Unilateral Diaphragmatic Paralysis

What is Unilateral Diaphragmatic Paralysis?

The diaphragm is a crucial muscle that plays a key role in our breathing process and separates our chest and abdomen. It’s the primary muscle we use when we inhale, more so than other muscles in our neck or between our ribs. We have something called the phrenic nerve that sends signals to the diaphragm, allowing it to move and work correctly. When we breathe in, our diaphragm contracts, creating a drop in pressure in our chest, which helps our lungs to expand and draw air in.

Sometimes, either the right or left side of the diaphragm can lose its ability to contract properly, making breathing difficult. This condition is known as unilateral diaphragmatic paralysis. This can happen due to overall muscle problems in the diaphragm or issues with the phrenic nerve’s signaling to that part of the diaphragm. When this happens, people may have trouble breathing at rest or during exercise, may struggle with sleep disturbances, and in severe instances, it could potentially reduce life expectancy.

Various factors can lead to diaphragm dysfunction, including damage to the phrenic nerve from injury or pressure on it, certain medications, disorders that cause the protective layer around nerves to deteriorate, injuries to the neck portion of the spinal cord, and even some conditions people are born with.

This easy-to-understand breakdown of unilateral diaphragmatic paralysis aims to offer an overview and help you better understand the condition. Knowledge of the condition can improve recognition of the symptoms, as well as familiarize you with diagnosis and treatment options.

What Causes Unilateral Diaphragmatic Paralysis?

Diaphragmatic paralysis, or the inability to move one side of the diaphragm, can be caused by a variety of problems either directly in the diaphragm muscle or due to issues with the phrenic nerve that controls it. The extent and impact of this paralysis can vary depending on what causes it, and it’s even possible in some cases to recover fully. Here are some of the common sources of this condition:

Injury or Trauma:
This is the leading cause of weakness within the diaphragm. Any direct injury, be it from an accident or during surgery, can harm the phrenic nerve and potentially lead to weakness or paralysis of half of the diaphragm. During some specific heart surgeries, this kind of temporary weakness can happen in up to a fifth of patients because of the cooling needed for the operation, and this eventuality is more frequent on the left side than the right. It has been observed during surgeries involving the center of the chest, the esophagus, the lungs, and even with laparoscopic gallbladder removal.

Compression:
Anything that puts pressure on the phrenic nerve, such as cervical spondylosis (a type of neck arthritis), a tumor or deformation nearby, chest tubes or chronic sclerosing mediastinitis (a rare inflammatory disease causing fibrosis in the chest) can impact its proper function. In fact, up to 5% of lung cancer cases have shown to affect the phrenic nerve.

Neuropathy:
Conditions that usually cause nerve damage may lead to paralysis or weakness of the diaphragm by interfering with the function of the phrenic nerve. Diabetes can cause such damage, especially if blood sugar isn’t well-controlled. Similarly, multiple sclerosis might also impair the functioning of the phrenic nerve, depending on where the lesions occur and other conditions that cause the loss of the protective covering of the nerve. It’s also reported that a condition called neuralgic amyotrophy, or Parsonage Turner Syndrome, frequently overlooked can affect the phrenic nerve in around 7.6% of patients.

Inflammation:
Various viral infections such as herpes, Zika, polio, and others have been connected to one-sided diaphragm paralysis. For example, a case series on congenital Zika syndrome has documented four infants with diaphragm weakness who eventually died from breathing failure. Apart from viral infections, some bacterial infections, like Lyme disease, can also affect the phrenic nerve. Non-infectious inflammation such as conditions like sarcoidosis and amyloidosis can also cause diaphragm weakness. There have been cases indicating neuromyelitis optica, a rare autoimmune disorder that affects the nerves of the eyes and the spinal cord, also can cause one-sided diaphragm paralysis.

Medical Intervention:
Sometimes, patients get nerve blocks for pain relief before or after surgery. If the anesthetic spreads to the phrenic nerve, it can hinder signals to the diaphragm and cause one-sided diaphragm paralysis. This is more common during certain type of nerve blocks, such as ones for the neck, shoulder, and upper back.

Unknown causes:
In some instances, the cause for both one-sided and both-sided diaphragm paralysis and weakness remains unknown. Almost 20% of cases fall into this category, known as idiopathic.

Risk Factors and Frequency for Unilateral Diaphragmatic Paralysis

Unilateral diaphragmatic paralysis, or weakness in one side of the diaphragm, frequently occurs due to trauma or injury to either the diaphragm itself or the phrenic nerve which controls it. This issue can affect up to 20% of people who have had a cardiac bypass, particularly if cooling procedures were used. This condition tends to be more common on the left side than the right.

