Diagnostic Considerations
As with all reported symptoms, the differential diagnosis depends on presenting symptoms. With complaints of chest pain, coronary artery disease is the major concern and should be evaluated prior to an esophageal workup for esophageal motility disorders. Prolonged, nonexertional chest pain that is meal-related and relieved with antacids favors an esophageal etiology for chest pain. Heartburn and regurgitation further suggest esophageal etiology of chest pain with a component of reflux disease, whether it is related to esophageal dysmotility or complicating scleroderma.
In patients with dysphagia, mechanical obstructing lesions, benign or malignant, must be ruled out with esophageal endoscopic or radiographic imaging studies.
When considering a diagnosis of achalasia, the differential diagnosis includes Chagas disease secondary to Trypanosoma cruzi infection and pseudoachalasia from gastroesophageal junction tumors. An early form of achalasia, known as vigorous achalasia, can be confused with diffuse esophageal spasm.
Chagas disease
Chagas disease is an infectious disease with esophageal functioning that mimics achalasia. This condition is caused by the protozoan T cruzi, which is transmitted by a reduviid (kissing) bug bite. Chagas disease is endemic in South and Central America but has been discovered as far north as Texas. The initial manifestation is septicemia, ranging from clinically silent to life threatening; a chronic stage may then ensue. Pathophysiology reveals widespread ganglionic destruction throughout the body, involving the heart, gut, urinary tract, and respiratory tract. Clinically significant disease takes years to develop.
The most common cause of death is cardiac involvement with cardiomyopathy, conduction disturbances, and arrhythmias. Gastrointestinal tract involvement includes megaesophagus, megacolon, and megaduodenum. Esophageal involvement starts with atonic esophageal body and a nonrelaxing LES, subsequently leading to esophageal dilation. The diagnosis is confirmed by serologic testing.
Treatment of patients with esophageal Chagas disease is similar to the treatment of patients with idiopathic achalasia. Treatment is geared toward disrupting the LES. Once esophageal nerve loss has occurred, regrowth or replacement of this nerve loss is not possible. For patients with acute infection, treatment with nifurtimox and benznidazole has shown limited efficacy and has no proven efficacy in patients with chronic infection.
Familial adrenal insufficiency with alacrima
Familial adrenal insufficiency with alacrima is an autosomal recessive childhood disease with autonomic nervous system dysfunction. This condition progresses to a picture of achalasia, alacrima, sinoatrial dysfunction, and delayed gastric emptying.
Pseudoachalasia
Pseudoachalasia is a term used to describe the clinical picture of gastroesophageal junction obstruction, most classically by tumor. This condition is present in as many as 5% of patients with the manometric and radiologic diagnosis of achalasia. This clinical presentation is more likely to occur with rapidly progressive disease (< 1 y), older age of onset (>50 y), and profound weight loss. Tumor infiltration, especially involving the gastric fundus, mimics the functional impairment observed with idiopathic achalasia.
A thorough workup for achalasia includes an upper endoscopy. Biopsies should be obtained with any suspicion of a malignant process. If a suspicious lesion is found, imaging studies, including CT scan, MRI, and endoscopic ultrasound, should be obtained as indicated. In 50% of patients, the pathology is adenocarcinoma of the gastroesophageal junction. Other causes for pseudoachalasia include other malignancies, mechanical obstruction (eg, neurofibromatosis, pancreatic pseudocyst), and infiltrative diseases (eg, amyloidosis, sphingolipids, eosinophilic gastritis, sarcoidosis).
Diffuse esophageal spasm
DES and vigorous achalasia can be confused, as both have the common feature of active, higher amplitude simultaneous contractions of the esophagus. Manometric criteria require that some normal esophageal peristalsis must be present intermittently for DES. In addition, LES relaxation, which commonly is incomplete in patients with achalasia, should be normal in patients with DES. This issue is further complicated in that DES may evolve into achalasia with time, so a continuum with progression to aperistalsis is likely.
Differential Diagnoses
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The typical picture of achalasia. Note the "bird-beak" appearance of the lower esophageal sphincter (LES), with a dilated, barium-filled esophagus proximal to it. Image courtesy of Andrew Taylor, MD, Professor, Abdominal Imaging, Department of Radiology, University of Wisconsin Medical School, Madison.
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The response to amyl nitrate (a smooth muscle relaxant), with partial relaxation of the lower esophageal sphincter (LES), allows some barium to pass through it into the stomach. Image courtesy of Andrew Taylor, MD, Professor, Abdominal Imaging, Department of Radiology, University of Wisconsin Medical School, Madison.
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Esophagram of a 65-year-old man with rapid-onset dysphagia over 1 year. Although esophagram shows a typical picture of achalasia, this patient had adenocarcinoma of the gastroesophageal junction. This is an example of pseudoachalasia, which reinforces the absolute need for esophagogastroduodenoscopy (EGD) in patients with radiologic diagnosis of achalasia. Image courtesy of Andrew Taylor, MD, Professor, Abdominal Imaging, Department of Radiology, University of Wisconsin Medical School, Madison.
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An esophagram demonstrating the corkscrew esophagus picture observed in a patient with manometry confirmed findings of diffuse esophageal spasm (DES). Image courtesy of Andrew Taylor, MD, Professor, Abdominal Imaging, Department of Radiology, University of Wisconsin Medical School, Madison.
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Response to amyl nitrate, with disappearance of the spasm on esophagram. Image courtesy of Andrew Taylor, MD, Professor, Abdominal Imaging, Department of Radiology, University of Wisconsin Medical School, Madison.
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Normal manometry results show normal esophageal body peristalsis with normal lower esophageal sphincter (LES) pressure and relaxation. The LES pressure tracing is at the level of the sleeve (tracing 6).
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Achalasia manometry picture Note the nonrelaxing lower esophageal sphincter (LES) and the absence of esophageal body peristalsis. The LES pressure tracing is at the level of the sleeve (tracing 6).
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Manometry demonstrates diffuse esophageal spasm with simultaneous contractions of the esophagus observed throughout the tracing. The lower esophageal sphincter (LES) pressure tracing is at the level of the sleeve (tracing 6).
