Neurologic perspectives of otosclerosis.

Of 500 patients with roentgenographically verified otosclerosis, 230 had vestibular manifestations. Because of its frequency in general practice, otosclerosis has a major impact on the differential diagnosis of vertigo and related symptoms. The vestibular syndrome encompasses the full symptomatic spectrum common to diseases of the vestibular system, from episodic violent rotational vertigo to a sense of almost continuous imbalance, and cannot usually be distinguished from idiopathic endolymphatic hydrops. Otosclerosis is easy to diagnose when vestibular symptoms occur in conjunction with conductive or mixed hearing loss and a normal tympanic membrane that excludes middle ear disease. However, in approximately one-third of patients with a hearing loss that is purely sensorineural, the diagnosis can be confirmed only by compound-motion tomography of the petrous bones.