It can also be caused by nerve blocks, which can sometimes extend to the phrenic nerve.
Additionally, in 5% of lung cancer cases, the phrenic nerve is affected, leading to this kind of paralysis.
Unilateral diaphragmatic paralysis should also be considered if a patient is experiencing shortness of breath due to certain inflammatory conditions or infections.

Signs and Symptoms of Unilateral Diaphragmatic Paralysis

Unilateral diaphragmatic paralysis is a condition that may have no symptoms, and is often discovered by chance on a chest scan. In some cases, individuals experience varying degrees of shortness of breath (dyspnea), particularly those with underlying heart or lung conditions. The symptoms may seem similar to other heart and lung disorders, and may be overlooked at first.

The intensity can range from shortness of breath only during exertion to shortness of breath even at rest, particularly for those with other health conditions. These individuals may experience decreased ventilation, leading to high levels of carbon dioxide in the blood, which can intensify while sleeping and result in daytime tiredness.

Symptoms may be particularly severe just after the onset of the paralysis, as the body has not yet adjusted. Studies have shown that the pressure exerted by the diaphragm may initially decrease by 45% after the onset of paralysis, though this generally improves to a 25% decrease over the course of two weeks due to the body’s compensatory mechanisms.

When diagnosing unilateral diaphragmatic paralysis, doctors take into account the patient’s medical history to identify potential causes. This medical history could include information on past diseases, surgeries, infections, injuries, vaccinations, and travel.

The physical exam of a person with this condition may be normal in an otherwise healthy person. Sometimes, the exam may show less sensitivity to touch or reduced breathing sounds at the lower part of the lung on the affected side. Some specific signs such as a weird movement of the chest and abdomen during sleep, shortness of breath when laying flat (orthopnea) which generally gets better when positioned on the unaffected side, or issues with sleep-related breathing, particularly during REM sleep, are also associated with this condition.

Testing for Unilateral Diaphragmatic Paralysis

Essentially, when a doctor needs to explore a potential case of diaphragmatic paralysis, they are investigating the underlying cause. For instance, individuals who have had heart surgery may experience temporary weakness due to the cooling of the phrenic nerve – this nerve plays a significant role in controlling the diaphragm. Usually, these patients’ conditions improve over time, and they don’t require an immediate extensive checkup.

The diagnosis process involves understanding your health history, physical exam findings, multiple diagnostic tests, and imaging such as chest x-rays and the Snif test. The snif test uses scents to test reflexes, while spirometry tests how well you breathe and the strength of your respiratory muscles.

In many cases, diaphragmatic paralysis doesn’t show symptoms and is discovered by chance during a chest x-ray. A chest x-ray alone can diagnose up to 90% of such cases. Still, these scans aren’t entirely reliable – they can be sensitive but aren’t necessarily specific for diaphragmatic paralysis.

The Snif test might confirm the diagnosis if a patient shows symptoms based on the chest X-ray results. It works by observing the movement of the diaphragm during a deep breath or sniffing. In the case of diaphragmatic paralysis, the affected side may either show no movement or move inversely (rise instead of sinking).

For the breathing test, it is expected that someone with diaphragmatic paralysis breathe less efficiently. This inefficiency can reduce by up to 25% more when lying down. Obesity and paralysis on the right side can worsen the breathing test’s outcomes.

Electromyography (EMG), another test, goes further to examine if the paralyses lies in the nerve or the muscle. With this test, if the nerve is affected, it won’t stimulate the muscle to contract; however, if it’s a muscle problem, the nerve will stimulate the muscle, but there won’t be any contraction.

Another method is the thorax ultrasound, which can examine if the diaphragm paralysis exists. This test observes the movement of the paralyzed diaphragm during normal, quiet breathing, voluntary sniffing, or deep breathing.

The CT scan and the MRI scan are important imaging methods to determine the cause of the paralysis and inspect the tissues after trauma for closer examination. They can also check for any compression from tumors or other conditions within the chest.

A sleep study may also be recommended, as diaphragmatic paralysis can impact breathing during sleep.

Furthermore, lab testing, while non-specific for unilateral diaphragmatic paralysis, can help detect any underlying health issues that could potentially cause diaphragm paralysis such as thyroid diseases or Lyme disease. Anemia may also contribute to shortness of breath, so a complete blood count test may be beneficial.

