Dysphagia (Difficulty Swallowing): Causes, Diagnosis and Treatment

Dysphagia is difficulty in swallowing liquid or solid food due to disruption in swallowing mechanism from the mouth to pharynx. Dysphagia can lead to severe complications:

• Aspiration pneumonia
• Dehydration
• Malnutrition
• Death because of choking

Dysphagia (Difficulty Swallowing)

Symptoms

Signs and symptoms associated with dysphagia may include:

• Having pain while swallowing (odynophagia)
• Being unable to swallow
• Having the sensation of food getting stuck in your throat or chest or behind your breastbone (sternum)
• Drooling
• Being hoarse
• Bringing food back up (regurgitation)
• Having frequent heartburn
• Having food or stomach acid back up into your throat
• Unexpectedly losing weight
• Coughing or gagging when swallowing

Causes

Swallowing is complex, and a number of conditions can interfere with this process. Sometimes the cause of dysphagia can't be identified. However, dysphagia generally falls into one of the following categories.

Esophageal dysphagia

Esophageal dysphagia refers to the sensation of food sticking or getting hung up in the base of your throat or in your chest after you've started to swallow. Some of the causes of esophageal dysphagia include:

Achalasia. When your lower esophageal muscle (sphincter) doesn't relax properly to let food enter your stomach, it may cause you to bring food back up into your throat. Muscles in the wall of your esophagus may be weak as well, a condition that tends to worsen over time.

Diffuse spasm. This condition produces multiple high-pressure, poorly coordinated contractions of your esophagus, usually after you swallow. Diffuse spasm affects the involuntary muscles in the walls of your lower esophagus.

Esophageal stricture. A narrowed esophagus (stricture) can trap large pieces of food. Tumors or scar tissue, often caused by gastroesophageal reflux disease (GERD), can cause narrowing.

Esophageal tumors. Difficulty swallowing tends to get progressively worse when esophageal tumors are present.

Foreign bodies. Sometimes food or another object can partially block your throat or esophagus. Older adults with dentures and people who have difficulty chewing their food may be more likely to have a piece of food become lodged in the throat or esophagus.

Esophageal ring. A thin area of narrowing in the lower esophagus can intermittently cause difficulty swallowing solid foods.

GERD. Damage to esophageal tissues from stomach acid backing up into your esophagus can lead to spasm or scarring and narrowing of your lower esophagus.
Eosinophilic esophagitis. This condition, which may be related to a food allergy, is caused by an overpopulation of cells called eosinophils in the esophagus.

Scleroderma. Development of scar-like tissue, causing stiffening and hardening of tissues, can weaken your lower esophageal sphincter, allowing acid to back up into your esophagus and cause frequent heartburn.
Radiation therapy. This cancer treatment can lead to inflammation and scarring of the esophagus.

Oropharyngeal dysphagia

Certain conditions can weaken your throat muscles, making it difficult to move food from your mouth into your throat and esophagus when you start to swallow. You may choke, gag or cough when you try to swallow or have the sensation of food or fluids going down your windpipe (trachea) or up your nose. This may lead to pneumonia.

Causes of oropharyngeal dysphagia include:

Neurological disorders. Certain disorders — such as multiple sclerosis, muscular dystrophy and Parkinson's disease — can cause dysphagia.

Neurological damage. Sudden neurological damage, such as from a stroke or brain or spinal cord injury, can affect your ability to swallow.

Pharyngoesophageal diverticulum (Zenker's diverticulum). A small pouch that forms and collects food particles in your throat, often just above your esophagus, leads to difficulty swallowing, gurgling sounds, bad breath, and repeated throat clearing or coughing.

Cancer. Certain cancers and some cancer treatments, such as radiation, can cause difficulty swallowing.

Physiology of Swallowing

A sound knowledge of anatomy and physiology of swallowing and eating helps in the diagnosis and treatment of dysphagia. There are four stages involved in the physiology of swallowing :

Oral preparatory stage:

This stage prepares bolus for the next stage i.e, propelling food to pharynx and it prevents liquid and solid food from entering to pharynx until the bolus is ready for swallowing food.

Oral propulsive stage:

As the solid and liquid food is ready to swallow, the bolus is transfered into oropharynx with help of tongue,
Pharyngeal stage :Main feature of this stage is to prevent food from entering it into respiratory tract and prevent from aspiration.

Esophageal stage:

This stage starts after the bolus enters the Upper Esophageal Sphincter(UES).In this phase, through the peristaltic movement and with help of gravity, food enters the stomach.
Physiologically, swallowing dominates the respiration because of closure of the airway by elevation of the soft palate and tilting of the epiglottis and also of neural suppression of respiration in the brainstem. The duration of respiratory pause is different while eating liquid and solid bolus.

There are various causes for alteration in normal swallowing physiology. Broadly it can be categories into two heading :

• Structural abnormalities
• Functional abnormalities
• Structural Abnormalities

Cleft palate

It can be acquired or congenital. Cleft palate, cervical osteophytes, webs or strictures in the passage are some of the examples of the structural abnormalities. The abnormalities might affect in any stage of the swallowing and alter the normal physiology.

