Dysphagia: A Comprehensive Guide for MCCQE1

Introduction

Dysphagia, defined as difficulty in swallowing, is a common and high-yield presentation in Internal Medicine and Gastroenterology for the MCCQE1. It represents a sensation of “sticking” or obstruction of the passage of food through the mouth, pharynx, or esophagus.

For Canadian medical students and international medical graduates (IMGs) preparing for the MCCQE1, distinguishing between oropharyngeal and esophageal dysphagia is the critical first step in clinical reasoning. This distinction dictates the investigative pathway and management within the Canadian healthcare system.

Note: Dysphagia should be distinguished from odynophagia (painful swallowing) and globus sensation (the feeling of a lump in the throat without actual difficulty swallowing).

Classification and Pathophysiology

Understanding the anatomical location and mechanism is essential for the Medical Council of Canada (MCC) objectives.

Clinical Evaluation

In the CanMEDS framework, the Communicator role is vital here. A precise history often yields the diagnosis before any testing.

History Taking: The “Dysphagia Tree”

Use the following logic to narrow your differential diagnosis:

1. Difficulty initiating swallow? $\rightarrow$ Oropharyngeal.
2. Food sticking after swallowing? $\rightarrow$ Esophageal.
   • Solids only? $\rightarrow$ Mechanical Obstruction.
     • Intermittent: Lower Esophageal Ring (Schatzki ring), Eosinophilic Esophagitis.
     • Progressive: Peptic stricture (hx of GERD), Esophageal Cancer (weight loss, older age).
   • Solids and Liquids? $\rightarrow$ Motility Disorder.
     • Intermittent: Diffuse Esophageal Spasm (DES).
     • Progressive: Achalasia, Scleroderma (CREST).

Physical Examination

Perform a focused exam to identify systemic causes.

Diagnostic Investigations

The choice of investigation depends on the suspected location and pathology.

Medical Abbreviations:
- EGD: Esophagogastroduodenoscopy
- LES: Lower Esophageal Sphincter
- GERD: Gastroesophageal Reflux Disease
- VFSS: Videofluoroscopic Swallowing Study

1. Barium Swallow (Esophagram)

• Indication: Often the initial test for oropharyngeal dysphagia (modified barium swallow/VFSS) or if a complex stricture/diverticulum (e.g., Zenker’s) is suspected.
• Canadian Context: Useful in rural settings where endoscopy access may be delayed, but EGD is preferred for esophageal symptoms.

2. Upper Endoscopy (EGD)

• Indication: Gold standard for esophageal dysphagia.
• Utility: Visualizes mucosa, allows for biopsy (cancer, eosinophilic esophagitis), and therapeutic dilation.

3. Esophageal Manometry

• Indication: When EGD is normal, but a motility disorder (Achalasia, DES) is suspected.
• Utility: Measures pressure and coordination of the LES and esophageal body.

Differential Diagnosis Summary

Management Strategies

Management is tailored to the underlying cause.

General Measures

• Dietary Modification: Texture modification (thickened liquids, pureed diet) often managed by Speech-Language Pathologists (SLP).
• Chewing: Instructing patients to chew food thoroughly.

Specific Treatments

• Achalasia: Pneumatic dilation, Heller myotomy (surgical), POEM (Peroral Endoscopic Myotomy), or Botulinum toxin injection (poor surgical candidates).
• Peptic Stricture: PPIs and Endoscopic dilation.
• Eosinophilic Esophagitis: Elimination diet (6-food elimination), PPIs, swallowed topical steroids (fluticasone/budesonide).
• Malignancy: Staging (CT/PET/EUS) followed by resection, chemotherapy, or radiation. Palliative stenting for advanced disease.

Canadian Guidelines & Context

When preparing for the MCCQE1, be aware of guidelines from the Canadian Association of Gastroenterology (CAG) and Choosing Wisely Canada.

1. Wait Times: Canada monitors wait times for cancer care. A patient with dysphagia and alarm features is prioritized for endoscopy (target often < 2 weeks).
2. PPI Usage: Choosing Wisely Canada recommends against maintaining long-term PPI therapy for gastrointestinal symptoms without an attempt to stop/reduce them at least once a year.
3. Eosinophilic Esophagitis (EoE): The incidence of EoE is rising in Canada. Canadian guidelines emphasize biopsies from both the proximal and distal esophagus even if the mucosa appears normal during EGD for dysphagia.

