If you've ever gulped a cup of coffee while simultaneously searching for car keys, packing lunch for a 5-year-old and giving directions over the phone, you probably didn't notice that a miracle was occurring literally underneath your nose.
Swallowing is a seemingly simple but extraordinary act, one we usually take for granted at least until something goes wrong with the process.
Dysphagia — which isn't a disease in itself but the medical term for a disruption to the normal swallowing process — can lead to a number of serious effects, some gradual and some that are immediately life- threatening.
Various diseases in the muscular dystrophy family have been known to cause dysphagia, including the oculopharyngeal (OPMD), myotonic (MMD), facioscapulohumeral (FSHD) and limb-girdle (LGMD) forms and possibly Duchenne (DMD) in its later stages.
Dysphagia is a common feature of amyotrophic lateral sclerosis (ALS) and occurs in some of the spinal muscular atrophies as well as in polymyositis, myasthenia gravis and Friedreich's ataxia.
In some cases, swallowing difficulties may be the first sign that a neuromuscular disease is present. Head injuries, strokes and other conditions also may cause dysphagia.
An everyday miracle
Normal swallowing, although it seems to take place quickly and without any special planning or conscious effort, is a complex, multistage process requiring the seamless cooperation of both voluntary and involuntary muscles.
In the mouth, the lips, teeth and tongue help prepare the bolus (food mass) for further stages of swallowing.
Access between the nasal cavity and mouth closes as the bolus moves into the pharynx (throat).
|The bolus is propelled toward and into the esophagus as the esophagus entrance opens and the epiglottis helps guard against access to the lungs.||The airway reopens and the esophagus entrance closes as muscle contrctions move the bolus toward the stomach.|
In the first stage, food matter, whether solid or liquid, is introduced into the mouth and chewed, manipulated and consolidated into a mass called the bolus. The lips, the tongue and the jaw each play a part in controlling the bolus and moving it toward the region at the back of the mouth called the pharynx.
The pharynx gives way to two openings. One goes into the esophagus, the tube leading to the stomach. The other opens into the larynx and leads to the "windpipe," or trachea, which delivers air to the lungs. Swallowing enters a critical phase here: The aim is for all of the bolus to enter the esophagus and not the larynx.
Muscles in the pharynx contract and push the food down as a valve at the top of the esophagus relaxes and opens. At the same time, the larynx closes and rises to form a seal against a piece of tissue called the epiglottis, momentarily cutting off the air supply and preventing any matter from entering the lungs.
As soon as the bolus has moved safely into the esophagus, the airway reopens and breathing is allowed to resume. Though complicated, this pharyngeal phase of swallowing may only take a few seconds to get the bolus from the mouth to the esophagus.
The next part of the swallowing process, the esophageal phase, may be the longest.
The esophagus, a tube of muscle, relaxes at first to allow the entry of the bolus. Then muscle contractions called peristaltic waves push the bolus down the tube. These contractions are so efficient that it's possible to defy gravity and swallow while standing on one's head.
Once the bolus passes through another valve at the bottom of the esophagus and enters the stomach, the normal process of swallowing is complete.
An important but generally unnoticed function of normal swallowing is the removal of secretions such as saliva and phlegm that can accumulate in the mouth and the throat.
Serious repercussions are possible
Dysphagia can disrupt any or all stages of the swallowing process and, in turn, can interfere with two vitally important body processes: nutrition and respiration.
Muscle weakness affecting the oral area (including the tongue) can cause difficulty with such tasks as chewing, keeping all the food in the mouth and moving the bolus to the back of the mouth.
In the pharyngeal stage, weakened muscle may lead to problems propelling the bolus into the esophagus. Some particles may remain in crevices in the pharynx, and can later fall into the airway. Muscle weakness may also cause an incomplete covering of the entrance into the larynx. Then coughing or choking results as unwanted material enters the larynx and/or trachea.
"With neuromuscular weakness, there is a generalized slowing as well as diminished muscle force, which just throws everything off," says Jeanne Thomson, who works with ALS patients at the Eleanor and Lou Gehrig MDA/ALS Center at Columbia Presbyterian Medical Center in New York.
Thomson is a speech language pathologist (SLP), a professional who focuses on speech and swallowing problems.
Other professionals who may be involved in evaluating swallowing problems may include a gastroenterologist (an expert in the stomach and intestines) and an otolaryngologist (an ear, nose and throat expert), as well as a neurologist.
In a person with neuromuscular slowing and weakness, solid matter or liquid (especially liquid, because it travels more quickly) may reach the larynx before the protective mechanisms have had time to take effect.
If coughing fails to dislodge a blockage in the trachea in order to free up the airway, death can result. Those who care for a person affected by dysphagia may wish to take a CPR or first aid course that includes instruction on the Heimlich maneuver, a technique that, when done correctly, can quickly clear the trachea of obstruction. Anyone can experience choking, so this training is a good idea in general.
If food, saliva or phlegm enters the larynx without causing coughing or choking, it may then go into the lungs. This event, called aspiration, can breed bacteria, which can cause aspiration pneumonia. Like other forms of pneumonia, this can be fought with antibiotics and may require hospitalization.
"If someone develops aspiration pneumonia and the immune system is weakened to the point where they can't fight it, the person can die," Thomson says.
Food matter reaching the esophagus can get stuck there because of weakness of the esophageal muscles or inefficient chewing in earlier stages that leaves unmanageable particles.
Although most people are unaware of the esophageal stage of swallowing, people with dysphagia may experience spasms as the muscles have to work extra hard to move the bolus along. Food that gets stuck in the esophagus can sometimes go back up, resulting in acid reflux (heartburn).
