Abnormal gait evaluation of patients with chronic vestibular syndrome based on dynamic stability analysis

Gait abnormalities are common in patients with chronic vestibular syndrome (CVS). Accurate evaluation of the degree of instability in CVS patients is of great clinical significance for the diagnosis and treatment of CVS. The objective of this study was to explore the accuracy, specificity and sensitivity of dynamic stability analysis and conventional kinematic analysis to assess the degree of instability in chronic vestibular syndrome. 16 CVS subjects were graded with DHI scale as the gold standard. The kinematic data of the subjects were collected using a 3D motion capture system. The conventional kinematics parameters such as sagittal, coronal and 2-D body center of mass (COM) velocity and acceleration, and the dynamic stability parameters such as sagittal, coronal and 2-D velocity stability domain are calculated. Finally, the accuracy, specificity and sensitivity of different analysis methods in evaluating the degree of instability in CVS patients were carried out. For CVS patients and controls, the maximum sensitivity, specificity and accuracy of COM velocity or acceleration peak were 75.0%, 93.7% and 90.2%, respectively, while the corresponding indexes of two-dimensional velocity stability domain parameters were 100.0%. For patients with mild CVS disorder and patients with moderate CVS disorder, the sensitivity, specificity and accuracy of COM velocity or acceleration peak can reach up to 87.5%, 50.0% and 40.6%, respectively, and the two-dimensional velocity stability domain parameters can reach 100.0%, 75.0% and 73.4%, respectively. The sensitivity, specificity and accuracy of 2-D velocity stability region and COM acceleration peak comprehensive evaluation are improved to 100.0%, 87.5% and 100.0%, respectively. In terms of sensitivity, specificity and accuracy of evaluating the degree of gait instability in patients with CVS, the two-dimensional velocity stability domain parameters are better than the traditional kinematics parameters. Dynamic stability parameters can be used to quantitatively describe the difference of dynamic stability during walking between CVS patients and control subjects of different degrees. This study can provide reference for the subsequent quantitative evaluation of gait stability in patients with CVS.