Vestibular and Oculomotor Findings in Vestibular Migraine Patients

Round 1

Reviewer 1 Report

I think it may of interests to describe clinical signs in subjects with VM.

Some changes should be done to improve the quality. Firstly in Materials and Methods. I understand that an overlap between MD and VM is known, but NOS (who do not have yet diagnostic criteria) by definition do not have probable - definite VM. Try to clarify this. Moreover, you stated that of 60 remaining cases most (but not all) were ictal; it sounds like to put togethet different conditions. The same for drfinite and probable VM.

Line 81: for the control group, selection criterioa wer lifetime negative history for vertigo AND MIGRAINOUS HEADACHE?

In Results: Auditory symptoms are often reported by patients. Phonophobia is included in diagnostic criteria, but cochlear symptoms are not (tinnitus, fullness and hearing loss); you can check (and decide if include in references), VM Phenotypes. How many presented also fullness? In ictal period? All of them presented an identical hearing level on both sides?

Line 116: spontaneous nystagmus was detected in the ictal phase, did they present also a positive video-HIT? (i.e. it was peripheral)

Some doubts on the control group for the saccades; how were they selected? mean age? did you ask for previous disorders of CNS and vertigo episodes?

As for Video head impulse: gain was normal for all canals (but did you find corrective saccades, overt or covert?); may the increase of gain be due to slippage (or attention of the patient), which is very common.

 

In discussion (lines 208 anf followings) some papers have been recently written, one of them a review on K channels also in journal of vestibular researc

Line 118: I cannot understand (n=17/20)

Author Response

Reviewer 1:

I think it may of interests to describe clinical signs in subjects with VM. Some changes should be done to improve the quality. Firstly in Materials and Methods. I understand that an overlap between MD and VM is known, but NOS (who do not have yet diagnostic criteria) by definition do not have probable - definite VM. Try to clarify this. Moreover, you stated that of 60 remaining cases most (but not all) were ictal; it sounds like to put together different conditions. The same for definite and probable VM.

We agree with the reviewer that adding this information is confusing, it was only 6 patients, and we removed them from the assessment and manuscript. As for VM and pVM, yes most were ictal upon evaluation.

 

Line 81: for the control group, selection criteria were lifetime negative history for vertigo AND MIGRAINOUS HEADACHE?

No, some of the control patients did have a history of vertigo, but from other causes. The diagnoses for these patients were: tinnitus, sudden sensorineural hearing loss, benign paroxysmal positional vertigo (BPPV), anxiety disorders or acute vestibular vestibulopathy that had recovered. None reported migraine headaches. This information was added to the manuscript.

 

In Results: Auditory symptoms are often reported by patients. Phonophobia is included in diagnostic criteria, but cochlear symptoms are not (tinnitus, fullness and hearing loss); you can check (and decide if include in references), VM Phenotypes. How many presented also fullness? In ictal period? All of them presented an identical hearing level on both sides?

We do have this information, n = 40/60 patients reported auditory symptoms, however, this included tinnitus and/or aural fullness and/or hearing loss (that did not meet the criteria for Méniere's disease). Because it is not data that was necessarily separated, we decided not to include it and also this was not the objective of the study, we wanted to evaluate vestibular and oculomotor abnormalities in these patients.

 

Line 116: spontaneous nystagmus was detected in the ictal phase, did they present also a positive video-HIT? (i.e. it was peripheral)

Not always, no. Of the 13 patients with spontaneous nystagmus, six had a normal vHIT, five had saccades in the horizontal canal (mostly bilateral), and two had a low gain and saccades in the horizontal canal.  This information was added to the manuscript.

 

Some doubts on the control group for the saccades; how were they selected? mean age? did you ask for previous disorders of CNS and vertigo episodes?

The control group consisted in a group of 30 patients that were seen consecutively within a 3 month period, averaging a similar age group as the cases. The diagnoses for these patients were: tinnitus, sudden sensorineural hearing loss, benign paroxysmal positional vertigo (BPPV), anxiety disorders or acute vestibular vestibulopathy that had recovered. They did not have previous CNS disorders. Mean age was 52.8 ± 16.7 years of age, this information is in the manuscript.

