Improvement in Tongue Pressure Precedes Improvement in Dysphagia in Dermatomyositis

Round 1

Reviewer 1 Report

In the current manuscript, authors presented two cases of severe dysphagia dermatomyositis cases. The story is interesting, but also I believe it can be improved by clarifying the following issues:

1. Tongue pressure is recently an interesting issue. However, I noticed that the device used in your country is often different from the western countries. I think it will be helpful to provide the device's data.

2.  For videofluoroscopy (VF), I would like to learn more about your protocol. What kind of thickness did you use in these cases, and how much amount did you try?

3. In page 4, line 145, you mentioned "Videoendoscopy". I believe Fiberoptic Endoscopic Evaluation of Swallowing (FEES) will be a better term.

4. For case 2, PAS score of 5 is quite severe condition. You started oral diet in page 4, line 104. What kind of diet did you suggest in the beginning? Did you use feeding tubes or even arranged tracheostomy?

Author Response

Reviewer 1

Response: We wish to express our appreciation to the reviewer for his or her insightful comments, which have helped us significantly improve the quality of our manuscript.

In the current manuscript, authors presented two cases of severe dysphagia dermatomyositis cases. The story is interesting, but also I believe it can be improved by clarifying the following issues:

1. Tongue pressure is recently an interesting issue. However, I noticed that the device used in your country is often different from the western countries. I think it will be helpful to provide the device's data.

Response： We added　the description of the tongue pressure in Introduction “We used a new digital tongue pressure measurement device (JMS Co., Ltd., Hiroshima, Japan). Two patients compressed the balloon of a disposable intraoral pressure probe upward onto their palates for 7 seconds using the maximum voluntary effort of the tongue. Wengue pressures recorded tongue pressures 3 times at 1-minute intervals and adopted the maximum pressure recorded as the maximal tongue pressure (kPa). We used the average of the maximal tongue pressures for our evaluation [7].”(Line41-45, page2)

2. For videofluoroscopy (VF), I would like to learn more about your protocol. What kind of thickness did you use in these cases, and how much amount did you try?

Response： We added　the protocol of VF in Introduction “To examine the responsiveness to treatment, we evaluated the swallowing function, using tongue pressure, videofluoroscopy (VF), and a questionnaire. VF with a modified Logemann protocol was recorded after participants were instructed to swallow 3 mL of 40% w/v barium sulfate twice in a standing position, which was viewed in the lat-eral plane. Each swallowing was recorded, and the recording included at least 20 sec of the period after the initial swallow, at a speed of 30 frames per second, using a digital capture card. The recorded images were analyzed frame-by-frame and scored based on the penetration-aspiration scale (PAS) and the pharyngeal residues were measured by semiquantitative scales: 0, 2, 5, 10, 20, 30, 40, 50, 60, 70, 80, 90, and 100%. Two experi-enced speech-language pathologists verified the results.”(Line39, Page1-Line40, Page2)

3. In page 4, line 145, you mentioned "Videoendoscopy". I believe Fiberoptic Endoscopic Evaluation of Swallowing (FEES) will be a better term.

Response： Thank you for your advice. We changed it to Fiberoptic Endoscopic Evaluation of Swallowing (FEES) as suggested.

4. For case 2, PAS score of 5 is quite severe condition. You started oral diet in page 4, line 104. What kind of diet did you suggest in the beginning? Did you use feeding tubes or even arranged tracheostomy?

Response： Thank you for your advice. We added the explanation about oral diet in Case 2 (Line 110-111, Page4)

Author Response File: Author Response.pdf

Reviewer 2 Report

This case study describes the course of dysphagia from acute onset through pharmacological intervention of two patients with dermatomyositis. Tongue pressure was measured, videofluoroscopy (VF) was performed, and the patient-reported outcome, the EAT-10, was completed by patients longitudinally. The authors concluded that tongue pressures may be useful for measuring swallowing function across time in this population.

This a population in which dysphagia is rare, per the authors (although is 18-20% of the population experiencing dysphagia really that rare?), so the longitudinal assessment of swallowing in patients with dermatomyositis is an interesting and potentially important investigation, particularly when the dysphagia is as severe and debilitating as noted in the two patients in this manuscript. The effect of interventions on swallowing function, as in the pharmacological ones used for these two patients, is also of critical importance. However, this manuscript is flawed by several crucial methodological issues. Additionally, the literature review is not complete and the rationale/purpose of the paper is unclear. The most glaring issues are as follows:

1.      The rationale/purpose of the paper is unclear. Aside from simply describing the longitudinal course of dysphagia, what is the relation to intervention? For example, is the purpose to examine swallowing function in this population where it has not been previously reported? Without a clear rationale, the entirety of the manuscript appears unplanned and unfocused.

