Dysphagia refers to difficulty in swallowing.
The process of swallowing comprises of three phases:
oral phase: This is when food is prepared in the mouth and propelled towards the pharynx (throat). This stage can be consciously controlled.
pharyngeal phase: This is where food moves through the pharynx (throat) towards the oesophagus. This stage cannot be consciously controlled.
oesophageal phase: This is where food is transferred through the oesophagus into the stomach. This stage also cannot be consciously controlled.
Difficulty swallowing can happen in any of these three phases.
Patients with dysphagia affecting the oropharyngeal phase of swallowing may complain of the following symptoms:
Patients with dysphagia affecting the oesophageal phase of swallowing may complain of the following symptoms:
1. Neurological Disorders
Patients who have suffered a previous stroke or spinal cord injury can have difficulty swallowing. Other neurological conditions such as Parkinson’s disease, muscular atrophy, multiple sclerosis can cause difficulty in swallowing.
The presence of certain cancers may cause difficulty in swallowing (e.g. tongue cancer). Additionally, patients who have undergone surgery or radiotherapy to the head and neck region may also develop difficulty swallowing.
1. Oesophageal Tumour
Tumours in the oesophagus can cause obstruction. Difficulty swallowing is usually progressive and usually starts, with solid food and later as the tumour grows larger, liquids.
This is a condition where the lower oesophageal muscle (sphincter) fails to relax adequately to allow food to enter the stomach from the oesophagus.
3. Gastro-oesophageal Reflux Disease
When the muscle in the lower oesophagus (sphincter) is inappropriately lax, acid from the stomach can reflux back into the oesophagus. This can lead to spasm and even scarring and narrowing of the oesophagus.
4. Oesophageal Stricture
Narrowing in the oesophagus can be a result of scarring from repeated irritation by acid reflux from the stomach or other caustic substances, previous radiotherapy or previous procedures done.
5. Connective Tissue Disease
Connective tissue diseases such as scleroderma can sometimes cause hardening of the tissue in the oesophagus and cause it to become stiff. This can in turn cause difficulty in swallowing.
6. Oesophageal Spasm
In this condition, multiple involuntary poorly co-ordinated contractions of the oesophagus occur after swallowing.
7. Foreign Body
Objects that get lodged can block the passage of food down the oesophagus. This is seen more commonly in older people who may have difficulty chewing their food well and resultantly swallow a large piece of food bolus that gets lodged in the oesophagus.
What tests can be done to investigate Dysphagia?
Depending on your symptoms and your doctor’s findings, he or she may order one of the following tests:
A thin flexible tube with a camera and light source can be passed via one of the nostrils to look at the back of the nasal passage, throat and voice box. This is a quick test that can be done in the clinic itself to look for abnormalities in the upper aerodigestive tract.
2. Oesophago-gastroduodenoscopy (OGD)
In an OGD, the doctor will pass a flexible tube with a camera and light through your mouth into your oesophagus, stomach and the duodenum (first part of the small intestine). An OGD is useful for looking for mechanical causes of dysphagia (e.g. tumours, strictures). It is usually a day procedure.
3. Videofluoroscopic swallow (VFS) Study
This procedure is where a speech therapist examines your oropharyngeal swallow with the aid of a video X-ray. You will be instructed to take a variety of liquid and solid food in an X-ray suite. This is useful to look for anatomical and functional changes in the oral and pharyngeal phases of swallowing. The procedure is not invasive and takes about half an hour.
4. Other Imaging Studies
Your doctor may order some X-rays or scans. One of these X-rays is a barium swallow. In a barium swallow, an X-ray of your oesophagus and stomach is taken after swallowing some dilute barium to outline the stomach. This test is good to assess for mechanical causes of obstruction such as tumours and strictures.
In manometry, a small tube is inserted into your oesophagus to record the pressure and pattern of the contractions of your oesophagus. This test is useful to diagnose functional causes of dysphagia such as achalasia and diffuse oesophageal spasm.
The type of treatment you will need to undergo will depend on the underlying cause of the dysphagia. Your doctor will usually discuss this with you.