Treatment Options for Unilateral Diaphragmatic Paralysis

Unilateral diaphragmatic paralysis is a condition where one side of the diaphragm, the muscle that helps with breathing, is not working correctly. In many cases, people with this condition don’t show any symptoms and the condition is only found when testing for other things. The good news is that as long as there are no other heart or lung conditions present, these individuals should have a good outlook. In some cases, doctors might observe the condition over time, particularly after certain heart surgeries or nerve blocks that might have caused weakness. Often, without any treatment, the nerve that controls the diaphragm muscle will start functioning normally again over time.

In cases where symptoms do appear or when the condition arises suddenly due to a correctable cause, there are a few treatment options to consider.

Addressing the Underlying Cause

If doctors can identify a cause for the diaphragm not working properly, the best approach would be to treat that problem directly. For example, if a virus is suspected to be causing muscle weakness because it’s inflaming the nerve that signals the diaphragm, the best treatment would include antiviral medications that target that specific virus, sometimes in conjunction with anti-inflammation medications. If a neck-related issue is placing pressure on the nerve causing the problem, releasing this pressure would be the most effective solution. Studies have shown that when a surgical option is available, such as releasing the pressure or improving the nerve pathway, it can lead to a major improvement in breathing function.

Support for Breathing

Non-invasive or invasive ventilation can be a treatment option if needed. There may be situations where patients without symptoms start showing symptoms if they develop a lung disease or an intensification of their underlying condition. In these cases, temporary assisted ventilation strategies may be used until the patient recovers completely. However, this doesn’t cure the condition, it simply helps with breathing. Options like CPAP or BiPAP machines can be considered for patients who have mild symptoms or to use at night time, as lying down can worsen shortness of breath with a weak diaphragm. Patients with weakening of both sides of the diaphragm are more likely to need BiPAP than those with a single side affected. If a patient’s diaphragm is not working at all, undergoing testing in a lab may be key to figuring out the best treatment strategy.

Surgical Adjustment

For patients who are exhibiting symptoms, a surgical procedure known as plication might be a viable treatment option. This procedure involves stitching the diaphragm into a stable position to stop it from moving abnormally when you take a breath. If possible, it’s recommended to wait at least six months before opting for this surgery, as in most cases, symptoms usually start to get better over time. This surgery can now be done with minimal invasion using robots. Numerous studies have shown this surgery to improve vital capacity (the maximum amount of air a person can expel from the lungs after maximum inhalation), tolerance for exercise, and reduce shortness of breath. Plication has also been shown to increase levels of oxygen in the blood, improve the pressures across the diaphragm, and makes the diaphragm more efficient.

Nerve Pacing

Nerve pacing could be a suitable option for individuals who suffer from diaphragmatic paralysis but who still have nerves that control the diaphragm intact. This involves implanting a pacemaker that stimulates the nerve controlling the diaphragm to contract the diaphragm correctly. Studies have shown promising results for diaphragmatic pacing. One study involving 27 patients showed that 81 percent of patients benefited from diaphragmatic pacing, and four of them were even able to come off the ventilator.

Unilateral diaphragmatic paralysis, a condition where one side of the diaphragm is unable to move, can have symptoms that closely resemble other heart and lung diseases. To diagnose it accurately, doctors need to conduct an in-depth medical history review, a thorough physical examination, and various imaging studies.

Here is a brief explanation of some other conditions that could be confused with unilateral diaphragmatic paralysis:

Diaphragmatic Conditions: Similar symptoms could be due to problems with the phrenic nerve or the muscles of the diaphragm. Conditions such as a diaphragmatic hernia or tumors under the diaphragm could look similar on X-rays and make it hard to breathe.
Respiratory Diseases: Conditions like asthma, chronic obstructive pulmonary disease (COPD), fluid around the lungs (pleural effusion), or pneumonia all can cause shortness of breath, just like unilateral diaphragmatic paralysis. Other issues such as collapse of a part of the lung (atelectasis) may also raise one side of the diaphragm and cause similar symptoms. It’s also possible to have diaphragm paralysis alongside conditions like pneumonia or pleural effusion.
Heart Disease: Unilateral diaphragmatic paralysis may cause difficulty breathing when lying flat (orthopnea), a symptom often wrongly linked to heart issues. However, a good physical check-up can differentiate between the two by looking for symptoms such as swelling in the feet and ankles (peripheral edema) or an enlarged vein in the neck (jugular venous distention).
Neuromuscular Disease: Conditions like cholinergic crisis, myasthenia gravis, or Lambert-Eaton syndrome can lead to breathing difficulties due to weakness in the diaphragm muscle, presenting similarly to unilateral diaphragmatic paralysis. A comprehensive medical history and specific tests can help to differentiate these conditions.

