Disorders of the vestibular system

Humans have developed a sophisticated system for maintaining balance, which requires the integration and modulation of visual, vestibular, and proprioceptive information within the central nervous system. For the geriatrician, an understanding of the pathophysiology of the vestibular system and its central connections is particularly important if the common complaint of disequilibrium is to be managed successfully. Vestibular symptoms result from an asymmetry of afferent information arising within the vestibular apparatus, and degenerative changes tend to occur symmetrically. In the history, the character, time course, and associated symptoms of the dizziness/vertigo are valuable pointers in elucidating the underlying diagnosis. Both the peripheral and central vestibular apparatus are supplied by the vertebrobasilar circulation, and as cerebrovascular disease is common in developed countries, disequilibrium in the elderly is commonly ascribed to vascular pathology. Many neurological disorders may affect the central vestibular connections. Chronic vestibular symptoms may be caused by central vestibular pathology or uncompensated peripheral vestibular disorders.