2.      The literature review in the introduction, as well as the connection to published literature in the discussion, is inadequate, and is unclear if this is because there is a lack of existing literature on this population. However, if this is the case, connections between literature in other populations could/should be drawn as an alternative. From my reading of the instructions for authors, there is not a restriction on the length of case reports, so this should not be a factor in determining the thoroughness of the literature reviewed. Relatedly, some of the information in the discussion should be present in the introduction – for example, the point that dysphagia is uncommon in dermatomyositis would be important to know earlier in the manuscript. Also, many claims are made that are not adequately substantiated by the published literature (as examples: lines 30-31 “Patients with dysphagia experience…” do you mean patients with dysphagia in general? Or patients with dermatomyositis with dysphagia? In either case, this is not necessarily true. These are possible symptoms of dysphagia but are certainly not the only ones nor necessarily impaired in all people with dysphagia; lines 150-151; lines 152-153; line 128 “Unlike patients in previous studies…” which previous studies?)

3.      Overall, the discussion is unfocused and lacks clarity. I’m not sure what point the authors are trying to make or how the case studies presented lead to the points raised in the discussion/conclusion.

4.      The largest and most compromising issue I have with this paper is methodological. The use of tongue pressure as a primary outcome measure is concerning. The authors state that “Maximum tongue pressure reflects swallowing function…” (lines 32-33), but I’m not sure how true this is. Tongue pressure could be an indication of swallowing function, but it certainly does not always reflect or predict swallowing function, especially across a variety of patient populations. Secondarily, only the penetration-aspiration scale and residue are reported from the videofluoroscopic evaluation (for example, lines 54-55). Videofluoroscopy provides so much more valuable information than this and it is unclear why more complete findings from these evaluations are not reported. The bigger concern I have with this is that the use of videofluoroscopy here is a misrepresentation of how it can/should be used as a clinical tool by speech-language pathologists. It should not be used as a simple pass/fail or improved/declined test, but rather a technique to describe the swallows observed. For example, the caption for figure 2 in line 81 says “…followed by improvement on VF…” which is very vague/incomplete. Just because a PAS score is higher, does not necessarily mean that the swallow as a whole has improved. Additionally, the authors need to identify what measure of swallowing is of primary concern. Based on the title and focus on tongue strength in the introduction, it appears that the primary measure is tongue strength; however, this isn’t a functional measure of swallowing and the rationale for its use is not strongly constructed. Videofluoroscopy, in contrast, is a preferred source of functional data, but this has not been discussed in any amount of detail/used to its full potential.  

In addition to the points above, a few more minor concerns are as follows:

·         Figure 2:

o   It is a bit misleading to have the SWAL-QOL and the PAS score/EAT-10 on the same graph like this since the SWAL-QOL is on a totally different scale. Also, it doesn’t look like the SWAL-QOL is discussed at all in the text.

o   What is the scale of the x-axis (i.e., days vs. weeks)?

o   What does the height of the treatment bars in black demonstrate?

·         Case 2:

o   What was this patient’s swallowing like at baseline (besides “poor laryngeal elevation on palpation”)?

§  Lines 100-101 “Two months after dysphagia onset, she was able to swallowing saliva…” Unclear is this is an improvement from baseline since there is no description of swallowing abilities at baseline.

o   Line 103 – do you mean Figure 2B?

o   Line 109 – what does “normal swallowing function” mean? Without any objective data to support this, this is a concerning statement.

·         It was unclear to me until the discussion that both patients had difficult swallowing their own secretions.

·         Lines 134-135 – this is not correct as clinicians use videofluoroscopy to track clinical course of swallowing regularly in practice and there are many studies that have used it to look at longitudinal changes in swallowing. I also don’t see how this statement is supported by the cited publication.  

·         Line 146 – it could be argued that endoscopy is not ‘easier to perform’ than videofluoroscopy (i.e., there are a lot of factors that go into the ease of performing a certain evaluation, including training, experience, institutional workflow, etc.); what aspects of it are the authors referring to?

o   Lines 146-147 – the same is true for videofluoroscopy

·         Line 149 – I would argue that collecting tongue pressure data does require at least some level of training, though obviously much less than that needed to perform and evaluate videofluoroscopy (i.e., to place the probe correctly, what instructions to give patients, etc.)

