Decline in semicircular canal and otolith function with age

Abstract

Objective: To characterize the physiologic nature of the vestibular dysfunction that occurs with the normative aging process.

Study design: Cross-sectional study.

Setting: Tertiary care academic medical center.

Patients: Fifty individuals age 70 years and above.

Interventions: Head thrust dynamic visual acuity testing and cervical and ocular vestibular-evoked myogenic potential (VEMP) testing.

Main outcome measures: Semicircular canal function measured by head thrust dynamic visual acuity testing in each of the 3 semicircular canal planes, and saccular and utricular function measured by cervical VEMP and ocular VEMP testing, respectively.

Results: We observed significant declines in semicircular canal function in each of the canal planes as well as otolith function associated with aging. We found that individuals with impaired horizontal and superior semicircular canal function also were likely to have concomitant deficits in utricular but not saccular function. Overall, we noted that the prevalence of semicircular canal dysfunction was highest followed by saccular then utricular impairment, although we did observe individuals with isolated otolith deficits.

Conclusion: These data suggest an overall decline in semicircular canal as well as otolith function associated with aging, although the magnitude of impairment was greater for the semicircular canals than the otoliths in this elderly population. A better understanding of the specific vestibular deficits that occur with aging can inform the development of rational screening, vestibular rehabilitation, and fall risk reduction strategies in older individuals.

Figures

Figure 1

Head thrust dynamic visual acuity in the horizontal semicircular canal plane by age. Overall differences are statistically significant (p

Figure 2

Head thrust dynamic visual acuity in the superior semicircular canal plane by age. Overall differences are statistically significant (p

Figure 3

Head thrust dynamic visual acuity in the posterior semicircular canal plane by age. Overall differences are statistically significant (p

Figure 4

Cervical VEMP amplitudes (as a measure of saccular function) by age. Overall differences are statistically significant (p

Figure 5

Ocular VEMP amplitudes (as a measure of utricular function) by age. Overall differences are statistically significant (p

Figure 6

Cervical and ocular VEMP amplitudes as a function of quartiles of head thrust dynamic visual acuity in the horizontal semicircular canal plane in individuals age ≥70 years. SCC: semicircular canal; μV: microvolts.

Figure 7

Cervical and ocular VEMP amplitudes as a function of quartiles of head thrust dynamic visual acuity in the superior semicircular canal plane in individuals age ≥70 years. SCC: semicircular canal; μV: microvolts.

Figure 8

Cervical and ocular VEMP amplitudes as a function of quartiles of head thrust dynamic visual acuity in the posterior semicircular canal plane in individuals age ≥70 years. SCC: semicircular canal; μV: microvolts.

Figure 9

Right and left-sided vestibular abnormalities by end-organ in each of the 50 subjects. A colored box indicates dysfunction of that end-organ. SCC: semicircular canal.

Figure 10

Prevalence (%) of vestibular abnormalities by end-organ. SCC: semicircular canal.