Diagnosis of olfactory disorders
If an olfactory disorder is suspected, a detailed medical history should be taken by the physician, as important information about a possible cause can already be obtained. Following the anamnesis and the examination, the presence of an olfactory disorder should be checked with tests. Checking olfaction: Our olfactory ability can be checked with two types of tests.
On the one hand, there are the so-called subjective test procedures, which presuppose that the patient is fit and can provide information about what he/she has smelled, and on the other hand there are objective test procedures, which are used when the person affected cannot cooperate and cannot provide any information himself/herself, as is the case with small children or dementia patients.Subjective procedures: Sniffin’ sticks: There are a large number of different smelling sticks, each with a different smell, which are held under the nose of the affected person for a short period of time. With the help of selection cards, the patient can determine the odor just perceived. UPSI Test: According to the place of development, this test was called the US State Pennsylvania University of Pennsylvania Smell Identification Test (UPSI Test).
Here, the various odours are enclosed in microcapsules which are then released. CCCRC test: This test also owes its name to the place of origin in the USA. This test consists of considerably more odours than the two test procedures described above, which are stored in plastic or glass bottles.
In addition, it is also tested where the odour threshold for the characteristically pungent odour of butanol lies, i.e. at what concentration of butanol the affected person smells it. In the Aachen Rhinotest, six dissolved fragrances are sprayed into the mouth of the affected person. The person must then determine the perceived odor with the help of six given adjectives (floral, fruity, resinous, pungent, fruity, spicy).
However, the Aachen Rhinotest is rarely used. Objective methods: If one cannot rely on the active cooperation of the patient, objective test procedures are used. Here, it is possible to derive so-called olfactory evoked potentials (OEP).
However, this complex examination is only performed in a few centers, such as Berlin, Rostock, Cologne, Mainz, Mannheim, Basel or Vienna. By means of three different scents an excitation of the nerve fibers is to be triggered. Phenylethyl alcohol, vanillin and hydrogen sulfide are used as fragrances. The fragrances should actually trigger electrical signals, which are then recorded and displayed by electrodes.