 

As for Video head impulse: gain was normal for all canals (but did you find corrective saccades, overt or covert?); may the increase of gain be due to slippage (or attention of the patient), which is very common.

The vHIT was normal in 34 patients, this consisted in normal gains and absence of saccades.  We did observe saccades; in at least one canal with a low gain in at least one canal was seen in six patients (11.7%). Also, in at least one canal with normal gains in 11 cases (18.3%). This information is in the manuscript. We do not consider this to be due to slippage or attention of the patient, when in doubt, it is repeated in our health care center.

 

In discussion (lines 208 and followings) some papers have been recently written, one of them a review on K channels also in journal of vestibular research

Line 118: I cannot understand (n=17/20)

I understand why the reviewer had a doubt about this information, the tables were not uploaded properly to the website. As can be seen in table 1, you can appreciate that 20 patients had positional nystagmus, of which 17 had central characteristics. This is what is meant by n=17/20.

Reviewer 2 Report

Dear Editor, thank you for giving me the opportunity to review this original manuscript.

The objective of the present study is to determine was to determine the most frequent abnormalities in videonystagmography (VNG), caloric testing (Cal) and video head impulse test (vHIT) in patients with Vestibular Migraine.

The present study is a retrospective cohort study and this type of studies depend on data that were entered into a clinical database and not collected for research.

In light of this, present authors stated “Not all patients had a caloric test performed”. For this reason some data, just like these, are inevitably missed.

This concept must be discussed in the paper

I have another point to highlight.

Present authors have inserted in fig.2 a patient with high VOR gain when the head is turned in the plane of the Hor SCCs.

I recommend entering a raw data comparison also with a patient with normal VOR gain.

I also recommend stressing the concept in the discussion that all the tests used have provided only data regarding the function of the Semicircular Canals, neglecting information from the otolithic function, in particular the utricular function which, as it is known, projects onto the extraocular muscles.

Where is Tab.1 ?

In the present form the paper is suitable for publication.

 

Author Response

Reviewer 2:

Dear Editor, thank you for giving me the opportunity to review this original manuscript. The objective of the present study was to determine the most frequent abnormalities in videonystagmography (VNG), caloric testing (Cal) and video head impulse test (vHIT) in patients with Vestibular Migraine.

The present study is a retrospective cohort study and this type of studies depend on data that were entered into a clinical database and not collected for research.

In light of this, present authors stated “Not all patients had a caloric test performed”. For this reason some data, just like these, are inevitably missed.

This concept must be discussed in the paper

We agree with the reviewer, we have added a small paragraph at the end of the manuscript describing the limitations of this kind of study.

 

I have another point to highlight.

Present authors have inserted in fig.2 a patient with high VOR gain when the head is turned in the plane of the Hor SCCs.

I recommend entering a raw data comparison also with a patient with normal VOR gain

As suggested, we have added a normal VHIT: figure 3.

 

I also recommend stressing the concept in the discussion that all the tests used have provided only data regarding the function of the Semicircular Canals, neglecting information from the otolithic function, in particular the utricular function which, as it is known, projects onto the extraocular muscles.

We have added this information in the limitations of the study, at the end of the manuscript.

 

Where is Tab.1 ?

Thank you for noticing, the tables were not uploaded properly to the website, they are now added.

 

In the present form the paper is suitable for publication.