In a person with dysphagia, fatigue and muscle weakness, especially if they're coupled with breathing problems while eating, can be so discouraging that the person pushes his plate away at mealtime. Malnutrition and dehydration can result.
Dysphagia can also contribute to social isolation, since so many social and family activities revolve around eating.
As an added complication, when malnutrition occurs, the body uses muscle as a source of energy and protein, accelerating weakness.
Scoping out the problem
Weight loss may be one of the first signs that a swallowing problem exists. Other signs of dysphagia include changes in voice quality after eating, anxiety about eating, taking a longer time to finish meals, frequent bouts of pneumonia, coughing, heartburn, drooling and discernible tongue weakness. Some medications can contribute to dysphagia, so all medication information should be shared with health care providers.
An evaluation done by an SLP at bedside or during mealtimes may provide some insights as to what's going wrong, but it's not a reliable way of determining if aspiration is taking place. A fiberoptic swallowing study, in which a tiny camera descends through the nose and down the patient's throat, may be useful in some cases, and is done by an otolaryngologist in conjunction with an SLP.
A full evaluation can highlight the point at which swallowing goes awry and show where food particles are being trapped and whether aspiration is occurring. This involves a modified barium swallow, also called a videofluoroscopy.
This X-ray study of the patient swallowing various consistencies of food combined with liquid barium is performed by an SLP in conjunction with a radiologist and is captured on videotape.
Afterward, the SLP and patient may examine the videotape together to identify swallowing problems.
"That's a very personal thing, so it differs from person to person," Thomson says. "Hopefully, the family will be there, too. We look at the point of breakdown and see what needs to be done to accommodate it."
Treatment options for dysphagia
In milder cases of dysphagia, the SLP may suggest muscle exercises to help in the oral and pharyngeal phases, such as lip exercises and strengthening exercises for the tongue.
A number of swallowing techniques may be useful. Consciously holding one's breath during swallowing, or consciously looking at one's toes, are techniques that may reduce risk of aspiration, depending on the individual case.
Postural modifications can sometimes help. If one side of the throat is weaker than the other, a person can turn the head so food doesn't go down the weaker side.
Mealtime habits may have to be altered. When chewing becomes difficult, taking small bites may be advisable. Having six small meals a day instead of three large ones may be a good idea.
People with dysphagia must take in sufficient liquids to avoid dehydration, but liquids are likely to cause aspiration, since they travel quickly down the throat.
Commercial thickeners are available to give liquids a more manageable consistency. They're supposed to be tasteless, although, Thomson says, some patients detect an unpleasant taste. There are also prethickened liquids available that don't require any mixing.
The SLP may also advise about the use of medications or portable suction machines to deal with problems handling saliva. Papaya juice or hot teas may be useful in reducing saliva thickness.
Thomson points out that people with ALS don't, in fact, produce excess saliva.
"They're making the same amount of saliva," she says. "But they're not swallowing frequently enough or effectively enough to clear it."
In progressive conditions such as ALS, patients should be informed in advance that the ability to swallow may deteriorate and that certain food consistencies may become hard or impossible to manage. A nutritionist should be consulted.
Special cookbooks such as Meals for Easy Swallowing, which is available from MDA, can help caregivers prepare foods that are palatable and pleasing to the eye as the patient progresses from hard to soft consistencies.
If all other methods fail and the patient isn't getting sufficient nutrition and hydration, a percutaneous gastrostomy tube (PEG), also known as a feeding tube, may be necessary.
Dr. Robert McMichael, a neurologist and MDA clinic director in Arlington, Texas, believes that with diseases such as ALS there are advantages to performing a PEG placement soon after dysphagia symptoms appear.
One reason is to stop the debilitating effects of malnutrition. Also, the patient may have greater tolerance for the procedure early in the disease process, before respiratory problems have become advanced.
Although it's possible for the procedure to be done on an outpatient basis, McMichael likes to have patients stay in the hospital a day or so before and after the procedure. This allows him to correct dehydration and offer respiratory therapy before the surgery, and gives him a chance to teach the patient and family how to use the PEG after the tube is in place.
The decision to get a PEG is highly personal. Patients are understandably reluctant to undergo an invasive procedure that bypasses the normal eating process, yet some are ultimately relieved after the surgery and find they get some of their strength back after receiving adequate nutrition again.
There's also a procedure to help control excessive saliva production, which involves cutting the nerves to the major salivary glands.
Another surgical procedure that may be considered in some cases of dysphagia is the cricopharyngeal myotomy, which involves cutting one of the muscles of the pharynx.
This muscle is meant to serve as a kind of gatekeeper as food passes from the pharynx into the esophagus. However, if the muscle fails to relax properly and allow food passage, it may become more of an impediment than a help. In such cases, the muscle's surgical removal may cause marked improvement in the ability to swallow.
American Speech-Language-Hearing Association
ASHA Action Center
10801 Rockville Pike
Rockville, MD 20852
ASHA can help direct you to an speech language therapist.
Communication Independence for the Neurologically Impaired (CINI)
116 John St., Suite 1304
New York, NY 10038
Nonprofit organization that serves as a resource for patients and professionals about communication and swallowing problems. CINI offers a book called Communication and Swallowing Problems for the ALS/MND Community: A CINI Manual.
Company offers various products for people with dysphagia, including starch-based thickeners and fiber supplements. The company also offers free booklets about swallowing difficulties, including "Dysphagia: A Review for Health Professionals."
Purchase a variety of fully prepared meals for people with dysphagia that arrive on your doorstep frozen and ready for the microwave.