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Table of Contents
ORIGINAL ARTICLE
Year : 2020  |  Volume : 22  |  Issue : 1  |  Page : 7-12

The association between age-related sensorineural hearing loss and saccular dysfunction in the elderly


Department of Audiology, Hearing and Speech Institute, Giza, Egypt

Date of Submission03-Nov-2019
Date of Decision09-Dec-2019
Date of Acceptance22-Jan-2020
Date of Web Publication01-Jun-2020

Correspondence Address:
Dr. Gehan Mohamed Shafeek Abdel-Salam
Abdel-Salam, Hearing and Speech Institute, Giza
Egypt
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Source of Support: None, Conflict of Interest: None


DOI: 10.4103/SJOH.SJOH_19_19

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  Abstract 


Introduction: Presbycusis or age-related sensorineural hearing loss (ARSNHL) is a complex disorder that results in a slow deterioration in auditory function. A considerable high number of these presbycusis or ARSNHL patients also suffer from dizziness and related vestibular symptoms. Although auditory and vestibular systems are distinct, they work just alike. Hence, there is a great relation among their functions. Once one is stimulated, the other suffers changes as well. Methodology: Participants in this study comprised forty adult patients (60–75 years) divided into two groups: control group with normal hearing and without any vestibular symptoms or diagnosed vestibular diseases and study group with mild-to-moderately severe sensorineural hearing loss with or without dizziness in the form of a sense of imbalance during walking or a sense of rotation of the surrounding, especially on sitting or standing from lying position. All patients in this study were without any history of noise exposure in their life. The audiological status was measured with pure-tone audiometry and auditory brainstem response (ABR). The vestibular system was assessed using videonystagmography test battery and cervical vestibular-evoked myogenic potential (cVEMP). Timed up and go test was used as a quick screening tool for detecting balance problems. ABR and cVEMP results of the groups were calculated and compared. Results: The absolute peak latencies of ABR wave I, III, and V were prolonged in the study group than that in the control group. Vestibular-evoked myogenic potential results showed that P13 and N23 latencies were prolonged and P13–N23 amplitude was decreased in the study group when compared to the control group. Conclusion: Thoughtful examination of the vestibular system, in conjunction with auditory functions in elderly persons, is recommended. This may help discover their subclinical vestibular problem and guide physicians to design a suitable treatment plan that helps in decreasing the risk of falls for aged persons.

Keywords: Age-related sensorineural hearing loss, auditory brainstem response, cervical vestibular-evoked myogenic potential, presbycusis, vestibular, videonystagmography


How to cite this article:
Abdel-Salam GM. The association between age-related sensorineural hearing loss and saccular dysfunction in the elderly. Saudi J Otorhinolaryngol Head Neck Surg 2020;22:7-12

How to cite this URL:
Abdel-Salam GM. The association between age-related sensorineural hearing loss and saccular dysfunction in the elderly. Saudi J Otorhinolaryngol Head Neck Surg [serial online] 2020 [cited 2020 Sep 21];22:7-12. Available from: http://www.sjohns.org/text.asp?2020/22/1/7/285554