Author Response

Reviewer 2

This case study describes the course of dysphagia from acute onset through pharmacological intervention of two patients with dermatomyositis. Tongue pressure was measured, videofluoroscopy (VF) was performed, and the patient-reported outcome, the EAT-10, was completed by patients longitudinally. The authors concluded that tongue pressures may be useful for measuring swallowing function across time in this population.

This a population in which dysphagia is rare, per the authors (although is 18-20% of the population experiencing dysphagia really that rare?), so the longitudinal assessment of swallowing in patients with dermatomyositis is an interesting and potentially important investigation, particularly when the dysphagia is as severe and debilitating as noted in the two patients in this manuscript. The effect of interventions on swallowing function, as in the pharmacological ones used for these two patients, is also of critical importance. However, this manuscript is flawed by several crucial methodological issues. Additionally, the literature review is not complete and the rationale/purpose of the paper is unclear. The most glaring issues are as follows:

Response: We wish to express our appreciation to the reviewer for his or her insightful comments, which have helped us significantly improve the quality of our manuscript.

1. The rationale/purpose of the paper is unclear. Aside from simply describing the longitudinal course of dysphagia, what is the relation to intervention? For example, is the purpose to examine swallowing function in this population where it has not been previously reported? Without a clear rationale, the entirety of the manuscript appears unplanned and unfocused.

Response： Thank you for your advice. We agree that the purpose was ambiguous. We examined which index was optimized to assess the longitudinal course of dysphagia. We added the text in Introduction. “Severe dysphagia to liquids, solids, and even saliva without severe limb weakness is uncommon in dermatomyositis [5]. In these , no indicators of the effectiveness of treatment have been established.”(Line28-30, Page2)

2. The literature review in the introduction, as well as the connection to published literature in the discussion, is inadequate, and is unclear if this is because there is a lack of existing literature on this population. However, if this is the case, connections between literature in other populations could/should be drawn as an alternative. From my reading of the instructions for authors, there is not a restriction on the length of case reports, so this should not be a factor in determining the thoroughness of the literature reviewed. Relatedly, some of the information in the discussion should be present in the introduction – for example, the point that dysphagia is uncommon in dermatomyositis would be important to know earlier in the manuscript. Also, many claims are made that are not adequately substantiated by the published literature (as examples: lines 30-31 “Patients with dysphagia experience…” do you mean patients with dysphagia in general? Or patients with dermatomyositis with dysphagia? In either case, this is not necessarily true. These are possible symptoms of dysphagia but are certainly not the only ones nor necessarily impaired in all people with dysphagia; lines 150-151; lines 152-153; line 128 “Unlike patients in previous studies…” which previous studies?)

Response: Thank you for providing important comments. Accordingly, we rewrote the text.

3. Overall, the discussion is unfocused and lacks clarity. I’m not sure what point the authors are trying to make or how the case studies presented lead to the points raised in the discussion/conclusion.

Response: Thank you for providing important comments. We added the sentence in Discussion “We reported two cases of patients who experienced sudden-onset aphagia without severe limb weakness, and were monitored for treatment responsiveness and patho-logical control [9]. In particular, the treatment response with muscle weakness was evaluated using the following parameters: serum creatine kinase level, muscle strength, disease activity score, and disability score [10]. However, patients with only dysphagia could not be monitored.”(Line137-142, page4)

4. The largest and most compromising issue I have with this paper is methodological. The use of tongue pressure as a primary outcome measure is concerning. The authors state that “Maximum tongue pressure reflects swallowing function…” (lines 32-33), but I’m not sure how true this is. Tongue pressure could be an indication of swallowing function, but it certainly does not always reflect or predict swallowing function, especially across a variety of patient populations. Secondarily, only the penetration-aspiration scale and residue are reported from the videofluoroscopic evaluation (for example, lines 54-55). Videofluoroscopy provides so much more valuable information than this and it is unclear why more complete findings from these evaluations are not reported. The bigger concern I have with this is that the use of videofluoroscopy here is a misrepresentation of how it can/should be used as a clinical tool by speech-language pathologists. It should not be used as a simple pass/fail or improved/declined test, but rather a technique to describe the swallows observed. For example, the caption for figure 2 in line 81 says “…followed by improvement on VF…” which is very vague/incomplete. Just because a PAS score is higher, does not necessarily mean that the swallow as a whole has improved. Additionally, the authors need to identify what measure of swallowing is of primary concern. Based on the title and focus on tongue strength in the introduction, it appears that the primary measure is tongue strength; however, this isn’t a functional measure of swallowing and the rationale for its use is not strongly constructed. Videofluoroscopy, in contrast, is a preferred source of functional data, but this has not been discussed in any amount of detail/used to its full potential.

