Diaphragm is a muscle that divides the abdominal cavity and the thorax. It is a dome shaped muscle, the superior surface of the dome becomes floor for the thoracic cavity and the inferior of the C shape forms the roof of the abdomen. There are two diaphragms each on either side the chest. The main function of diaphragm is to assist easy respiration. Contraction of diaphragm increases the volume of the chest cavity and the air gets inspired into the lungs. Diaphragm is innervated by phrenic nerve which takes its origin from cervical nerve.
Causes:
Diaphragm is the main muscle for respiration. Paralysis of diaphragm is rare. Several diseases and conditions can cause dysfunction of diaphragm. Like any muscle diaphragm is also innervated by a nerve called phrenic nerve having its origin from the cervical nerve roots. Any damage to this nerve or its origin from the cervical region of the spine or from the brainstem can lead to paralysis of diaphragm. The condition can affect both adults as well as children. Following are the main risk factors considered to cause paralysed diaphragm:
- Bronchical and lung cancer. The tumor can grow and compress the phrenic nerve.
- Unintentional trauma to the nerve during cardiothoracic surgery or surgery of cervical spine.
- Infants and newborns can be affected with diaphragmatic paralysis during child birth. During child birth, the phrenic nerve may get damaged.
- Spinal cord injury, tumor, or compression in cervical spine, neck trauma, chiropractic manipulations etc.
- Diseases such as multiple sclerosis, muscular atrophy, amyotrophic lateral sclerosis, systemic lupus erythematosus etc.
- Thyroid disease or any autoimmune disease that affects the function of muscles and nerves.
Symptoms:
Paralysis or weakness of diaphragm can be unilateral or bilateral. If paralysis develops only in one diaphragm, the symptoms may mild and may not be easily noticeable. If the paralysis is bilateral, the symptoms tend to be more severe. It also depends on whether a pre-existing lung disease is present. Distressed breathing and shortness of breath while lying flat or while walking are characteristic of this condition. Paralysis causes reduced lung capacity and hence there is low oxygen saturation in the body. Low oxygen level is more at rest and even during exercise and sleep. Low oxygen is common when both the diaphragms are affected. Newborn experiences more respiratory distress than adults because of weak muscles. Newborn crying is weak and sometimes there is associated distress in the gastrointestinal tract leading to vomiting. Abdominal pain, night sweats, severe breathing difficulty when lying down, pain in shoulder, fatigue, are frequent symptoms in case of acute paralysis of diaphragm.
Diagnosis:
Diagnosis of paralyzed diaphragm is as follows:
- Physical examination and medical history: When the patient lie flat the abdomen moves inwards while inhalation which in normal circumstance must move outwards.
- Lung function test
- Chest X-ray
- Ultrasound examination and CT scan
- Stimulation of phrenic nerve in neck
- Arterial blood gas test to detect the saturation of oxygen level and carbon dioxide level.
Treatment:
While treating diaphragm paralysis the physician takes into consideration following aspects: Patients over health, whether it is acute onset or chronic, severity of symptoms, other coexisting lung disease, and the cause for paralysis. Treatment is as follows:
- Mild or moderate symptoms in adults with unilateral paralysis of diaphragm may need observation as there is chance of spontaneous recovery of the condition.
- In some cases where patient complains of breathing difficulty during night while is lying flat may need supportive oxygen therapy.
- In case of severe form of paralysis, surgical correction may be need. The surgery is called diaphragm plication. In this procedure the paralyzed diaphragm is sutured and pulled so that it becomes taut. With this surgery the lung gets enough space to expand and breathing improves.
- A pacemaker may be used if the phrenic nerve is functioning normally as in case of cervical spine injury or ALS.
The prognosis of unilateral paralysis of diaphragm is good, especially if the patient does not have any other illness of lung or heart. In case of bilateral paralysis of diaphragm, the overall health of the patient may decide the prognosis.