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Objective: To investigate the altered function of the semicircular canal and otolith graviceptive pathway in patients diagnosed with motion sickness disorder (MSD) based on the diagnostic criteria of the Bárány society, and explore its relevance to the pathogenesis of MSD. Methods: This is a case-control study. Twenty patients with MSD and age-and sex-matched healthy controls without a history of MSD from the Department of Neurology of Aerospace Center Hospital between March and August 2022 were recruited. All subjects completed the motion sickness susceptibility questionnaire-short version (MSSQ-short) and the motion sickness assessment questionnaire (MSAQ). Canal function was evaluated using caloric stimulation test and video head impulse test (vHIT), and subjective visual vertical/horizontal (SVV/SVH) and vestibular evoked myogenic potential (VEMP) were employed to assess otolith graviceptive function. Differences in vestibular function and correlations between the two groups were analyzed. Results: Each group consisted of 20 cases (9 males and 11 females). The mean age of the MSD and control groups was (26.9±3.9) years and (27.0±3.4) years, respectively. The scores of MSSQ-short [27.0 (22.5, 38.8) vs 1.2 (0, 3.2), P <0.001] and MSAQ [70.1 (54.5, 78.1) vs 11.8 (11.1, 13.9), P <0.001] were significantly higher in the MSD group compared with those of the control group. Evaluation of canal function revealed a significantly higher incidence of caloric stimulation intolerance in MSD patients (60.0%, 12/20) compared with that of the control group (20.0%, 4/20) ( P =0.010). Evaluation of otolith graviceptive pathway indicated no significant difference in SVV, SVH and cervical VEMP (cVEMP) abnormality rates between the two groups (all P >0.05). The ocular VEMP (oVEMP) abnormality rate was significantly higher in the MSD group (55.0%, 11/20) than that of the control group (10.0%, 2/20) ( P =0.002), with a delayed P1-wave latency compared with the control group [(18.4±1.2) ms vs (17.6±0.8) ms, P =0.018]. Further correlation analysis revealed that P1-wave latency in oVEMP was positively correlated with MSSQ-short ( r =0.486, P =0.002) and MSAQ ( r =0.391, P =0.015) scores, and duration of caloric intolerance symptoms ( r =0.377, P =0.004). Conclusion: The presence of hypersensitivity to caloric stimulation and delayed latency of otolith function in patients with MSD suggests a "separation" between semicircular canal and otolithic function, which may be related to sensory conflict.

Objective: We tested more frequency (0.01-3.0 Hz) of the sinusoidal harmonic acceleration test(SHAT) by the NKI rotation chair, aimed to analyze the results of the normal youth. Methods: Fifty normal young people were tested with sinusoidal harmonic acceleration by NKI rotation chair. Including 24 men and 26 women, aged from 20 to 40 years old, with median age of 27 years, with no vestibular dysfunction participated in the present study. All the volunteers accepted the sinusoidal harmonic acceleration test by the NKI rotation chair, the frequency included 0.01 Hz, 0.02 Hz, 0.03 Hz, 0.05 Hz, 0.1 Hz, 0.2 Hz, 0.3 Hz, 0.6 Hz, 1.0 Hz, 1.5 Hz, 2.0 Hz, 3.0 Hz. Taken the gain, phase, and asymmetry as the parameters, the trait of each frequency was analysed. Results: From 0.01 Hz to 1.5 Hz, the gain increased close to 1 gradually, and with fluctuates slightly at the 2.0 Hz and 3.0 Hz frequencies. The phase decreased as frequencies increased close to 0 at 0.3 Hz. The frequency above 0.6 Hz presented negative. Asymmetric values were distributed on both positive and negative sides at each frequency and were different from each other, both values were less than 20%. Conclusion: Broadband SHAT can accurately assess the horizontal semicircular canal function at different frequencies in a wider frequency range, and objectively, reflect the physiological function of the horizontal semicircular canal, and expand the clinical value of traditional SHAT.

Objective: To explore the age stability of the video head impulse test(vHIT) in healthy subjects. Method: This was a prospective study on healthy subjects referred to our department. One hundred and eighty healthy subjects(age range 21-80) without any current or previous history of brain disorder, vertigo, neck stiffness or eye diseases participated in this study and the vHIT was carried out in all 180 cases. The relationship between VOR gain and age was analysed using univariate regression model and one-way ANOVA for subjects. Result: The VOR gains of the left horizontal semicircular canal, posterior semicircular canal and anterior semicircular canal were 1.02±0.12, 1.04± 0.15 and 0.94±0.16 respectively. The VOR gains of the right horizontal semicircular canal, posterior semicircular canal and anterior semicircular canal were 1.05±0.14, 1.00±0.16, 0.97±0.15 respectively. The difference of VOR gain between left and right corresponding semicircular canals was not statistically significant( P >0.05). For male subjects, the VOR gains of horizontal, anterior and posterior semicircular canal were 1.05±0.13, 1.02±0.16, 0.99±0.16 respectively, and for female subjects, the VOR gains of horizontal, anterior and posterior semicircular canal were 1.05±0.13, 1.01±0.16, 0.97±0.16 respectively. There was no significant difference in VOR gain of three semicircular canals between male and female( P >0.05). The VOR gain in different age groups was analyzed by one-way ANOVA. There was no significant difference in the VOR gain among different age groups( P >0.05). Univariate linear regression analysis was performed between the age and the VOR gain of the three semicircular canals. The slopes of the regression equations were 0.001 8, 0.000 2 and 0.000 3, respectively. Conclusion: The VOR gain of the six semicircular canals in healthy subjects is not significantly influenced by gender, and it varies slightly with age without requirement for adjustment with age. ., Competing Interests: The authors of this article and the planning committee members and staff have no relevant financial relationships with commercial interests to disclose., (Copyright© by the Editorial Department of Journal of Clinical Otorhinolaryngology Head and Neck Surgery.)

