2017 年 76 巻 3 号 p. 225-232
Video head impulse testing (vHIT), which can quantitatively evaluate semicircular canal function, has been gaining popularity. However, there are multiple types of devices in use even in Japan, and evaluation methods differ between institutions. We conducted and compared vHIT measurements of the lateral semicircular canal with EyeSeeCam VOG® (EyeSeeCam) and ICS Impulse® (ICS).
We conducted vHIT using EyeSeeCam and ICS on 72 patients (37 females, 35 males; average age: 52.6 years [22-76 years]), diagnosed with ailments that could lead to unilateral peripheral vestibular disorders such as vestibular neuritis or unilateral acoustic neuroma. The results were evaluated using vHIT gain values from the affected and unaffected sides, as well as vHIT gain differences (|[unaffected side vHIT gain - affected side vHIT gain]|/[unaffected side vHIT gain+affected side vHIT gain]) and vHIT gain ratios (affected side vHIT gain/unaffected side vHIT gain).
On comparing the lateral semicircular canal vHIT measurements conducted with ICS and EyeSeeCam, we found the results to have a high degree of concordance. Although the vHIT gain for the unaffected and affected sides was larger with EyeSeeCam, vHIT gain differences and gain ratios indicated no significant differences between the device types. Furthermore, vHIT gain differences and gain ratios were strongly correlated between device types, more so than gain measurements alone.
Considering that multiple vHIT device types are presently in use, when comparing vHIT gain across different models, comparisons based on vHIT gain differences or gain ratios may be more useful than those based on gain values alone.