Conditions: Difficulty Swallowing (Dysphagia)

What is dysphagia?

Normal swallowing, described:

Swallowing is a complex process that involves several coordinated phases, categorized mainly into three stages: the oral phase, the pharyngeal phase, and the esophageal phase.

1. Oral Phase

The oral phase begins when food is placed in the mouth. It involves the following steps:

• Mastication: The teeth chew the food, breaking it down into smaller pieces and mixing it with saliva.

• Bolus Formation: The tongue manipulates the chewed food to form a cohesive mass known as a bolus.

• Transmission to the Pharynx: The tongue pushes the bolus to the back of the mouth, triggering the swallowing reflex.

2. Pharyngeal Phase

Once the bolus reaches the pharynx, the pharyngeal phase commences, involving:

• Swallow Reflex Initiation: The bolus triggers sensory receptors, leading to the involuntary swallowing response.

• Closure of the Nasopharynx: The soft palate elevates to prevent food from entering the nasal cavity.

• Airway Protection: The larynx elevates and the epiglottis covers the trachea, preventing aspiration.

• Pharyngeal Contraction: Muscles in the pharynx contract to propel the bolus downward toward the esophagus.

3. Esophageal Phase

The esophageal phase begins as the bolus enters the esophagus and involves:

• Peristalsis: Rhythmic contractions of the esophageal muscles push the bolus through the esophagus.

• Lower Esophageal Sphincter (LES) Relaxation: The LES relaxes to allow the bolus to enter the stomach.

• Completion: Once the bolus passes through the LES, swallowing is complete, and digestive processes begin in the stomach.

Each of these phases plays a crucial role in ensuring that food is efficiently and safely transported from the mouth to the stomach.

What is aspiration?

Aspiration refers to the act of inhaling foreign material into the trachea and possibly the lungs instead of swallowing it down the esophagus. This can occur when a person breathes in food, liquid, or other substances, which can lead to complications such as aspiration pneumonia. While it is normal for an individual to occasionally aspirate a small amount, often called “swallowing wrong,” frequent aspiration, large quantities of aspiration, and unhealthy lungs (such as with COPD) increase the risk of developing pneumonia. Often, an aspiration event is followed by strong coughing, which is a protective mechanism to clear the aspirated material. However, aspiration without a coughing or throat clearing response, called silent aspiration, is more dangerous because it lacks the clearance mechanism and may go unrecognized. Aspiration may be observed directly on x-ray with a modified barium swallow study, a barium swallow study, or a CT esophagram. Aspiration pneumonia most commonly occurs in the right lower lobe of the lungs because the straightest and most downward pathway from the trachea to the lung is to the right lower lung.

What is velopalatal insufficiency?

Velopharyngeal insufficiency (VPI) refers to the condition where the soft palate does not adequately close the gap between the nose and mouth during speech or swallowing. This can lead to air escaping through the nasal passages, resulting in speech that may be nasal-sounding or unclear. Similarly, VPI can lead to food or liquid passing into the nose rather than passing down the throat during swallowing. VPI can have several causes, including anatomical abnormalities, neurological conditions, or following treatments such as radiation therapy and surgery on the soft palate.

Depending on the situation, treatment options may include speech therapy, which can help individuals develop compensatory strategies, or surgical interventions aimed at improving closure. A plastic prosthesis (like a modified denture) may also be used to block the passageway between the throat and the nose.

COMMON descriptions OF DYSPHAGIA:

Descriptors of swallowing difficulty may be helpful in determining its cause. Common descriptors that are useful include the following:

• Dysphagia to liquids vs. to solids

• Food getting stuck on the way down

• Coughing after swallowing

• Pneumonia (characteristically in the right lower lobe of the lung if caused by aspiration)

• Weight loss

• Pain with swallowing (odynophagia)

Associated symptoms of that may help with the diagnosis include the following:

• change in voice

• pain with swallowing

• timing of onset (sudden vs. gradual)

• progressive worsening of swallowing over time

• heartburn, throat clearing, or regurgitation of liquid into the throat (which suggest reflux)

What causes oral dysphagia?

Oral dysphagia refers to difficulty in swallowing that originates in the oral phase of the swallowing process. This condition can be caused by various factors, including:

1. Neurological Disorders: Conditions such as stroke, Parkinson's disease, multiple sclerosis, and amyotrophic lateral sclerosis (ALS) can impair the nerves involved in swallowing.

2. Muscle Disorders: Diseases that affect muscle function, such as myasthenia gravis or muscular dystrophy, can lead to weak oral muscles, making it difficult to chew or move food effectively.

3. Structural Abnormalities: Anatomical issues, such as cleft palate, oral tumors, or dental problems, can affect the mouth's ability to process food and initiate swallowing.

4. Infections and Inflammation: Infections in the mouth can cause pain and discomfort during swallowing, leading to difficulty swallowing.

