Video Head Impulse Testing (vHIT): A Deep Dive

[@valred0507]

Very interesting, thank you! I have a question - how would you interpret unilateral catch-up saccades with normal VOR gain and normal calorics?

[@InteracousticsTV]

Hi valred, Thanks for the great question! Please see the answer from one of our in-house clinicians below: ------------------------- This all depends on the size and occurance of the saccades along with an assessment of google slippage. Small irregular saccades are common in most patients. But large consistent saccades are an indication of pathology. Here I would want to look at the gain asymmetry between the sides to see if the ear with normal gain and saccades is substantially different to the opposite side. ------------------------- Best regards, Shane

[@valred0507]

@@InteracousticsTV thanks for your reply, very much appreciated.

[@raghavjha3267]

I had a question. For unilateral vestib lesions, the VOR gain would be less on ipsi-lesional side. I understood that but Why would gain on that side decrease with increasing velocity. Will not the inhibitory side get clipped, and if it gets clipped how would it interfere when we stimulate the ipsi-lesional side?? So should not the gain be static even with increasing velocity

[@InteracousticsTV]

Hello Raghav. Thank you for your interest. We have posed your question to Michelle Petrak Ph.D, Clinical Director of Audiology at Interacoustics. This is her reply: "Referring to the slide at 13:30, it is clear that the inhibitory neural firings saturate for high head velocities. Once the inhibitory responses saturate, they do not increase no matter how much the head velocity increases. As a result, eye velocities do not increase and VOR gains decrease with increasing head velocities beyond that point. This happens in normal individuals and patients with canal dysfunction but it is more noticeable in patients because the saturation occurs at lower head velocities."

[@ghukifymooth3827]

Tomorrow I am taking that test in the hospital and I am so nervous

[@Rozzawood]

Heya, can you let me know how it goes please as I have one of these coming up at somepoint. Good luck :)

[@saurabhsuman8423]

Cost?