Smelling Disorder Signs of Alzheimer's and Parkinson's

Smelling disorders can indicate illnesses

10/01/2013

Many people suffer from a loss of sense of smell without perceiving it as a serious impairment. However, the olfactory disorders can be an expression of diseases such as „Inflammation of the nose or paranasal sinuses“ or of craniocerebral trauma, reports the Department of Otolaryngology at the University of Cologne. In addition, studies - for example at the TU Dresden - have found a connection between the loss of the sense of smell and the occurrence of Parkinson's. In addition, the trade magazine published „Archives of General Psychiatry“ already in 2007 several articles in which attention is drawn to possible connections between Alzheimer's and the loss of the sense of smell.

Odors are usually perceived much less consciously than pictures or sounds, which is why an olfactory disorder is often barely noticeable to people at first. If you can not see well, you will usually go to an optician or ophthalmologist relatively quickly. When hearing loss, those affected usually go to a specialist soon. But with a dwindling sense of smell, it often takes years before even a doctor's visit is considered. It could „loss of the sense of smell is associated with a significant loss of quality of life“, cited „The world“ the director of the ear, nose and throat clinic at the University of Cologne, Professor Karl-Bernd Hüttenbrink. The consequence is that people with olfactory disorders would also be more depressed. Patients should therefore not delay the doctor's visit if they lose their sense of smell.

Sense of smell closely related to the sense of taste
The sense of smell plays an essential role in everyday life, even if people often perceive smells rather subconsciously. For example, the sense of smell is crucial when tasting. If the nose is blocked by a cold, the sense of taste also suffers. The so-called „retronasal smelling“, which significantly influences the sense of taste is actually the main function of the olfactory organ, the Cologne ENT Clinic on its website. According to the experts, ascending fragrances are passed through the throat during the drinking or chewing of food and during the early phase of the act of swallowing. This aromatic tasting would „often misunderstood as the power of the tongue, but aromatic perceptions are always olfactory performances“, so the ENT clinic on.

Tens of thousands of patients with olfactory disorders
According to the experts, humans have about 400 different olfactory receptors, which react differently to different fragrance spectra. If appropriate fragrances reach the receptors provided for this purpose, a signal is passed on to the sensory cells, as a result of which, depending on the perceived fragrance mixture, a unique activity pattern of different receptors arises. This allows a differentiated perception of the taste or the odors. But the smell perception can be disturbed in different ways. According to the ENT clinic in Cologne will be „In Germany alone, approximately 79,000 patients with olfactory disorders are treated in ENT clinics per year.“ Be there „sinunasal diseases“ such as inflammation of the nose or paranasal sinuses the most common cause of the olfactory disorder. Also, impairments of the sense of smell following a viral infection, according to the expert are not uncommon. Less frequently, the olfactory disturbances occur as a result of craniocerebral trauma or toxic damage to the olfactory epithelium. In addition, neurodegenerative diseases such as Alzheimer's and Parkinson's were already associated with the olfactory disorders.

Smelling test for the diagnosis of an olfactory disorder
According to the experts, for example, (hobby) cooks and wine lovers, ie persons who become aware of the loss of their sense of taste at an early stage, are among the patients who approach a doctor early because of their olfactory disorder. For other patients, however, it should be observed that they delay the visit to the doctor for a very long time. „For a long time first the partner has to check the perfume or try the homemade meal“, emphasized Prof. Hüttenbrink. The ENT specialist first performs an odor test, which enables a detailed assessment of the sense of smell. In doing so, for example „Fragrance from felt pens released by removing the pen cap“ and held in front of the nose of the patients, reports the ENT clinic in Cologne. The test shows which fragrances the patients can identify and distinguish (identification test and discrimination test) as well as from which intensity they perceive the odors (threshold test). In addition, if an olfactory disorder is suspected, nasal endoscopy, in which the olfactory mucosa is inspected, is usually carried out, the Cologne ENT clinic continues. In addition, there is the option of an objective measurement of the sense of smell with the help of the detection of olfactory evoked potentials in the brain of the subjects. The diagnosis differs in terms of the quantitative perception of smell, a diminished (hyposmia), a reversed (anosmia) and an increased (hyperosmia) sense of smell.

Causes of olfactory disorders must be checked
If the test concludes that there is actually an impairment of the sense of smell, the doctors are looking into the question of which diseases can be considered as triggers of the olfactory disorders in order to subsequently initiate appropriate therapeutic measures. In addition to the inflammation of the nose or paranasal sinuses, viral infections and their long-term consequences as well as possible head injuries are to be examined. Allergies can also lead to swelling of the mucous membranes, a stuffy nose and corresponding impairment of the sense of smell, so that under certain circumstances an allergy test is appropriate. If the causes of the olfactory disturbance can not be determined in the usual investigations, a possible Parkinson's or Alzheimer's disease should also be considered. Because the loss of the sense of smell have already been identified in several studies as an early sign of these neurodegenerative diseases.

Smelling training to rebuild the sense of smell
At the Dresden University of Technology, researchers led by Professor Thomas Hummel have for some time been testing the use of an olfactory training to combat the loss of the sense of smell, and have in some cases achieved considerable success. The 12-week training session, in which patients are expected to smell twice daily (morning and evening) on ​​four vials of different scents, has, according to the experts, led to significant improvements in the sense of smell in patients with anosmia. The physicians assume that new odor receptors are created by the olfactory training and the subjects also learn to perceive smells better. Those affected can train their sense of smell with the help of the olfactory training downright. However, if the loss of the sense of smell is due to a disease, however, a corresponding treatment should first be carried out before the olfactory training attempts to rebuild the sense of smell. (Fp)

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Picture: Lupo