Accurate and timely assessment of dysphagia can improve the quality of life for those affected. But what are the most common diagnostic tests?

Dysphagia is a condition that affects approximately 20% of the Italian population over the age of 50. In particular, significant swallowing difficulties are observed in people with Parkinson’s disease (50–90%), stroke patients (40–80%), and those with multiple sclerosis (33–43%). In addition to these figures, there is a percentage of people who suffer from dysphagia but have not yet received a precise diagnosis. We are talking about a percentage as high as 95%. For this reason, too, areliable and timely assessment of the disorder is essential, so that all possible measures can be taken to improve the quality of life of those affected. But how is dysphagia assessed? What are the most common diagnostic tests?

An important prerequisite for any dysphagia assessment test is the patient’s level of consciousness. If the patient is unresponsive or experiencing shortness of breath, it is not possible to perform any swallowing tests. Furthermore, before proceeding to the actual tests, it is essential to collect data and interview the patient as an integral part of the evaluation phase.

Once these preliminary assessments have been completed, screening tests for dysphagia can begin. The most common ones are as follows:

Gugging Swallowing Screen (GUSS)

This is an international clinical trial consisting of two phases:

• Indirect assessment of swallowing function
• Direct swallowing tests of semi-solid, liquid, and solid substances.

Each patient who undergoes the examination receives a score (from 0 to 20) that determines the severity and category of their dysphagia.

Three-ounce Water Swallow Test (WST, Smithard Test)

This dysphagia assessment test involves giving the patient 5 ml of room-temperature water with a spoon three times and, each time, checking to see if the patient has swallowed it. If the patient experiences severe coughing or a gurgling voice, the test is stopped. In this case, a grade 4 (severe dysphagia) is assigned. If, on the other hand, the patient does not cough, the test continues by offering them water directly from a glass, and after a few seconds, the quality of their voice is assessed. If, in this case as well, a hoarse and/or gurgling voice and coughing are observed, the patient is classified as grade 3 (moderate dysphagia). If, however, only a hoarse and/or gurgling voice is observed, a grade 2 (Mild Dysphagia) is assigned. If the test is negative, a new test is performed, this time with 50 ml of water. If, in this case as well, the patient shows no difficulty swallowing, a grade 1 (Absent Dysphagia) can be confirmed. 

Finally, it is worth noting that there are two versions of this test: the pulse oximeter-based WST and the auscultation-based WST.

Bedside Swallowing Assessment

Much like the WST, this test involves giving the patient a teaspoon of water at room temperature. After 10–15 seconds, the examiner checks for any hoarseness or episodes of coughing. If the patient responds positively, the test continues with the administration of 50 ml of water, and the presence of pharyngeal retention, coughing, or gurgling is assessed in the following minutes. Each finding is assigned a score that determines the presence or absence of dysphagia. The Bedside Swallowing Assessment also includes the evaluation of parameters such as level of consciousness, head and trunk control, and respiration.

Daniels' Test

This refers to a table listing the six symptoms of aspiration: dysphonia, dysarthria, voluntary coughing, reduced post-swallowing cough, altered or absent gag reflex, and changes in the voice after swallowing. A case of dysphagia is diagnosed when at least two of these symptoms are present.