The term "esophageal spasm" is used to designate a specific kind of esophageal motility disorder whose symptoms include dysphagia, regurgitation and noncardiac chest pain. Esophageal spasm is characterized by spastic contractions of the esophagus, and it is traditionally subdivided in two categories: Diffuse esophageal spasm (DES), in which the contractions are uncoordinated, and nutcracker esophagus (NE), in which the contractions are coordinated, but the muscular pressure during peristalsis is excessive and leads to chest pain.
Esophageal spasm has not been extensively studied and the data about this medical condition in the literature remains scarce. Because the intensity of the symptoms can range from mild to severe, only a portion of those affected by the condition actively seek medical attention, and its incidence in the general population is undetermined. Esophageal spasm may be more common in women and in individuals of white ethnicity.
The cause of esophageal spasm is presently unknown, but several theories have been advanced to explain its pathophysiology. An abnormal release of acetylcholine or an abnormal gradient of this neurotransmitter from the proximal to the distal esophagus may trigger the abnormal contractions characteristic of the condition. Another possible explanation is that inhibitory factors, that may normally counteract contractile factors, could be deficient in patients affected by esophageal spasm. For example, insufficient nitric oxide (NO) synthesis and/or release has been proposed to underlie the presence of symptoms, and some empirical evidence has been presented supporting this hypothesis. Regardless of whether contractile, inhibitory or a combination of both types of factors are involved, abnormalities in the nervous system are likely to be the underlying cause, and they can be either motor or sensory in nature.
Nutcracker esophagus is often associated with gastroesophageal reflux disease (GERD), leading to the speculation that the refluxes may trigger the spastic contractions. Microvascular compression of the Vagus nerve in the brainstem has also been mentioned as a possible cause. Esophageal wall thickening has also been observed in association with the symptoms, but it is not clear whether this is a cause or a consequence of symptoms present with esophageal spasm.
Typical symptoms of esophageal spasm include:
- Dysphagia (difficulty in swallowing) (more common in diffuse esophageal spasm (DES))
- Noncardiac Chest Pains (more common in nutcracker esophagus (NE))
- Globus (feeling of a foreign object lodged in the throat)
The symptoms of esophageal spasm tend to be intermittent and may occur with or without food. Many patients do not have any symptoms at all and the motility deficit only becomes evident after they undergo esophageal manometry studies.
The diagnostic modalities most commonly used for esophageal spasm are barium swallow and esophageal manometry.
A barium swallow shows a characteristic appearance of multiple simultaneous contractions (known as a "corkscrew" esophagus) in about 30% of patients affected by diffuse esophageal spasm due to the intermittent nature of the symptoms. However, barium swallow studies are usually normal in the case of the nutcracker esophagus, and so are the results of an endoscopy, unless the case is associated with gastroesophageal reflux disease.
The diagnosis of nutcracker esophagus is typically made after an esophageal motility study, also known as esophageal manometry, which evaluates the pressure of the esophagus at various points along its length. According to the criteria established by the American gastroenterologist D.O. Castell for the diagnosis of nutcracker esophagus and that are universally accepted, the mean peristaltic amplitude in the distal esophagus has to be higher than 180 mm Hg, accompanied by repetitive contractions of more than six seconds in duration. For diffuse esophageal spasm, the classic definition is more than 2 uncoordinated contractions during 10 consecutive wet swallows.
Because the causes of esophageal spasm are unknown, all medical treatments are directed at symptom relief. Some of the commonly employed treatment options include calcium channel blockers, nitrates, tricyclic antidepressants, smooth muscle antispasmodics, BTX, sildenafil, dietary modification, and peppermint oil.
