Posted on 18 Feb 2011 21:45
What is dysphagia?
Dysphagia is a word that refers to having any difficulty with swallowing. People with dysphagia may even have pain while swallowing (odynophagia). They may be unable to swallow at all or have trouble swallowing food, liquids or saliva safely. Eating becomes a great challenge and the difficulty this causes in getting enough calories and fluids for the body can cause serious malnutrition or other medical problems.
Dysphagia is described as a sensation of "sticking" or obstruction of food through the mouth, pharynx, or esophagus and it is often used as an umbrella term to include different specific difficulties with swallowing:
- Aphagia - complete esophageal obstruction or complete inability or unwillingness to swallow because of organic or psychological disease. This term is also relevant when the bolus1 is completely impacted or "stuck"
- Difficulty initiating a swallow - this means that there is a disorder of the voluntary phase of swallowing when food is first leaving the mouth, but that there is no trouble with completing the swallow once it has been initiated
- Odynophagia - this means painful swallowing and frequently occurs with dysphagia in general
- Globus pharyngeus - the sensation of a lump stuck in the in the throat when swallowing but with no difficulty encountered when actually swallowing
- Misdirection of food - as with oropharyngeal dysphasia, when nasal regurgitation or pharyngeal or pulmonary aspiration occurs during swallowing
- Phagophobia - fear of swallowing; occurs in tetanus and rabies or with pharyngeal paralysis as the patient is afraid that aspiration will occur when swallowing. Fear of the pain caused by swallowing in case of inflammatory lesions or odynophagia may cause someone to fear swallowing and some people physically feel the sensation of swallowing in the esophagus, which is a very uncomfortable feeling that makes one feel they are choking, even though there is no physical sticking of the food in the esophagus 1
How do we swallow?
Swallowing is a complex process that involves around 50 pairs of muscles and many nerves working to receive food into the mouth, prepare it, and move it from the mouth to the stomach.
This happens in stages. The first stage is the voluntary oral phase, which itself consists of two phases. This phase includes a preparatory phase where the tongue collects the food or liquid, and the tongue and jaw move the solid food around the mouth to be chewed. Chewing mixes the food with saliva, which softens and moistens the food. Chewing and moisture makes the food right size and texture to be swallowed so that a suitable bolus is prepared. The second phase is the transfer phase where the bolus is pushed into the pharynx by contraction of the tongue. Normally, the only solid we swallow without chewing is in the form of a pill or caplet. Everything else that we swallow is in the form of a liquid, a puree, or a chewed solid.
The pushing of the food into the pharynx initiates a reflexive swallowing response by stimulating the oropharyngeal sensory receptors to trigger the deglutition reflex. During this phase, called the pharyngeal phase, the larynx (voice box) closes tightly and breathing stops to prevent food or liquid from entering the airway and lungs.
The third stage begins the the superior pharyngeal constrictor contracts against the contracted soft palate, thus initiating a peristaltic contraction that proceeds rapidly downward from the pharynx through the esophagus. This peristaltic wave pushes the food or liquid through the esophagus in about 4 to 8 seconds. This is called the esophageal phase. Deglutition and peristaltic contraction triggers the lower esophageal sphincter (LES) to relax and allows food to enter the stomach. 1
What Kind of Symptoms Occur with Swallowing Problems?
- Slow chewing or eating
- Coughing or choking during or after eating
- Gurgling sounds from the throat during or after eating
- Throat clearing after drinking or swallowing
- Coughing food back up after eating
- Hiccups after swallowing
- Chest discomfort during or after swallowing
- Unexplained weight loss
What Causes Dysphagia and Who Gets It?
Dysphagia happens most frequently in older adults and occurs when there is a problem with the neural control or the structures involved in any part of the swallowing process. Weak tongue or cheek muscles may make it hard to move food around in the mouth for chewing. A stroke or other nervous system disorder may make it difficult to start the swallowing response, a stimulus that allows food and liquids to move safely through the throat. Another difficulty can occur when weak throat muscles, such as after cancer surgery, cannot move all of the food toward the stomach. Dysphagia may also result from disorders of the esophagus or a combination of problems with the esophagus and the action of the LES, such as achalasia, a rare but serious condition.
