Rare Diseases of the Vestibular System

Abstract

Dizziness is one of the most common symptoms that patients complain about to their doctors. It can be said that around one third of the entire human population experiences dizziness during their lifetime, and hence its great public health significance. It is not a single disease, however: in the case of dizziness, it is rather a syndrome, which involves hundreds of different causes. It may seem scary to a clinician, but we might realize subsequent to an in-depth analysis that ten dizziness causes are most common, while the remaining ones might be classified as rare diseases, according to the current definition. Consequently, they should not be ignored in a differential-diagnostic process. Actually, any disease that affects < 5:10.000 people is considered rare. It can be said that rare diseases are infrequent, but the patients suffering from them are numerous. Five to eight thousand different rare diseases affect 6-8% of the European Union (EU) population--that is, between 27 and 36 million people. In this article, we have paid attention to those rare vestibular disorders that are significant for quotidian diagnostics, especially with regard to a differential-diagnostic excogitation method. In spite of their major differential-diagnostic importance, some of these disorders are still not included in the ORPHA list of rare entities. On the other hand, the well-known and established disorders, or those that are completely insignificant for everyday medical practice, are enlisted due to their enormously low frequency.