Objective: To observe the parameters of the results of suppression head impulse paradigm (SHIMP) in healthy adults, and to provide reference for evaluating vestibular oculomotor reflex function in patients with peripheral vertigo. Methods: Fifty healthy adults, 22 males and 28 females, aged from 23-65 years, with an average age of (38.5±11.6) years, were recruited from January to March 2018. Parameters provided by the video head pulse software included the gains, the latency and the peak velocity of saccades, and comparison was made with head impulse paradigm (HIMP). Results: All subjects were elicited anti-compensatory saccades in SHIMP. The normal values of left and right gains were 1.02 and 1.10 in HIMP, and 0.93 and 1.01 in SHIMP respectively. The left and right saccades latency were (201.1± 50.8)ms and (187.0± 42.9)ms, and the peak saccadic velocity were (302.7±58.5)°/s and (291.5±46.5)°/s in SHIMP; there were small but significant difference between two sides about gains in HIMP and SHIMP, as well as latency in SHIMP( P <0.05); there were small but significant difference between HIMP and SHIMP about gains in ipsilateral( P <0.01); there were no significant difference between two sides about peak saccadic velocity in SHIMP( P >0.05). Conclusions: SHIMP can be used for the examination of vestibular oculomotor reflex function in adult population. It is easy to be operated and is convenient for clinical application. Combined with head pulse test, the function of the semicircular canal can be evaluated together.

Objective: The purpose of this study was to report two cases of light cupulopathy, and describe the characteristics of these cases and analysis the possible physiopathological mechanisms. Methods: The histories, clinical features, characteristics of nystagmus, and vestibular function, as well as audiologic results of the two patients with light cupula were analyzed. Results: The two patients showed persistent geotropic direction changing positional nystagmus(DCPN)in the supine head roll tests. The null plane was present when the head was turn slightly towards affected side. Canalith repositioning maneuver was not effective. A mild sensorineural hearing loss was found on the involved ear in one patient but not in the other. The vestibular functions of two patients were abnormal. Conclusions: The characteristics of nystagmus with light cupulopathy are persistent geotropic DCPN with a null plane. The clinical features are similar with the horizontal semicircular canal canalolithasis. Canalith repositioning maneuver is not recommended for its ineffectiveness.

Objective: The purpose of this study was to set up a method to analyze the vertical semicircular canal function and study the normal values of the vertical semicircular canal function using the vertical plane swing test., Methods: A prospective analysis of 100 normal persons (aged from 18 to 59 years), who were treated by using the vertical plane swing test with the newly developed automatic vestibular function diagnosis and therapy system (SRM-IV). These persons were rotated 180° at a sinusoidal speed (acceleration 45°/s, maximum speed 90°/s) in the vertical semicircular canal plane. Using a PC, evoked vertical nystagmus was analyzed in order to evaluate the excitability of vertical semicircular canals, including the number and the duration of nystagmus, the slow phase velocity and other parameters. Meanwhile, the all persons were divided into two groups, order and younger than 45 years respectively. In the test procedure, with the two pairs of the right anterior vertical semicircular canal and left posterior vertical semicircular canal (RALP) as well as the left anterior vertical semicircular canal and the rear right vertical semicircular canals (LARP), the average slow phase velocity of the vertical nystagmus and the canal paresis (CP) of the two pairs of vertical semicircular canals were calculated using PC and SPSS13.0 software for statistical analysis., Results: There was no significant difference between the two groups (P > 0.05). The general CP of RALP was 10.2% ± 7.1%, and LARP was 10.4% ± 6.2%. The normal CP range of the vertical semicircular canal in the health group was identified (idea: ≤ 20%; normal high: 20% - 25%)., Conclusion: The 180° vertical plane sinusoidal swing method is effective in functional analysis of the vertical semicircular canal, it is expected to be reliably used in clinical treatment.

Objective: To calculate and compare the change of canal paresis (CP) and directional preponderance (DP) before and after changing air flow rate of testing ear, and to discuss the influence of air flow rate change of single ear on the final result of caloric test., Method: The CPs and DPs were calculated when the caloric tests were carried out with the air flow rate 6 L/min in both ears as symmetry stimulation, and with the air flow rate 6 L/min in left ear and 3 L/min in right ear as asymmetric stimulation. Paired T test was used in analysis between symmetry and asymmetric group., Result: CPs and DPs declined significant in asymmetric group, and the difference was statistically significant., Conclusion: When air flow rate declined, CP was to the same side, while DP was to opposite side. There might be false positive or negative result.

Vestibular velocity steps test (VVST) to impulsive stimulus of horizontal rotation (90 degrees/S and 180 degrees/S) were performed in 22 normal subjects. Gain (G) was defined as the ratio of the initial slow phase eye velocity (ISPV) to head velocity. The time constant (T) was the time to find the point where it was 0.37 of ISPV. Duration (D) of induced nystagmus was the time between first and final nystagmus. The directional preponderance (DP) for G, T and D was calculated from the formula, (R-L)/(R+L) x 100%. These normal limits were 0.37-1.09 and 0.27-0.83 for G, 8.0--20.4s and 6.5-17.3s for T, 30.4-65.0s and 30.0-54.4s for D, +/- 21.4% and +/- 21.5% for DP(G), +/- 24.2% and +/- 20.3% for DP(T), +/- 16.5% and +/- 17.9% for DP(D) of 90 degrees/S and 180 degrees/S, respectively. The advantages and shortcomings of VVST and its value were discussed.