Profound sensorineural hearing loss in polyarteritis nodosa. An atypical case of Cogan's syndrome.

Parameters of importance for the development of thrombosis were investigated in a patient with polyarteritis nodosa (PAN) and profound sensorineural hearing loss. During the acute phase, platelet hyperaggregability, shortened platelet survival, and decreased fibrinolytic activity were found. The possibility is discussed that the etiology of the acoustico-vestibular symptoms in this patient could be an inner ear thromboembolic disorder. It is suggested that platelet functions and fibrinolytic activity should be investigated in patients with acoustico-vestibular symptoms and PAN or other systemic diseases. If abnormalities are found, specific platelet inhibitory and/or fibrinolysis-increasing treatment should be considered as an addition to the conventional medical treatment.