167 - Peripheral Vestibular Disorders

Abstract

The peripheral vestibular system transduces head movement and the orientation of the head relative to gravity to allow visual stabilization, perception of motion, and maintenance of equilibrium. Derangements in this system can likewise lead to oscillopsia, vertigo, and increased fall risk. The basics of vestibular physiology and major causes of peripheral vestibular pathology are discussed. Benign paroxysmal positional vertigo (BPPV) leads to brief episodes of vertigo and nystagmus associated with changes in head position and is often easily treated using repositioning maneuvers. Vestibular neuritis is a sudden onset of vertigo due to the acute loss of unilateral vestibular function. Symptoms typically improve with time, and vestibular rehabilitation may be helpful. Ménière disease is associated with endolymphatic hydrops and is characterized by episodes of vertigo with fluctuating hearing loss and tinnitus. Many treatments have been proposed, including lifestyle changes, transtympanic therapies, and ablative therapy. Superior canal dehiscence syndrome is caused by absence of bone over the superior canal, which can lead to sound- or pressure-induced vertigo, oscillopsia, conductive hearing loss, pulsatile tinnitus, and autophony. It can be treated by plugging the superior canal. Bilateral vestibular loss is characterized by the loss of balance function and oscillopsia. Although bilateral vestibular loss can occur as a result of aminoglycoside toxicity, it can also have genetic or idiopathic etiologies. Symptoms include oscillopsia with head motion and increased fall risk. Treatments are currently limited, but vestibular implants are an area of active investigation. There are other rare causes of peripheral vestibular dysfunction, including Cogan syndrome, otosyphilis, perilymph fistula, trauma, and enlarged vestibular aqueduct.