Correlation of SVINT and Sensory Organization Test in Children with Hearing Loss

Round 1

Reviewer 1 Report

This is an interesting paper supporting the hypothesis that a high rate of pediatric patients with hearing loss also present a vestibular disorder.

Anyway I suggest some changes, beginning from the title; your work has been more complex than a correlation between Svint and SOT, and include a correlation between SVINT from one side and calorics and video HIT on the other. I suggest to change the title including calorics and video HIT.

It's unclear why the control group included 120 subjects, while hearing impaired children were 60. Moreover, were normal subjects excluded after performing calorics if not normal? May it be a bias in your opinion? How many "normal" subjects were excluded for "pathological" calorics? Wasn't in controls a clinical history reporting lifetime absent vertigo \ dizziness enough?

Have you any data regarding the reason of hearing loss in the 60 subjects?

Explain briefly why only unilateral CI were included. Did you noted differences between the ear with and without implant for vestibular testing?

Line 164: in the group of HL did you noted a hearing level effect on calorics?

 

Author Response

Dear Editors and Reviewers,

Thank you for giving us the opportunity to submit a revised draft of my manuscript titled [mention the manuscript’s title] to [include the name of the journal, italicized].  We appreciate the time and effort that you have dedicated to providing your valuable feedback on our manuscript. We are grateful to the reviewers for their insightful comments on my paper. We have been able to incorporate changes to reflect  the suggestions provided by the reviewers. We have highlighted the changes within the manuscript.

Here is a point-by-point response to the reviewers’ comments and concerns.

Reviewer 1

This is an interesting paper supporting the hypothesis that a high rate of pediatric patients with hearing loss also present a vestibular disorder.

Anyway I suggest some changes, beginning from the title; your work has been more complex than a correlation between Svint and SOT, and include a correlation between SVINT from one side and calorics and video HIT on the other. I suggest to change the title including calorics and video HIT.

Reply: Thank you for this suggestion. it would have been interesting to explore this aspect. however, in the case of our study, it seems slightly out of scope because the results from svint and calorics were previously published as benchmark (gold-standard) in our article “the skull vibration-induced nystagmus test: a useful vestibular screening test in children with hearing loss”. we hoped in this article to focus on sensory organization test using those two tests (calorics & vhit)for catergorizing the patients’ groups (bilateral, unilateral weakness, normal).

It's unclear why the control group included 120 subjects, while hearing impaired children were 60.

Reply: The number of control is double the number of subject for a better statistical power.

Moreover, were normal subjects excluded after performing calorics if not normal? May it be a bias in your opinion? How many "normal" subjects were excluded for "pathological" calorics? Wasn't in controls a clinical history reporting lifetime absent vertigo \ dizziness enough?

Reply: To include children in the group of normal subjects, all tests (tympanometry, audiometry, calorics, and vhit) needed to be in normal range. moreover, any history of vertigo episodes or motion sickness was considered as an exclusion criteria. both elements are essential for control group to be able to have a correct benchmark for comparison.

Have you any data regarding the reason of hearing loss in the 60 subjects?

Reply: We agree with this and have incorporated your suggestion throughout the manuscript in the participants section.

Explain briefly why only unilateral CI were included. Did you noted differences between the ear with and without implant for vestibular testing?

Reply: In lebanon, where the study took place, only unilateral ci are provided by the government thus the majority of children have only one implant. rare are the children in lebanon with two implants for comparisons. it is now mentioned in the new  version of the ms

Line 164: in the group of HL did you noted a hearing level effect on calorics?

Reply: We found that “a tendency for decreased responses during a caloric test in the implanted ear was noted but was not statistically significant (p-value = 0.08)” this was noted in our previously published article(ref8 ).

Reviewer 2 Report

The authors describe results for the SVINT in pediatric cases of hearing loss and normal controls. The sample size is large and the idea of the project is great, however, certain details need to be reviewed for publication.

Abstract

The objective is very weak: “This study aimed to analyze the SVINT results of healthy children with hearing loss (HL) corrected by hearing aids (HA) or by unilateral cochlear implant (CI) and to correlate it with sensory organization test (SOT) results”. Analyse? What was your hypothesis, did you care about hearing loss or the actual amplification? Think about it.

