Skull Vibration-Induced Nystagmus Test in a Human Model of Horizontal Canal Plugging

Round 1

Reviewer 1 Report

The study presents interesting results on SVIN and other vestibular tests in a human model of lateral canal plugging for intractable MD. Overall it is an interesting paper and comparing pre and post operative results enlightening vestibular mechanisms related to nystagmus provoked by different tests in MD subjects.

Some points nonetheless in my opinion should be clarified

• In materials and methods authors should include if subjects presented all diagnostic criteria for definite MD (according to the Barany Society? AAONHS 1995? If so, a sentence stating that you included grading among saved data should be added). This is an important point since on line 176 authors said that 1 subject presented a normal hearing level pre and post plugging
• Regarding calorics, I suggest to add a sentence clarifying which stimulation has been used (Fitzgerald Hallpike?) and if Jongkees formula has been used, considering only Directional Preponderance as significative
• For head shaking: you considered positive only post head shaking with more than 1 nystagmus?
• Do lines 167-171 belong to the caption?
• Lines 198-201: you didn’t mention rotatory tests in materials and methods; since it doesn’t add anything to the paper, I suggest to remove the sentence
• Line 230: impairment or worsening?
• Lines 335 and following: I suggest to add a short sentence regarding theories on the discrepancy betwee calorics and videoHIT in MD subjects

Author Response

Please see the attachment

Author Response File: Author Response.docx

Reviewer 2 Report

The paper deals with an innovative theme as it compares the otoneurological data after a Horizontal Semicircular Canal  plugging operation carried out in order to reduce the symptoms of menière patients. The theme is particular for its physiological implications because the study shows the effectiveness of vibration on a human model in which the receptor remains active while the endolymphatic movement is blocked. The data confirm that in humans: 1) the vibratory test does not act through the endolymphatic movement but directly on the hair cells; 2) the macular hair cells are not affected by the vibration 3); the vibratory nystagmus is related to the hydropic receptor damage; 4) confirms the validity of the test as an indicator of labyrinthine asymmetry. 

The only point that the authors could clarify is about what is written in line 299 which expresses a concept of "hyperpressure induced by plugging". This is a supposition that cannot be confirmed and therefore should be expressed as a hypothesis and not as a certainty.

Author Response

Please see the attachment

Author Response File: Author Response.docx