Respiratory Complications and Breathing Problems

Just as neuromyelitis optica spectrum disorder (NMO or NMOSD) can cause weakness in your legs or arms, NMO can also affect your breathing muscles. Additionally, areas of damage to the brain and spine from NMO can cause breathing problems.1,3

About 1 in 5 people with NMO have respiratory problems related to the disease. Of those, the most serious complications are more rare. Understanding what these problems are, how they occur, and treatment-related to these problems helps you recognize possible problems before they get severe.3

How is breathing controlled in the body?

When you breathe in (inhale), air enters your lungs and oxygen from the air moves from your lungs to your blood. When you breathe out (exhale), carbon dioxide is removed from your blood through the lungs. Your breathing is controlled by your nervous system and muscles in your body.4

Nervous system

Most of the time, you do not have to think about breathing in and out. Breathing is an automatic process controlled by the autonomic nervous system (ANS). To help adjust to your daily breathing needs, sensors in your body send signals to the breathing center of your brain.4

Breathing muscles

The main muscle of breathing is the diaphragm. Your diaphragm is a dome-shaped muscle that sits in your upper belly, below your lungs. When you breathe in, your diaphragm contracts and moves down.4

Additional muscles for breathing include:4

  • Abdominal muscles
  • Muscles between your ribs (intercostals)
  • Muscles of your face, mouth, and throat
  • Muscle in your neck and near your collarbone

How does NMO impact breathing?

Location of lesions

Spinal cord injury above the 5th cervical level in your neck may result in severe breathing problems. This area of the spine sends signals to your diaphragm. If this area is damaged, your diaphragm may not work right or might be completely paralyzed. Cervical cord damage in NMO occurs in about 6 out of 10 people. However, damage that leads to severe breathing problems is rare.2,5

Muscle weakness

Breathing muscle weakness can become a serious problem in those with NMO who are not able to walk or move well. This causes problems such as:1,2,6

  • Problems expanding the lungs or taking a deep breath
  • Weak cough, making it harder to remove secretions
  • Pooling of secretions in the airway

Breathing muscle weakness and a poor cough can lead to pneumonia, an infection of the lungs. If serious, pneumonia can be life-threatening or fatal.

Respiratory failure

Respiratory failure occurs when your breathing is not adequate, leading to low blood oxygen or too much carbon dioxide. Though this can happen in those with NMO who have lesions that impact breathing, this complication is rare. Respiratory failure in NMO may occur with high cervical or brainstem lesions.7

How are breathing problems in NMO treated?

Because many breathing problems occur due to muscle weakness, treatment involves breathing exercises. Some of these techniques include:6

  • Deep breathing and coughing, which helps to clear secretions
  • Using an incentive spirometer to help keep airways open. To use this device, you inhale deeply through the mouthpiece, hold your breath, then slowly exhale. This forced deep breathing is helpful to prevent pneumonia and breathing complications.
  • Wearing a CPAP (continuous positive airway pressure) or BiPAP (bilevel positive airway pressure) machine at night

If respiratory failure occurs, you may need a ventilator to help you breathe. Being on a ventilator may be temporary or permanent, depending on your condition.6

Breathing problems from NMO may occur. However, in most cases, these problems can be mild and treated with breathing exercises. Talk to your doctor about these possible problems and how to best manage them.

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Written by: Katie Murphy | Last reviewed: September 2021