  Introduction Top


The auditory and vestibular systems experience age-related changes causing functional decline, which is considered part of the normal aging process. Presbycusis or age-related sensorineural hearing loss (ARSNHL) is a complex phenomenon consisting of elevation of the hearing threshold levels as well as changes in the auditory processing.[1] ARSNHL was largely attributed to the periphery, with various types of hearing loss related to different structural and anatomical deficits in the cochlea, caused by cochlear degeneration, most pronounced in the basal cochlear coil.[2],[3] Even individuals with normal speech detection thresholds can still suffer age-related hearing deficits. For those patients, these deficits generally manifest as a decreased ability to understand speech, particularly in noisy environments. Usually social settings are in noisy environments (i.e. restaurants, shops, parties, etc.), difficulties facing those with ARSNHL to have satisfactory interactions in these environments can be challenging, and potentially giving rise to the social isolation that is commonly seen in geriatric.[4] Although many adults keep good hearing as they age, hearing loss associated with aging is common among elderly persons. A considerable high number of these ARSNHL patients also suffer from dizziness and related vestibular symptoms.[5] They are more prone to experience dizziness and have an increased risk for falls, which is a major public health problem. Although auditory and vestibular systems are distinct, there is a great relation among their functions, as cochlea and saccule have same embryologic origin, which results in anatomic and physiologic coupling of these organs.[6] Many patients present to otolaryngology clinics with dizziness and hearing loss problems with no obvious pathology and are diagnosed with presbycusis or age-related vestibulopathy.[7] The auditory brainstem response (ABR) is an objective electrophysiological method for assessing the auditory pathways from the auditory nerve to the brainstem.[8] ABR is a valuable tool in understanding the auditory brainstem. It is used for estimating the auditory sensitivity in patients with presbycusis.[9] Traditional videonystagmography (VNG) can evaluate occulomotor test battery and function of semicircular canals but not otolith organs. Cervical vestibular-evoked myogenic potential (cVEMP) presents a viable means to evaluate the integrity of saccule and inferior vestibular nerve.[10] Pathologies such as vascular and noise exposure affecting cochlea of the inner ear may, therefore, cause a dysfunction in the saccule as they have the same embryological origin. This study aims to investigate the association between hearing loss and deficits in saccular functions in the elderly.


  Methodology Top


Subjects

Participants in this study were divided into two groups. The study group consisted of twenty patients in the age range of 60–75 years diagnosed with bilateral mild-to-moderately severe sensorineural hearing loss (SNHL) with or without dizziness in the form of a sense of imbalance during walking or a sense of rotation of the surrounding, especially on sitting or standing from lying position. The control group consisted of twenty healthy individuals of the same age group with normal hearing, who were not complaining of dizziness. Participants in both groups had no history of noise exposure. Patients with mixed types of hearing loss or perforated tympanic membrane were excluded from the study.

Equipment

  1. A two-channel audiometer (Interacoustics, model AC40, Kingdom of Denmark Scandinavian, Europe) with air and bone conduction facilities
  2. Sound-treated room (I. A. C model 1602, North Aurora, USA)
  3. Middle-ear analyzer (Impedance Audiometer Interacoustic AZ26, Denmark)
  4. ABR was evaluated using Audera GSI, Eden Prairie, MN, USA
  5. A VNG test using Interface controller 2000, Torrance, CA, USA
  6. cVEMP was evaluated using Computerized Four-Channel Evoked Potential System Biologic model Navigator, Denmark.


Methods

All participants in this study were subjected to the following:

  1. Full history taking regarding any vestibular symptoms and hearing complaints
  2. Otological examination
  3. Basic audiological evaluation in the form of:


    • Pure-tone audiometry (PTA)


      • Air conduction thresholds were tested at the following frequencies: 0.25, 0.5, 1, 2, 4, and 8 KHz
      • Bone conduction thresholds were tested at the following frequencies 0.5, 1, 2, and 4 KHz.


    A pure-tone threshold in the range of 26–40 dB HL was considered mild SNHL, whereas threshold in the range of 41–55 dB HL was considered as moderate SNHL and threshold in the range of 56–70 dB HL was considered as moderately severe SNHL.

    • Acoustic immittancemetry testing: It included tympanometry and acoustic reflex threshold measurements
    • Speech reception threshold (SRT): Using Arabic spondee words
    • Word discrimination score: Using Arabic phonetically balanced words.[11]


  4. ABR response to rarefaction acoustic clicks was used as the acoustic stimulus; at rate of 21.1 clicks per se cond were delivered through insert phones at an intensity of 95 dBnHL, totaling 2000 stimuli. Absolute latencies for waves I, III, and V and interpeak latencies I–III, III–V, and I–V were recorded for each participant and compared for both groups


