Diseases of the brain
- Stroke. The most common disease affecting swallowing is a stroke (cerebrovascular accidents) that affect the swallowing center.
- Tumors of the brainstem. These tumors interfere with the transmission of nerves that carry information between the esophagus and the swallowing center in the brain.
- Degenerative diseases of the brain. The three most common degenerative diseases are Parkinson's disease, multiple sclerosis (MS) and amyotrophic lateral sclerosis (ALS).
- Degenerative diseases of the motor nerves. Motor nerves are nerves that control the contraction of skeletal muscle. Poliomyelitis (polio, caused by a virus) is an example of a degenerative disease of motor nerves in the brain that impairs swallowing by interfering with the control of skeletal muscle in the pharynx.
Diseases of the smooth muscle of the esophagus
- Achalasia. Achalasia is a condition that affects the smooth muscle portion of the esophagus, that is, the lower esophagus and the lower esophageal sphincter. Specifically, the peristaltic wave disappears, and the lower sphincter does not relax. As a result of this "double whammy," the food bolus sticks in the esophagus. With prolonged obstruction the esophagus enlarges (dilates) causing additional problems. The cause of achalasia is not clear but probably involves abnormalities of the nerves within the smooth muscle that lead to abnormal function of the muscle. In one sense, therefore, achalasia may be considered primarily a neurological problem. There is a parasitic infectious disease, called Chagas disease that mimics achalasia and occurs with a higher prevalence among individuals from Central and South America. In Chagas disease the parasite appears to destroy the nerves that control the smooth muscle.
- Ineffective peristalsis. Ineffective peristalsis is not really a disease but rather a condition in which the force of the peristaltic wave of contraction is reduced to the point that the wave no longer is strong enough to push the bolus of food through the esophagus and into the stomach. By itself, ineffective peristalsis usually does not cause a serious problem. The reason for this is that almost all meals are eaten in the upright position, and the effect of gravity on the bolus provides an additional and important force that alone can propel most boluses into the stomach. Severe problems only occur when a second impediment to passage of the bolus occurs such as a stricture of the esophagus. Ineffective peristalsis usually occurs by itself but it may be associated with other diseases such as collagen-vascular diseases (for example, scleroderma) and diabetes. Theoretically, ineffective peristalsis could be due to either muscular or neurological problems within the smooth muscle.
- Spastic motility disorders. Spastic motility disorders are a group of conditions of unknown cause in which contractions of the esophagus are not orderly. Rather than a progressing, peristaltic wave, contraction of all or a large portion of the esophagus is simultaneous (spastic), and thus the bolus of food is not propelled forward. Other disorders that are classified with the spastic disorders include peristaltic pressures that are abnormally high and spontaneous contractions of the esophagus, that is, contractions that are not triggered by a swallow. In addition to dysphagia, the spastic motility disorders may cause severe chest pain mimicking heart pain (angina) that occurs spontaneously, that is, unassociated with eating. The most common spastic disorder is referred to as "nutcracker" esophagus, a term that emphasizes the appearance of the esophagus on X-rays that is due to very high peristaltic pressures rather than spasm. The second most common spastic disorder is diffuse esophageal spasm, a name that emphasizes the spasm.
Medically Reviewed by a Doctor on 3/9/2016