The abstract is too long, it needs to be shortened and refocused. For instance, it is not necessary to write “lower frequency” or “higher frequency” for the tests. A native English speaker should review the article there are various little details.  Examples in introduction:

Line 48, adapts

Line 52, than

Line 54, change throughout the life span, analyses

Line 70, Although in humans, Borsetto et al showed, should be reversed

Etc…Review the whole text

Should avoid self citations, in this case these references do not aid in the reading of the project: This work resulted in other publications: SVINT as a screening tool in children (8), Oculomotor normative data in children (9), and Posturography normative data in children (2).

Methods:

Description of the hearing-impaired children is lacking. More details are needed, hearing aids bilaterally? unilaterally? Cochlear implants were unilateral but for bilateral or unilateral hearing loss? This is important when evaluating the results. Not only is the degree of hearing loss important, but the cause also. Please provide more information. Post-meningitis? Congenital? Malformations? Ototoxicity? Etc etc

Please provide clear details for calorics, the description in the figure is poor, I assume you followed Jongkees’ formula. Also, in the table “robust response” what do you mean?  Why did you choose 15% as the cut-off for abnormal calorics, usually 25% is used. Also, why 12 for bilateral, please explain or cite references.

Results:

Three children had clinically significant SVINT in the NH group, why were they included? Shouldn’t you include 117 children instead?

You mention strong correlation between SVINT and calorics, and SVINT with SOT results. Your VHIT results are not so clearly described. What about SVINT with VHIT?

Discussion

Should be modified to include what I have mentioned in the methods, did the patients have bilateral congenital hearing loss, then maybe it makes sense they would have bilateral weakness on calorics and/or VHIT and/or SOT.  Were you trying to see the relationship between hearing loss and vestibular hypofunction? Or the benefits/cons of hearing aids or implants on hearing impaired children’s balance? You need to focus your results and discussion.

Also, you do not even mention something that seems very important, is it safe to perform vibration tests on patients with cochlear implants??

Conclusion

You cannot conclude what you didn’t do in your study. You say it is non-invasive and rapid test, this is not one of your conclusions, eliminate or move to discussion. Do NOT include references in the conclusions please move to discussion: The SVINT is mainly relevant to the contributions of the SCC and the utricle, but not to the contribution of the saccule (21).

Author Response

Dear Editors and Reviewers,

Thank you for giving us the opportunity to submit a revised draft of my manuscript titled [mention the manuscript’s title] to [include the name of the journal, italicized].  We appreciate the time and effort that you have dedicated to providing your valuable feedback on our manuscript. We are grateful to the reviewers for their insightful comments on my paper. We have been able to incorporate changes to reflect  the suggestions provided by the reviewers. We have highlighted the changes within the manuscript.

Here is a point-by-point response to the reviewers’ comments and concerns.

The authors describe results for the SVINT in pediatric cases of hearing loss and normal controls. The sample size is large and the idea of the project is great, however, certain details need to be reviewed for publication.

Abstract

The objective is very weak: “This study aimed to analyze the SVINT results of healthy children with hearing loss (HL) corrected by hearing aids (HA) or by unilateral cochlear implant (CI) and to correlate it with sensory organization test (SOT) results”. Analyse? What was your hypothesis, did you care about hearing loss or the actual amplification? Think about it.

Reply: Thank you for this comment, we have amended the sentence to the following “this study aimed to analyze the svint results of healthy children with hearing loss (hl)) as a vestibular screening tool and to correlate it with sensory organization test (sot) results as a functional balance evaluation tool”.

The abstract is too long, it needs to be shortened and refocused. For instance, it is not necessary to write “lower frequency” or “higher frequency” for the tests.

Reply: We have, accordingly, revised and shortened the abstract.

A native English speaker should review the article there are various little details.  

Examples in introduction:

Line 48, adapts

Line 52, than

Line 54, change throughout the life span, analyses

Line 70, Although in humans, Borsetto et al showed, should be reversed

Etc…Review the whole text

Reply: Thank you for pointing this out, these modifications have now been performed in the new ms accordingly to these comments.

Should avoid self citations, in this case these references do not aid in the reading of the project: This work resulted in other publications: SVINT as a screening tool in children (8), Oculomotor normative data in children (9), and Posturography normative data in children (2).