Thank you

Reviewer 3 Report

Vestibular migraine (VM) is diagnosed mainly on the basis of clinical presentation. In recent years, there has been increasing research on abnormal oculomotor and vestibular findings during and between attacks in patients with VM. Abnormal findings in oculomotor and vestibular function tests may provide diagnostic and differential diagnostic clues for VM. Although the intention of this article is good, it fails to fully demonstrate the clinical value and significance. There are also the following problems:

1. The time of collection of clinical data is inconsistent between the abstract and the main text;

2. Patient demographics should be presented in a tabular way;

3. The description of the results in the article is simplistic. The title of the article is "Vestibular and oculomotor findings in vestibular migraine", so the article should focus on the abnormal oculomotor and vestibular function test findings. Although there is a description in the text, it is not prominent. Figures and tables are recommended;

4. It is recommended to add a description of the clinical significance at the end of this study.

Author Response

Reviewer 3:

Vestibular migraine (VM) is diagnosed mainly on the basis of clinical presentation. In recent years, there has been increasing research on abnormal oculomotor and vestibular findings during and between attacks in patients with VM. Abnormal findings in oculomotor and vestibular function tests may provide diagnostic and differential diagnostic clues for VM. Although the intention of this article is good, it fails to fully demonstrate the clinical value and significance. There are also the following problems:

1. The time of collection of clinical data is inconsistent between the abstract and the main text;

Thank you, this is a mistake and was corrected.

 

2. Patient demographics should be presented in a tabular way;

We did not feel it was necessary to add another table since we did not want to repeat the same information as described in the result section, first paragraph.

 

3. The description of the results in the article is simplistic. The title of the article is "Vestibular and oculomotor findings in vestibular migraine", so the article should focus on the abnormal oculomotor and vestibular function test findings. Although there is a description in the text, it is not prominent. Figures and tables are recommended;

We noticed there was a mistake when uploading the initial manuscript, the tables (3 tables) were missing and they are now added.

 

4. It is recommended to add a description of the clinical significance at the end of this study.

We have added this as suggested, thank you

Round 2

Reviewer 1 Report

I have no other remarks for the authors

 

Author Response

I think it may of interests to describe clinical signs in subjects with VM. Some changes should be done to improve the quality. Firstly in Materials and Methods. I understand that an overlap between MD and VM is known, but NOS (who do not have yet diagnostic criteria) by definition do not have probable - definite VM. Try to clarify this. Moreover, you stated that of 60 remaining cases most (but not all) were ictal; it sounds like to put together different conditions. The same for definite and probable VM.

We agree with the reviewer that adding this information is confusing, it was only 6 patients, and we removed them from the assessment and manuscript. As for VM and pVM, yes most were ictal upon evaluation.

 

Line 81: for the control group, selection criteria were lifetime negative history for vertigo AND MIGRAINOUS HEADACHE?

No, some of the control patients did have a history of vertigo, but from other causes. The diagnoses for these patients were: tinnitus, sudden sensorineural hearing loss, benign paroxysmal positional vertigo (BPPV), anxiety disorders or acute vestibular vestibulopathy that had recovered. None reported migraine headaches. This information was added to the manuscript.

 

In Results: Auditory symptoms are often reported by patients. Phonophobia is included in diagnostic criteria, but cochlear symptoms are not (tinnitus, fullness and hearing loss); you can check (and decide if include in references), VM Phenotypes. How many presented also fullness? In ictal period? All of them presented an identical hearing level on both sides?

We do have this information, n = 40/60 patients reported auditory symptoms, however, this included tinnitus and/or aural fullness and/or hearing loss (that did not meet the criteria for Méniere's disease). Because it is not data that was necessarily separated, we decided not to include it and also this was not the objective of the study, we wanted to evaluate vestibular and oculomotor abnormalities in these patients.

 

Line 116: spontaneous nystagmus was detected in the ictal phase, did they present also a positive video-HIT? (i.e. it was peripheral)

Not always, no. Of the 13 patients with spontaneous nystagmus, six had a normal vHIT, five had saccades in the horizontal canal (mostly bilateral), and two had a low gain and saccades in the horizontal canal.  This information was added to the manuscript.

 

Some doubts on the control group for the saccades; how were they selected? mean age? did you ask for previous disorders of CNS and vertigo episodes?