Functinal Abnormalities

Dysfunction in any of the four stages of swallowing process can affect the swallowing physiology an cause dysphagia.

Problem in oral stage of swallowing may lead to drooling of the food, dehydration, feeling of food trapped in oral cavity. and difficulty chewing and mastication.

Dysfunction in the pharyngeal stage leads to impaired swallowing initiation, feeling of retention of bolus in pharynx. Impairment in pharyngeal stage may result in nasal regurgitation and aspiration (due to insufficient UES opening).

Esophageal dysfunction is common and is often asymptomatic.Esophageal dysphagia can lead to feeling of retention of food in the esophagus which might lead to aspiration of food.

Diagnosis

There are many bedside and instrumental tools available for the diagnosis and treatment of dysphagia. Dysphagia evaluation tools can be grouped broadly as:

Imaging (Ultrasound, Videofluroscopy, Fiberoptic endoscopic evaluation of swallowing, and Fiberoptic endoscopic evaluation of swallowing with sensory testing)

Treatment

Treatment for dysphagia depends on the type or cause of your swallowing disorder.

Esophageal dysphagia

Treatment approaches for esophageal dysphagia may include:

Esophageal dilation. For a tight esophageal sphincter (achalasia) or an esophageal stricture, your doctor may use an endoscope with a special balloon attached to gently stretch and expand the width of your esophagus or pass a flexible tube or tubes to stretch the esophagus (dilation).

Surgery. For an esophageal tumor, achalasia or pharyngoesophageal diverticulum, you may need surgery to clear your esophageal path.

Medications. Difficulty swallowing associated with GERD can be treated with prescription oral medications to reduce stomach acid. You may need to take these medications for an extended period. If you have eosinophilic esophagitis, you may need corticosteroids. If you have esophageal spasm, smooth muscle relaxants may help.

Severe dysphagia

If difficulty swallowing prevents you from eating and drinking adequately, your doctor may recommend:

A special liquid diet. This may help you maintain a healthy weight and avoid dehydration.

A feeding tube. In severe cases of dysphagia, you may need a feeding tube to bypass the part of your swallowing mechanism that isn't working normally.

Surgery

Surgery may be recommended to relieve swallowing problems caused by throat narrowing or blockages, including bony outgrowths, vocal cord paralysis, pharyngoesophageal diverticulum, GERD and achalasia, or to treat esophageal cancer. Speech and swallowing therapy is usually helpful after surgery.

The type of surgical treatment depends on the cause for dysphagia. Some examples are:

Laparoscopic Heller myotomy, which is used to cut the muscle at the lower end of the esophagus (sphincter) when it fails to open and release food into the stomach in people who have achalasia.

Peroral endoscopic myotomy (POEM). The surgeon uses an endoscope inserted through your mouth and down your throat to create an incision in the inside lining of your esophagus. Then, as in a Heller myotomy, the surgeon cuts the muscle at the lower end of the esophageal sphincter.

Esophageal dilation. Your doctor inserts a lighted tube (endoscope) into your esophagus and inflates an attached balloon to gently stretch and expand its width (dilation). This treatment is used for a tight sphincter muscle at the end of the esophagus (achalasia), a narrowing of the esophagus (esophageal stricture), an abnormal ring of tissue located at the junction of the esophagus and stomach (Schatzki's ring) or a motility disorder. Alternatively, your doctor may pass a flexible tube or tubes of different diameters instead of a balloon.

Stent placement. The doctor can also insert a metal or plastic tube (stent) to prop open a narrowing or blockage in your esophagus. Some stents are permanent, such as those for people with esophageal cancer, while others are temporary and are removed later. 

Management and Rehabilitation

Rehabilitative exercises changes and improves the swallowing physiology in force, speed or timing, with the goal being to produce a long-term effect, as compared to compensatory interventions used for a short-term effect. Rehabilitative exercises also involve retraining the neuromuscular systems to bring about neuroplasticity, since pushing any muscular system in an intense and persistent way will bring about changes in neural innervation and patterns of movement. Rehabilitation exercise can be broadly divided into :

• Swallowing exercises
• Non-swallowing exercises

Swallowing Exercises

Swallowing exercises often are used to treat dysphagia with the goal of altering swallowing physiology and promoting long-term changes. Exercises are expected to impact swallowing mechanics and impact bolus flow.[5] Effortful swallow, Mendelsohn, super-supraglottic, Masako are some of the swallowing exercises.Swallowing exercises follow many of the neuroplasticity principles listed below:

• Use it or loose it
• Use it and improve it
• Specificity
• Transference
• Intensity

Non-Swallowing Exercises

Non-swallowing exercises are those that do not involve the act of swallowing, for example tongue strengthening exercises. Non-swallowing exercises can be:

done by patients who cannot eat orally (are tube fed) or those post-surgery who are temporarily restricted from eating orally.

Shaker head lift, tongue strengthening, Lee Silverman voice treatment, expiratory muscle strength training are some of the non-swallowing exercises. Non-swallowing exercises follow few neuroplasticity principles and they are:

• Transference
• Intensity
• Therapeutic Interventions