Peer Review History

Original SubmissionJune 21, 2019
Decision Letter - Wisit Cheungpasitporn, Editor

PONE-D-19-17566

Clinical features of chronic cluster headache based on the third edition of the International Classification of Headache Disorders: A prospective multicentre study

PLOS ONE

Dear Dr. Min Kyung Chu,

Thank you for submitting your manuscript to PLOS ONE. After careful consideration, we feel that it has merit but does not fully meet PLOS ONE’s publication criteria as it currently stands. Therefore, we invite you to submit a revised version of the manuscript that addresses the points raised during the review process.

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ACADEMIC EDITOR: Our expert reviewer(s) have recommended some minor revisions to your manuscript. Therefore, I invite you to respond to the reviewer(s)' comments as below and revise your manuscript.

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We look forward to receiving your revised manuscript.

Kind regards,

Wisit Cheungpasitporn, MD, FACP

University of Mississippi Medical Center

Twitter: @wisit661 Email: wcheungpasitporn@gmail.com 

Academic Editor

PLOS ONE

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1. Thank you for including your competing interests statement; "SJ Cho was involved as a site investigator of a multicentre trial sponsored by Otsuka Korea, Eli Lilly and Company, and Novartis, worked as an advisory member for Teva, and received research support from Hallym University Research Fund 2016 and a grant from the Korean Neurological Association (KNA-16-MI-09).

MK Chu was a site investigator for a multi-centre trial sponsored by Otsuka Korea, Novartis International AG, and Eli Lilly and Company. He worked as an advisory member for Teva, and received lecture honoraria from Allergan Korea, Handok-Teva, and Yuyu Pharmaceutical Company in the past 24 months.

The other authors, except for SJ Cho and MK Chu, declare no potential conflicts of interest."

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Reviewers' comments:

Reviewer's Responses to Questions

Comments to the Author

1. Is the manuscript technically sound, and do the data support the conclusions?

The manuscript must describe a technically sound piece of scientific research with data that supports the conclusions. Experiments must have been conducted rigorously, with appropriate controls, replication, and sample sizes. The conclusions must be drawn appropriately based on the data presented.

Reviewer #1: Yes

Reviewer #2: Yes

Reviewer #3: Yes

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2. Has the statistical analysis been performed appropriately and rigorously?

Reviewer #1: Yes

Reviewer #2: Yes

Reviewer #3: Yes

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3. Have the authors made all data underlying the findings in their manuscript fully available?

The PLOS Data policy requires authors to make all data underlying the findings described in their manuscript fully available without restriction, with rare exception (please refer to the Data Availability Statement in the manuscript PDF file). The data should be provided as part of the manuscript or its supporting information, or deposited to a public repository. For example, in addition to summary statistics, the data points behind means, medians and variance measures should be available. If there are restrictions on publicly sharing data—e.g. participant privacy or use of data from a third party—those must be specified.

Reviewer #1: Yes

Reviewer #2: Yes

Reviewer #3: Yes

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4. Is the manuscript presented in an intelligible fashion and written in standard English?

PLOS ONE does not copyedit accepted manuscripts, so the language in submitted articles must be clear, correct, and unambiguous. Any typographical or grammatical errors should be corrected at revision, so please note any specific errors here.

Reviewer #1: Yes

Reviewer #2: Yes

Reviewer #3: Yes

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5. Review Comments to the Author

Please use the space provided to explain your answers to the questions above. You may also include additional comments for the author, including concerns about dual publication, research ethics, or publication ethics. (Please upload your review as an attachment if it exceeds 20,000 characters)

Reviewer #1: The definition of chronic cluster headache has been changed in the last ICHD3 classification, increasing the time for relapse period from 1 to 3 months. The authors tested of the Korean cluster headache registry the effect of this modification in order to test the new definition and the clinical featurs of the CCH.

The most relevant observation is that the number of patients with CCH doubles with the new criteria.

The number of patients with CCH vs ECH are much less (176 vs 12) but the authors were able, with the statistical correction to still be able to find some significant diferences between the two populations. In particular they found out that the patients with CCH has higher age and lower CH history vs patients with ECH, they have less nasal congestion and rhinorrhea, and have more comorbidity with migraine. Interestingly the authors did not find any differenced in the population reclassified as CCH with the new criteria, meaning that the patients are probably right classified with the new criteria.

They observed how smoke habit may lead CH to become chronic lathough to clearly significant (probably due to the small numeber of pts).

The limits of the study where well stated.

- It would be interesting in the discussion to speculate if there might be a possible role of chronic pain networks disfunction in both conditions (Colombo B et al Neurol SCI 2015).

Reviewer #2: This is the multi-center, prospective study to investigate the clinical feature of chronic cluster headache using the new definition in hospitala in south korea. Overall, manuscript is well written. I cannot identify the major of this study.

