Lung Function Tests

[Guest guest]

Geri,

Read below and consider Breathinng/Lung Function/Weak Diaphram tests. I don't

know what your Oxygen question refers to - sleep/bi-pap, anesthesia or what?

Gretchen

Breathing Problems in CMT

by K.N. Chan MD, FRCPC

The association of CMT disease with diaphragm weakness resulting in major

breathing difficulty was first reported by us in 1985.

In 1985, my colleagues and I at Yale diagnosed a paralysed diaphragm in a

72-year-old woman who had CMT for about 60 years. Looking back, this patient had

major difficulties with her breathing for about 10 years. Unfortunately,

physicians caring for her

did not appreciate the possible link of CMT with phrenic nerve impairment and

thus diaphragm weakness or paralysis because it was not previously reported. As

a result of the paralysed diaphragm, this patient suffered major complications

in her heart and lungs and had impaired mental function. Even when the

diaphragms are not working, most patients breathe reasonably well in the upright

position with the help of gravity and the other breathing (accessory) muscles in

their necks and chests. However, when they lie down the benefit of gravity is

lost and the work of breathing required of these accessory breathing muscles

increases. This is the reason why the very first indication of diaphragm

weakness is difficulty breathing lying down. Over a period of time, months to

years, the overworked breathing muscles become tired. The consequence of that is

inadequate breaths which leads to a long-term deprivation of oxygen.

The effects of poor breaths and lack of oxygen can be summarized in the

following categories: (1) The major impairment in breathing and oxygen intake is

obviously at night during sleep when patients are lying flat, and since the

brain needs a good supply of oxygen, any major drop in the oxygen supply will

alert the brain. The response is

awakening of patients from sleep so they can sit up to breathe deeper in order

to get some oxygen into the blood. When these episodes occur repeatedly during

the course of 7-8 hours sleep, major deprivation of sleep and rest follows.

Because of these events

during the night time, patients with these sort of problems typically complain

of morning headaches, daytime sleepiness and poor mental function.

A long-term lack of oxygen means strains on the heart and lungs and will lead to

major impairment of the heart and lung functions. The results are heart failure,

presenting as swelling of the ankles, poor exercise tolerance, generalized

weakness, and in severe

cases, death.

Since there was nothing in the medical literature on diaphragm impairment or

breathing problems in CMT, we decided in the fall of 1985 to conduct a series of

lung and diaphragm tests on the brother of our patient. He also has had CMT for

about 45 to 50 years. To our surprise, even though he has minor difficulty with

his breathing, his diaphragm turned out to be substantially weaker than most

healthy individuals in his age group. That is why we became concerned that

diaphragm weakness leading to breathing difficulties may actually be a late and

perhaps rare complication in people with CMT. And especially in those

individuals who have other medical problems that may affect the phrenic nerves

and/or the diaphragm, such as diabetes.

With the collaboration of Mrs. Carol Barker of Connecticut, we have assessed two

additional people with CMT in the State of Connecticut, one of these also had

significant weakness of her diaphragm although it was much less severe compared

to our index

patient. After presenting these observations at the American College of Chest

Physicians annual scientific meeting in September of 1986, we are pleased to

report that similar patients were seen by some of our Chest colleagues in the

United States.

References:

Chan CK, Mohsenin V, Ferranti R, Virgulto J, Loke J. Diaphragmatic dysfunction

in association with Charcot-Marie-Tooth disease and diabetes mellitus. Chest

1986, 89: 454S.

2. Chan CK, Mohsenin, V, Loke J, Virgulto J, Sipski ML, Ferranti R.

Diaphragmatic dysfunction in siblings with hereditary motor and sensory

neuropathy (Charcot-Marie-Tooth disease). Chest 1987, in press.