The Correlation Of Amplitude And Velocity Asymmetry During Visually Guided Saccade In First-episode Schizophrenia Patients

Objective Schizophrenia is a group of chronic mental illness that pathogenic is not clear. In clinical, the diagnosis of Schizophrenia based mainly on clinical symptoms of patient, which short of effective and objective indicators of biological diagnostic. Especially when early symptom is not obvious, diagnosis has more difficult. Some researchers found that schizophrenic existing eye tracking dysfunction(ETD) compared with the normal. This feature had been used by many researchers for discover the objective biological indicators in early diagnosis and screening of schizophrenia. In previous studies, researchers using the basic visually guided saccades paradigm to discuss the index of relationship between peak velocity, amplitude and duration of saccades, meanwhile, established an Acceleration Asymmetric Index(AAI) and Spearman index between AAI and Saccade amplitude(Raa). These results suggested that the difference between schizophrenic and the normal. In this study, with first-episode schizophrenia, to discuss the different in correlation of saccade amplitude and the peak of saccadic acceleration and saccadic deceleration with the normal in a basic visually guided saccades. Raa potential become the biological indicators of auxiliary diagnosis for the schizophrenic.Methods Research group select thirty cases of first-episode and no taking antipsychotic drugs schizophrenia which follows the diagnostic code of international classification of diseases and related health problems the tenth edition(ICD- 10), at the same time, random select another thirty cases of healthy adult volunteers for visually guided saccade check, respectively.(1) The result import to computer for calculates the Acceleration Asymmetric Index(AAI) and Spearman Raa between AAI and Saccade amplitude.(2) Fitting the exponential equation for the two groups, and simulates the fitting curve equation related to Saccadic peak velocity and Saccade amplitude.(3) The AAI, Peak acceleration and Peak deceleration as the dependent variable, the Saccadic peak velocity, Saccade duration and Saccade amplitude as a covariate, and compare the general linear relationship between the Peak acceleration, Peak deceleration and the Saccade amplitude.(4) Mann-Whitney U inspection and analysis of differences between Raa values of two groups.Results The saccade peak velocity for the health normal group is 469.157(95% CI =458.708~479.605), the research group is 84.039(95% CI=470.252~497.19), there was no statistically significant difference between this two groups. Curve fitting equation of the health normal group is: y= 469.157 ×(1- exp(-x/ 8.800), R2 = 0.704; and Curve fitting equation of schizophrenic is: y = 484.039×(1- exp(-x/8.755), R2 = 0.624. General linear model result shows that when saccade amplitude is 11.446, saccade peak velocity is 326.529 and duration is 63.01, the mean value of the normal group Peak acceleration more than schizophrenia group, but group difference is not significant(p=0.663); the mean absolute value of the normal group Peak deceleration less than schizophrenia group, and group difference is significant(p = 0.004); AAI value of the normal group more than schizophrenia group, group difference is also significant(p = 0.017). Raa value of schizophrenia group less than the normal group(Mann-Whitney U checking, Z =-3.567, P< 0.001).Conclusion This research find out the differences between first-episode schizophr enia group and normal group of AAI in the basic visual guide saccademission, t he differences has statistical significance. This suggests Raa as an diagnosis for s chizophrlogical indicators of the potential.