Clinical Conditions-Dysphagia

Written by Wesam Tamimi, M.D.

Keywords: Dysphagia, swallowing difficulty, oropharyngeal dysphagia, esophageal dysphagia, barium swallow, esophagogastroduodenoscopy.

Buzzwords Scenario: A 67-year-old man presents with difficulty swallowing solid foods for the past 6 months, progressively worsening to include liquids. He reports unintentional weight loss and occasional coughing after eating. Physical examination reveals no significant abnormalities.

Overview

Dysphagia, or difficulty swallowing, is a clinical symptom that can arise from a variety of underlying conditions. It is typically classified into two categories: oropharyngeal dysphagia, which affects the initiation of the swallowing process, and esophageal dysphagia, which occurs within the esophagus. Dysphagia can be caused by structural abnormalities, motility disorders, or neurologic conditions. Early recognition and diagnosis are crucial for preventing complications such as aspiration pneumonia, malnutrition, and dehydration.

Definitions

Dysphagia is characterized by difficulty in swallowing, which may affect the oral, pharyngeal, or esophageal phases of the swallowing process.

Aphagia: Complete inability to swallow, often due to esophageal obstruction, typically seen in acute settings involving food bolus or foreign body impaction.

Odynophagia: Painful swallowing usually caused by mucosal ulceration in the oropharynx or esophagus, often accompanied by dysphagia.

Classifications

Table 1: Classification and Causes of Dysphagia

Etiology

Table 2: Causes of Dysphagia

Physiology

Swallowing is initiated voluntarily in the oral phase, involving mastication and mixing of food with saliva. The bolus is then pushed into the pharynx, triggering the pharyngeal swallow response. This complex series of actions propels the bolus through the pharynx and esophagus while preventing aspiration. Key muscles and nerves involved include:

●       Oral cavity muscles: Innervated by cranial nerves V (trigeminal) and VII (facial).

●       Tongue: Innervated by cranial nerve XII (hypoglossal).

●       Pharyngeal muscles: Innervated by cranial nerves IX (glossopharyngeal) and X (vagus).

Pathophysiology

Oropharyngeal dysphagia:

●       Neurological impairment → Reduced muscle control → Difficulty initiating swallowing → Risk of aspiration.

Esophageal dysphagia:

●       Structural obstruction or motility dysfunction → Impaired passage of food → Sensation of obstruction, regurgitation.

Clinical features

Table 3: Signs and symptoms of dysphagia according to cause

Figure 1. Bird peak appearance in esophageal achalasia

Farrokhi, F., & Vaezi, M. F. (2007, October 21). Barium swallow. Dilated esophagus with retained column of barium and “bird’s beaking” suggestive of achalasia [Photograph]. Wikimedia Commons. Idiopathic (primary) achalasia. Orphanet Journal of Rare Diseases, 2:38. https://commons.wikimedia.org/wiki/File:Acha.JPG 

Figure 2. Esophageal pouch seen in a patient with Zenker's diverticulum

Heilman, J. (2012, September 19). Lateral X-ray of a Zenker's diverticula [Photograph]. Wikimedia Commons. Own work. https://commons.wikimedia.org/wiki/File:Zenker22015Lateral.JPG

Diagnosis

Endoscopy (Esophagogastroduodenoscopy - EGD):

●       Purpose: Direct visualization of the esophagus, stomach, and duodenum; allows for biopsy and therapeutic interventions.

●       Indication: Primarily used for structural dysphagia.

●       Advantages: High sensitivity for detecting mucosal lesions, Barrett's metaplasia, and vascular lesions. Allows biopsy and dilation of strictures.

Radiography (Barium swallow):

●       Purpose: Contrast imaging of the esophagus and surrounding structures.

●       Advantages: Effective for detecting reflux, hiatal hernia, mucosal abnormalities, and esophageal strictures, especially with barium tablets. Useful for visualizing tracheoesophageal fistulas and post-surgical anatomy.

Esophageal manometry:

●       Purpose: Measures esophageal pressure and motility.

●       Indication: Used for propulsive dysphagia.

●       Advantages: Diagnoses motility disorders (e.g., achalasia, diffuse esophageal spasm), and assesses peristaltic integrity. High-resolution manometry and impedance monitoring enhance diagnostic accuracy.

Differential diagnosis of dysphagia

First step is to differentiate between:

●       Dysphagia localized to neck, nasal regurgitation, aspiration → oropharyngeal dysphagia →Illustration 1

●       Dysphagia localized to chest or neck, food impaction → esophageal dysphagia → Illustration 2

Illustration 1. Oropharyngeal dysphagia differential diagnosis

Illustration 2. Esophageal dysphagia differential diagnosis

Management

Treatment depends on the underlying cause.

Table 4: Management of dysphagia

Complications

●       Nutritional deficiencies: Resulting from reduced food intake and potential malabsorption.

●       Aspiration pneumonia: Risk of pneumonia due to aspiration of food or liquids into the lungs.

●       Impact on quality of life: Social isolation, difficulty eating in public, and weight loss due to impaired swallowing function.

Reference

Hirano, I., & Kahrilas, P. J. (2022). Dysphagia. In Harrison's principles of internal medicine (pp. 287–291). McGraw Hill.