ESOPHAGEAL MOTILITY DISORDERS

Esophageal neuromuscular dysfunction: dysphagia,chest pain, or heartburn ACHALASIA Diffuse Esophageal Spasm (DES) GERD Secondary Motility disorders : pseudoachalasia, Chagas’ disease, scleroderma

ACHALASIA Rare disease , loss of ganglion cells within the esophageal myenteric plexus Incidence 1:100,000 , age 25 and 60 , Aganglionosis in longstanding disease Both excitatory (cholinergic) and inhibitory (nitric oxide) ganglionic neurons Inhibitory neurons (deglutitive LES relaxation) and sequential propagation peristalsis Absence Inhibitory neurons … impaired deglutitive LES relaxation and absent peristalsis Causes of ganglion cell degeneration :autoimmune process (latent infection HSV1 combined with genetic susceptibility)

Long-standing achalasia : progressive dilatation sigmoid deformity of the esophagus with hypertrophy of the LES Clinical manifestations : Dysphagia, regurgitation, chest pain (early course result from esophageal spasm), weight loss , solid and liquid food dysphagia Regurgitation (retention of food, fluid, and secretions in the dilated esophagus) In advanced achalasia : Bronchitis, pneumonia or lung abscess (chronic regurgitation and aspiration)

Patients describe a squeezing, pressure-like retrosternal pain, sometimes radiating to the neck, arms, jaw, and back. Some patients complain of heartburn that may be a chest pain equivalent Treatment of achalasia is less effective in relieving chest pain than it is in relieving dysphagia or regurgitation DDx : DES, Chagas’disease, and pseudoachalasia Chagas’ disease : endemic in central Brazil, Venezuela, and northern Argentina , spread by the bite of the reduviid bug that transmits the protozoan, Trypanosoma cruzi

The chronic phase of the disease develops years after infection and results from destruction of autonomic ganglion cells throughout the body, including the heart, gut, urinary tract, and respiratory tract. Pseudoachalasia : Tumor infiltration, most commonly in gastric fundus or distal esophagus carcinoma, can mimic idiopathic achalasia Up to 5% , advanced age, abrupt onset of symptoms (<1 year), weight loss Endoscopy is a necessary part of the evaluation of achalasia

When endoscopy nondiagnostic, computed tomography (CT) scanning or EUS may be of value Rarely, pseudoachalasia can result from a paraneoplastic syndrome with circulating antineuronal antibodies Dx : barium swallow x-ray (dilated esophagus with poor emptying, an air- fluid level, and tapering at the LES giving it a beak-like appearance) Occasionally, an epiphrenic diverticulum is observed Endoscopy has a relatively minor role other than to exclude pseudoachalasia Esophageal manometry :Impaired LES relaxation and absent peristalsis High-resolution manometry (HRM) : The most sensitive diagnostic test , identifies early disease before esophageal dilatation and food retention , three subtypes differentiated based on the pattern of pressurization in the nonperistaltic esophagus

Tx : There is no known way of preventing or reversing achalasia Reducing LES pressure so that gravity and esophageal pressurization promote esophageal emptying. Peristalsis rarely, if ever, recovers Reduced LES pressure by pharmacologic therapy, pneumatic balloon dilatation, or surgical myotomy No large, controlled trials of the therapeutic alternatives exist, and the optimal approach is debated Pharmacologic therapies are relatively ineffective but are often used as temporizing therapies

Nitrates or calcium channel blockers ,caution because of their effects on blood pressure Botulinum toxin, injected into the LES under endoscopic guidance, inhibits acetylcholine release from nerve endings and improves dysphagia in about 66% of cases for at least 6 months Sildenafil and alternative phosphodiesterase inhibitors effectively decrease LES pressure The only durable therapies for achalasia are pneumatic dilatation and Heller myotomy

DIFFUSE ESOPHAGEAL SPASM (DES) Episodes of dysphagia and chest pain due to abnormal esophageal contractions with normal deglutitive LES relaxation The pathophysiology and natural history of DES are ill defined Radiographically : tertiary contractions …“corkscrew esophagus (indicative achalasia) Manometrically : Uncoordinated (“spastic”) activity in the distal esophagus, spontaneous and repetitive contractions, or high amplitude and prolonged contractions DES is actually much less common than achalasia Esophageal chest pain closely mimics angina pectoris , pain that is nonexertional, prolonged, interrupts sleep, meal-related, relieved with antacids, and accompanied by heartburn, dysphagia, or regurgitation.

Both chest pain and dysphagia are also characteristic of peptic or infectious esophagitis Dx : Manometry , Endoscopy (useful to identify structural and inflammatory lesions that may cause chest pain) Radiographically : “corkscrew esophagus,” “rosary bead esophagus,” pseudodiverticula, or curling can be indicative of DES, but these are also found with spastic achalasia. Tx : Medical (nitrates, calcium channel blockers, hydralazine, botulinum toxin, and anxiolytics) Surgical therapy (long myotomy or even esophagectomy) in severe weight loss or unbearable pain These indications are extremely rare