What to expect with Unilateral Diaphragmatic Paralysis

In general, if a person has one paralyzed side of the diaphragm, they are likely to recover well. Most often, people don’t notice any symptoms, and even those who do usually get better over time, even without specific treatment.

However, the chances of recovery aren’t as good if the person also has problems with their heart or lungs, or if the paralysis makes an existing health condition worse. Additionally, if the cause of the paralysis is a disease that usually results in serious health problems or death, this also lowers the chances of recovery.

There are many different things that can cause one side of the diaphragm to become paralyzed. Identifying what caused it in the first place is important for choosing the best treatment method and for improving the chances of recovery.

Possible Complications When Diagnosed with Unilateral Diaphragmatic Paralysis

The complications from unilateral diaphragmatic paralysis, where one side of the diaphragm stops working, are usually limited unless there are other existing health issues. The main complications can include difficulty breathing, becoming easily tired from physical exercise, sleep-related breathing problems, decreased breathing when falling asleep (such as in chronic spinal cord injury), or high carbon dioxide levels in the blood if these conditions are not treated. The most severe issue that can occur is respiratory failure.

Unilateral diaphragmatic paralysis itself can also be a side effect of a medical procedure performed on a patient. Specifically, it’s been found that nearly 20% of all heart bypass surgeries may result in a complication involving diaphragm weakness. Another common cause is residual weakness after a nerve block, but both these situations usually improve with conservative treatment.

There are several treatment options available for diaphragmatic paralysis, many of which involve surgery. However, as with any surgery, each procedure carries its own set of risks, such as excessive bleeding, infection, harm to nearby organs, or the requirement for additional procedures.

Complications:

Difficulty breathing
Exercise intolerance
Sleep-related breathing issues
Decreased breathing during sleep initiation
High carbon dioxide levels in the blood
Respiratory failure
Complications from surgical treatment, such as:

Excessive bleeding
Infection
Damage to local organs
Need for further surgery

Recovery from Unilateral Diaphragmatic Paralysis

There are many potential causes for shortness of breath or respiratory difficulties after surgery. Depending on the type of surgery, one of these causes might be paralysis of one side of the diaphragm, which is the muscle that helps you breathe. However, other causes may be more likely. One study pointed out key situations to watch out for, such as sudden myasthenic states, which is a condition that weakens your muscles; injuries to the phrenic nerve or the diaphragm itself, and the impact of certain medications, such as those that can cause long-lasting muscle weakness. It’s important to keep these in mind when dealing with diaphragm paralysis.

Preventing Unilateral Diaphragmatic Paralysis

The diaphragm is the most crucial muscle involved in breathing. When one side of the diaphragm becomes unable to function properly, this is known as unilateral diaphragmatic paralysis. Our diaphragm is controlled by certain nerves that originate from cervical nerve roots in our neck called the phrenic. When something hinders either the diaphragm muscle or the phrenic nerve’s function, it can result in diaphragm paralysis. Trauma is the most common cause of this condition, but there could be other reasons.

In many cases, this condition doesn’t show any noticeable symptoms, and even when it does, they often get better over time without any treatment. However, people with prior conditions of heart or lung disease, or those who are overweight, may be more likely to experience symptoms. These symptoms could include difficulty breathing, which might feel more intense during physical activity or when lying flat on their back during sleep.

Medical imaging techniques can help identify whether the diaphragm is paralyzed. The type of treatment provided typically depends on the root cause of the diaphragm’s weakness. Treatments may vary from simple observation to ensure the condition doesn’t get worse, to performing surgery to fix the primary problem.

Frequently asked questions

The prognosis for Unilateral Diaphragmatic Paralysis is generally good. Most people don't notice any symptoms, and even those who do usually get better over time, even without specific treatment. However, the chances of recovery are lower if the person has problems with their heart or lungs, or if the paralysis worsens an existing health condition. The prognosis is also less favorable if the cause of the paralysis is a disease that usually results in serious health problems or death.

Unilateral Diaphragmatic Paralysis can be caused by trauma or injury to the diaphragm or the phrenic nerve, nerve blocks, lung cancer, certain inflammatory conditions or infections.

