Mechanism of Compensation After Unilateral Loss

Abstract

A variety of etiologies are responsible for loss of vestibular function. These include aging, head trauma, ototoxic drugs, infection, inflammation, or tumors. Unilateral peripheral vestibular weakness affects a patient’s posture, oculomotor control, spatial perception, and navigation. Patients experience postural asymmetry and gait problems related to impaired vestibulospinal reflex, visual disturbances as a result of impaired vestibular-ocular reflex, and internal spatial disorientation. Most patients recover functionally over weeks and months through a process called vestibular compensation. In unilateral peripheral vestibular loss, vestibular compensation engages neuronal and behavioral plasticity in the central nervous system to overcome the loss of unilateral vestibular input. The time course and exact mechanism of vestibular recovery depend on the etiology of vestibular loss and cannot be generalized for all patients. However, knowledge of several processes of vestibular compensation can guide the treatment and rehabilitation for unilateral vestibular loss.