Reviewer #3: -Please discuss in the limitations the types of biases the findings of this study may be influenced by

-The limitations of the study particularly in regards to the validation of diagnosis needs to be more robust.

-Some revision of the English language is needed.

“Diagnosis of ECH (code 3.1.1) and CCH (code 3.1.2) were based on criteria” is not correct in grammar.

“huge” should be avoided in academic writing.

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Reviewer #1: No

Reviewer #2: No

Reviewer #3: No

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Revision 1

Author Response Letter

We thank the reviewers for their constructive comments. We believe our paper has been improved based on the Reviewers’ comments. In this letter, we have provided a point-by-point response to each comment below. Textual changes based on the Reviewers’ comments are tracked in the revised manuscript. We hope our paper can meet the journal’s requirements.

Reviewer #1

1. The definition of chronic cluster headache has been changed in the last ICHD3 classification, increasing the time for relapse period from 1 to 3 months. The authors tested of the Korean cluster headache registry the effect of this modification in order to test the new definition and the clinical features of the CCH.

Response: We thank the reviewer for his/her time and efforts in reviewing our paper.

2. The most relevant observation is that the number of patients with CCH doubles with the new criteria.

Response: We agree with the reviewer that this is the major finding of our study. The latest ICHD-3 criteria broadened the spectrum of CCH without compromising its functional impact.

3. The number of patients with CCH vs ECH are much less (176 vs 12) but the authors were able, with the statistical correction to still be able to find some significant diferences between the two populations. In particular they found out that the patients with CCH has higher age and lower CH history vs patients with ECH, they have less nasal congestion and rhinorrhea, and have more comorbidity with migraine. Interestingly the authors did not find any difference in the population reclassified as CCH with the new criteria, meaning that the patients are probably right classified with the new criteria. They observed how smoke habit may lead CH to become chronic lathough to clearly significant (probably due to the small numeber of pts). The limits of the study where well stated.

Response: We appreciate the reviewer for properly summarizing our findings and giving us constructive comments.

4. It would be interesting in the discussion to speculate if there might be a possible role of chronic pain networks dysfunction in both conditions (Colombo B et al Neurol SCI 2015).

Response: Thank you for the insightful suggestion. We have added discussions regarding the role of pain networks in CH chronification. (Line 307 – 314 in the track-changes version)

Reviewer #2: This is the multi-center, prospective study to investigate the clinical feature of chronic cluster headache using the new definition in hospitala in south korea. Overall, manuscript is well written. I cannot identify the major of this study.

Response: We thank the reviewer for his/her time and efforts in reviewing our paper and constructive comments. We are pleased that the reviewer was satisfied with our paper.

Reviewer #3:

1. Please discuss in the limitations the types of biases the findings of this study may be influenced by

Response: We thank the reviewer for his/her time and efforts in reviewing our paper. The classification of ECH and CCH was based on patients’ description of their clinical courses, so recall bias may be present. Our study may also have type II error because the number of patients with CCH was small. We have added these information in the Limitations section. (Line 316 – 318, 328 – 329 in the track-changes version)

2. The limitations of the study particularly in regards to the validation of diagnosis needs to be more robust.

Response: Thank you for this comment. In our study, the validation of the ICHD-3 criteria was based on the comparison between 6 and 12 patients. This may be affected by biases because the number of patients was small, and the two groups were not completely independent to each other. We have added this in the Limitation section. (Line 332 – 334 in the track-changes version)

3. Some revision of the English language is needed.

3-1. “Diagnosis of ECH (code 3.1.1) and CCH (code 3.1.2) were based on criteria” is not correct in grammar.

Response: Thank you for pointing this out. The expressions have been revised. (Line 96 – 97, 108 – 112 in the track-changes version)

3-1. “huge” should be avoided in academic writing.

Response: Thank you for the suggestion. This expression has been also revised. (Line 278 in the track-changes version)

Attachments
Attachment
Submitted filename: author response letter_R1.docx
Decision Letter - Wisit Cheungpasitporn, Editor

Clinical features of chronic cluster headache based on the third edition of the International Classification of Headache Disorders: A prospective multicentre study

PONE-D-19-17566R1

Dear Dr. Min Kyung Chu,

We are pleased to inform you that your manuscript has been judged scientifically suitable for publication and will be formally accepted for publication once it complies with all outstanding technical requirements.

Within one week, you will receive an e-mail containing information on the amendments required prior to publication. When all required modifications have been addressed, you will receive a formal acceptance letter and your manuscript will proceed to our production department and be scheduled for publication.

