Dysphagia is the medical term for swallowing difficulties. Swallowing is just something that happens for most people without having to think about it, but dysphagia can affect all people of all ages, from newborn babies to elderly people.
At the back of the mouth is the pharynx. Just below the pharynx we have two passages, one for air (the trachea) and one for food and fluid (the oesophagus). Only one is supposed to be open at a time, so that we stop breathing momentarily when we swallow and then start breathing immediately afterwards.
Swallowing is actually one of the most complex actions that our body has to do. First, the brain has to plan out the whole action then tell at least thirty pairs of muscles what to do. This is called a motor program or motor plan.
Food is processed in the mouth to the point that it is safe to swallow, and for most food this includes chewing. Food or fluid needs manoeuvring to the back of the mouth and into the pharynx, ready to go into the oesophagus. This prompts the area around the larynx (the ‘voice box’) to be pulled up. It is all connected and protected by muscles and ligaments.
If you want to appreciate this movement, feel your larynx as you take a swallow.
As the larynx is pulled up, it drags up a small flap of skin called the epiglottis which covers the airway. The airway is also protected by the vocal cords which close, and the false vocal cords above them, so that normally there are three layers of protection for the airway.
As the airway is covered, the entry to the oesophagus (the sphincter) opens and food is quickly manoeuvred into the opening. From there, the oesophagus moves the food down to the stomach, in a movement over which we have no control, by gravity.
The oesophageal sphincter then closes and the airway opens – and breathing continues.
Everyone knows the feeling of something going down the wrong way. Usually we are able to cough and splutter until we get rid of whatever it was. This is fortunate, because food going down the wrong way can cause choking, and fluid in the airway or lungs can cause chest infections and even pneumonia. If food or fluid penetrates the larynx and enters the airway then this is called aspiration.
All sorts of things can go wrong with swallowing. Because it is a complex and finely tuned action, even a small amount of coordination difficulty can cause a problem. Other problems arise when the swallow is not initiated (started), or if the airway is not covered, or if it is not covered quickly and completely. If residue of food or fluid is left in the pharynx after the swallow it can slip into the airway seconds later when we breathe or talk.
Sometimes babies may have a difficulty swallowing from birth. Or they may have an illness of some kind that requires an alternate way of feeding, and swallowing then may be established later if at all possible. For most of the life span swallowing difficulties occur because of accident or disease, such as traumatic brain injury or thyroid deficiency). In elderly people swallowing is more prevalent, particularly when a disease is present or people are unwell.
Often after surgery, such as a fracture repair, elderly people are particularly vulnerable. In ‘the olden days’ most people used to die following a hip fracture, for example, because they aspirated fluid which resulted in pneumonia. As well as coping with the pain, and having poor mobility, being unable to sit up straight, people are often well-medicated at this time and this makes the brain less able to make a motor program and carry it out accurately.
Elderly people who are unwell are at high risk for dysphagia. The elderly in residential facilities or nursing homes, for example, who often have limited mobility and communication skills, need to be monitored closely for swallowing difficulties.
The clinician responsible for diagnosing and managing dysphagia is a Speech Pathologist. A Speech Pathologist can assess, manage and rehabilitate swallowing.
A Speech Pathologist can use a combination of resources, depending on technology available. In some cases, patients may have access to fibre-endoscopy with an ENT specialist, where a probe can be inserted to see if there are physiological difficulties. A video-fluoroscopy can be performed in a hospital or radiography clinic, where a moving X-ray can be taken while a patient swallows. More often a Speech Pathologist can do a bedside examination or a manual examination in a clinic, where they can feel and observe swallowing of different consistencies of food and fluid. This is often done with cervical auscultation where the swallow can be listened to with a stethoscope.