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Objective:To study the effect of eye-open/closed state on 40 Hz auditory steady state response (ASSR) in first-degree relatives of schizophrenia.Methods:Thirty-eight first-degree relatives of schizophrenic patients treated in Shanghai Mental Health Center from March 2010 to October 2011 were selected, and 31 healthy controls were recruited in the same period. All subjects were assessed with schizotypal personality questionnaire (SPQ). The 40 Hz EEG ASSR signals lasting for 3 min under open and closed eyes of all subjects were sequentially collected.Event-related spectrum perturbation (ERSP) and intertribal phase coherence (ITC) were used to evaluate ASSR. SPSS 22.0 software was used for statistical analysis. Two-way analysis of variance was used to compare ITC and ERSP between the two groups under open and closed eyes. Spearman correlation analysis was used to analyze the correlation between each measurement.Results:ITC in group main effect and group×the eye open/closed interaction effect were not significant (both P>0.05), but the main effect of eye-open and eye-closed was significant ( F(1, 67)=10.61, P=0.002). In the healthy control group, the ITC in eye-open state was significantly higher than that in eye-closed state ( P=0.014), and in the first-degree relatives group, the ITC in eye-open state was higher than that in eyes closed state ( P=0.039). ERSP in the main effect of eye-open and eye-closed ( F(1, 67)=0.195, P=0.660), group main effect ( F(1, 67) =0.627, P=0.431), group × the eye-open/closed interaction effect ( F(1, 67)= 1.034, P=0.313) was not significant. Spearman correlation analysis showed that there was no correlation between ERSP (eye open: r=-0.260, P=0.210; eye closed: r=-0.318, P=0.122), ITC (eye open: r=-0.248, P=0.232; eye closed: r=-0.260, P=0.209) and SPQ score in the healthy control group. There was also no correlation between ERSP (eye open: r=-0.387, P=0.226; eye closed: r=-0.363, P=0.238) or ITC (eye open: r=0.126, P=0.485; eye closed: r=0.096, P=0.595) and SPQ score in the first-degree relatives group of schizophrenia. Conclusion:The regulation pattern of 40 Hz ASSR in schizophrenic first-degree relatives is not significantly impaired in the eye-open/closed state, suggesting that the open/closed regulation pattern of 40 Hz ASSR may not be a potential marker for predicting the genetic high-risk prognosis of schizophrenia.
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Background: Postural control involves controlling body’s position in space for dual purpose of stability and orientation. Postural stability or balance is defined as the ability to maintain the projected Center of motion (COM) within the limits of Base of Support (BOS). During quite stance there is a separate Center of Pressure (COP) under each foot. The net center of pressure lies between the feet and depend on each limb support. Normally no one stand erect, instead the body sways in small amount, mainly forward and backward. Thus quite stance is characterized by small amount of spontaneous postural sway. The device (sway meter) consists of inflexible 40 cm long rod with vertically mounted pen at its end. The rod was mounted 20 cm wide metal plate which wil be fitted at the level of PSIS (Posterior superior iliac spine) over lower back region of participants by firm belt. A low tech Sway meter was designed to address the needs of clinicians and researcher with limited resources (e.g. no access to force plates or motion laboratories). It is a useful field test, as it is compact, lightweight, has short administration and data processing time. Unlike otherlightweight and easily applied systems, such as accelerometers and gyroscopes, the Sway meter involves no electronics or computer processing. Thus, assessment can be conducted in a variety of community settings and health care facilities. Several research groups have found the Sway meter to be feasible for use in different populations of young and older people. The Sway meter has been used in numerous studies of balance as well as retrospective and prospective investigations of falls risk in older people. The purpose of study was to find out normative data of postural sway by using sway meter in among young adults and the validity of the Sway meter against the floor and foot print. Aim and objectives: To study the normative data of postural sway by using sway meter among young healthy adults, to study the normative data of postural sway by using sway meter among young healthy adults with eye open and eye close, to study the normative data of postural sway by using sway meter compare with the normal values of the lord’s and Sherrington’s study. Material and methods: The subjects were instructed to keep their hand by their sides during standing. Subjects were informed about procedure before starting. Duration of each trial was 30 second. A starting point was marked on the graph paper. At end of the 30 seconds, the rod of the sway meter was taken away from the graph sheet. 5-10 seconds rest was given during trial, but they were not allowed to move away from the foot print. The procedure was repeated for each trial. A total of six trials were taken including, 3 trial with eyes opened and 3 for eyes closed. Maximum duration for all trial was 6-7 minutes and maximum deviation in 3 trials was taken for analysis. Results: In eye open condition, in anterior direction, total 60 (100%) subjects are had sway in 0.1 to 2 cm. In Posterior direction, total 60(100%) subjects are had sway in 0.1 to 2 cm. In right lateraldirection, total 59 (98%) subjects had sway in 0.1 to 2 cm; remaining 1 (2%) subject had sway in 2.1 to 3 cm. In left lateral direction, total 56 (95%) subjects had sway in 0.1 to 2 cm; remaining 2 (3%) subjects had 2.1 to 3 cm sway and 2 (2%) subjects had 3.1 to 4 cm sway in left side. In eye closed condition, in anterior direction 57 (95%) subjects had 0.1 to 2 cm sway in anteriorly, but remaining 2 (3%) subjects had 2.1 to 3 cm sway, and 1 (2%) subject had 3.1 to 4 cm sway. In posterior direction 59 (98%) subjects had 0.1 to 2 cm sway in posterior; rest 1 2%) subject had nil sway in posterior. in right lateral direction 56 (93%) subjects had 0.1 to 2 cm sway, and rest of the 2(4%) subjects had nil sway, and 2 (3%) had 2.1 to 3 cm sway in right direction. In left lateral direction 57 (95%) subjects had 0.1 to 2 cm sway, and 1 (2%) subjects had nil sway, rest 2(3%) subjects had sway in 2.1 to 3 cm. Conclusion: It has been concluded that this study support the self constructed sway meter as a clinical tool for identifying sways in various directions (anterior, posterior, right lateral and left lateral). Similarly 100% of sway was seen in anterior and posterior direction with eye open.
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The results of rotation chair test were known to variable by many parameters such as eye opening and alertness, etc. The situational change in rotation chair test must be considered to interpretation of its result. But in Korea, there were no reports or articles about parameters which influence the result of rotation chair test. So, we assumed that eye opening and alertness were main parameters and took rotation chair test in neurotologically normal subjects. For evaluation of the effect of eye-open or eye-closure and alertness on the rotational vestibular stimulation, we have taken sinusoidal harmonic acceleration test in 30 otoneurologically normal subjects. The maximal slow phase eye velocity, gain and asymmetry were obtained and compared with each other in four different conditions with properly fixed conditions such as in darkness and 0.05Hz frequency. At least five minutes interval was given between the tests and recalibrations were done before each tests. The results of this test were as follows. 1) Vestibular-ocular reflex(VOR) changes according to eye open or closure. In cases of examinees which were given alerting tasks, larger gain was obtained with eyes opened than with eyes closed, and that was statistically significant(p0.05). 2) VOR changes according to alertness. In cases of examinees which opened their eyes, larger gain was obtained with alerting tasks than without alerting tasks, and that was statistically significant(p<0.05). In cases of examinees which closed their eyes, larger gain was obtained with alerting tasks than without alerting tasks, and that was statistically significant(p<0.05). 3) There was no significant changes of asymmetry according to the conditions. Therefore, from above results, we recommend the condition in which examinees open their eyes and be given alerting tasks as one of the optimal condition in sinusoidal harmonic acceleration test.