Shortly after the formal acceptance letter is sent, an invoice for payment will follow. To ensure an efficient production and billing process, please log into Editorial Manager at https://www.editorialmanager.com/pone/, click the "Update My Information" link at the top of the page, and update your user information. If you have any billing related questions, please contact our Author Billing department directly at authorbilling@plos.org.

If your institution or institutions have a press office, please notify them about your upcoming paper to enable them to help maximize its impact. If they will be preparing press materials for this manuscript, you must inform our press team as soon as possible and no later than 48 hours after receiving the formal acceptance. Your manuscript will remain under strict press embargo until 2 pm Eastern Time on the date of publication. For more information, please contact onepress@plos.org.

With kind regards,

Wisit Cheungpasitporn, MD, FACP

University of Mississippi Medical Center

Twitter: @wisit661 Email: wcheungpasitporn@gmail.com 

Academic Editor

PLOS ONE

Additional Editor Comments:

I want to commend the authors on their superb efforts to revise the manuscript according to all reviewers’ suggestions. The quality of the manuscript has improved substantially.

Reviewers' comments:

Reviewer's Responses to Questions

Comments to the Author

1. If the authors have adequately addressed your comments raised in a previous round of review and you feel that this manuscript is now acceptable for publication, you may indicate that here to bypass the “Comments to the Author” section, enter your conflict of interest statement in the “Confidential to Editor” section, and submit your "Accept" recommendation.

Reviewer #1: All comments have been addressed

Reviewer #2: (No Response)

Reviewer #3: All comments have been addressed

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2. Is the manuscript technically sound, and do the data support the conclusions?

The manuscript must describe a technically sound piece of scientific research with data that supports the conclusions. Experiments must have been conducted rigorously, with appropriate controls, replication, and sample sizes. The conclusions must be drawn appropriately based on the data presented.

Reviewer #1: Yes

Reviewer #2: (No Response)

Reviewer #3: Yes

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3. Has the statistical analysis been performed appropriately and rigorously?

Reviewer #1: Yes

Reviewer #2: (No Response)

Reviewer #3: Yes

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4. Have the authors made all data underlying the findings in their manuscript fully available?

The PLOS Data policy requires authors to make all data underlying the findings described in their manuscript fully available without restriction, with rare exception (please refer to the Data Availability Statement in the manuscript PDF file). The data should be provided as part of the manuscript or its supporting information, or deposited to a public repository. For example, in addition to summary statistics, the data points behind means, medians and variance measures should be available. If there are restrictions on publicly sharing data—e.g. participant privacy or use of data from a third party—those must be specified.

Reviewer #1: Yes

Reviewer #2: (No Response)

Reviewer #3: Yes

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5. Is the manuscript presented in an intelligible fashion and written in standard English?

PLOS ONE does not copyedit accepted manuscripts, so the language in submitted articles must be clear, correct, and unambiguous. Any typographical or grammatical errors should be corrected at revision, so please note any specific errors here.

Reviewer #1: Yes

Reviewer #2: (No Response)

Reviewer #3: Yes

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6. Review Comments to the Author

Please use the space provided to explain your answers to the questions above. You may also include additional comments for the author, including concerns about dual publication, research ethics, or publication ethics. (Please upload your review as an attachment if it exceeds 20,000 characters)

Reviewer #1: (No Response)

Reviewer #2: All of my comments have been addressed properly. I have no further recommendation to improve this manuscript.

Reviewer #3: It is an interesting and relevant article. I consider it a useful contribution in its field. Revised manuscript is acceptable for publication.

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7. PLOS authors have the option to publish the peer review history of their article (what does this mean?). If published, this will include your full peer review and any attached files.

If you choose “no”, your identity will remain anonymous but your review may still be made public.

Do you want your identity to be public for this peer review? For information about this choice, including consent withdrawal, please see our Privacy Policy.

Reviewer #1: No

Reviewer #2: No

Reviewer #3: No

Formally Accepted
Acceptance Letter - Wisit Cheungpasitporn, Editor

PONE-D-19-17566R1

Clinical features of chronic cluster headache based on the third edition of the International Classification of Headache Disorders: A prospective multicentre study

Dear Dr. Chu:

I am pleased to inform you that your manuscript has been deemed suitable for publication in PLOS ONE. Congratulations! Your manuscript is now with our production department.

If your institution or institutions have a press office, please notify them about your upcoming paper at this point, to enable them to help maximize its impact. If they will be preparing press materials for this manuscript, please inform our press team within the next 48 hours. Your manuscript will remain under strict press embargo until 2 pm Eastern Time on the date of publication. For more information please contact onepress@plos.org.

For any other questions or concerns, please email plosone@plos.org.

Thank you for submitting your work to PLOS ONE.

With kind regards,

PLOS ONE Editorial Office Staff

on behalf of

Dr. Wisit Cheungpasitporn

Academic Editor

PLOS ONE

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