  5. VNG test battery using video-goggle was conducted on all participants in the study, searching for spontaneous, gaze-evoked, positional, and positioning nystagmus. The oculomotor test battery included saccade; eye tracking and optokinetic tests were done. In addition, bithermal caloric test was performed


  6. Saccular function was tested by cVEMP which was recorded from the sternocleido-mastoid muscle (SCM). An active electrode was placed on the upper third of each SCM with a reference on the lateral end of the upper sternum, while the common electrode was placed on the forehead. During the test, the patient is instructed to turn his/her heads toward the contralateral side of the tested ear to activate SCM. Stimuli were presented mono-aurally using the insert phones; 500 Hz tone burst was presented at a rate of 5 pulses per se cond and an intensity of 100 dBnHL with a window of 100 ms. The response was averaged twice, and the latency of cVEMP of waves P13, N23, and P13–N23 amplitude was measured for each participant and compared for both groups


  7. Timed up and go (TUG) test: This is a quick screening tool for detecting balance problems. It requires the participant to stand up from a chair, walk 3 m, turn around, return, and sit down again. Patients without neurological impairment who are independent with normal balance and mobility skills can perform the test in <10 s. Patients who take longer than 30 s to complete the test have been found to be dependent for most activities of daily living and mobility skills.[12] This study was done at the Audiology Department, Hearing and Speech Institute, Giza, Egypt. An informed consent was obtained from all participants.


Statistical methods

IBM SPSS statistics (V. 23.0, IBM, Armonk, New York, USA) was used for data analysis. Data were expressed as mean ± standard deviation (SD) for quantitative measures. Comparison between the two participant groups was done using Student's t-test. The probability of error (P values) was considered as follows: P > 0.05 as nonsignificant, P < 0.05 as significant (S), and P < 0.01 as highly significant.


  Results Top


The mean age in the study group was 68.2 years, whereas it was 67.4 in the control group (P > 0.05). The mean PTA value was 23.3 dB in the control group and was 43.2 dB in the study group (P< 0.05). There are no significant differences between right and left ears in both groups [Table 1] and [Table 2]. All participants in the control group had bilateral speech discrimination scores in the range of 88%–100% with a mean of 96.7 and an SD of 3.1. Patients in the study group had bilateral speech discrimination scores in the range of 72%–84% with a mean of 74.3 and an SD of 3.4. All participants in this study had Type (A) tympanogram with proportionate acoustic reflexes to pure-tone thresholds. ABR results showed that wave I was absent in 60% (12) of cases in the study group. Absolute peak latencies of wave I, III, and V were prolonged in the study group than that in the control group, and this prolongation was statistically significant. In addition, interpeak latencies (IPLs) were prolonged in the study group than that in the control group, but this prolongation was not statistically significant as shown in [Table 3] and [Figure 1]. History taking revealed that the vestibular symptoms were present in 60% of the study group patients (12 patients). Most of them have a sense of imbalance during walking followed by a sense of rotation of the surrounding, especially on standing or sitting from lying position. Based on VNG results, it was found that all participants showed normal occulomotor test battery, no positional or positioning nystagmus, and normal caloric results. Regarding cVEMP results, [Table 4] and [Table 5] show that there was no statistically significant difference between the right and left ears in the control and study groups. [Table 6] shows that P13 and N23 latencies were prolonged in the study group when compared to the control group, and this prolongation was statistically significant; also, amplitude of P13–N23 was reduced in the study group in comparison to the control group, and this reduction was statistically significant as shown in [Figure 2]. TUG test results showed that all participants were able to perform the test in the range between 10 and 25 s.
Table 1: Mean±standard deviation of pure-tone thresholds in db HL in the control group

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Table 2: Mean±standard deviation of pure-tone thresholds in db HL in the study group

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Table 3: Comparison between absolute and interpeak auditory brainstem response latencies in the study and control groups

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Figure 1: Comparison between absolute and interpeak auditory brainstem response latencies in the study and control groups

