Gastroenterology · USMLE Step 1 and Step 2

Achalasia song

Achalasia - Diagnosis & Treatment, as a song. Hear the short teaser here. The full song is on YouTube and Spotify.

Achalasia

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Key points in this song10

Achalasia results from loss of inhibitory neurons (VIP and NO-producing) in the myenteric (Auerbach's) plexus, causing failure of lower esophageal sphincter (LES) relaxation and absent peristalsis.
Classic presentation: progressive dysphagia to BOTH solids and liquids simultaneously, distinguishing it from mechanical obstruction (solids first).
Manometry is the gold standard for diagnosis: aperistalsis in the esophageal body plus incomplete LES relaxation; Type II (panesophageal pressurization) has the best treatment response.
Barium swallow shows the classic "bird's beak" tapering at the gastroesophageal junction with proximal esophageal dilation.
Patients often regurgitate undigested food (not acidic), and nocturnal regurgitation can cause aspiration pneumonia.
Secondary achalasia (pseudoachalasia) must be ruled out—especially from gastric cardia adenocarcinoma or Chagas disease (Trypanosoma cruzi destroys myenteric neurons).
Endoscopy is mandatory to exclude malignancy before confirming primary achalasia, particularly in older patients with rapid weight loss.
First-line treatments include pneumatic dilation or Heller myotomy (surgical LES division); per-oral endoscopic myotomy (POEM) is an emerging effective option.
Botulinum toxin injection into the LES inhibits acetylcholine release and is reserved for poor surgical candidates due to its temporary effect.
Long-standing achalasia significantly increases the risk of esophageal squamous cell carcinoma due to chronic stasis and mucosal irritation.