Diaphragm paralysis in NA (Neuralgic amyotrophy)

What is diaphragm paralysis in NA?

Neuralgic amyotrophy (NA) is an acute inflammation, often very painful, of a number of nerves in the shoulder, arm and/or hand. As a result, a number of muscles become paralyzed to some extent. Patients usually recover during 1 to 2 years, but it is possible that you will continue to have trouble from the affected arm(s) in your daily life and while working. In about 1 of every 15 people with NA, the phrenic nerve that innervates the diaphragm also becomes paralyzed. Sometimes this nerve can also become paralyzed without nerves in the arm being affected.

Functions of the diaphragm

The diaphragm is a dome-shaped structure of muscle and fibrous tissue that separates the thoracic cavity from the abdomen. It has an important function during respiration: it is the most important muscle involved in our breathing. The diaphragm muscle contracts at the beginning of the breath, resulting in the central tendon being pulled downwards toward the abdomen. This results in negative pressure in the chest, causing air to flow into the lungs.

Consequences

Diaphragm paralysis leads to various problems:

Shortness of breath
If the diaphragm muscle no longer functions properly, the central tendon is no longer pulled sufficiently downwards. This results in difficulty in breathing and shortness of breath, especially when lying flat or bending over. The lung capacity during inhalation is limited, leading to problems when exercising and sleeping.

Difficulty sleeping
With a paralyzed diaphragm, it is difficult to lie flat. In this position, your abdomen presses against your diaphragm, making it difficult to breathe. In addition, when you are dreaming (during the REM phase of sleep) all your muscles become paralyzed, except the diaphragm. But if your diaphragm is also paralyzed, your auxiliary respiratory muscles do not work. As a result, you can wake up whenever you enter the REM phase. While sleeping, you may breathe more noisily or very shallowly at times.

Daily life
When you eat or drink, breathing can become more difficult due to the counterpressure on the diaphragm from the abdomen. Counterpressure can also occur when you jump into a swimming pool or the sea. Due to your reduced physical fitness and poor sleep, you are often very tired. This also has consequences for your concentration and mood.