5. Dry mouth (xerostomia): Insufficient saliva can impair the oral phase of swallowing. Conditions causing xerostomia include Sjogren’s syndrome, a history of radiation therapy including the salivary glands, and many medications.

6. Trauma: Physical injury to the oral structures may impair swallowing.

7. Aging: As individuals age, muscle strength and coordination can decline, potentially affecting their ability to swallow properly.

8. Psychological Factors: Anxiety or previous trauma associated with swallowing can lead to learned aversions or difficulties in the oral phase.

What causes pharyngeal dysphagia?

Pharyngeal dysphagia refers to difficulty swallowing that occurs in the pharynx, the part of the throat that sits behind the mouth and nasal cavity. This condition can arise from a variety of causes:

1. Neurological Disorders: Conditions such as stroke, Parkinson's disease, multiple sclerosis, and amyotrophic lateral sclerosis (ALS) can affect the nerves responsible for swallowing. These disorders may lead to impaired muscle coordination and strength.

2. Muscle Disorders: Myasthenia gravis and muscular dystrophy can lead to weakened muscles, which can interfere with the swallowing process.

3. Anatomical Abnormalities: Structural issues, including very large tonsils and tumors in the throat or neck, can obstruct the passage of food. Zenker’s diverticulum is a dead end pouch that can form in the lower throat, causing progressive dysphagia. Additionally, congenital deformities such as cleft palate may also cause pharyngeal dysphagia.

4. Dry mouth (xerostomia): Insufficient saliva can impair the oral phase of swallowing. Conditions causing xerostomia include Sjogren’s syndrome, a history of radiation therapy including the salivary glands, and many medications.

5. Inflammation or Infection: Conditions like pharyngitis and tonsillitis can cause swelling and pain, leading to difficulty swallowing.

6. Aging: The natural aging process can lead to changes in muscle strength and coordination, increasing the likelihood of dysphagia.

7. Radiation Therapy: Treatments for head and neck cancers can lead to stiffness of the throat, decreased sensation of the throat affecting coordination of the swallowing reflex, and decreased saliva production (xerostomia).

8. Gastroesophageal Reflux Disease (GERD) and Laryngopharyngeal Reflux (LPR): Acid reflux can lead to inflammation and discomfort in the throat, complicating the swallowing process.

what causes esophageal dysphagia?

Esophageal dysphagia is a condition characterized by difficulty in swallowing. Several factors can contribute to this condition, which can be broadly categorized into structural, motility, and neurological causes.

1. Structural Causes:

   • Esophageal strictures: Narrowing of the esophagus can be caused by chronic inflammation, scar tissue, or tumors.

   • Tumors: Benign or malignant growths can obstruct the passage of food.

   • Webs and rings: Thin membranes (esophageal webs) or areas of circumferential narrowing (Schatzki rings) may form in the esophagus, leading to narrowing.

   • Foreign bodies: Ingested objects can become lodged in the esophagus.

2. Motility Disorders:

   • Achalasia: Achalasia is a rare esophageal condition that occurs when the nerves in the esophagus become damaged, leading to a loss of peristalsis, which is the coordinated muscle movement required to push food down into the stomach.

   • Esophageal spasm: Irregular contractions of the esophagus can interfere with the normal swallowing process. Nutcracker esophagus is a condition of very strong esophageal contractions often associated with chest pain, dysphagia, and regurgitation.

3. Inflammation:

   • Reflux: Inflammation and scar tissue from chronic acid reflux can lead to dysphagia.

   • Eosinophilic esophagitis can cause dysphagia due to the inflammation and swelling of the esophageal lining, which narrows the esophagus and makes swallowing difficult.

4. Neurological Causes::

   • Stroke: Damage to the brain can impact the muscles and nerves involved in swallowing.

   • Parkinson's disease: This neurodegenerative condition can affect motor control, including the muscles used for swallowing.

   • Multiple sclerosis: This condition can disrupt nerve signals necessary for swallowing coordination.

5. Other Factors:

   • Infections: Certain infections, such as candidiasis or herpes, can cause swelling and discomfort in the esophagus.

   • Medications: Some medications may cause esophageal irritation or difficulty swallowing as a side effect.

   • Age-related changes: Aging can lead to decreased coordination of the muscle contractions, strength and thus reducing swallowing efficiency. This is called presbyesophagus.

   • Trauma: Physical injury to the esophagus may cause short or long-term impairment of bolus transport.

How is dysphagia treated?

Treatment of dysphagia depends on its cause and severity. History, examination, and diagnostic testing may be needed to identify the cause. In many cases, techniques and exercises recommended by a speech and language therapist may be helpful in addition to addressing the underlying problem. In extreme cases where safe swallowing cannot be accomplished, use of a feeding tube or nutrition by IV may be necessary.