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Table 4: Mean±standard deviation for different cervical vestibular-evoked myogenic potential parameters in the control group and comparison between the right and left ears

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Table 5: Mean±standard deviation of different cervical vestibular-evoked myogenic potential parameters in the study group and comparison between the right and left ears

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Table 6: Comparison between P13 and N23 latencies in the study and control groups

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Figure 2: Comparison between P13 and N23 latencies in the study and control groups

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[Table 1] shows the pure-tone thresholds of the control group, matching with the mean hearing thresholds as a function of age.[13] The mean hearing sensitivity for all frequencies was 23.3 dB.

The mean hearing sensitivity of all frequencies was 43.2 dB in the study group.

[Table 2], [Table 3], and [Table 5] show that there was no statistically significant difference between the right and left ears in the control and study groups.


  Discussion Top


Identifying risk factors for falls in older adults is of significant public health importance. While hearing is not typically considered a risk factor for falls, researches had demonstrated a significant association between audiometric hearing loss and incident falls in the elderly.[13] Patients in the study group were complaining of gradual and progressive hearing loss noticed after the age of 60 years of variable duration. The mean PTA of the control group was 23.3 dB, which was comparable with the mean hearing thresholds as a function of age [14] [Table 1]. In contrast, the mean PTA in the study group was 43.2 [Table 2]. The elevated PTA thresholds in the study group were suggested to be due to aging process, however, it was aggravated by the influence of various damaging factors such as systemic diseases. The mean of SRT and speech discrimination scores was matched with the pure-tone thresholds in all participants. In addition, all participants in this study had Type (A) tympanogram with proportionate acoustic reflexes to the pure-tone thresholds. Results of ABR showed that wave I was absent in 60% (12 participants) of the study group cases with moderate SNHL. Comparison of both groups [Table 3] showed that the absolute peak latencies of waves I, III, and V were prolonged in the study group than that in the control group, and this prolongation was statistically significant. This latency shift may be due to a peripheral mechanism producing a partial delay and desynchronization of the normal discharge. Khullar and Babbar [9] reported similar results, and they attributed this shift in absolute latencies to high-frequency hearing loss, as the peak of basilar membrane motion occurs at a point of hair cell loss. Thus, hair cells located apically to the peak of membrane motion respond to the signal, resulting in an increase in response latency. Otto and McCandless [15] concluded that when advanced age and high-frequency hearing loss interact, high-frequency hearing loss is the greater factor in morphologic and latency changes. They indicated that the hearing impairment in the aged is probably due not only to changes in the end organ but also to brainstem changes, but changes in the end organ have the upper hand in morphologic and latency changes. IPLs were prolonged in the study group, but this prolongation was not statistically significant. Similar results were obtained by Boettcher [16] as he did not find any IPL abnormalities in older adults with normal hearing. Many authors examined patients with presbycusis or ARSNHL to identify possible changes in the auditory periphery. They stated that absolute latencies of ABR waves tend to increase with increasing age with no changes for IPLs.[17] On the other hand, Mazelová et al.[18] compared the hearing abilities of a group of thirty elderly (67–93 years of age) patients with those of a group of thirty young (19–27 years of age) normal hearing volunteers to characterize changes in the peripheral and central parts of the auditory system. They concluded that presbycusis or ARSNHL represents a combination of deteriorated function of the auditory periphery with deteriorated function of the central auditory system. This variability is most probably related to age difference in each study. The mechanism of interaction between auditory and vestibular system is not clear. There is a great relation among their functions. There is a complex relationship between ARSNHL or presbycusis and vestibular system function. Vestibular symptoms were present in 60% of the study group (12 patients). Most of them have a sense of imbalance during walking followed by a sense of rotation of the surrounding, especially on standing or sitting from lying position. Similar results were obtained by Gananca and Caovilla [19] who reported that vertigo is the most common symptom in patients above 65 years. In addition, De Moraes et al.