ROSH Gastrointestinal Practice Exam

Which study is considered the most sensitive for diagnosing achalasia?

1. Barium swallow

2. Electromyography

3. Esophageal manometry

4. Esophagogastroduodenoscopy

The correct answer is: Esophageal manometry

Esophageal manometry is considered the most sensitive study for diagnosing achalasia because it directly measures the pressures and contractions of the esophagus, providing detailed information about esophageal motility and the function of the lower esophageal sphincter (LES). In achalasia, there is a characteristic pattern of absent peristalsis and increased resting pressure of the LES, which can be clearly identified through this procedure. Other diagnostic tests, while useful, do not provide the same level of detail regarding the functional aspects of the esophagus. A barium swallow can reveal an enlarged esophagus and delayed emptying, but it does not give specific information about LES pressure or peristalsis. Electromyography primarily assesses the neural control of muscles, which is less relevant in the diagnosis of achalasia compared to the mechanical function of the esophagus itself. Esophagogastroduodenoscopy can visualize the esophagus and rule out other conditions but does not assess motility or pressure dynamics, making it less sensitive for achalasia diagnosis than manometry.