Dysphagia is difficulty swallowing. It is a symptom of many different disorders, including various neurological abnormalities. These include diseases such as amyotrophic lateral sclerosis (ALS) and multiple sclerosis, as well as injuries that cause damage to the brain (e.g., stroke) or spinal cord.
Dysphagia can develop at any point in the swallowing process from the mouth to the pharynx, esophagus or stomach. In some cases, dysphagia is marked by choking or coughing that occurs when a person is eating. In other cases, the person may not be able to swallow at all.
Of the various types of dysphagia, oropharyngeal dysphagia is most commonly associated with neurological problems. This type of dysphagia occurs as a result of neuromuscular problems that weaken the throat muscles and make it difficult to move food from the mouth to the throat and esophagus.
Other symptoms associated with dysphagia usually result from not consuming proper amounts of foods or liquids. They may include weight loss and dehydration. Some patients may also be at increased risk of contracting aspiration pneumonia, which occurs when food or fluids are inhaled down the windpipe or up the nose.
Treatment of dysphagia depends on its cause. For oropharyngeal dysphagia, occupational or speech therapy is frequently used to help patients learn to swallow better. For example, positioning the head and neck in certain ways can aid in swallowing. Certain exercises can also help patients coordinate swallowing muscles or restimulate the nerves that trigger the swallowing reflex.
Dysphagia is difficulty swallowing. Some people may experience difficulty swallowing under all circumstances, while others may have trouble swallowing just certain substances (e.g., foods, liquids, saliva). When dysphagia makes eating difficult, people may be at increased risk for malnourishment.
About 50 pairs of muscles and scores of nerves are involved in the swallowing process. Normally, swallowing is a process that begins with combined action of the tongue and jaw muscles which chew the food, moisten it with saliva and then push food to the back of the throat. This process is controlled voluntarily. Combinations of involuntary and voluntary muscle contractions trigger the reflexes that push the food to the back of the throat (pharynx) and down past the windpipe (trachea) and into the tube that connects the throat to the stomach (esophagus). The involuntary contractions that propel food into the esophagus are controlled by a brain region called the medulla oblongata. Voluntary swallowing is controlled by the cerebral cortex.
Bands of muscle (sphincters) at the top and bottom of the esophagus open when a person swallows to allow food to pass, and then quickly close. The sphincter at the bottom of the esophagus is controlled by an involuntary reflex, which opens to allow food to enter the stomach and closes to keep stomach acid from entering the esophagus.
Dysphagia occurs when an abnormality develops in any stage of the swallowing process, from the mouth to the pharynx, esophagus or stomach.
In some cases, dysphasia is marked by choking or coughing that occurs when a person is eating. In other cases, a person may not be able to swallow at all. Some people may experience a feeling of food getting stuck in their throat or chest, or behind the breastbone. Pain may be felt when swallowing (odynophagia), or eating may be accompanied by regurgitation or frequent heartburn. Patients may also hear a gurgling sound in the throat when swallowing.
Damage associated with certain neurological events, such as stroke or damage to the brain or spinal cord, can also cause dysphagia. In infants and children, nervous system disorders such as cerebral palsy or meningitis may cause dysphagia.
Several degenerative neurological conditions are associated with dysphagia. These include:
- Amyotrophic lateral sclerosis(ALS)
- Huntington’s disease
- Multiple sclerosis
- Muscular dystrophy
- Myasthenia gravis
- Parkinson’s disease
- Postpolio syndrome
- Wilson’s disease
Dysphagia can also result from disorders not associated with neurological conditions. These include cancer and cancer treatment, heart problems, cleft lip or palate, aging, inhaled foreign objects and many other diseases and conditions.
Other symptoms related to dysphagia
Other symptoms associated with dysphagia usually result from not consuming proper amounts of foods or liquids. They may include weight loss and dehydration. Some patients also may be at increased risk of developing aspiration pneumonia, which occurs when food or fluids are inhaled down into the windpipe or up the nasal passages.
Dysphagia in infants and young children is usually first detected by noticing other symptoms that occur with it. For example, children with this symptom may not pay attention during feeding or meals. They may tense their bodies during feeding or reject foods with certain textures.
Other signs that may accompany dysphagia in young children include:
- Coughing and gagging during meals
- Difficulty coordinating breathing with eating and drinking
- Feeding times that last a half-hour or longer
- Leaking of food or liquid from the mouth
- Poor growth or weight gain
Types and differences of dysphagia
There are several different types of dysphagia. Neurological conditions are most likely to cause a type of dysphagia called oropharyngeal dysphagia. This involves weakened throat muscles that make it difficult to move food from the mouth to the throat and esophagus. Many patients choke or cough when swallowing and may have food or fluids go down the windpipe instead of the esophagus, or up the nose. This can allow harmful bacteria to grow, resulting in a condition known as aspiration pneumonia.
