CMT, COVID-19, and Respiratory Health

Are people with CMT at greater risk of dying from coronavirus? Maybe, maybe not. As a group, people with a “rare disease” are assumed to have some degree of heightened risk, but whether that risk is a a lot or a little can vary widely from person to person.

With the Coronavirus, the main threat is to your respiratory system. Everyone weakens in their ability to use and clear their lungs fully after reaching their twenties — slow but steady respiratory decline is a part of aging. The virus kills by causing lungs to fill with fluid, and then pneumonia sets in. This can happen to anyone, and anyone with diminished respiratory strength is at a disadvantage, which is often older people — but by no means are they the exclusive or even majority group to contract the virus and die from its effects.

That said, if you diagnosed respiratory problems along with CMT, you may be considered high risk for COVID-19. If you get it, it may take you longer to recover and increase the progression of your CMT. If you were to become very ill with Coronoavirus or a similar illness leading to pneumonia, intubation (a trach tube) should not be rushed into or done without doctors knowing you have a neuromuscular disease (NMD). Extubating and returning patients to breathing on their own requires special care in the case of a NMD.

Respiratory Health and Neuromuscular Disease

A few weekends ago, I listened to the HNF webinar on COVID-19 and CMT with Dr. John Bach of Rutgers University Medical School, a leader in the field of pulmonary rehabilitation, particularly for people with neuromuscular diseases. You can watch it and get a bunch of other materials now — for free — thanks to the HNF.

Since the outbreak of the coronavirus and growing awareness of the prevalence of respiratory problems among people with CMT, there has been a lot of interest in the CMT community about their potentially greater risk of dying from the virus. To help answer questions and support CMTers, the HNF got hold of Dr. Bach.

Dr. Bach is quite a character who offered many off the cuff remarks and humorous asides, but the things he had to say in his direct area of expertise were serious and very helpful. While he is not an expert in CMT, his presentation educated me about the respiratory system and breathing in ways that are relevant to things I’ve been learning about CMT, sleep apnea, and assistive breathing devices that are commonly used for sleep apnea.

Respiratory decline is a fact of life for most CMTers, some far more than others, but most of us are not too much worse off than people without CMT. From age 19 on, we all lose 1% or more each year in our vital capacity to take deep breaths and cough strongly. That vital capacity matters when you’re fighting a cold or the flu, and it underscores how important breathing and aerobic exercises are for everyone.

COVID-19 kills people by attacking the lungs and eliciting an immune response that causes pneumonia.

COVID-19 kills people by attacking the lungs and eliciting an immune response that causes pneumonia. The lungs get filled with dead cellular gunk produced by the lymphatic system as it tries to fight the virus, and this can lead to bacterial pneumonia where that gunk is infecting your bloodstream. If your lungs and breathing are already strained from CMT or anything else, coping with this situation is all the more difficult.

Should you be worried? Probably not, if your respiratory capacities are not especially impaired — something that’s hard to miss and easily tested. Dr. Bach says ask yourself if you can hold your breath 10-20 seconds. If so, good, you’re not short of breath. Dr. Bach also pointed out that oximeters are cheap devices anyone can get to monitor their blood oxygen levels. If you have concerns about your respiratory capacity and you get a cold, you can monitor your oxygen levels. If you get cold symptoms and become worried about COVID, you don’t need to go to an ER if you’re not having problems breathing and your bloodstream is oxygenated. Even if you have walking pneumonia, you can deal with it if your breathing is normal. And even if you were to develop real breathing problems, the idea that you will absolutely need a ventilator at a hospital to survive is a really unhelpful, fear-based myth.

If you do have limited lung capacity from CMT and find yourself short of breath, you should be sure any doctor or hospital staff you see know you have a neuromuscular disease impacting your diaphragm and your ability to expel carbon dioxide. If you were to stop breathing, knowing this will help doctors and nurses know to be prepared to intubate you if you stop breathing. No oxygen should be given without ventilation to people who can’t clear their lungs properly on their own otherwise they’ll get hypercapnia.

Dr. Bach has written seven books on breathing problems associated with different respiratory diseases. He literally wrote the book on pulmonary rehabilitation, which is his career specialty. In Bach’s view, ventilators and supportive breathing devices are generally unnecessary and harmful for people with neuromuscular diseases who are otherwise healthy.