The control group consisted in a group of 30 patients that were seen consecutively within a 3 month period, averaging a similar age group as the cases. The diagnoses for these patients were: tinnitus, sudden sensorineural hearing loss, benign paroxysmal positional vertigo (BPPV), anxiety disorders or acute vestibular vestibulopathy that had recovered. They did not have previous CNS disorders. Mean age was 52.8 ± 16.7 years of age, this information is in the manuscript.

 

As for Video head impulse: gain was normal for all canals (but did you find corrective saccades, overt or covert?); may the increase of gain be due to slippage (or attention of the patient), which is very common.

The vHIT was normal in 34 patients, this consisted in normal gains and absence of saccades.  We did observe saccades; in at least one canal with a low gain in at least one canal was seen in six patients (11.7%). Also, in at least one canal with normal gains in 11 cases (18.3%). This information is in the manuscript. We do not consider this to be due to slippage or attention of the patient, when in doubt, it is repeated in our health care center.

 

In discussion (lines 208 and followings) some papers have been recently written, one of them a review on K channels also in journal of vestibular research

Line 118: I cannot understand (n=17/20)

I understand why the reviewer had a doubt about this information, the tables were not uploaded properly to the website. As can be seen in table 1, you can appreciate that 20 patients had positional nystagmus, of which 17 had central characteristics. This is what is meant by n=17/20. 

Reviewer 2 Report

The paper has greatly improved.

The paper is in the present form suitable for publication

Author Response

Reviewer 2:

Dear Editor, thank you for giving me the opportunity to review this original manuscript. The objective of the present study was to determine the most frequent abnormalities in videonystagmography (VNG), caloric testing (Cal) and video head impulse test (vHIT) in patients with Vestibular Migraine.

The present study is a retrospective cohort study and this type of studies depend on data that were entered into a clinical database and not collected for research.

In light of this, present authors stated “Not all patients had a caloric test performed”. For this reason some data, just like these, are inevitably missed.

This concept must be discussed in the paper

We agree with the reviewer, we have added a small paragraph at the end of the manuscript describing the limitations of this kind of study.

 

I have another point to highlight.

Present authors have inserted in fig.2 a patient with high VOR gain when the head is turned in the plane of the Hor SCCs.

I recommend entering a raw data comparison also with a patient with normal VOR gain

As suggested, we have added a normal VHIT: figure 3.

 

I also recommend stressing the concept in the discussion that all the tests used have provided only data regarding the function of the Semicircular Canals, neglecting information from the otolithic function, in particular the utricular function which, as it is known, projects onto the extraocular muscles.

We have added this information in the limitations of the study, at the end of the manuscript.

 

Where is Tab.1 ?

Thank you for noticing, the tables were not uploaded properly to the website, they are now added.

 

In the present form the paper is suitable for publication.

Thank you

Reviewer 3 Report

The format of the table can be further optimized.

Author Response

Reviewer 3:

Vestibular migraine (VM) is diagnosed mainly on the basis of clinical presentation. In recent years, there has been increasing research on abnormal oculomotor and vestibular findings during and between attacks in patients with VM. Abnormal findings in oculomotor and vestibular function tests may provide diagnostic and differential diagnostic clues for VM. Although the intention of this article is good, it fails to fully demonstrate the clinical value and significance. There are also the following problems:

1. The time of collection of clinical data is inconsistent between the abstract and the main text;

Thank you, this is a mistake and was corrected.

 

2. Patient demographics should be presented in a tabular way;

We did not feel it was necessary to add another table since we did not want to repeat the same information as described in the result section, first paragraph.

 

3. The description of the results in the article is simplistic. The title of the article is "Vestibular and oculomotor findings in vestibular migraine", so the article should focus on the abnormal oculomotor and vestibular function test findings. Although there is a description in the text, it is not prominent. Figures and tables are recommended;

We noticed there was a mistake when uploading the initial manuscript, the tables (3 tables) were missing and they are now added.

 

4. It is recommended to add a description of the clinical significance at the end of this study.

We have added this as suggested, thank you