the muscles used for breathing becoming weakened and impairing the ability to fully expand the chest with each breath, leading to a reduction in the ability to fully inflate the lungs. This is called hypoinflation. Because lung tissue is unaffected, oxygen levels will typically remain normal. CO2 levels, however, can become elevated, leading to a condition called hypercapnia.
CMT-induced neuromuscular respiratory muscle weakness is treated with non-invasive ventilation, or NiV for short. While this is a scary term, NiV is a small tabletop device that resembles a CPAP. CPAP (Continuous Positive Airway Pressure) and BiPap (Bi-Level Positive Airway Pressure) are common devices most have heard of. There’s a newer one called VPAP (Variable Positive Airway Pressure). These three devices are intended only to keep the airway open and nothing else. Individuals with CMT-induced neuromuscular respiratory muscle weakness, however, often require assistance with fully inflating their lungs. Conventional treatment, therefore, is insufficient. Instead, AVAPS is the therapy CMT experts prefer.
What is AVAPS? The conventional CPAP, BiPap, and VPAP therapies do not provide the type of therapy needed by somebody who has CMT-related respiratory impairment. Instead, what is needed, is a type of NiV device and technology called AVAPS. AVAPS stands for Average Volume Assured Pressure Support. AVAPS provides pressure support for keeping the airway open like CPAP, BiPap, and VPAP do, but then adds what’s called volume support. Volume support provides a volume of air with each breath that’s equal to the person’s tidal volume. Providing this measured volume of air with each breath helps the lungs to more fully inflate, thereby assisting the muscles used for breathing with doing their job.
