Questions and Answers about breathing

Question asked by Linda Crabtree to Dr. Greg Carter, Medical Director, Providence Rehabilitation Hospital, Chehalis, WA, U.S.A and Dr. K. N. Chan, a specialist in pulmonary and internal medicine in Toronto, Canada.

Q: Why is it so important for our breathing to be tested lying down?
When I was seeing Dr. Charlie Chan he told me that when I get my breathing checked for MIP and MEP I should have it done sitting and lying down. He stressed the horizontal position and told me that because I didn't have the benefit of gravity when lying down I'd breathe more shallowly and it was good for the docs to know that when lying down I took in and especially pushed out quite a bit less air (one litre less). I've told folks to be tested lying down as well as sitting up but their doctors just poopoo that mainly because it comes from me and I'm not a doctor. Could you please answer the question (Why be tested lying down as well as sitting?) or suggest that people with CMT have their breathing tested both sitting and lying down and tell us WHY so I can print it in the CMT Newsletter with your name on it and then, maybe, pulmonary specialists will listen. Mine did and it made a big difference in how he saw my breathing and sleep problems.
A: Dr. Carter -You and Dr. Chan are absolutely right. People with CMT and NMD in general should have MIP and MEP done sitting and lying down. The horizontal position puts your diaphragm at a disadvantage by removing the effects of gravity. When you are upright, gravity helps lower the diaphragm and fill your lungs with air. This is why people often have breathing problems at night, which can be helped by sleeping sitting up or propped up with pillows. The heart also has a harder time pumping when you are lying flat, which further compounds the problem.
By checking your MIP and MEP lying down, your physician gets a better idea of how you might be breathing at night. A more extensive, expensive way of doing this is with a formal sleep study where they can observe you sleeping and check the amount of O2 in your blood, etc. Any physician who doesn't agree with this has forgotten basic physiology!

Q: to Dr. Carter: I have CMT breathing problems, my left diaphragm is not working very well and I get lower lobe pneumonia a lot. Why?
A: - Please see my article on fatigue. Sounds like you are among the small percentage of CMT folks who get respiratory involvement. The diaphragm can be affected just like muscles in your arms and legs. (Linda Crabtree here - Also, if you cannot cough well and some of us lose our cough reflex, you cannot bring up the sputum associated with pneumonia and it can settle way down in the lower lobes of your lungs.)

Question to Dr. Charles K.N. Chan, formerly a specialist in pulmonary and internal medicine in Toronto, Ontario, Canada. Dr. Chan has done quite a bit of research into CMT and breathing and published several papers on the subject.
Question: Can shoulder pain be associated with diaphragm problems in CMT?
Answer: It is reasonable to say that any disease process that affects the proximity of the diaphragm can potentially create shoulder pain. In other words, pain actually occurred elsewhere in the body but was referred to some other parts of the body at the time you perceived it.
My experience in dealing with people with established diaphragm problems is that they usually have a bit of pain, and this is usually more to the chest wall because of the overuse of the muscles, but whether they have frank pain to the shoulder is less likely but possible. The reason I say it is possible is because the muscles around both shoulders that are connected to the neck are often utilized when the patients' diaphragms are weak, but frequently it occurs in people with advanced diaphragm problems.
In terms of early sign of diaphragm involvement I would recommend symptoms along the line of breathing difficulty or shortness of breath while lying down as the very first indication. This happens months or even years before more profound symptoms follow and usually transpires to shortness of breath on minimal exertion.

Question to Dr. Chan: I get a very tight feeling across my chest as if someone is pushing down on it really hard, then I find it hard to breathe properly. Also, I get sharp pains in my ribs. Would you please tell me if this could have anything to do with my diaphragm muscles and have you ever heard of this before?
Answer: The tight feeling across the chest as described may be secondary to cardiac disease such as angina due to poor circulation to the heart. Alternatively, the sensation can sometimes be felt by asthma patients because of narrowing of the airways and thus making it difficult to breathe with a tight sensation. This tightness sensation with breathing difficulty and sharp pain in the ribs may also be secondary to muscle weakness.
I would urge an assessment by a physician in regard to those three possibilities. An electrocardiogram to check the heart and lung function test, perhaps with some breathing muscles tests such as maximal inspiration and expiratory pressures may be done. After those evaluations, your physician will be in a better position to assess if it is related to the heart or the lungs.

Question: Are breathing problems common in people who have CMT?
Answer: No, only in a small percentage of patients with severe CMT.

Question: What type of CMT is the most likely to have breathing problems connected with it?
Answer: Patients with major CMT involvement of the upper arms and neck.

Question: How important is it for people to have their breathing checked if they think they have a breathing problem?
Answer: They should at least have a consultation with a lung specialist.

Question: Can breathing problems in CMT be life threatening?
Answer: Yes, in advanced cases, the patient may need a breathing machine.

Question: If you think you have breathing problems and are going to have an operation involving anesthetic, how important is it to have your breathing checked BEFORE the operation? How about having it checked lying down? What should the person checking your breathing be looking for?
Answer: Definitely BEFORE surgery. They need to check vital capacity sitting and lying and look for major disparities. They also should be monitored closely after the operation.

Question: Most people look to you for information on CMT and breathing but not everyone can visit you for help. Are there other centres in North America where specialists such as yourself work with people who have CMT and breathing problems?
Answer: I can think of none specifically, but any major university centers should have the know-how and up-to-date knowledge.