Gustometry

Alternative names

Taste study.

Definition

Diagnostic test used in the field of Otolaryngology to study the sense of taste (recognition of the different types and intensities of flavors) and detect possible alterations.

The study requires the use of different taste stimuli that are applied to the surface of the tongue:

• When the stimulus used during the study is a substance (solutions with the four basic flavors such as: sweet, salty, acid and bitter are generally used), we speak of chemical gustometry.
• When the stimulus used during the study is a small galvanic current emitted by a small electrode, we speak of electrogustometry.

How is the study done?

The taste study is carried out in the Otorhinolaryngology Unit and proper oral cleaning is required prior to the study. During the entire process, which usually takes just a few minutes, the patient will remain seated.

In chemical gustometry, increasing concentrations of four substances corresponding to the four basic flavors are used: glucose, sodium chloride, lemon juice, and quinine. Taking turns and following the order described, a drop or filter paper soaked in each of the substances described is applied to different areas of the tongue. The patient will be asked to indicate when he detects the presence of each substance and when he recognizes the taste of each one of them on the different applied areas. Mouthwash should be done between one substance and another.

In electrical gustometry, small electrodes are applied to different areas of the surface of the tongue that emit galvanic stimuli of increasing intensity and frequency. The patient will be asked to indicate when he begins to detect the stimulus and when he recognizes a characteristic metallic taste (similar to acidic taste) produced by the current itself.

Preparation for the study

The study of taste does not require preparation except for proper prior oral hygiene.

What does it feel like during and after the study?

The study of taste is painless for the patient.

In chemical gustometry, the patient may momentarily perceive some of the substances used during the test as unpleasant.

In electrogustometry a small temporary irritation may appear on the surface of the tongue in which the electrodes are applied.

Risks and contraindications of the study

The study of taste has no contraindications except for the presence of lesions on the oral mucosa or surface of the tongue.

What is the study done for?

The study of the sense of taste allows detecting alterations in the perception of flavors of a quantitative nature (increase, decrease or absence of taste for one or more flavors) and of a qualitative nature (to identify the flavor or flavors that the patient does not recognize). It allows to differentiate the affected areas from the healthy areas. It allows to identify if the taste alteration is located in the tongue and / or in the nerve endings responsible for the sense of taste or, on the contrary, has another origin (nasal, central nervous system ...) that should be studied later by using tests more specific diagnostic tools.

The study must be completed with a study of smell since both senses are closely related. At the same time, the study of the sense of taste is a screaning test that should be expanded with subsequent complementary studies (in the case of detecting alterations in it) until the cause that causes said alterations is identified.