Objective. To increase the effectiveness of the applied diagnostic actions based on studying video-nystagmographic schizophrenia indicators within the framework of the dimensional and staged disease models.
Materials and methods. Three research subgroups of schizophrenic persons were examined: those with prevailing negative symptoms (NS) (n=109), with prevailing productive symptoms (PS) (n=74), those with predominantly disorganization symptoms (SD) (n=42) as well as a group of people at an ultrahigh risk for psychosis (UHR) (n=60) and
a group of healthy individuals (n=90).
Results. Diagnostic significance of the saccadic eye movement test in diagnosing the directional orientation of schizophrenia according to the values of «Apathy-Abulia» and «Anhedonia-Associality» factors with constant and random signals of the video generator by latency: the latency cut-off point is 320 ms, sensitivity — 0.796, specificity — 0.819, AUC=0.849; by accuracy: the accuracy cut-off point is 80%, sensitivity — 0.64, specificity — 0.92, AUC=0.782. According to the values of the factor «Positive formal disturbances in thinking» factor: the cut-off point of saccade accuracy is 54%, sensitivity — 0.709, specificity — 0.92, AUC=0.896. The significance of the test of smooth tracking eye movements in diagnosing the thinking disorganization syndrome at the visual stimulus speed of 0.4 Hz: the cutoff point of tracking smoothness (G) is 0.69%, sensitivity — 0.732, specificity — 0.873, AUC=0.903, risk syndrome of the first psychosis at the visual stimulus speed of 0.7 Hz: the cutoff point for tracking smoothness (G) is 0.63%, sensitivity — 0.753, specificity — 0.869, AUC=0.852.
Conclusion. Violations of the following parameters of fine motor skills of the eye are potential biological markers of schizophrenia symptoms within the dimensional and staged models framework: an increase in the latency of saccadic eye movements of more than 320 ms and a decrease in the accuracy of saccadic eye movements of less than 80% for the presence of symptom complexes Apathy-Abulia and Anhedonia-Associality, a decrease in the accuracy of saccadic eye movements of less than 54% with a random signal from a video generator for “Positive formal disturbances in thinking”;
a decrease in the tracking smoothness coefficient of less than 69% at the visual stimulus speed of 0.4 Hz for the thinking disorganization syndrome in schizophrenia within the framework of the dimensional model, a decrease in the tracking smoothness coefficient of less than 63% at the visual stimulus speed of 0.7 Hz for risk of first psychosis.
Автор(ы): I. V. Obyedkov, M. M. Skuharevskaya