Response: We analysised the retention rate of the larynx and added it to Fig 2-A, B. We understand that videofluoroscopic evaluation is intended to examine useful. But, we need the  convenient surrogate markers in bedside. We add the sentence in Discussion “VF can reveal the status of swallowing and the presence and severity of dysphagia [12].Two months after dysphagia onset, patient 2 showed complete clinical recovery, but VF revealed silent aspiration with liquids. Therefore, VF is considered to be a more sensitive test method than subjective symptoms. Indeed, many studies have reported that routine videofluoroscopy followed the clinical course of swallowing. On the other hand, VF should be performed despite the disadvantages of radiation exposure, aller-gic reaction, and the requirement of the patient to visit the radiography room [8]. Fi-beroptic Endoscopic Evaluation of Swallowing (FEES) is another option for semi-quantitative and precise swallowing evaluation and can be performed at the bedside. However, the FEES operator requires training, experience, and skill, and there is a possibility of bias.”(Line162, Page6-Line 172, Page7)

In addition to the points above, a few more minor concerns are as follows:

• Figure 2:

o   It is a bit misleading to have the SWAL-QOL and the PAS score/EAT-10 on the same graph like this since the SWAL-QOL is on a totally different scale. Also, it doesn’t look like the SWAL-QOL is discussed at all in the text.

Response: Since SWAL-QOL was measured only in Case 1, it was removed from Fig2. We added pharyngeal residue rate instead of SWAL-QOL to Fig 2 in both cases.

o   What is the scale of the x-axis (i.e., days vs. weeks)?

Response: Thank you for your point. We added the scale of the x-axis in Fig 2.

o   What does the height of the treatment bars in black demonstrate?

Response: Thank you for your point. The dose of methylprednisolone had been shown, but it was difficult to understand, so the notation has been changed.

• Case 2:

o   What was this patient’s swallowing like at baseline (besides “poor laryngeal elevation on palpation”)?

Response: Thank you for your point. We added the sentence “Poor laryngeal elevation was noted on palpation, so she could not swallow liquids, solids, or even saliva. She was initiated on tube feeding after admission.”（Line110-111, Page4）

• Lines 100-101 “Two months after dysphagia onset, she was able to swallowing saliva…” Unclear is this is an improvement from baseline since there is no description of swallowing abilities at baseline.

Response: Thank you for your point.

o   Line 103 – do you mean Figure 2B?

Response: Thank you for your point. We amended it to Figure 2B.

o   Line 109 – what does “normal swallowing function” mean? Without any objective data to support this, this is a concerning statement.

Response: Thank you for your point. We changed the phrasing.

• It was unclear to me until the discussion that both patients had difficult swallowing their own secretions.

Response: Thank you for your point. We removed the sentence in the Abstract.

• Lines 134-135 – this is not correct as clinicians use videofluoroscopy to track clinical course of swallowing regularly in practice and there are many studies that have used it to look at longitudinal changes in swallowing. I also don’t see how this statement is supported by the cited publication.

Response: Thank you for your point. We added a sentence on Discussion

• Line 146 – it could be argued that endoscopy is not ‘easier to perform’ than videofluoroscopy (i.e., there are a lot of factors that go into the ease of performing a certain evaluation, including training, experience, institutional workflow, etc.); what aspects of it are the authors referring to?

   Lines 146-147 – the same is true for videofluoroscopy

Response: Thank you for your point. We added a sentence on Discussion “Fiberoptic Endoscopic Evaluation of Swallowing (FEES) is another option for semi-quantitative and precise swallowing evaluation and can be performed at the bedside. However, the FEES operator requires training, experience, and skill, and there is a possibility of bias.” (Line169-172, Page5)

• Line 149 – I would argue that collecting tongue pressure data does require at least some level of training, though obviously much less than that needed to perform and evaluate videofluoroscopy (i.e., to place the probe correctly, what instructions to give patients, etc.)

