What is Esophageal Motility Disorders?
The esophagus is like a tube that carries food from your mouth to your stomach. It’s designed to move food along its length in a well-organized way, from the near end, close to your mouth (the proximal esophagus), to the far end, near your stomach (the distal esophagus). If this methodical movement is interrupted, it can result in various disorders affecting the movement of the esophagus, which can either be the main problem (primary) or caused by something else (secondary).
The esophagus is about 25 cm long and has two “gate-keepers” or sphincters; one at the top (near the mouth) and one at the bottom (near the stomach). The upper esophagus sphincter is a ring-like muscle that stops air from going into the stomach. The bottom sphincter is made up of smooth muscles that always have a certain level of tightness to keep stomach content from flowing back up (refluxing) into the esophagus.
The esophagus body is made up of two types of muscles: striated (striped) muscles in the near portion (proximal esophagus) and smooth muscles in the far portion (distal esophagus). The switch from striped to smooth muscles happens halfway along the esophagus. These muscles can be found in two layers, the outer lengthwise (longitudinal) and inner circular layers. When they contract in a coordinated manner described as peristalsis, they push the food towards the stomach.
What Causes Esophageal Motility Disorders?
Esophageal motility disorders, which affect the muscle movements of your esophagus (the tube that connects your mouth to your stomach), come in two main categories:
1. Primary disorders, which are caused by diseases affecting the esophagus itself.
2. Secondary disorders, which are part of other, bigger diseases. This includes conditions like pseudo-achalasia (which can be caused by things like tumors), Chagas disease, and scleroderma, a disease that causes hardening of the skin.
These disorders can also be grouped based on where they occur in the esophagus:
In the upper part, which includes the throat (oropharynx), you can have neuromuscular disorders. These are caused by problems with the nerves and muscles and can include conditions like ALS (a disease that affects nerve cells in the brain and spinal cord), certain types of tumors, malfunction of the upper esophageal sphincter (the muscle at the top of the esophagus), multiple sclerosis, Parkinson’s disease, and strokes, among others. There can also be structural disorders in this area, like cancer, infections, and damage from surgery or radiation therapy.
Esophageal motility disorders can also involve the lower part of the esophagus. Primary disorders in this area include achalasia (a rare disorder that makes it hard to swallow food and liquids), distal esophageal spasm (irregular contractions in the lower part of the esophagus), and hypertensive lower esophageal sphincter (where the muscle at the bottom of the esophagus is abnormally tight). Secondary disorders can include Chagas disease and conditions relating to acid reflux.
There are also structural disorders that can happen in the esophagus. These include both internal issues, like tumors and rings or webs in the esophagus, and external ones, like a mass in the chest cavity (mediastinum) or issues with the spine.
Lastly, problems with swallowing (dysphagia) could be due to issues in the throat or upper esophagus, but these are usually part of a more widespread issue with the nerves and muscles. This article mostly deals with primary motility disorders, especially achalasia, but secondary disorders and those affecting the upper esophagus are also mentioned when they have unique features.
Risk Factors and Frequency for Esophageal Motility Disorders
Dysphagia, or difficulty swallowing, is a condition often found in people older than 50 years of age. Its prevalence ranges from 16% to 22%, mostly due to dysfunction in the part of the throat that helps in swallowing, known as the oropharynx. This dysfunction is primarily caused by diseases affecting the nerves and muscles.
One rare anatomical cause of dysphagia, called Zenker’s diverticulum, affects a tiny proportion of the population in the U.S., between 0.01% and 0.11%, and is more common in men between their 70s and 90s. Dysphagia can have severe consequences including dehydration, malnutrition, aspiration of food or liquid into the lungs, choking, pneumonia, and even death. It’s a common problem in healthcare institutions, affecting up to 13% of hospital patients and 60% of nursing home residents. The mortality rate for nursing home residents with this condition can reach 45% within a year.
Another form of swallowing disorder is called achalasia, which affects the esophagus. This condition affects about 2.9 out of every 100,000 people in the U.S., regardless of gender, and usually starts showing between the ages of 25 and 60. Since achalasia is a chronic condition, there are more people who have it than people who are newly diagnosed. There have been some instances where achalasia seems to run in families, but this is not common. There’s also a rare genetic form of achalasia, associated with adrenal insufficiency and alacrima (a condition affecting tear production), which usually appears in childhood due to a mutation in a particular gene.
Data regarding other esophageal motility disorders beyond achalasia is limited. Due to lack of population-based studies, the frequency of spastic disorders (conditions that involve the abnormal contraction of muscles) is estimated by comparing them to achalasia prevalence. Patients experiencing chest pain or swallowing difficulties are those who are especially at risk for these motility disorders. While these disorders are prevalent amongst these patients, the actual significance of these findings often remains unclear.
