Paralyzed Diaphragm (Diaphragmatic Paralysis)

The diaphragm is a muscle that separates the thoracic and abdominal cavities and is controlled by the phrenic nerve. Diaphragmatic paralysis, whether it occurs in one or both sides of the diaphragm, is uncommon.  In patients where one side of the diaphragm is paralyzed, the paralysis occurs in the left and right side with equal frequency. Whether the paralysis occurs in one (unilateral) or both (bilateral) sides of the diaphragm, all patients will experience some amount of reduction in lung capacity, particularly noticeable when lying down.



Patients with diaphragmatic paralysis may experience shortness of breath, headaches, blue lips and fingers, fatigue, insomnia and overall breathing difficulty.  Also:

  • Unilateral diaphragmatic paralysis may go undiagnosed. Often patients compensate for the discomfort of reduced lung capacity by sleeping in a semi-upright position or reducing physical activity when there is shortness of breath.
  • Bilateral diaphragmatic paralysis presents more severe symptoms, which leads patients to seek medical attention. The shortness of breath is more severe, even with mild exertion.

Newborns and children with unilateral diaphragmatic paralysis may experience more severe respiratory distress than an adult, due to weaker muscles and a more compliant chest wall. The newborn may have a weak cry or show signs of gastrointestinal distress, with frequent vomiting.  Children with bilateral diaphragmatic paralysis require immediate medical attention and ventilator intervention because the condition can be life threatening

The tools used to diagnose diaphragmatic paralysis include:

  • Pulmonary function testing while lying down and again while upright.  Lung capacity is often reduced about 10 percent when a person is lying down; patients with bilateral diaphragmatic paralysis may experience a 70 to 80 percent reduction in lung capacity while patients with unilateral diaphragmatic paralysis may experience a 50 percent reduction.
  • Chest X-rays or an upright, inspiratory chest radiograph.
  • A blood test to measure the amount of oxygen in the blood.
  • Measuring transdiaphragmatic pressure and thickness.
  • Phrenic nerve stimulation testing.
  • Electromyography, a test that evaluates and records electrical activity produced by skeletal muscles.
  • Computed tomography (CT) scanning of the thorax and/or abdomen.
  • Magnetic resonance imaging (MRI) to determine if there is an underlying condition involving the spinal column or nerve roots.
  • Ultrasound to see the activity of the diaphragm and to identify any unusual movement or lack of movement.

Causes and Risk Factors

The causes and risk factors that compromise diaphragmatic function include:

  • Cancer in the lung or in the lymph nodes may grow into or compress the nerve which leads to nerve compression.
  • Surgical trauma, such as unintentional injury after a cardiothoracic or cervical procedure.
  • In newborns and infants, birth trauma can injure the phrenic nerve.
  • ALS, multiple sclerosis, muscular dystrophy or other neuromuscular disorders
  • Spinal cord disorders and quadriplegia.
  • Injury to the phrenic nerve, the nerve that controls the function of the diaphragm.
  • Neuropathic disease including thyroid and autoimmune disease, Guillain-Barre syndrome, etc.


Physicians take into consideration the overall health of the patient, the severity of symptoms as well as any underlying cause for the paralysis:

Diaphragmatic plication, a surgical procedure that pulls the diaphragm down, is commonly used in patients with unilateral paralysis.  The surgery allows the diaphragm to moves so as to expand better and improve ventilation.  Patients with more severe symptoms, such as a respiratory infection, asthma or COPD (chronic obstructive pulmonary disease), can benefit from diaphragmatic plication.

Breathing pacemakers may be used in patients who have functioning phrenic nerves, such as patients with ALS or spinal cord injury. The devices may result in improved respiratory function and lower infection rates.

Thoracoscopic diaphragm plication may be an option for some patients, resulting in a shorter hospital stays than other techniques.

A tracheostomy, the surgical formation of an opening in the trachea, helps allow the passage of air. This approach is commonly used for patients with a life threatening disease or a diagnosis of high quadriplegia.

In severe cases of patients on a ventilator due to bilateral diaphragmatic paralysis, the diaphragm might be plicated to help get patients off the ventilator.

If the patient has no symptoms, or the symptoms are mild, and the patient is in otherwise good health, no treatment may be necessary.

The prognosis for unilateral paralysis is quite good, providing there is no underlying pulmonary disease. Sometimes, patients recover without any medical intervention.The prognosis for bilateral paralysis also depends on the overall health of the patient but surgery may be the best option for patients who continue to have a poor quality of life.

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