Changes in Vestibulo-ocular Reflex of Elderly People

Abstract

and 4Depurtment of' Ceriutry, Health Center Hospital oJ' Oulu, Finland Hirvonen TP, Aalto H, Pyykko 1, Juhola M, Jantti P. Changes in i~estibirlo-ocukrr rej7e.v of elderly people. Acta Otolaryngol (Stockh) 1997; Suppl 529: 108-110.Dizziness is a common symptom in elderly people. Head autorotation test (HART) has earlier shown no significant vestibulo-ocular reflex (VOR) disturbances in healthy elderly subjects. We used our recently developed HART to determine VOR in 14 elderly volunteers without otoneurological diseases and sedative medications. Gain and phase were determined in 5 frequency bands from 0.5 to 5 Hz. The gain of the elderly was significantly increased to 1.11-1.27 in the frequency range of 3-5 Hz compared with the controls. The phase lead of 7-8 degrees in the frequency bands of 2 and 4 Hz differed significantly from normative values of the controls. The percentage of the elderly to reach high-frequency head movements was diminished to 50% in the frequency band of 3 Hz and to 36% in the frequency band of 4 Hz (controls 100% and 95%, respectively). The individual HART results were abnormal in 86%) of the elderly. The high-frequency VOR of the elderly was inaccurate in magnitude and timing. More than half of aged subjects were not able to generate voluntary fast head movements. These findings may explain the high prevalence of dizziness and Palls in elderly subjects.

Vestibulosympathetic reflex during orthostatic challenge in aging humans

“…Changes in the vestibular system of these types would likely produce generalized deficits in vestibular function. Consistent with this suggestion, the vestibulosympathetic reflex and both the vestibuloocular and vestibulospinal reflexes are impaired with age (7,16,29). Thus, it is likely that functional and morphological changes within the vestibular system contribute to the age-associated impairment in the vestibulosympathetic reflex.…”

Aging Attenuates the Vestibulosympathetic Reflex in Humans

“…20 These physical changes correspond with reported reductions in the vestibulo-ocular and vestibulospinal reflexes with age in humans. 11,21 On the basis of these data, we suspect that anatomic changes in the vestibular system with aging are the primary factors for the attenuation of the vestibulosympathetic reflex as observed in this study.…”

Auto-rotação cefálica ativa em pacientes com tontura/ vertigem

“…Meulenbroeks e col. 23 Hirvonen e col. 18 , testando pessoas idosas, encontraram alterações em 86% dos casos. Mais da metade dos pacientes não foi capaz de realizar movimentos rápidos da cabeça, para alcançar altas freqüências.…”