Downbeat nystagmus (DBN) is the central oculomotor disorders based on different causes. Unlike the Upbeat nystagmus or nystagmus of vestibular origin DBN belongs to chronic nystagmus that may persist in a patient for years or throughout life.
Clinically it is manifested with oscilopsia DBN, and balance dysfunction. In this case report is presented patient with Downbeat nystagmus diagnosed in the otoneurological ambulance at the University Hospital Motol.
Although DBN is the type of central nystagmus and certainly belongs to the hands of neurologists, we consider that it necessary every ENT specialist should have knowledge about this problem and be able to direct the patient to appropriate specialists. More than once we have seen that nystagmus of peripheral origin was described ENT doctors in a patient with DBN.
This mistake may harm the patient. This report should also highlight the complexity of this issue, including its extensive differential diagnosis and also the fact that despite all diagnostic efforts a clear cause of DBN is not always reveal.