Reply: We agree with this and have incorporated your suggestion. these considerations have been moved and included in the discussion of the new version of the ms

Methods:

Description of the hearing-impaired children is lacking. More details are needed, hearing aids bilaterally? unilaterally? Cochlear implants were unilateral but for bilateral or unilateral hearing loss? This is important when evaluating the results. Not only is the degree of hearing loss important, but the cause also. Please provide more information. Post-meningitis? Congenital? Malformations? Ototoxicity? Etc etc

Reply: The description of hearing-impaired children have been  added in participant section in the new version of the ms.

Please provide clear details for calorics, the description in the figure is poor, I assume you followed Jongkees’ formula. Also, in the table “robust response” what do you mean?  Why did you choose 15% as the cut-off for abnormal calorics, usually 25% is used. Also, why 12 for bilateral, please explain or cite references.

Reply: Caloric testing was performed following the british society of audiology's recommendation(british society of, audiology. recommended procedure: the caloric test. br socaudiol 2010;2010:1–25.). the test was performed by irrigating for 60 seconds cool air in the ears of normal children (24 °c), and in case of asymmetry the child was excluded. for children with hl, warm and cool air (24-50 °c) was irrigated in the ears. meanwhile, a mental task was given to the child to ensure a maximum intensity and regularity of the nystagmus response. an interval of 5 minutes was given between two irrigations allowing the child to rest and insuring the absence of influence on the following contra lateral caloric test. the results of the cat were analyzed in the categorical format: a uw was defined for a caloric asymmetric hypofunction > 15% and a bw for a total bilateral reflectivity < 12°/s. the asymmetry was calculated from maximum slow phase velocities using jongkees' formula. these notifications have now been added in the new version of the ms.

Results:

Three children had clinically significant SVINT in the NH group, why were they included? Shouldn’t you include 117 children instead?

Reply: In normal children, clinically significant nystagmus was recorded in only 2.50% of the cases (n = 3), a negative svint result was observed in the rest (97.50%) in accordance with the criteria defined. such rare positive svin test ( but with low spv < 2.5 °/s) in normal subjects  have already been described in other large series (ref zamora 2018. dumas acta stockholm 2008)

You mention strong correlation between SVINT and calorics, and SVINT with SOT results. Your VHIT results are not so clearly described. What about SVINT with VHIT?

Reply: Thank you for this suggestion; this was added.

Discussion

Should be modified to include what I have mentioned in the methods, did the patients have bilateral congenital hearing loss, then maybe it makes sense they would have bilateral weakness on calorics and/or VHIT and/or SOT.  Were you trying to see the relationship between hearing loss and vestibular hypofunction? Or the benefits/cons of hearing aids or implants on hearing impaired children’s balance? You need to focus your results and discussion.

Reply: This work main aim was to compare the sensitivity of svint / sot and their respective accuracy to uncover vestibular balance impairments  possibly associated in children with an important hearing loss; however patients with bilateral hl may have or not have bilat or unilat vestibular dysfunction measured and categirized in this work by calorics and vhit; the main aim was to determine the sensitivity of svint or sot to reveal in such patients absence of vestibular impairment, presence of a unilateral or of a bilatateral disfunction ; in this way svint was much efficient to reveal patients with a unilateral vestibular loss (uvl) but was not efficient in case of bilat symmetrical dysfunction (bvl). Conversely sot was abnormal and as efficient to show  patients with uni or bilateral vestibular impairment

Also, you do not even mention something that seems very important, is it safe to perform vibration tests on patients with cochlear implants??

Reply: This was not mentioned here because we already published this study.

Conclusion

You cannot conclude what you didn’t do in your study. You say it is non-invasive and rapid test, this is not one of your conclusions, eliminate or move to discussion. Do NOT include references in the conclusions please move to discussion: The SVINT is mainly relevant to the contributions of the SCC and the utricle, but not to the contribution of the saccule (21).

Reply: We agree with this and have incorporated your suggestion and accordingly  modified the conclusion in  the new version of the ms.