Nitrates such as nitroglycerin have been observed to improve manometric findings and chest discomfort. The antidepressants trazadone and imipramine have been shown to reduce chest pain symptoms effectively, perhaps through the modification of visceral sensory perception. Phosphodiesterase-5 (PDE-5) inhibitors such as Sildenafil can reduce the amplitude of contractions by blocking the degradation of nitric oxide-stimulated 3'5'-cyclic monophosphate and thus eliciting more prolonged smooth muscle relaxation. Peppermint oil also appears to provide some improvement in manometric abnormalities in patients with diffuse esophageal spasm (DES). Endoscopic therapy with botulinum toxin (Botox) can also be used to temporarily improve symptoms.
Since cold water can induce or exacerbate the symptoms of esophageal spasm in some patients, swallowing hot water is also used to relieve symptoms, and it appears to have an effect by improving esophageal clearance and decreasing the amplitude and duration of esophageal contractions.
Selected patients who fail to respond to medical therapy should be considered candidates for surgery. In the case of diffuse esophageal spasm, the operation involves myotomy (removal of the muscles in the esophagus) and is performed either by an open (thoracotomy) or a laparoscopic approach. This procedure is also used to treat nutcracker esophagus (NE), but the percentage of success tends to be much lower in this case. Complications of surgical myotomy include the development of reflux esophagitis and Barrett esophagus.
Balloon dilatation has occasionally been used to treat esophageal spasm, although it is much more commonly used in cases of achalasia. Esophagectomy (resection of the esophagus) is occasionally used as a last-resort treatment, with the stomach, small intestine or colon used to restore the continuity of the gastrointestinal tract.
The prognosis for esophageal spasm is moderate, with most patients showing an improvement in their symptom scores over time (3 - 10 years). However, a follow up study found that only 29% of patients with nutcracker esophagus and 39% of those diagnosed with diffuse esophageal spasm had found a specific treatment helpful. This demonstrates that some patients do not respond to any treatment, but symptoms are nevertheless controllable with a combination of treatment modalities.
The surgical treatment of diffuse esophageal spasm gives very good results, with dysphagia relief observed in 80% of patients after thoracoscopic myotomy, and in 86% of patients after laparoscopic myotomy. Similar percentages were seen for chest pain relief. Unfortunately, the results are much less encouraging for patients affected by nutcracker esophagus, with only 50% reporting any improvement in their chest pain.
Since the events that trigger an episode of esophageal spasm remain poorly understood, there are no clear preventive measures. The consumption of very hot or very cold drinks is however not advised, as this habit has been associated with the development of symptoms.
Gastroesophageal reflux disease (GERD) is often associated with esophageal spasm, and therefore taking measures to treat this condition is thought to contribute to prevention. These measures may include reducing alcohol intake, quitting tobacco use, avoiding excessively fatty or spicy foods, losing weight and taking antacids.
There are no formal studies on the quality of life of patients affected by esophageal spasm, but the quality of life in achalasia patients, who also experience dysphagia as one of the most common symptoms, is known to be significantly reduced. Patients with esophageal spasm are known to periodically experience episodes of excruciating chest pain that resemble a heart attack, but these symptoms can be controlled in the majority of cases with appropriate medical treatment and monitoring.
Newer anticholinergic agents that target the muscarinic type 3 receptor specifically are currently being tried in a clinical setting. These agents, which include zamifenacin and darifenacin, help relax smooth muscle, but are less likely to cause side effects such as blurry vision, increased heart rate or dry mouth.
High-resolution manometry, esophageal electrical impedance monitoring and high frequency intraluminal ultrasound imaging are among the new techniques that have revealed novel information on the sensory and motor function of the esophagus and can be expected to contribute significantly in the effort to further understand the still obscure etiology of esophageal spasm. High-resolution manometry has increased sensitivity for detecting motor disorders of the esophagus through increased efficiency of recording and better visualization. Intraluminal esophageal electrical impedance can detect esophageal clearance of bolus and thus identify the abnormal transit for liquid or viscous boluses associated with esophageal spasm. High frequency intraluminal ultrasound imaging can be used to detect hypertrophy of the muscles of the esophagus, study longitudinal muscle function and coordination between circular and longitudinal muscle contraction in normal subjects, and discoordination in patients with nutcracker esophagus.