[Gain characteristics of three pairs of semicircular canals in video head impulse paradigm test and suppression head impulse paradigm test in healthy young Chinese population].

To summarize gain characteristics of three pairs of semicircular canals in head impulse paradigm （HIMP） and suppression head impulse paradigm （SHIMP） in healthy young Chinese population. HIMP and SHIMP tests were performed on 40 healthy young volunteers enrolled as study group, by using EyeseeCam examiantion system （Interacoustics，Denmark）. The elicitation rates and gain values of the two saccades were recorded, and the gain values were compared and analyzed. The results of 40 healthy young people were as follows: in HIMP, the instantaneous gain at 60 ms of the horizontal semicircular canals were 1.11±0.07 on the left side and 1.08±0.07 on the right side; the regression gain of the horizontal semicircular canals were 1.09±0.06 on the left side and 1.10±0.06 on the right side; the regression gain of the vertical semicircular canals were 1.08±0.12 on the right anterior, 1.07±0.11 on the left posterior, 1.41±0.16 on the right posterior and 1.42±0.16 on the left anterior. So in HIMP, no significant difference could be found between left and right side in both horizontal and vertical semicircular canal conjugate plane regarding regression gain （>0.05）, except that 60 ms instantaneous gain on the left horizontal semicircular canals was slightly higher than that on the right side （<0.05）.The instantaneous gain values of the horizontal semicircular canal at 60 ms in SHIMP were 1.08±0.08 on the left side and 1.06±0.07 on the right side; the regression gain in horizontal semicircular canals were 1.06±0.07 on the left side and 1.07±0.06 on the right side, respectively; the regression gains of vertical semicircular canal were 1.06±0.13, 1.08±0.16, 1.49±0.16, 1.39±0.15, on the right anterior, left posterior, right posterior, and left anterior side. So in SHIMP, no significant difference could be found in 60 ms instantaneous gain in horizontal conjugate plane, regression gain in horizontal conjugate plane and regression gain in right anterior left posterior conjugate plane （>0.05）, while the regression gain of the left anterior right posterior conjugate plane in the right was found slightly higher than that of the left （<0.05）.Both 60 ms instantaneous gain and regression gain in horizontal conjugate plane in HIMP were slightly higher than that of SHIMP （<0.05）, while no significant difference could be found in vertical conjugate planes （>0.05）. In both HIMP and SHIMP tests, gains of the left anterior right posterior conjugate plane was slightly higher than that of both horizontal plane and the right anterior left posterior conjugate plane （<0.05）, while no significant difference could be found in gains between horizontal and the right anterior left posterior conjugate plane （>0.05）. Gain values of HIMP and SHIMP were slightly different among different semicircular canals conjugate planes.It is suggested that each examination center should establish normal values for their own and make correction regularly.