Alchalsia

Motility disorder of the oesophagus caused by degenerative changes in the inhibitory neurons around the lower oesophagus

Aetiology

Primary (Idiopathic) Achalasia

  • Most common form
  • Due to degeneration of inhibitory neurons (nitric oxide–producing neurons) in the myenteric (Auerbach) plexus

Secondary Achalasia (Pseudoachalasia)

Caused by conditions mimicking primary achalasia:
  • Esophageal or gastric cardia malignancy
  • Chagas disease (Trypanosoma cruzi)
  • Infiltrative disorders (amyloidosis, sarcoidosis)
  • Post-surgical or post-radiation injury

Pathophysiology

Normal swallowing requires:
  • Coordinated esophageal peristalsis
  • LES relaxation mediated by inhibitory neurons
In achalasia:
  • Loss of inhibitory neurons → unopposed excitatory cholinergic activity
  • LES remains tonically contracted
  • Esophageal body becomes dilated and aperistaltic
  • Progressive food stasis → esophageal dilation and inflammation

Clinical presentation

Core Symptoms

  • Progressive dysphagia to both solids and liquids
  • Regurgitation of undigested food
  • Chest pain (retrosternal)
  • Heartburn-like symptoms (non-acidic)

Associated Features

  • Nocturnal cough or aspiration
  • Weight loss
  • Halitosis
  • Recurrent respiratory infections

Classification (Chicago Classification)

Type
Manometric Features
Clinical Implication
Type I (Classic)
Aperistalsis, minimal pressurization
Poor esophageal emptying
Type II
Aperistalsis + pan-esophageal pressurization
Best treatment response
Type III (Spastic)
Premature/spastic distal contractions
Most difficult to treat

Alarm Features (Suggest Pseudoachalasia)

  • Rapid onset of symptoms
  • Significant weight loss
  • Age >60 years

Investigations

Esophageal Manometry (Gold Standard)

  • Incomplete LES relaxation
  • Absent peristalsis
  • Classifies achalasia subtype

Barium Swallow Study

Classic findings:
  • Bird’s beak / rat’s tail narrowing at LES
  • Dilated esophageal body
  • Delayed esophageal emptying
  • Air-fluid level
      • notion image

Upper GI Endoscopy

  • Excludes malignancy (pseudoachalasia)
  • Retained food or saliva
  • Resistance at gastroesophageal junction
  • Manometry - to confirm, measures pressure within the oesophagus

Management

Definitive Therapies (Preferred)

Pneumatic Balloon Dilatation
  • Endoscopic disruption of LES muscle
  • Good short- to mid-term results
  • Risk: esophageal perforation
Surgical Heller Myotomy
  • Laparoscopic LES muscle division
  • Usually combined with partial fundoplication
  • Durable long-term results
Peroral Endoscopic Myotomy (POEM)
  • Endoscopic myotomy
  • Highly effective, especially Type III
  • Higher risk of post-procedure reflux

Pharmacologic Therapy (Limited Role)

Used in poor surgical candidates:
  • Nitrates
Drug
Dose
Timing
Mechanism
Key Adverse Effects
Isosorbide dinitrate (ISDN)
5 mg SL
10–15 min before meals
↓ LES pressure via NO
Headache, hypotension
Nitroglycerin
0.3–0.6 mg SL
Before meals
Potent LES relaxation
Syncope, flushing
  • Calcium channel blockers
Drug
Dose
Frequency
Mechanism
Notes
Nifedipine
10 mg SL or PO
30 min before meals
↓ LES tone
Most studied
Diltiazem
60–90 mg PO
3–4× daily
Smooth muscle relaxation
Less hypotension
  • Botulinum toxin injection (temporary relief)
Parameter
Details
Dose
80–100 units total
Administration
Injected into LES (4 quadrants)
Onset
Within days
Duration
3–6 months
Best for
Elderly, severe comorbidity