Esophageal Spasm

Introduction

Background

Broadly, esophageal spasm can be subdivided into 2 distinct entities: (1) diffuse esophageal spasm (DES), in which contractions are uncoordinated, and (2) nutcracker esophagus, in which contractions proceed in a coordinated manner, but the amplitude is excessive.

Symptoms can include dysphagia, regurgitation, and noncardiac chest pain. Because of the vague symptoms and difficulty in diagnosis, esophageal spasm often is not diagnosed and is undertreated. Many patients with manometric and radiologic aberrations may not have any appreciable symptoms.

Currently, manometry is the best diagnostic modality. Treatment includes calcium channel blockers, botulinum toxin, nitrates, tricyclic antidepressants, dilatation, myotomy, and esophagectomy. Research is ongoing to unlock the underlying causes to improve our diagnostic capabilities and therapeutic regimens in the future.

Pathophysiology

The esophagus is comprised of 2 layers of muscle, the inner circular and the outer longitudinal layers. Arbitrarily, the esophagus can be divided into 3 zones, each with separate yet integrated anatomy and physiology.

Esophageal zones

Upper zone: Comprised entirely of striated muscle, this zone initiates the contractions that propel the food bolus down the esophagus. The upper esophageal sphincter (UES), named the cricopharyngeus muscle, is located in the upper zone.

Middle zone: Comprised of striated and smooth muscles, the inner circular muscle layer and the outer longitudinal muscle layer work in conjunction to propel the food bolus.

Lower zone: The lower segment is the lower esophageal sphincter (LES). This sphincter is a thickening of the smooth muscle that is contracted tonically to prevent reflux. At rest, the pressure in the LES is usually 15-25 mm Hg. For food to pass into the stomach, the LES relaxes.

Upper esophageal sphincter

When functioning properly, the esophagus can detect the presence of a food bolus at the UES and then coordinate progression of the food down the esophagus to the stomach. When this does not occur in a coordinated fashion, the patient can develop symptoms of esophageal spasm.

The UES is contracted tonically. Manometric evaluation of the UES reveals constant spiking activity. As food is sensed at the UES, the laryngeal muscles contract to move the cricoid cartilage anteriorly. The tonic contraction of the UES is inhibited, opening the UES to allow passage of food. The inner circular muscles and longitudinal muscles of the remainder of the upper zone then propel the food. To propel the food, the longitudinal muscles must contract, followed immediately by contraction of the circular muscles. At the end of the upper zone, the initial wave dies out as another wave starts, propelling the food down to the middle zone. The nucleus solitarius in the brainstem controls swallowing in the upper zone.

Esophageal middle zone

The middle zone propels the food bolus from the upper zone to the lower zone. This segment consists of 2 muscle layers, an inner circular and outerlongitudinal layer.

In the middle zone, the striated muscle transitions to smooth, or involuntary, muscle. The wave propagates down the esophagus by coordinated contractions. Again, the longitudinal muscles must contract before the circular muscle contracts. Furthermore, contraction of the muscles must proceed caudally in an organized manner. If the muscle contraction is not orderly, the food bolus cannot progress.

Two forces propel the food from cephalad to caudad. First, gravity pulls the food caudally. The organized contractions of the muscles propel the food caudally. If a myotomy is performed, the contractions will be ineffective. Only gravity forces the food caudally. Thus, patients who have had a myotomy are more likely to have dysphagia.

Lower esophageal sphincter

The lower zone is comprised of the LES. This is a condensation of the smooth muscles. Tonically, this muscle is contracted and must relax to allow food to pass. Failure of the LES to relax to allow a food bolus to pass is termed achalasia (see Achalasia).

Diffuse esophageal spasms

Simplistically, DESs occur when the propagative waves do not progress correctly. Usually, several segments of the esophagus contract simultaneously, preventing the propagation of the food bolus. The usual presentation is intermittent dysphagia with occasional chest pain. Myotomy, which is performed only in extreme cases, can relieve the uncoordinated contractions.

Nutcracker esophagus

Nutcracker esophagus occurs when the amplitude of the contractions exceeds 2 standard deviations from normal. The contractions proceed in an organized manner, propelling food down the esophagus. These patients often present with chest pain, but they present with dysphagia less often than patients with DES.

Because the progression of the contractions occurs normally, patients often do not benefit from a myotomy. Even though the increased amplitude of the contractions can be demonstrated using manometry, the symptoms often do not correlate with the manometrically documented contractions.

The symptoms of DES and nutcracker esophagus may overlap and can be distinguished only by motility study.

Frequency

United States

The true incidence of esophageal spasm cannot be determined. The symptoms range from mild to severe. Patients with mild symptoms often do not seek medical attention. Because of the similarity of symptoms of reflux disease and esophageal spasm, many patients may be misdiagnosed with reflux. Furthermore, reflux and spasm can occur concomitantly.

International

Because the symptoms are mild (or even absent) in many patients, true incidence is not known.

Mortality/Morbidity

• Mortality is very rare, but morbidity can be significant.
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• Morbidity arises from an inability to eat, secondary to the pain, and the subsequent decline in nutritional status. The pain can be incapacitating, preventing normal activity and leading to considerable psychological challenges and impairment in the patient's quality of life.
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• The chest pain can mimic cardiac, pulmonary, or rheumatological chest pain, instigating appropriate workup.

Race

• This condition seemingly is more common in whites.

Sex

• This condition may be more common in women than in men.

Age

• This condition is rare in children, and incidence increases with age.