The signs and symptoms of Unilateral Diaphragmatic Paralysis include: - Varying degrees of shortness of breath (dyspnea), especially in individuals with underlying heart or lung conditions. - Shortness of breath during exertion or even at rest, particularly in those with other health conditions. - Decreased ventilation, leading to high levels of carbon dioxide in the blood, which can worsen while sleeping and cause daytime tiredness. - Severe symptoms may occur just after the onset of paralysis, as the body has not yet adjusted. - Initial decrease in diaphragm pressure by 45% after paralysis onset, improving to a 25% decrease over two weeks due to compensatory mechanisms. - Medical history is taken into account when diagnosing, including past diseases, surgeries, infections, injuries, vaccinations, and travel. - Physical exam may appear normal in an otherwise healthy person, but may show reduced sensitivity to touch or breathing sounds on the affected side. - Specific signs associated with this condition include abnormal chest and abdomen movements during sleep, shortness of breath when lying flat (orthopnea) that improves when positioned on the unaffected side, and sleep-related breathing issues, particularly during REM sleep.

The types of tests that are needed for Unilateral Diaphragmatic Paralysis include: 1. Chest X-ray: This imaging test can diagnose up to 90% of cases of diaphragmatic paralysis, although it is not entirely reliable. 2. Snif test: This test observes the movement of the diaphragm during a deep breath or sniffing. It can confirm the diagnosis if a patient shows symptoms based on the chest X-ray results. 3. Spirometry: This breathing test measures how well a person breathes and the strength of their respiratory muscles. It can determine if someone with diaphragmatic paralysis is breathing less efficiently. 4. Electromyography (EMG): This test examines if the paralysis lies in the nerve or the muscle. It can determine if the nerve is affected and not stimulating the muscle to contract, or if it's a muscle problem and the nerve is stimulating the muscle but there is no contraction. 5. Thorax ultrasound: This test observes the movement of the paralyzed diaphragm during normal, quiet breathing, voluntary sniffing, or deep breathing. 6. CT scan and MRI scan: These imaging methods can determine the cause of the paralysis and inspect the tissues after trauma for closer examination. They can also check for any compression from tumors or other conditions within the chest. 7. Sleep study: This study may be recommended to assess the impact of diaphragmatic paralysis on breathing during sleep. 8. Lab testing: While non-specific for unilateral diaphragmatic paralysis, lab tests can help detect any underlying health issues that could potentially cause diaphragm paralysis, such as thyroid diseases or Lyme disease. A complete blood count test may also be beneficial to check for anemia.

The doctor needs to rule out the following conditions when diagnosing Unilateral Diaphragmatic Paralysis: 1. Diaphragmatic Conditions: Problems with the phrenic nerve or the muscles of the diaphragm, such as diaphragmatic hernia or tumors under the diaphragm. 2. Respiratory Diseases: Conditions like asthma, chronic obstructive pulmonary disease (COPD), pleural effusion, pneumonia, or atelectasis. 3. Heart Disease: Symptoms that may be wrongly linked to heart issues, such as difficulty breathing when lying flat (orthopnea). A physical check-up can differentiate between the two. 4. Neuromuscular Disease: Conditions like cholinergic crisis, myasthenia gravis, or Lambert-Eaton syndrome that can lead to breathing difficulties due to weakness in the diaphragm muscle.

The side effects when treating Unilateral Diaphragmatic Paralysis can include difficulty breathing, exercise intolerance, sleep-related breathing issues, decreased breathing during sleep initiation, high carbon dioxide levels in the blood, and respiratory failure. Additionally, surgical treatment options carry their own set of risks, such as excessive bleeding, infection, damage to local organs, and the potential need for further surgery.

A pulmonologist or a respiratory specialist.

Unilateral diaphragmatic paralysis can affect up to 20% of people who have had a cardiac bypass, particularly if cooling procedures were used.

Unilateral Diaphragmatic Paralysis can be treated in several ways. The treatment options depend on the underlying cause and the severity of symptoms. If a specific cause is identified, such as a virus or neck-related issue, addressing that problem directly is the best approach. This may involve antiviral medications, anti-inflammation medications, or surgical procedures to release pressure or improve the nerve pathway. Support for breathing can also be provided through non-invasive or invasive ventilation, such as CPAP or BiPAP machines. In more severe cases, a surgical procedure called plication may be recommended to stabilize the diaphragm. Another option is nerve pacing, which involves implanting a pacemaker to stimulate the nerve controlling the diaphragm.

Unilateral diaphragmatic paralysis is a condition where either the right or left side of the diaphragm loses its ability to contract properly, making breathing difficult. It can be caused by muscle problems in the diaphragm or issues with the phrenic nerve's signaling.