Response: We added　the description of the tongue pressure in Introduction “We used a new digital tongue pressure measurement device (JMS Co., Ltd., Hiroshima, Japan). Two patients compressed the balloon of a disposable intraoral pressure probe upward onto their palates for 7 seconds using the maximum voluntary effort of the tongue. Wengue pressures recorded tongue pressures 3 times at 1-minute intervals and adopted the maximum pressure recorded as the maximal tongue pressure (kPa). We used the average of the maximal tongue pressures for our evaluation [7].”(Line41-45, page2)

Author Response File: Author Response.pdf

Reviewer 3 Report

The Iowa Oral Performance Instrument® (IOPI) and KAY Swallowing Workstation® are internationally used for tongue pressure measurement, but for legal reasons cannot be used in Japan; rather the JMS tongue pressure measurement device® has been approved for use in Japan. I would like a sentence added in the discussion, with regard to the use of the JMS and the potenial utility, also of similar intruments, in other parts of the world.

Author Response

Responses to reviewer’s comments

Reviewer3

The Iowa Oral Performance Instrument® (IOPI) and KAY Swallowing Workstation® are internationally used for tongue pressure measurement, but for legal reasons cannot be used in Japan; rather the JMS tongue pressure measurement device® has been approved for use in Japan. I would like a sentence added in the discussion, with regard to the use of the JMS and the potenial utility, also of similar intruments, in other parts of the world.

Response: The authors would like to thank the reviewer for his/her constructive critique to improve the manuscript. We have made every effort to address the issues raised and to respond to all comments. The revisions are indicated highlighted in the revised manuscript. Please, find next a detailed, point-by-point response to the reviewer's comments. We hope that our revisions will meet the reviewer’s expectations.

We add the sentence in Introduction “We used a digital tongue pressure measurement device (TPM-01) (JMS Co., Ltd., Hiro-shima, Japan), which has been approved for use in Japan. The previous study reported that the maximum tongue pressure measured by the internationally used for tongue pressure measurement, such as Iowa Oral Performance Instrument (IOPI) was slightly higher than that measured by TPM-01 [6, 16].”　and new reference.

16. Yoshikawa M, Yoshida M, Tsuga K, Akagawa Y, Groher ME. Comparison of three types of tongue pressure measure-ment devices. Dysphagia. 2011 Sep;26(3):232-7. doi: 10.1007/s00455-010-9291-3.

Author Response File: Author Response.docx

Round 2

Reviewer 2 Report

This reviewer thanks the authors for their attempts to respond to the significant concerns I laid out in my initial review. I appreciate the purpose that is better laid out in the introduction, however it still lacks clarity as the treatment examined is not discussed and appears to differ between the two participants. Although a few of the issues raised have been adequately responded to, there are many outstanding concerns which I believe have not been sufficiently addressed. I continue to believe these concerns are significant enough to preclude publication of this manuscript. This tracked-changes version is also very difficult to read and evaluate as it is unclear what has been deleted. Currently, there are many grammatical errors, but some of this may be due to the tracked-changed showing incorrectly. The organization and focus of the manuscript have, overall, not been improved in this revision.

There continue to be several unsupported claims in this manuscript (for example, lines 32-35) and the study cited in line 38 is not relevant for patients with dermatomyositis (i.e., just because tongue pressure reflects swallowing function in neuromuscular disease does not mean this holds for all populations). Additions to the discussion section are mostly unclear and do not contribute to a more focused review of the study/relevant literature. The lack of supporting literature in the introduction and discussion is an ongoing problem and previous work in this area does not appear to be sufficiently cited. 

Additionally, a few more minor concerns:

·         The semiquantitive scale of pharyngeal residue is not clear (lines 57-59)

·         What is meant by two SLPs verifying the results? (lines 59-60)

·         Just because a patient has poor laryngeal elevation on palpation does NOT mean they cannot swallow liquids, solids, or saliva (lines 110-111) – this is just incorrect

·         VF results at the baseline assessment has not been included

·         In the cover letter, the authors’ point about needing “convenient surrogate markers in bedside” is well-taken; however this is only stated at the end of the manuscript and, if this is part of the purpose of the paper, should be made more clear earlier  

·         The issue with the scales of the y-axes in Figure 2 was not addressed

Author Response

Responses to reviewer’s comments

Reviewer2

This reviewer thanks the authors for their attempts to respond to the significant concerns I laid out in my initial review. I appreciate the purpose that is better laid out in the introduction, however it still lacks clarity as the treatment examined is not discussed and appears to differ between the two participants. Although a few of the issues raised have been adequately responded to, there are many outstanding concerns which I believe have not been sufficiently addressed. I continue to believe these concerns are significant enough to preclude publication of this manuscript. This tracked-changes version is also very difficult to read and evaluate as it is unclear what has been deleted. Currently, there are many grammatical errors, but some of this may be due to the tracked-changed showing incorrectly. The organization and focus of the manuscript have, overall, not been improved in this revision.