Key Points to Remember for MCCQE1

• Solids only suggests a mechanical obstruction (stricture, ring, cancer).
• Solids and Liquids suggests a motility disorder (achalasia, spasm, scleroderma).
• “Steakhouse Syndrome” refers to acute food impaction, often due to a Schatzki ring or EoE.
• Adenocarcinoma is now more common than Squamous Cell Carcinoma in Canada, largely driven by obesity and GERD rates.
• Zenker’s Diverticulum is a posterior outpouching through Killian’s triangle; diagnose with Barium swallow to avoid perforation.

Study Checklist

• Can distinguish Oropharyngeal vs. Esophageal dysphagia based on history.
• Memorized the “Alarm Features” necessitating urgent endoscopy.
• Understand the difference between Achalasia and Scleroderma on manometry.
• Know the first-line investigation for a patient with a history suggestive of Zenker’s.
• Review the management of acute food impaction.

Sample Question

Case Presentation

A 68-year-old male presents to his family physician complaining of difficulty swallowing. He reports that the problem began about 4 months ago with solid foods, specifically meat and bread, but has recently progressed to involve softer foods and occasionally liquids. He has lost 7 kg (15 lbs) unintentionally during this period. He has a 40-pack-year smoking history and consumes 2-3 alcoholic beverages daily. Physical examination reveals temporal wasting but is otherwise unremarkable.

Question

Which one of the following is the most appropriate next step in the management of this patient?

• A. Trial of proton pump inhibitors (PPI) for 8 weeks
• B. Barium esophagram
• C. Esophageal manometry
• D. Upper endoscopy (Esophagogastroduodenoscopy)
• E. CT scan of the chest and abdomen

Explanation

The correct answer is:

• D. Upper endoscopy (Esophagogastroduodenoscopy)

Detailed Explanation: This clinical scenario is highly suspicious for esophageal malignancy. The key features are:

1. Age: > 50 years.
2. Symptoms: Progressive dysphagia (classic for mechanical obstruction growing in size).
3. Red Flags: Unintentional weight loss and progression from solids to liquids.
4. Risk Factors: Significant smoking and alcohol history (strong risk factors for Squamous Cell Carcinoma; GERD/Obesity are risks for Adenocarcinoma).

Upper endoscopy (EGD) is the gold standard for investigating dysphagia with alarm features because it allows for direct visualization of the lesion and, crucially, tissue biopsy for pathological confirmation.

• Option A (PPI trial): Inappropriate. While peptic strictures can cause progressive dysphagia, the presence of weight loss and the high-risk profile mandate ruling out cancer immediately. Delaying diagnosis for a PPI trial is malpractice in this context.
• Option B (Barium esophagram): While useful for defining anatomy or for proximal lesions (Zenker’s), it does not allow for biopsy. In a patient with alarm features, EGD is the preferred initial test in Canadian practice to expedite diagnosis.
• Option C (Esophageal manometry): This is used to diagnose motility disorders (e.g., Achalasia). While Achalasia can cause weight loss, the history of progressive dysphagia starting with solids strongly points to a mechanical obstruction first. Structural causes must be ruled out by EGD before investigating motility.
• Option E (CT scan): This is a staging tool. It is indicated after a diagnosis of cancer is confirmed via biopsy to assess for metastasis and local invasion. It is not the primary diagnostic test for the symptom of dysphagia.

References

1. Medical Council of Canada. (2023). MCCQE Part I Clinical Decision-Making and Multiple-Choice Question Objectives.
2. Canadian Association of Gastroenterology. (2020). Clinical Guidelines for the Management of Dysphagia. Link to CAG 
3. Toronto Notes 2023. Gastroenterology Chapter: Dysphagia Approach. Toronto Notes for Medical Students, Inc.
4. Choosing Wisely Canada. Gastroenterology: Proton Pump Inhibitors. Link to Choosing Wisely 
5. UpToDate. (2024). Approach to the evaluation of dysphagia in adults. Wolters Kluwer.