Dysphagia: causes, symptoms and treatment

The digestive system is an essential part of all living things that carry it, and the human being is no exception. Thanks to the mouth, esophagus, stomach and intestines, we are able to transform organic matter in food into energy, through a complex process known as digestion. The hydrolysis of nutritional molecules allows them to exceed the plasma membrane of the cell and, therefore, that the mitochondria can use it for energy production.

This whole process is a dance of muscle movements, hormones, nerve signals and, above all, enzymes and intestinal juices. Every human being is capable of noticing when something is wrong in his digestive system due to its importance, and therefore we do not It is surprising to learn that gastrointestinal symptoms are one of the main reasons for visiting the consultation primary. Without going any further, it is estimated that up to 20% of the population has gastroesophageal reflux at some point in their life, and 22% irritable bowel syndrome (IBS).

Beyond aches, cramps, heartburn and pathogens,

things can also be complicated at the oral and esophageal level, the first entry point for food. If you want to know everything about this premise, read on: today we address dysphagia in all its facets.

• We recommend you read: "Eating Disorders (Eating Disorders): What Are They and What Types Are There?"

What is dysphagia?

Dysphagia is defined as an objective impediment or difficulty in swallowing, which results in the slowing of the liquid or digestive bolus through the esophageal tract. This problem can occur at two levels: the oropharyngeal (from the soft palate to the hyoid bone) and the esophageal, that is, in the tract between the mouth and the stomach.

In any case, the definition of the term also has a meaning that needs to be highlighted: the subjective feeling of dysphagia in the patient. Neuronal dysfunction may (or may not) attenuate or increase the sensation of difficulty swallowing, although anatomical failure may not be present. The same happens in the opposite case: a person may not perceive his dysphagia, but it is observed in imaging tests.

Dysphagia is a common problem in the population and it usually appears due to neurological and muscular processes, myasthenia, post-radiation fibrosis and many other clinical entities. We then distinguish the etiology of dysphagia based on its subtypes.

1. Oropharyngeal dysphagia

This type of dysphagia is due to disorders affecting the hypopharynx and upper esophagus. For this reason, the patient who experiences this variant is usually unable to initiate swallowing and must try it repeatedly. This causes a delay in the movement of the food bolus in the oropharyngeal phase of swallowing. The clinical entity can be divided into three different branches:

• Neurological cause- Includes stroke (post-stroke dysphagia), basal ganglia injury, or a symptom of Parkinson's disease.
• Muscular cause: due to polymyositis (chronic inflammatory myopathy), muscular dystrophy and myasthenia gravis.
• Anatomical causes: from an enlarged thyroid, tumors, abscesses and external compressions, for example, due to an aortic artery aneurysm.

Because of any of these clinical events, the food bolus cannot be propelled effectively into the hypopharynx (via the upper esophageal sphincter) and into the esophagus. Symptoms are localized in the region of the cervical esophagus, and dysphagia occurs one second after swallowing. In other words, the patient feels that the food "does not pass" beyond his oral cavity and immediately posterior structures.

2. Esophageal dysphagia

In this case, patients have difficulty transporting the bolus, once it has crossed the pharynx and the upper esophageal sphincter. The time interval between the act of swallowing and the appearance of symptoms can show the portion of the esophagus that has been affected. 1-2 seconds indicates that the obstruction is in the upper esophageal tract, 2-4 seconds it is located in the middle third and more than 4 seconds indicate a failure in the esophageal third lower. In addition, the type of food that causes problems and the time of onset of symptoms are also very important to classify this entity.

For example, people who have difficulty eating solid foods (but not liquids) often have an esophageal problem on a mechanical level. In other words, this means that something is obstructing proper circulation in one of the the thirds of the esophagus, either an esophageal mass or eosinophilic esophagitis, among others paintings. In the latter case, an accumulation of lymphocytes occurs in the esophagus tissue, causing chronic inflammation, damage, and a reduction in the diameter of the canal.

On the other hand, people who have difficulty eating solids and liquids show a different cause, generally a disorder in esophageal motility. Some of the clinical entities that can cause this picture are the following:

• Esophageal spasms: painful contractions in the muscular lining of the esophagus. The causes of this pathology are not known.
• Achalasia: the esophagus is unable to carry food to the stomach.
• Ineffective esophageal motility.
• Scleroderma with esophageal manifestation: the body's immune system recognizes tissues bodily harm and injury, resulting in a build-up of scar tissue and collagen. 90% of patients with scleroderma have an affected esophagus.

There are other clinical entities that can cause esophageal dysphagia, but these are some of the most obvious.

Pathogenesis

Especially in elderly people, dysphagia can be oropharyngeal, esophageal, or mixed. In the most severe cases of the oropharyngeal variant, the patient cannot swallow his own saliva, which causes drooling (excessive accumulation of fluid in the oral cavity), loss of strength in the bite and problems oral.

In patients who have suffered a cerebral infarction (cerebrovascular accident, CVA), dysphagia can further complicate the feeding process. Lack of swallowing can make it impossible to consume drugs and voluntarily chew food, among many other things. Even lesions in the cortical area of ​​the precentral gyrus can cause, in addition to dysphagia, lack of control in the facial muscles, lips, tongue and mouth. Prolonged medical assistance is necessary in all the people who present these joint pictures.

In the case of patients with esophageal cancers and other neoplasms, these may develop dysphagia after chemotherapy and radiotherapy treatments, due to inflammation of the surface of the esophagus (mucositis). In addition, saccharomycete species of the genus Candida can infect 70% of these patients during their recovery. This fungus is commensal in the oral cavities, but unfortunately, if the mucosa is damaged, it finds an ideal environment in which to proliferate uncontrollably.

Schatzki's ring and dysphagia

Schatzki's ring (also referred to as the lower esophageal ring) is a narrowing of the inner portion of the esophagus which can cause sporadic swallowing problems. It is a very frequent anomaly in the general population (up to 10% present it), but it is not often diagnosed, since it causes very few symptoms. This dysfunction can present in the form of episodic and non-progressive dysphagia.

In the vast majority of cases, this abnormality does not require treatment, as it usually occurs silently. In any case, if it causes a lot of discomfort in the patient, a forced dilation of the affected esophagus area may be necessary by surgery.

Resume

In summary, dysphagia is more of a symptom than a condition, since it shows an underlying problem, be it immune, neurodegenerative, muscular or mechanical. Unfortunately, the best known triggers for dysphagia are Parkinson's, other parkinsonism, and multiple sclerosis. When the neurons that send signals to the esophagus are damaged, swallowing can become very difficult. Difficulty swallowing, in these cases, is further evidence of severe and progressive neurological failure.

On the other hand, dysphagia can also be caused by slightly more anecdotal conditions, such as sporadic inflammation, idiopathic esophageal spasms, or Schatzki's ring. Depending on the underlying cause of the symptom, the treatment and the prognosis are very different.