Additional types of dysphagia include:
- Esophageal dysphagia. The most common type, it is a swallowing difficulty that originates in the esophagus. Patients with esophageal dysphagia may feel like food is stuck at the base of the throat or in the chest.
- Unexplained (or functional) dysphagia. This is a swallowing difficulty that has no identifiable anatomical cause. Examples include difficulty in swallowing pills and the sensation of having a lump in one’s throat (globus).
Potential causes of dysphagia
There can be many different causes of dysphagia. Neurological damage (e.g., brain or spinal cord damage) can weaken the throat muscles, making it difficult to move food from the mouth to the throat and esophagus. Dysphagia may be the first symptom of a neurological disease or disorder.
For example, after a stroke, nerve damage commonly causes difficulties with swallowing by preventing muscles from moving food through the swallowing process. Nerve damage can also inhibit swallowing by reducing sensation in the mouth and throat. Other neurological disorders can also cause dysphagia, including dementia, Parkinson’s disease, multiple sclerosis, amyotrophic lateral sclerosis (ALS) and corticobasal degeneration.
Additional conditions that can cause dysphagia include:
- Achalasia. Occurs when the lower esophageal muscle does not relax enough to let food enter the stomach.
- Diffuse spasm. A condition that produces high-pressure, poorly coordinated contractions of the esophagus after swallowing.
- Paralyzed vocal cords. Throat infections or surgery may cause temporary paralysis of one or more vocal cords, causing dysphagia.
- Esophageal stricture (narrowing of the esophagus).
- Esophageal tumors. Abnormal growths can block part of the esophagus.
- Foreign bodies. Food (e.g., large piece of meat) or other foreign objects can become lodged in the throat or esophagus.
- Gastroesophageal reflux disease (GERD). Condition in which stomach acid backs up into the esophagus. Damage to these tissues can cause dysphagia.
- Pharyngeal diverticula. Small pouch that forms and collects food particles in the throat, leading to dysphagia.
- Cancer and cancer treatment. Cancer can cause lesions in the pharynx, trachea and esophagus that may lead to dysphagia. Radiation and chemotherapy treatments can also damage the throat and esophagus and cause dysphagia.
- Medications. Certain medications may injure the mucus lining of the esophagus, causing dysphagia. These include antibiotics, antipsychotics, vitamin C and nonsteroidal anti-inflammatory drugs (NSAIDS). Other medications may reduce lower esophageal sphincter tone, interfering with swallowing. These include anticholinergics, antihistamines and opioid pain relievers. Recent injections of botulinum toxin can also cause dysphagia.
- Scleroderma. Disease marked by overgrowth of tissue resembling scars. It can weaken the lower esophageal sphincter and allow tissue-damaging acid to reflux into the esophagus and cause dysphagia.
Although dysphagia can affect all age groups, it is most likely to affect the elderly. Some degree of esophageal muscle strength loss and coordination occurs with age. However, aging usually causes mild problems with esophageal muscle mobility and does not typically cause noticeable symptoms. Although some esophageal weakness occurs naturally with age, dysphagia is not an inevitable part of becoming older.
Treatment and prevention of dysphagia
Treatment of dysphagia depends on its cause. For oropharyngeal dysphagia (which is most commonly associated with neurological conditions, particularly stroke), speech and occupational therapy is frequently used to help patients learn to swallow better. For example, positioning the head and neck in certain ways can aid swallowing. Certain exercises can also help patients coordinate swallowing muscles, restimulate nerves that trigger the swallowing reflex and learn to swallow with greater control.
Other treatments for dysphagia may include:
- Medications. Medications to treat gastroesophageal reflux disease (GERD) may help relieve conditions that contribute to dysphagia.
- Surgery and other procedures. Dysphagia caused by vocal cord paralysis or tumors may require surgery. An endoscope (a long, flexible tube) with a special balloon may be used to help stretch the esophagus to treat dysphagia as the result of other causes.
Some patients may need to have a feeding tube inserted into their stomach (gastrostomy) to help prevent malnourishment due to their dysphagia.
In many cases, there is no way to prevent dysphagia associated with neurological abnormalities. However, people who take appropriate safety precautions during potentially hazardous activities (e.g., bicycle or motorcycle riding, contact sports) by using appropriate headgear, can reduce the risk of brain or spinal cord injuries that sometimes results in dysphagia.
Questions for your doctor regarding dysphagia
Preparing questions in advance can help patients to have more meaningful discussions with healthcare professionals regarding their condition. Patients may wish to ask their doctor the following questions related to dysphagia:
- Is my dysphagia related to a neurological problem?
- What do you think is the cause of my dysphagia?
- Will I develop symptoms in addition to what I’m experiencing now?
- What are my treatment options?
- What are the potential side effects of these treatments?
- Is swallowing therapy an appropriate option for me?
- Who can provide this therapy for me?
- Will I require insertion of a feeding tube or another surgical procedure?
- What is my long-term prognosis?
- How can I tell if my child is experiencing dysphagia?