Why dizziness is likely to increase the risk of cognitive dysfunction and dementia in elderly adults

Dementia is recognised to be one of the most challenging diseases facing society, both now and in the future, with its prevalence estimated to increase substantially by 2050. The potential contributions of age-related sensory deficits have attracted little attention until recently, when a landmark study suggested that hearing loss could be a greater risk factor for dementia than hypertension, obesity, smoking, depression, physical inactivity or social isolation. Over the last decade, evidence has been gradually accumulating to suggest that the other part of the inner ear, the balance organs or 'vestibular system', might also be important in the development of cognitive dysfunction and dementia. Increasing evidence suggests that dizziness associated with vestibular dysfunction, a common reason for patients consulting their GPs, increases the risk of cognitive dysfunction, including dementia, and our understanding of the basic neurobiology of this sensory system supports this view. This paper aims to review and critically evaluate the relevant evidence.