Response: The authors would like to thank the reviewer for his/her constructive critique to improve the manuscript. We have made every effort to address the issues raised and to respond to all comments. The revisions are indicated highlighted in the revised manuscript. Please, find next a detailed, point-by-point response to the reviewer's comments. We hope that our revisions will meet the reviewer’s expectations.

There continue to be several unsupported claims in this manuscript (for example, lines 32-35) and the study cited in line 38 is not relevant for patients with dermatomyositis (i.e., just because tongue pressure reflects swallowing function in neuromuscular disease does not mean this holds for all populations). Additions to the discussion section are mostly unclear and do not contribute to a more focused review of the study/relevant literature. The lack of supporting literature in the introduction and discussion is an ongoing problem and previous work in this area does not appear to be sufficiently cited. 

Response: We would like to thank the reviewer for the insightful suggestions. Please note that we have revised the corresponding parts in the Introduction and Discussion sections and cited the following references:

6. Ebert, E.C. Review article: the gastrointestinal complications of myositis. Aliment. Pharmacol. Ther. 2010, 31, 359–365.
7. Yoshikawa, M.; Yoshida, M.; Tsuga, K.; Akagawa, Y.; Groher, M.E.. Comparison of three types of tongue pressure measurement devices. Dysphagia 2011, 26, 232–237.
8. Sandage, M.J.; Smith, A.G. Muscle bioenergetic considerations for intrinsic laryngeal skeletal muscle physiology. J. Speech Lang. Hear. Res. 2017, 60, 1254–1263.
9. Weinreb, S.F.; Piersiala, K.; Hillel, A.T.; Akst, L.M.; Best, S.R. Dysphonia and dysphagia as early manifestations of autoimmune inflammatory myopathy. Am. J. Otolaryngol. 2021, 42, 102747.
10. Langdon, P.C.; Mulcahy, K.; Shepherd, K.L.; Low, V.H.; Mastaglia, F.L. Pharyngeal dysphagia in inflammatory muscle diseases resulting from impaired suprahyoid musculature. Dysphagia 2012, 27, 408–417.
11. Zeng, R.; Schmidt, J. Impact and management of dysphagia in inflammatory myopathies. Curr. Rheumatol. Rep. 2020, 22, 74.

Additionally, a few more minor concerns:

• The semiquantitive scale of pharyngeal residue is not clear (lines 57-59)

Response: To avoid confusion, we have added the following part to the revised manuscript:

“percentage of residual volume in 3 mL” (Lines 49–50)

• What is meant by two SLPs verifying the results? (lines 59-60)

Response: We would like to thank the reviewer for the question. To respond to the reviewer’s question, we have added the following part to the revised manuscript:

“We used a digital tongue pressure measurement device (TPM-01) (JMS Co., Ltd., Hiroshima, Japan), which has been approved for use in Japan. A previous study reported that the maximum tongue pressure measured by the Iowa Oral Performance Instrument, an internationally-used instrument for tongue pressure measurement, was slightly higher than that measured by TPM-01 [7, 8].” (Lines 57–61)

• Just because a patient has poor laryngeal elevation on palpation does NOT mean they cannot swallow liquids, solids, or saliva (lines 110-111) – this is just incorrect

Response: We would like to thank the reviewer for the comment. Please note that we have revised this sentence as follows:

“She could not swallow liquids, solids, or even saliva. Poor laryngeal elevation was noted on palpation; therefore, tube feeding was initiated after admission.” (Lines 122–124)

• VF results at the baseline assessment has not been included

Response: Please note that we have presented the VF results of the baseline assessment for both patients.

• In the cover letter, the authors’ point about needing “convenient surrogate markers in bedside” is well-taken; however this is only stated at the end of the manuscript and, if this is part of the purpose of the paper, should be made more clear earlier  

Response: We would like to thank the reviewer for the comment. Please note that we have added the following part to the Introduction section:

“Surrogate markers that can be easily evaluated longitudinally at the bedside should be examined to find the optimal treatment for each patient.” (Lines 32–33)

• The issue with the scales of the y-axes in Figure 2 was not addressed

Response: Please note that we have addressed this issue in the revised manuscript. We add the treatment y-axis and display as a single graph to see changes in subjective symptoms and objective symptoms