The possible causes of dysphagia are many. Any condition that weakens or damages the muscles and nerves used for swallowing may cause dysphagia. For example, people with diseases of the nervous system, such as cerebral palsy or Parkinson’s disease, often have problems swallowing. Additionally, stroke or head injury may weaken or affect the coordination of the swallowing muscles or limit sensation in the mouth and throat.
People born with abnormalities of the swallowing mechanism may not be able to swallow normally. Infants who are born with an opening in the roof of the mouth (cleft palate) are unable to suck properly, which complicates nursing and drinking from a regular baby bottle.
In addition, cancer of the head, neck, or esophagus may cause swallowing problems. Sometimes the treatment for these types of cancers can cause dysphagia. Injuries of the head, neck, and chest may also create swallowing problems. An infection or irritation can cause narrowing of the esophagus. Finally, for people with dementia, memory loss and cognitive decline may make it difficult to chew and swallow.
The following is a list of diseases and conditions that can be associated with or lead to swallowing problems (dysphagia) (2):
- Alzheimer's disease
- Amyotrophic lateral sclerosis (ALS or Lug Gehrig's Disease)
- Cerebral palsy
- Closed head injury
- Head or neck cancer
- Hungtington's chorea
- Multiple sclerosis (MS)
- Muscular dystrophy (MD)
- Myasthenia gravis
- Myotonic dystonia
- Parkinson's disease
- Sjörgren's disease
- Pharynx inflammation
- Esophagus inflammation
Problems caused by dysphagia
Dysphagia can be serious. Someone who cannot swallow safely may not be able to eat enough of the right foods to stay healthy or maintain an ideal weight.
Food pieces that are too large for swallowing may enter the throat and block the passage of air. In addition, when foods or liquids enter the airway of a person who has dysphagia, coughing or throat clearing sometimes cannot remove it. Food or liquid that stays in the airway may enter the lungs and allow harmful bacteria to grow, resulting in a lung infection called aspiration pneumonia.
Swallowing disorders may also include the development of a pocket outside the esophagus caused by weakness in the esophageal wall. This abnormal pocket traps some food being swallowed. While lying down or sleeping, a person with this problem may draw undigested food into the throat.
The esophagus may also be too narrow, causing food to stick. This food may prevent other food or even liquids from entering the stomach.
How is dysphagia treated?
The various types of dysphagia have different treatments. Since there are several stages of the swallowing process, doctors and speech-language pathologists must use various tests to evaluate those different stages. One test, the Flexible Endoscopic Evaluation of Swallowing with Sensory Testing (FEESST), uses a lighted fiberoptic tube, or endoscope, to view the mouth and throat while examining how the swallowing mechanism responds to such stimuli as a puff of air, food, or liquids.
In a videofluoroscopic swallow study (VFSS), a clinician takes a videotaped X-ray of the entire swallowing process. First a patient consumes several foods or liquids along with the mineral barium to improve visibility of the digestive tract. In this way a "movie" can be made of the entire swallowing process to indentify where in the process the problem is occuring.
Once the clinician knows what is going wrong he or she can recommend what changes the patient use to help swallowing be easier and safer. The changes may be in food texture, size, head and neck posture, or behavioral maneuvers, such as “chin tuck,” a strategy in which a patient tucks her chin so that food and other substances do not enter the trachea when swallowing. If a patient is unable to swallow safely despite rehabilitation strategies, then medical or surgical intervention may be necessary for the short-term as the patient recovers. In progressive conditions such as amyotrophic lateral sclerosis (ALS, or Lou Gehrig’s disease), a feeding tube in the stomach may be necessary for the long-term.
For some people, treatment may involve muscle exercises to strengthen weak facial muscles or to improve coordination. For others, treatment may involve learning to eat in a special way. For example, some people may have to eat with their head turned to one side or looking straight ahead. Preparing food in a certain way or avoiding certain foods may help in some situations. For instance, people who cannot swallow thin liquids may need to add special thickeners to their drinks. Other people may have to avoid hot or cold foods or drinks.
For some, however, consuming enough foods and liquids by mouth may no longer be possible. These individuals must use other methods to nourish their bodies. Usually this involves a feeding system, such as a feeding tube, that bypasses or supplements the part of the swallowing mechanism that is not working normally.
"Dysphagia." National Institute on Deafness and Other Communication Disorders [NIDCD]. Web. 18 Feb. 2011. <http://www.nidcd.nih.gov/health/voice/dysph.html>.