 

Round 2

Reviewer 2 Report

I do not feel the authors made a strong effort in responding to the concerns mentioned in the first review. I still don’t understand the real objective and purpose of this study clearly. They mention sensitivity of the SVINT in their reviewer response, never was this mentioned.  There are basic errors, for instance they put materials and methods in the figure (calorics), that doesn’t go there, should be in the text and clearly described, English needs to be reviewed by native English speaker, they are not clear in the etiology of hearing loss, family history?? This is not a cause, you mean genetic? Hereditary?? The discussion is weak, they added those sentences from the results in the discussion but without context, they still self-cited, just in another way, they didn’t answer the point about safety, they say its in another study, well it is a basic thing that should be included here. Why include a control group of healthy children but then not remove those 3 patients that had significant nystagmus, I don’t understand why they didn’t standardize and instead tell me to read yet another one of their articles about it. They should remove those 3 patients from the calculations and stats.

If the point was to assess SVINT use for children with hearing loss, they why does it matter if they have hearing aids or cochlear implants? These are two completely different groups, one has been intervened with a surgery and could potential affect the vestibular system secondarily. The other does not, they cannot group these patients together.

If the point was to see SVINT sensitivity for children with significant hearing loss, then they should only include hearing loss without surgery and compare to normal children.

I feel they have a lot of information but do not know what to include. Please review correctly and think hard about what you want to say here.

I suggest you think about you hypothesis  and objectives and rewrite this article, some things are not necessary and confusing.

Author Response

Dear Editors and Reviewers,

Thank you for giving us the opportunity to submit a revised draft of my manuscript entitled “Correlation of SVINT and Sensory Organization Test in Children with Hearing Loss”

We appreciate the time and effort that you have dedicated to providing your valuable feedback on our manuscript. We are grateful to the reviewers for their insightful comments on our paper. We have been able to incorporate changes to reflect the suggestions provided by the reviewers. We have highlighted the changes within the manuscript using track changes and using yellow highlight.

Please find our response to each comment below:

Comment (1): I do not feel the authors made a strong effort in responding to the concerns mentioned in the first review.

Response (1): We apologize if you felt so; and we thank you so much for giving us this chance to improve the manuscript according to your insightful comments. We have invested more efforts in the following version, and we hope you find all your comments addressed in this version.

Comment (2): I still don’t understand the real objective and purpose of this study clearly.

Response (2): We agree with the reviewer and the following paragraph was added to the manuscript:

“The clinical significance of using the SVINT in evaluating vestibular function in pediatrics is still not fully established and requires more empirical investigation. Therefore, the present study examines the correlation between the SVINT and the SOT findings in normal hearing pediatric subjects vs. hearing impaired pediatric subjects who are rehabilitated with HAs and CI. Keeping in mind that performing the gold standard caloric test is challenging in pediatric population, the aim of the present study is to explore the clinical diagnostic value of using SVINT in identifying unilateral and asymmetrical vestibular lesions in children with hearing loss by correlating the SVINT results with the SOT results, as well as with the vHIT and CaT.”

Comment (3): They mention sensitivity of the SVINT in their reviewer response, never was this mentioned. 

Response (3): We agree with the reviewer and the following sentence and reference were added to the manuscript:

“In children, SVINT can detect unilateral vestibular deficit in the very high frequency with a sensitivity of 86% and specificity of 96%. The positive predictive value is 75% and negative predictive value is 98%(11).”

Sinno S, Perrin P, Smith Abouchacra K, Dumas G. The skull vibration-induced nystagmus test: A useful vestibular screening test in children with hearing loss. Eur Ann Otorhinolaryngol Head Neck Dis. 2020 Dec 1;137(6):451–7.

 

Comment (4): There are basic errors, for instance they put materials and methods in the figure (Calorics), that doesn’t go there, should be in the text and clearly described.

Response (4): We thank the reviewer for this important observation and we agree that the calorics and other tests need to be explained in details in the text of material and methods. Because of the limited number of words in the article we initially used a figure design.

The following paragraphs were added to the text and figure 1 was removed.

“The following procedure was used in previous publications by the authors about SVINT (2,8,9). Each child underwent an age appropiate audiological evaluation including otoscopy, pure tone audiometry, and immitance. Pure tone audiometry was performed using the (Garson-Stadler Audiostar pro audiometer) and the immitance testing was performed using the Garson-Stadler Tympstar pro tempanometer).