Signs and Symptoms of Esophageal Motility Disorders
Dysphagia, or trouble swallowing, is often a key sign of issues with the muscles in the esophagus, the tube connecting your throat to your stomach. Sometimes if someone doesn’t cough or have other symptoms like drooling, regurgitating through the nose, leftover food in the throat after swallowing, or any symptoms of muscle weakness or numbness, this can suggest the problem lies in the esophagus rather than the throat. Other symptoms that could hint at esophageal dysphagia include heartburn, regurgitation, chest pain, painful swallowing, or feeling like something is stuck in the throat from time to time.
However, it’s important to note that a patient might not be able to accurately pinpoint the location of the obstruction. For instance, if the lower part of the esophagus is obstructed, due to, say, a ring, narrowing, or a muscle disorder called achalasia, it’s often mistaken for throat dysphagia. This can be misleading as patients are correct about the exact location only about 60% of the time. Because of this, it’s usually better to examine the entire esophagus when looking for throat dysphagia.
The history of the patient is also helpful in differentiating whether the issue is with swallowing solids or liquids or both. Trouble with both may suggest a motility disorder while trouble with solids could point towards a mechanical obstruction. However, symptoms could match up with both, and usually the doctor needs to carry out tests like endoscopic, histologic or radiographic examination to ensure they’ve excluded other common causes.
It’s also worth noting that the goal of the patient’s history is to discern between esophageal dysphagia, oropharyngeal dysphagia (trouble swallowing due to abnormal throat muscles), xerostomia (dry mouth), or a feeling as though there’s a lump in the throat, also known as globus sensation. These conditions are often confused for each other, especially globus sensation and dysphagia. Unlike dysphagia, globus feeling typically persists at all times, not just while swallowing. It may be linked to symptoms of acid reflux or serious anxiety. The term “globus hystericus” was used in the past to describe instances when globus feeling was found alongside high levels of anxiety. Despite multiple studies, no specific physical or physiological cause has been found for this condition.
Testing for Esophageal Motility Disorders
When a doctor suspects a patient might have an esophageal motility disorder (a condition that affects the movement of the muscles in the esophagus, making it difficult to swallow), they may order several tests. The order of these tests can change based on the doctor’s judgment, the specifics of the case, and the need to avoid invasive procedures when possible.
An esophagography is often the first test. This test uses imaging to provide a view of the esophagus’s structure and function. In some conditions like advanced achalasia (a type of esophageal motility disorder), it could show a widened esophagus in the chest area with an air-fluid level. The test might also show a narrowing at the lower end of the esophagus that could look like a bird’s beak. This narrowing does not occur in early achalasia, but the imaging could show the pooling of the contrast material, indicating lack of typical muscle movements (peristalsis) in the esophagus. Sometimes the test could reveal a pocket or bulge (diverticula) above the lower esophageal sphincter (LES), the muscle at the bottom of the esophagus.
The esophagography for different disorders could show different characteristics. For example, in some cases of the disorder diffuse esophageal spasm (DES), the esophagus might look like a corkscrew or a string of beads. On the other hand, a scleroderma esophagogram (done for a certain type of autoimmune disorder) can show a widened esophagus, backflow of stomach contents (reflux), and weak or missing peristalsis.
The manometry test is also used to examine the pressure and movement of the esophagus when swallowing. The test measures the average pressure at the juncture between the esophagus and stomach, the time taken for the swallow to reach this juncture, and the strength of the esophageal muscle contractions. Manometry is key to diagnosing motility disorders like achalasia and DES. It helps to highlight absent muscle movements in the esophagus and failure of the LES muscle to relax. These findings are observed in about 90% of achalasia cases.
Lastly, endoscopy could be done, particularly when the patient has difficulty swallowing. It’s the only tool through which the doctor can both diagnose and treat the disorder. It might not show anything in the early stages of the disease, but later on, it could reveal food remaining in the esophagus. The presence of food can cause inflammation or ulcers, or make the tissue red or fragile (friable). The doctor can also take tissue samples for lab analysis or perform treatments at the same time during endoscopy.
Treatment Options for Esophageal Motility Disorders
If you are suspected to have a condition that affects the movement of your esophagus (the tube connecting your throat to your stomach), it’s recommended you go to a healthcare center with specialized digestive and surgical services.
