People who suffer from anosmia can hardly perceive any odours. Smell disorders can be caused by sinusitis, virus infections or craniocerebral injuries. Moreover, the ability to smell can diminish with increasing age. More seldom, smell disorders are diagnosed in connection with tumour diseases or Parkinsonʼs disease.

“Sinus inflammations can often be accompanied by smell disorders, because the reduced transport of respiratory air also affects the perception of odoursˮ, says Prof. Dr. Roland Laszig, medical director of the Department of Oto-Rhino-Laryngology (Medical Center, University of Freiburg). However, sinus inflammation, also known as sinusitis, is usually well treatable with medication.

Furthermore, nasal polyps can impede smelling. They are either located in the nose or in the sinuses. In most cases, polyps are treated with the help of drugs. If that turns out to be of no avail, ENT specialists usually advise a minor operation that helps to improve the patientsʼ respiration as well as their sense of smell. It is much more difficult, however, to treat smell disorders after virus infections of the upper airways, since the latter can result in the damage or even destruction of olfactory nerves. “To restore such nerves is often hardly possibleˮ, says Prof. Laszig.

Craniocerebral injuries can also have a negative effect on the olfactory nerves: “If somebody falls on the back of his or her head while skating, for instance, the impact causes a movement of the brain. This movement, however little, can lead to the rupture of so-called fila olfactoria. These olfactory ʻthreadsʼ are located in the nose and connect the olfacory nerves with the brainˮ, Prof. Laszig explains. Such damages bring about severe smell disorders. In some cases, they even induce a complete loss of the patientʼs ability to smell.

Taste Disorders after Surgery

Unlike olfactory disorders, gustatory disorders occur rather seldom. There is, however, a close connection between smelling and tasting, so that a flavour is perceived as something that is actually a scent. If a patient has the impression that, for example, the soup tastes bland or that the cake is no longer sweet, he or she might be affected by a gustatory disorder, or ageusia. Particularly people with a cold feel, that they can hardly taste anything. Basically, we distinguish five flavours: sweet, sour, bitter, salty and umami. The latter represents the taste of glutamate. It can also described as the flavour of meat broth. Anyone who perceives a piece of cake as something sweet, has activated his taste cells, which are situated in the taste buds of the mouth and throat. The small nodules on the tongue contain taste buds, too. Even though these can be destroyed in the course of a tonsil operation, they usually regenerate, so that the patient regains his sense of taste. Moreover, ear surgery can affect the gustatory nerves: “The surgical treatment of a middle ear inflammation presents a certain risk with regard to the gustatory nerv in the middle ear, because it might be cut through during operation. After some time, however, the patient will regain his sense of tasteˮ, Prof. Laszig assures. In such cases, the other half of the tongue automatically takes over the relevant perceptive functions.