Dizziness and Imbalance in the Elderly: Age-related Decline in the Vestibular System

Abstract

Dizziness and imbalance are amongst the most common complaints in older people, and are a growing public health concern since they put older people at a significantly higher risk of falling. Although the causes of dizziness in older people are multifactorial, peripheral vestibular dysfunction is one of the most frequent causes. Benign paroxysmal positional vertigo is the most frequent form of vestibular dysfunction in the elderly, followed by Meniere's disease. Every factor associated with the maintenance of postural stability deteriorates during aging. Age-related deterioration of peripheral vestibular function has been demonstrated through quantitative measurements of the vestibulo-ocular reflex with rotational testing and of the vestibulo-collic reflex with testing of vestibular evoked myogenic potentials. Age-related decline of vestibular function has been shown to correlate with the age-related decrease in the number of vestibular hair cells and neurons. The mechanism of age-related cellular loss in the vestibular endorgan is unclear, but it is thought that genetic predisposition and cumulative effect of oxidative stress may both play an important role. Since the causes of dizziness in older people are multi-factorial, management of this disease should be customized according to the etiologies of each individual. Vestibular rehabilitation is found to be effective in treating both unilateral and bilateral vestibular dysfunction. Various prosthetic devices have also been developed to improve postural balance in older people. Although there have been no medical treatments improving age-related vestibular dysfunction, new medical treatments such as mitochondrial antioxidants or caloric restriction, which have been effective in preventing age-related hearing loss, should be ienvestigated in the future.

Keywords: aging; fall; rehabilitation; vestibular.

Figure 1.

Age-dependent changes in the system maintaining postural stability. Postural stability is maintained by the integration of somatosensory, visual and vestibular inputs to the central nervous system, followed by outputs to the musculoskeltal system. Function of all the components deteriorates as the age advances.

Figure 2.

Age-dependent changes in amplitude and latency of oVEMPs to bone-conducted vibration. (Left panel) Amplitude of the n10 responses of oVEMP significantly decreases with age. (Right panel) Latency of the n10 responses of oVEMP significantly increases with age. The box and whisker plots show the median and quartiles (cited from ref. with permission).

Figure 3.

Age-dependent changes in the postural stability on the foam rubber. (Left panel) Age-dependent changes in the velocity of the center of pressure (COP) during standing with eyes closed on the foam rubber. (Right panel) Age-dependent changes in the envelopment area of the COP during standing with eyes closed on the foam rubber. Median value and interquatile ranges are shown (The data are from ref. 57).