Hi Jackie, good question.
Most of the vestibular patients i treat are concussion patients with a splash of chronic hypofunction. For these, I go by the vestibular rehab hypofunction guidelines in regard to volume of exercise. What i find more important than anything inregard to vestibular rehab interventions is the intensity. Symptoms should be increased with VOR exercises however should not be unbearable. whether this by symptom onset or gaze instability. For symptoms, their symptoms can increase by 1-2 above baseline and should subside after resolution of exercise and if they have any prolonged symptoms, it should be better <15min of resolution of total exercise. In regard to volume of exercise, i follow the CPG “Vestibular Rehabilitation for Peripheral Vestibular Hypofunction: An Evidence-Based Clinical Practice Guideline” Home Exercise Program:
— Acute: > 3x/day for > 12 minutes total
— Chronic: >3x/day for > 20 minutes total
i break these exercises into 2-3 bouts. acute i give them 3x/day for 5-10min each.
For specific articles, i do not have ready to cite. They are based off the Medbridge courses i have taken as well as the recommendations from co-workers.
To be more specific with your question i pose 2 thoughts here that i do and do not agree with. First the frequency: 2mHz would be 120bpm. However the VOMS tests the VORx1 at 180bpm. So this study may not be getting the right intensity of what is considered normal. This could be due to decreased rate for increased time. I have personally favored increased rates over decreased time (focussing on 180bpm for 20sec at at time) given this is very flexible with patient presentation. My second thought is a personal opinion, is i do not find 2min of straight VOR to be function. VOR is not an enduruance reflex, it is a quick compensation reflex. So i would not do this for 2min.
I kind of went off on tangents. But thought this was good discussion question so i wanted to join in.