Role of age and middle ear transmission characteristics in the frequency tuning of cVEMP and oVEMP
Faculty Advisor Name
Dr. Erin Piker
Department
Department of Graduate Psychology
Description
Project Description
Ageing causes a decline in the functioning of most sensory systems, including the vestibular system. Decrements in vestibular function are an independent risk factor for falling. Therefore, there is a need for efficient vestibular diagnostic tests that identify clinically meaningful vestibular impairments in older patients.
Background: Age related degenerative changes of the vestibular system occur in the vestibular end organs as well as the central vestibular structures. The vestibular end organs: saccule and utricle can be assessed using cervical evoked myogenic potential (cVEMP) and ocular vestibular evoked myogenic potential (oVEMP) respectively. The cVEMP and oVEMP are some of the most widely used vestibular diagnostic assessments; however previous works have showed that both responses, when elicited using a conventional and widely used stimulus of 500 Hz, are often bilaterally absent in older adults yielding results that are difficult to interpret. Therefore, there is a need to identify a stimulus that could best assess the older adult’s saccular and utricular functioning.
Objective and methods: The purpose of this study was: 1) to assess age-related changes on various stimuli that can be used to assess cVEMP and oVEMP, and 2) to determine the optimal stimulus frequency in the young adult, middle age, and older adult populations. Additionally, we performed middle ear evaluation, to delineate age related changes in the middle ear from changes occurring in the inner ear of balance. A total of 107 participants consented to be in the study. Participants were divided in three groups: young adults (18-30 years), middle aged adults (41-59 years) and older adults (60-80 years). All of the participants underwent cVEMP and oVEMP testing using 500 Hz, 750 Hz and 1000 Hz air conducted stimuli. Middle ear functioning was also calculated for each of the participants.
Results and Conclusion: It was found that age did not cause any change in measures of middle ear functioning. However, age did alter the saccular (cVEMP) and utricular (oVEMP) responses and this age effect was dependent on the stimulus frequency. The strength/amplitude of the cVEMP decreased with increasing age for the more conventional frequency (500 Hz), but the age effect was not observed at the higher frequency of 1000 Hz. Further, for the older adults, cVEMP was largest in amplitude and more often present at 1000 Hz. This differed from the young adult group where 500 Hz was the best frequency to elicit a cVEMP. For the oVEMP, the strength/amplitude decreased with increasing age for all the three stimuli/frequencies and the best stimulus frequency in all the three age groups was 1000 Hz. We also found that middle ear did not contribute towards shaping the response of cVEMP and oVEMP for various stimuli. Thus, the changes in the cVEMP and oVEMP frequency tuning observed in the older adults may not be stemming from middle ear but could be due to age related changes in the vestibular system.
Role of age and middle ear transmission characteristics in the frequency tuning of cVEMP and oVEMP
Project Description
Ageing causes a decline in the functioning of most sensory systems, including the vestibular system. Decrements in vestibular function are an independent risk factor for falling. Therefore, there is a need for efficient vestibular diagnostic tests that identify clinically meaningful vestibular impairments in older patients.
Background: Age related degenerative changes of the vestibular system occur in the vestibular end organs as well as the central vestibular structures. The vestibular end organs: saccule and utricle can be assessed using cervical evoked myogenic potential (cVEMP) and ocular vestibular evoked myogenic potential (oVEMP) respectively. The cVEMP and oVEMP are some of the most widely used vestibular diagnostic assessments; however previous works have showed that both responses, when elicited using a conventional and widely used stimulus of 500 Hz, are often bilaterally absent in older adults yielding results that are difficult to interpret. Therefore, there is a need to identify a stimulus that could best assess the older adult’s saccular and utricular functioning.
Objective and methods: The purpose of this study was: 1) to assess age-related changes on various stimuli that can be used to assess cVEMP and oVEMP, and 2) to determine the optimal stimulus frequency in the young adult, middle age, and older adult populations. Additionally, we performed middle ear evaluation, to delineate age related changes in the middle ear from changes occurring in the inner ear of balance. A total of 107 participants consented to be in the study. Participants were divided in three groups: young adults (18-30 years), middle aged adults (41-59 years) and older adults (60-80 years). All of the participants underwent cVEMP and oVEMP testing using 500 Hz, 750 Hz and 1000 Hz air conducted stimuli. Middle ear functioning was also calculated for each of the participants.
Results and Conclusion: It was found that age did not cause any change in measures of middle ear functioning. However, age did alter the saccular (cVEMP) and utricular (oVEMP) responses and this age effect was dependent on the stimulus frequency. The strength/amplitude of the cVEMP decreased with increasing age for the more conventional frequency (500 Hz), but the age effect was not observed at the higher frequency of 1000 Hz. Further, for the older adults, cVEMP was largest in amplitude and more often present at 1000 Hz. This differed from the young adult group where 500 Hz was the best frequency to elicit a cVEMP. For the oVEMP, the strength/amplitude decreased with increasing age for all the three stimuli/frequencies and the best stimulus frequency in all the three age groups was 1000 Hz. We also found that middle ear did not contribute towards shaping the response of cVEMP and oVEMP for various stimuli. Thus, the changes in the cVEMP and oVEMP frequency tuning observed in the older adults may not be stemming from middle ear but could be due to age related changes in the vestibular system.