Training and maintaining full lung volume recruitment so as not to lose it is an important, potentially lifesaving skill for people with respiratory ailments, and that really goes for all of us as we age.

If you get sick from COVID or anything else and your lungs fill with fluid because you can’t cough well enough to expel secretions from lungs, oxygen isn’t going to help you until your lungs are cleared. A worst case scenario with hospital care gone wrong is when someone has trouble breathing and gets trached and put onto a ventillator, which may not inflate more than one lung. Intubating and then extubating people to BiPap machines is invasive and traumatic — some people will not survive it. If their problem is respiratory weakness and a weak cough, a device called the Cough Assist can be used to provide continuous positive and negative pressure. (A peak flow meter is used to determine cough strength.) This helps clear the lungs and train them to do their job again. Ventilation, on the other hand, teaches the body it doesn’t need to breathe on its own. It’s not a panacea, it’s a last resort. The first and second resort is staying strong and out of hospitals.

Training and maintaining full lung volume recruitment so as not to lose it is an important, potentially lifesaving skill for people with respiratory ailments, and that really goes for all of us as we age. That was my big takeaway — everyone, especially people with any extra respiratory decline — should probably be educated about their breathing and intentionally exercise their lung capacity.

Sleep Apnea Complicated by Neuromuscular Disease

One of the things Dr. Bach addressed relates to the challenge of getting proper non-invasive ventilation support for sleep apnea. If you also have a neuromuscular disease like CMT that impairs the respiratory system gradually (more for some than others) this complicates what devices can be used and how they should be used.

Bach says everyone hyperventilates while sleeping, so carbon dioxide levels increase normally. How do you know if they’re too high? If you experience morning headaches and are sleepy during the day, these are symptoms of hypercapnia (very low O2 and very high CO2) during your sleeping hours. You should see a pulmonologist for further diagnosis if you have these symptoms and CMT. One simple solution may be to sleep on your side or with your upper body elevated, especially if you have orthopnea — shortness of breath only when lying on your back. The normally prescribed solution is an assistive breathing device.

Unfortunately, getting more oxygen from an assistive device will further increase your carbon dioxide levels too. CPAP and BiPAP machines are generally not calibrated correctly to deal with this, and even if they were, they would not be useful for people with weak diaphragms and chest muscles. With these machines, you often get too much carbon dioxide pushed back in your lungs. Maximum in, minimum out settings on BiPAP is best way to use it, according to Bach. NIV machines at full support levels will normalize blood gases. That’s the ideal goal, but it’s coming at the cost of training your body not to do the work of breathing on its own.

Compensating for Reduced Lung Capacity

Dr. Bach also brought up some breathing techniques I’ve never heard of. He mentioned “frog breathing” (glossal pharyngeal breathing) as a technique that lets people with paralyzed diaphragms and chest muscles breathe unassisted while they are awake even though they can’t inflate their lungs normally. Anyone who can talk or swallow can still breathe as frogs do, by using the mouth and throat muscles. Frogs have no diaphragms, and we can all re-learn to breathe like the amphibians we once were.

Stack breathing (or “breath stacking“) was also discussed — this is a breathing exercise that can improve and maintain your lung capacity and cough strength which helps clear mucus from your chest.

I found these techinques fascinating and also a bit terrifying! Thinking about breathing — and not being able to breathe is a bit dreadful. Fortunately, only a few rare forms of CMT really threaten the ability to breathe on one’s own. The rest of us may struggle more or less than others with age, so it’s good to know some ways to offset that decline.

There are so many variables with COVID and pneumonia that shape individual risk factors, it’s not really a question of whether CMT makes you more vulnerable — it’s more of a general question about your respiratory fitness (COVID or no COVID). That’s something almost everyone can work on improving and maintaining, but it’s still no guarantee (there are no guarantees) against COVID or anything else.

🏋️ Apart from keeping your lungs as healthy and strong as possible, supporting your immune system and preventing head and throat colds from spreading is the most important, simple thing anyone can (and should) do to stay free of invading viruses and bacteria. Here’s my family’s list of natural, over-the-counter aids for cold and flu season. 🤒

Dan Knauss

Dan Knauss

Hi, this is my CMT blog, and I wrote this article. You can read about me and my CMT story. Get in touch if you’d like; I’m always happy to answer questions about CMT and the medical system.

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