 

SVINT was performed using vibrator VVIB100 which was applied firmly and perpendicularly on 3 positions successively: the vertex, the right, and the left mastoid processes at the level of the external auditory canal for 5 to 20 sec at each position. The eye movement was recorded during each vibration position to identify the presence or absence of nystagmus.

 

CaT assessed the vestibulo-ocular reflex (VOR) of the horizontal canal function (at very low frequency) by irrigating cold and warm air in the external ear canal. Caloric testing was performed following the British Society of Audiology recommendation. In the group of normal children the right and left ears were irrigated for 60 seconds with cold air (24°c). The child was excluded from the study in case of asymmetrical cold caloric findings. For children with HL, the right and left ears were irrigated with warm and cold air (24-50°c). A mental task was given to all childrem during the caloric test to ensure a maximum intensity and regularity of the nystagmus response. An interval of at least 5 minutes was given between irrigations allowing the child to rest and insuring the absence of temprature influence on the following contralateral irrigation. The results of the CaT were analyzed in the categorical format and the asymmetry was calculated from maximum slow phase velocities using Jongkees' formula. The monothermal caloric asymmetry (MCA) criteria for unilateral weakness (UW) was defined as >15%, and the total bilateral reflectivity for bilateral weakness (BW) was defined as < 12°/s according to the British Society of Audiology guidelines.

 

vHIT measured the velocity of the eyes and records abnormalities in patients with VOR dysfunction at high frequencies of 4-7 Hz. The right and left lateral SCC vHIT findings were only analyzed for the purpose of the present study.

 

SOT assessed the overall balance and the use of specific sensory inputs to maintain postural control. This included the 6 common conditions: (1) eyes open, surround and platform stable, (2) eyes closed, surround and platform stable, (3) eyes open, sway-referenced surround, platform stable, (4) eyes open, sway-referenced platform, (5) eyes closed, sway-referenced platform, and (6) eyes open, sway referenced surround and platform. The composite-equilibrium-score (CES) and the sensory analysis ratios (SAS) were quantified and compared between the 6 conditions as follows:

• The somatosensory ratio compared Condition 2 to Condition 1 and assessed the ability of an individual to use somatosensory information for balance.
• The visual ratio compared Condition 4 to Condition 1 and assessed the ability of an individual to use visual information for maintaining balance.
• The vestibular ratio compared Condition 5 to Condition 1 and assessed the ability of an individual to use vestibular information for maintaining balance.
• The visual preference ratio compared Conditions 3 and 6 to Conditions 2 and 5 and assessed the degree to which an individual relied on visual information to maintain balance, even when the information was incorrect or misleading.”

Comment (5): English needs to be reviewed by native English speaker.

Response (5): We agree with the reviewer. We reviewed the grammar and spelling in the manuscript and have again revised it in this new version. If any more typos are noticed, we will be more than happy to correct them.

Comment (6): they are not clear in the etiology of hearing loss, family history?? This is not a cause, you mean genetic? Hereditary??

Response (6): Thank you for this observation. The following paragraph was edited and added to the text:

“The etiology of hearing loss was not the same across the groups: The main etiology of hearing loss in children with HA was due to hereditary factors; whereas idiopathic etiology was the highest reported cause of hearing loss, followed by hereditary factors and then meningitis in children with CI. The level of hearing loss was between moderate-severe (56-70 dB) and severe (71-90 dB) bilaterally for children with HA and bilaterally profound for children with CI.”

Comment (7): The discussion is weak, they added those sentences from the results in the discussion but without context, they still self-cited, just in another way, they didn’t answer the point about safety, they say its in another study, well it is a basic thing that should be included here. Why include a control group of healthy children but then not remove those 3 patients that had significant nystagmus, I don’t understand why they didn’t standardize and instead tell me to read yet another one of their articles about it. They should remove those 3 patients from the calculations and stats.

Response (7): Thank you for these valuable points.