[5] reported that a vestibular disorder is present in 50%–60% of the community among the elderly. Although many patients with ARSNHL or presbycusis suffer from vestibular dysfunction, the cause is not known if it is due to age-related changes in the central nervous system or due to an association with presbycusis.[6] On an embryological basis, the saccule and cochlea develop from the same origin in the membranous labyrinth; this is innervated by the inferior portion of the vestibular nerve.[5] In this study, patients with presbycusis or ARSNHL were examined carefully to detect any possible causes of vestibular dysfunction. This was done by taking full history about any vestibular insults and confirmed by normal VNG results and normal TUG test. Regarding cVEMP results, [Table 6] shows that P13 and N23 latencies were significantly prolonged in the study group when compared to the control group; also, amplitude of P13–N23 was reduced in the study group in comparison to the control group, and this reduction was statistically significant. These findings suggest that elderly patients with hearing loss are more vulnerable to saccular dysfunction than others. Similar findings were reported by some authors [20],[21] who studied the relation between SNHL and vestibular dysfunction; they reported that there was a significant correlation between cVEMP abnormalities in the form of reduced amplitude and hearing loss in patients with acquired SNHL, especially those with high-frequency SNHL. In addition, Dabbous [22] found a significant inverse relation between vestibular-evoked myogenic potential amplitude and duration of SNHL, but did not depend on the audiogram configuration. A possible explanation for the association between cochlear and saccular function is the shared embryologic origin of these structures, as cochlea and saccule arise from the pars inferior of the inner ear, after the three semicircular canals and utricle have completely developed from the pars superior.[23] The common embryological origin may result in the anatomic and physiologic pairing of these organs. In addition to the anatomic proximity of the saccule to the acoustic-energy delivery system, the great similarity in cochlear and vestibular hair cell ultrastructures and the common arterial blood supply all support the possibility of vestibular affection, especially saccular dysfunction, associated with the cochlear dysfunction. This suggests that with increased severity of cochlear damage, there is an increased tendency to have saccular affection.[24] As posture control is mostly dominated by vestibulo-spinal tract that is executed mainly through otolith (utricle and saccule), this may put these patients at risk for fall although they record normal TUG test. This may be due to the alteration in the transduction of linear acceleration forces including gravity. The otolith then provides erroneous information for the control of posture, eye–head coordination, as well as the sensation of upright posture.[25] Similar results were obtained by Kurtaran et al.[7] as they stated that pathologies affecting one part of the inner ear may cause a dysfunction in the parts with the same embryological origin. They concluded that ARSNHL or presbycusis may be accompanied by vestibular weakness without any possible predisposing factors for vestibulopathy. Santos et al.[6] found that congenitally severe hearing loss can cause a great vestibular disturbance in children. They stated that disturb in the auditory system can cause a big damage in the vestibular system as both systems have a close relationship. The weak point of this study is the complex and variable effect of aging on inner ear organs and its blood supply. Thus, further studies with larger number of patients and different age groups will expand awareness for this issue.


  Conclusion Top


Although auditory and vestibular systems are distinct, there is a great relation among their functions. Hence, thoughtful examination of the vestibular system, in conjunction with auditory functions in elderly persons, is recommended especially in those with ARSNHL or presbycusis. This may help discover their subclinical vestibular problem and guide physicians to design a suitable treatment plan that helps in decreasing the risk of falls for aged persons.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.



 
  References Top

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de Moraes SA, Soares WJ, Ferriolli E, Perracini MR. Prevalence and correlates of dizziness in community-dwelling older people: A cross sectional population based study. BMC Geriatr 2013;13:4.  Back to cited text no. 5
    
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Boettcher A. Presbycusis and the auditory brainstem response. J Speech Lang Hear Res 2002;45:1249-61.  Back to cited text no. 16
    
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    Figures

  [Figure 1], [Figure 2]
 
 
    Tables

  [Table 1], [Table 2], [Table 3], [Table 4], [Table 5], [Table 6]



 

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