Achalasia is one of these disorders, and it’s unfortunately not curable. The primary problem with achalasia – the inability of a muscle in your esophagus to relax – can’t be reversed. However, its symptoms like difficulty swallowing and chest pain can be managed, especially when the disorder is mild to moderate. We can use a combination of medication and procedures to provide relief.
In the early stages of the disorder, drugs can effectively help control symptoms. Historically, doctors have prescribed nitrates and a drug called nifedipine to treat esophagus movement disorders. There are other medicines, too, like anticholinergics, theophylline, beta-2 agonists, phosphodiesterase inhibitors, and nitroglycerin that have some effectiveness. If heartburn and reflux are the main problems, we can also use drugs that speed up your digestive process and reduce stomach acid. Sometimes, symptoms can come from or be worsened by anxiety. In these situations, we might prescribe low-dose antidepressants or medications that change the balance of one of your brain’s chemical messengers, serotonin.
There are procedures as well that can help widen any narrow areas in your esophagus. We can use a special scope to look into your esophagus and pinpoint exactly where the problem is. Then, we can use techniques such as a TTS pneumatic balloon or an EndoFlip dilation system to open up the area. Although the procedures are typically performed under anesthesia or sedation with pain control, they could result in chest pain, increased heartburn, and reflux afterward.
While we have the scope in, we could also inject botulinum toxin (a protein from bacteria) into the problem area to help it relax. But we usually reserve this for people who aren’t good candidates for surgery and aren’t responding to medications.
If these treatments don’t work or the disorder is severe, we then consider surgery. These procedures aim to decrease the pressure at the junction of the esophagus and stomach by making a cut in the muscle there. The three main surgical procedures are Heller’s myotomy, extended Heller’s myotomy, and esophagectomy with gastric pull-up or intestinal interposition. The last involves removing a section of the esophagus and replacing it with part of the stomach or intestines.
What else can Esophageal Motility Disorders be?
When a person goes to the doctor with chest pain, the first thing to check is heart disease. Other conditions like esophageal movement disorders are also considered. These conditions include:
- Coronary artery disease (CAD)
- Chagas disease
- Pseudoachalasia
- Diffuse esophageal spasm
- Hypercontractile esophagus
- Dry mouth (also called Xerostomia)
- A feeling of a lump in the throat (Globus sensation)
The key goal for the doctor is to identify what’s causing the patient’s symptom, whether it’s difficulty swallowing, dry mouth, or a feeling of a lump in the throat. Globus sensation, for example, is often mixed up with swallowing difficulties. But unlike swallowing issues, which occur only when swallowing, Globus sensation is felt even between swallows.
People with this condition describe it as a constant feeling of having something stuck in their throat. Sometimes, this sensation is connected to symptoms of acid reflux, or in other cases, extreme anxiety. This link to anxiety is why it was previously known as “globus hystericus”.
Unfortunately, it’s been hard for studies to pinpoint a physical reason for globus sensation. So, the patient’s description of what they feel becomes essential for identifying the issue, as the globus sensation remains, whether the person is swallowing or not.
What to expect with Esophageal Motility Disorders
The outlook for esophageal motility disorders – problems related to the movement of the esophagus, the tube that carries food from the mouth to the stomach – varies according to the type of disorder:
Achalasia is a disorder that gets worse over time, meaning patients will need long-term treatment and possibly repetitive endoscopic or surgical interventions. Even after treatment, patients often need to remain cautious about their diet.
Scleroderma esophagus is a condition where the severity heavily depends on the control of the primary disease, scleroderma – a chronic disease causing the hardening and tightening of the skin and connective tissues. As scleroderma gets worse over time, patients often experience significant acid reflux, which is a condition where stomach acid flows back into the esophagus, causing heartburn and other symptoms.
Spastic esophageal disorders, on the other hand, generally have a much better prognosis. Patients can usually maintain a good baseline health status. However, if their condition worsens, they may require further examination, as these disorders can sometimes develop into achalasia over time.
Possible Complications When Diagnosed with Esophageal Motility Disorders
In individuals with achalasia, it’s often said that they might have an increased chance of developing a type of skin cancer known as squamous cell carcinoma, compared to those who don’t suffer from this condition. However, there isn’t solid proof from scientific research to support this belief. The theory behind this link is thought to be the long-term irritation of the lining of the body’s digestive tract.
Common Points:
- Achalasia patients may have a higher risk of squamous cell carcinoma
- No substantial scientific evidence to prove this connection
- Potential reason could be long-term irritation of digestive tract lining
Preventing Esophageal Motility Disorders
Patients should be advised that their condition is long-term. It’s important to have an in-depth conversation with the doctor about the various treatment choices, the expected results of these treatments, and changes to diet and lifestyle that can help manage the condition.