The safety issue was addressed in the discussion section. The following paragraph was added to the discussion:

“All children in both (NH and HL) groups denied any change in hearing, any discomfort, any changes in the performance of the HA or CI, or any other negative effects at the end of data collection. Therefore, one can assume that all the procedures including the SVINT were safe and have no adverse effect on the children or their devices. Similar safety concerns were addressed and dissipated in previous literature (11).”

All the discussion section was rewritten to provide more coherent and concise thoughts and conclusions, and to address the reviewer’s comments.

Moreover, the below paragraph and references were added to the results section to clarify why the 3 subjects didn’t have an effect on the data analysis:

“Among the 120 healthy children in the NH group, three children (2.5% of cases) showed nystagmus with slow phase velocity < 2.5°/s during SVINT. These rare positive SVINT findings in normal subjects have been reported in the literature (9,10) and can be neglected here because the nystagmus magnitude was marginal and does not statistically affect the findings of the present study. A negative SVINT result was observed in the remaining 117 children (97.5%) according to the criteria defined in table 2. Among these children with negative SVINT, 94 children did not have any nystagmus and 23 children had a non-clinically significant nystagmus[1].”

9. Zamora EG, Araújo PE-S, Guillén VP, Gamarra MFV, Ferrer VF, Rauch MC, et al. Parameters of skull vibration-induced nystagmus in normal subjects. Eur Arch oto-rhino-laryngology Off J Eur Fed Oto-Rhino-Laryngological Soc  Affil with Ger Soc Oto-Rhino-Laryngology - Head Neck Surg. 2018 Aug;275(8):1955–61.
10. Dumas G, Perrin P, Schmerber S. Nystagmus induced by high frequency vibrations of the skull in total unilateral peripheral vestibular lesions. Acta Otolaryngol. 2008;128(3).

 

Comment (8): If the point was to assess SVINT use for children with hearing loss, they why does it matter if they have hearing aids or cochlear implants? These are two completely different groups, one has been intervened with a surgery and could potential affect the vestibular system secondarily. The other does not, they cannot group these patients together.

Response (8): We agree with this remark. Data from the CI and HA groups were analyzed first to ensure that no statistical difference is present between the CI and HA children. After that, both the CI and HA groups were merged in one group called the hearing loss (HL) group. This was corrected in the abstract and in the text to avoid confusion. For example MANOVA and all the present statistics included in the study analyze the NH group vs. the HL group. This is highlighted in the following statistical section:

“Multiway Analysis of Variance (MANOVA) was used to analyze the significance of the main effects of: [2 experimental groups: NH vs. HL groups] X [2 tests (SVINT vs. SOT)] X [4 age ranges (5-8 vs. 9-11 vs. 12-14 vs. 15-17 years)] X [2 Genders (Male vs. Female)].”

Comment (9): If the point was to see SVINT sensitivity for children with significant hearing loss, then they should only include hearing loss without surgery and compare to normal children. I feel they have a lot of information but do not know what to include. Please review correctly and think hard about what you want to say here.

Response (9): Since there is no significant statistical difference between the CI and the HA children in the HL group, this should not be a concern.

Comment (10): I suggest you think about you hypothesis and objectives and rewrite this article, some things are not necessary and confusing.

Response (10): We rewrote the manuscript taking into consideration your comments mentioned above, and we hope that we were able to address all of them in this new version of the manuscript.

Thank you so much for your wonderful feedback which was very helpful to improve our manuscript. If you have any further concerns, please don’t hesitate to let us know and we will be more than happy to edit accordingly.

 

[1] For more details please review full data published in SVINT as a screening tool in children (11).

Round 3

Reviewer 2 Report

I can see the authors have tried to answer all of my concerns. the article is now easier to read and the objective is now clearly described. 

I suggest changing hereditary to genetic, unless you have proof of hereditary deafness. 

Review English again, its immittance no immitance, vHIT was measured, using a vibrator, etc.. many little errors

Review typos again, there are many  ) & ( where they don´t belong in methods. childrem, also .. in table

Cite reference for: British Society of Audiology recommendation. 

Author Response

We would like to first thank the editor and reviewers for their response to our work and their constructive comments. We have addressed the concerns that were raised through further editing of the manuscript and believe it has significantly improved as a consequence of this process. We greatly appreciate the opportunity to submit this revised review manuscript and hope it is now suitable for publication

Author Response File: Author Response.docx