Dysphagia case 3

A 30-year-old man consults a physician because he has been having increasing difficulty swallowing both solids and liquids. Physical examination of the patient is noncontributory. Barium swallow studies show a mostly dilated esophagus with slow passage of barium into the
stomach. The very distal part of the esophagus appears narrowed into a "bird's beak." Esophageal manometry shows incomplete relaxation of the lower esophageal sphincter in response to swallowing, high resting lower esophageal pressure, and absent esophageal peristalsis.

Q 1

The manometry and barium swallow studies most strongly support which of the following diagnoses?
/ A. Achalasia
/ B. Adenocarcinoma
/ C. Barrett esophagus
/ D. Squamous cell carcinoma
/ E. Systemic sclerosis


Q 2
This patient's condition is most likely due to which of the following?
/ A. Acid reflux
/ B. Cancerous destruction
/ C. Candida infection
/ D. Fibrosis of the esophageal wall
/ E. Lack of ganglion cells

Q 3
Which of the following regulators would most likely inhibit the lower esophageal sphincter in normal individuals?
/ A. Acetylcholine and substance P
/ B. Substance P and nitric oxide
/ C. Substance P only
/ D. Vasoactive intestinal polypeptide and acetylcholine
/ E. Vasoactive intestinal polypeptide and nitric oxide


Q4
Which of the following medications is used to directly relax the lower esophageal sphincter?
/ A. Diphenoxylate
/ B. Famotidine
/ C. Granisetron
/ D. Isosorbide dinitrate
/ E. Metoclopramide


Q 5
Worldwide, which of the following parasitic diseases is most likely to produce a disorder that clinically resembles this patient's condition?
/ A. Ascariasis
/ B. African sleeping sickness
/ C. Chagas disease
/ D. Cysticercosis
/ E. Malaria

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Dysphagia case 3 answers

A1
The correct answer is A. The most likely diagnosis is achalasia. This condition is a neurogenic esophageal disorder that can occur at any age, but frequently is diagnosed when individuals are between the ages of 20 and 40. Characteristically, the swallowing difficulties involve both solid food and liquids. The manometry findings illustrated are typical; the barium swallow findings may be as illustrated or may instead show diffuse esophageal dilation without the "bird's beak" near the lower esophageal sphincter.
Larger cancers of the esophagus (choices B and D) would be more likely to cause either a mass or an ulceration, which would be visible on barium swallow.
Very small cancers and Barrett's esophagus (choice C) would require esophagogastroduodenoscopy with biopsy for diagnosis, and would be unlikely to cause dysphagia.
Systemic sclerosis (choice E) can involve the esophagus as well, however, physical examination would usually show obvious skin involvement.

A2
The correct answer is E. Individuals who have achalasia have been found to have a deficiency of inhibitory ganglion cells within the esophageal wall. This lack causes an imbalance in excitatory and inhibitory neurotransmission, with the result that the lower esophageal sphincter tends to have a higher-than-normal muscle tone and relaxes only with difficulty.
Acid reflux (choice A) can cause esophageal irritation, ulceration, and also predisposes for Barrett's metaplasia with subsequent risk of adenocarcinoma of the esophagus.
Cancerous destruction (choice B) would produce a mass, or area of stricture or ulceration.
Candida infection (choice C) of the esophagus resembles thrush of the mouth, and causes a usually superficial infection.
Fibrosis of the esophageal wall (choice D) can be the consequence of ulceration (due to reflux or ingestion of harsh chemicals such as lye) or systemic sclerosis.

A3
The correct answer is E. Physiologically important inhibitors of the lower esophageal sphincter include nitric oxide and vasoactive intestinal polypeptide. Physiologically important substances that stimulate the lower esophageal sphincter include acetylcholine and substance P.

A4
The correct answer is D. Commonly used medications to relax the lower esophageal sphincter in patients with achalasia include nitrates such as isosorbide dinitrate (remember that nitric oxide physiologically inhibits the lower esophageal sphincter) and calcium channel blockers such as nifedipine (which inhibit calcium flow into the smooth muscle of the lower esophageal sphincter, thereby inhibiting contraction.) For patients in whom medical therapy fails, other options include paralysis of the lower esophageal sphincter with intrasphincteric injection of botulinum toxin, pneumatic dilatation, and a Heller myotomy (which interrupts the muscles of the lower esophageal sphincter).
Diphenoxylate (choice A) is a opiate antidiarrheal, and would not be useful for achalasia.
Famotidine (choice B) is an H2 antagonist that would be useful in reducing stomach acidity, but would not directly affect lower esophageal pressure. Other drugs in this class include cimetidine, ranitidine, and nizatidine.
Granisetron (choice C) is a 5HT3 antagonist and is used to prevent nausea and vomiting in patients who receive chemotherapy, and after general anesthesia. Other members of this drug class include ondansetron and dolasetron.
Metoclopramide (choice E) stimulates gastric motility in patients with gastroparesis and is also a antiemetic agent.

A5
The correct answer is C. Chagas disease, which is found in South and Central America and is due to infection with Trypanosoma cruzi, can involve the heart, colon, and esophagus. The esophageal involvement clinically closely resembles achalasia.
The adult worms of ascariasis (choice A), or roundworm infection, live principally in the intestine, and can obstruct the intestine or a bile duct; the larvae can migrate to the liver, heart, and lungs.
African sleeping sickness (choice B), caused by Trypanosoma brucei and Trypanosoma gambiense, causes lymphadenopathy, rash, and CNS involvement.
Cysticercosis (choice D), due to the larval form of the pork tapeworm Taenia solium, can involve subcutaneous tissue, muscle, viscera (but not specifically the esophagus), and, most seriously, the CNS.
Malaria (choice E), due to various Plasmodium species, involves the blood, liver, kidney, spleen, and brain, but does not have a specific predilection for the esophagus.