[A pilot study of the unilateral centrifugation subjective visual vertical in healthy young people]

Objective: To evaluate the data of unilateral centrifugation subjective visual vertical (UC-SVV) in healthy young people.To study the function of utricle. Methods: Between Decem ber 2017 and May 2018, thirty-two healthy young volunteers were tested by static subjective visual vertical(SVV) and low velocity UC-SVV with Neuro Kinetics Inc I-portal 6.0 Video nystagmus recording system and NOTC rotating chair system.The static SVV preset angle were -15.00°, 15.00°, -20.00°, 20.00°, -12.00° and 12.00° respectively.UC-SVV test parameters: rotating chair's peak speed was 60°/s.The shift time from the middle to the lateral position was 30 s and the displacement was 3.85 cm.The chair rotated at 60 s at left, right and middle positions.Subjects underwent SVV during this period.SPSS 17.0 software was used to analyze the data. Results: The mean and standard deviation of static SVV deviation in 32 volunteers was 0.21°±0.17°, 95%CI (-0.14°, 0.55°). The mean and standard deviation of UC-SVV in the left, middle and right positions of the clockwise was 0.24°±0.25°, -0.10°±0.27°, -0.63°±0.26°, 95%CI(-0.26°, 0.74°), (-0.65°, 0.44°), (-1.16°, -0.10°). The mean and standard deviation of UC-SVV in the left, middle and right positions of the counter clockwise was 0.03°±0.27°, -0.11°±0.26°, -0.23°±0.26°, 95%CI(-0.52°, 0.59°), (-0.65°, 0.42°), (-0.76°, 0.30°). There was significant difference in the deviation between the left and the right side of counter clockwise rotation of UC-SVV(t=2.432, P<0.05), however, there was no significant difference in the angle of deviation between the left and right sides and the median position(t value was 0.951, -1.400, both P>0.05). There was no significant difference among each position in clockwise rotation of UC-SVV(F=0.253, P>0.05). Conclusion: UC-SVV test with peak speed of 60°/s can cause vertical line deviation in the left and right lateral position, but the angle is small and the value of clinical application is limited.