An estimated 90 million Americans (42% of the current population) will experience dizziness at least once in their lifetime. Some patients develop permanent balance deficits with subsequent functional limitations.
The etiology of peripheral and central vestibular deficits includes the following: age-related multisensory deficits, strokes and vascular insufficiencies, cerebellar degeneration, chemical and drug toxicities, benign paroxysmal positional vertigo, uncompensated Mnire disease, vestibular neuritis, labyrinthitis, and head trauma.
Balance disorders are significant risk factors for falls in elderly individuals. Falls have been estimated to be the leading cause of serious injury and death in persons older than 65 years. The projected annual direct costs of fall-related injuries will be $32 billion in the United States by the year 2020.
Vestibular rehabilitation therapy (VRT) has been a highly effective modality for most individuals with disorders of the vestibular or central balance system. In a number of studies, customized VRT programs were significantly more effective than generic exercises in resolving symptoms.
The basis for the success of VRT is the use of existing neural mechanisms in the human brain for adaptation, plasticity, and compensation. The extent of vestibular compensation and adaptation is closely related to the direction, duration, frequency, magnitude, and nature of the retraining stimulus. Specifically designed VRT exercise protocols take advantage of this plasticity of the brain to increase sensitivity and restore symmetry, which results in an improvement in vestibulo-ocular control, an increase in the gain of the vestibulo-ocular reflex (VOR), better postural strategies, and increased levels of motor control for movement.
Other factors that may affect the degree of individual compensation that can be achieved include overall physical status, the functional status of remaining sensory systems, integrity of central brain mechanisms, age, and higher sensory functions such as memory, motor coordination and cognitive ability.