Quantitative analysis of gait abnormality prior to step initiation in early Parkinson's disease

Objective To explore the gait characteristics prior to the step initiation in patients with early Parkinson's disease (PD). Methods A total of 20 patients diagnosed with early PD admitted to Tianjin Huanhu Hospital from July 2020 to June 2021, and 22 normal controls with normal cognitive and motor function matched by gender, age, body mass index (BMI) and education were included. The gait characters in the initial step stage [anticipatory postural adjustments (APAs) duration, fowward APAs peak, lateral APAs peak] and the first step period (first step duration, first step swing angle), as well as the gait characters in the walking stage (step speed and stride length) during the 7 m Stand and Walk Test (7MSAW) were recorded by gait analyzer. Receiver operating characteristic (ROC) curve was plotted to evaluate the value of gait characteristics in diagnosis of early PD. Results The APAs duration in early PD group was longer than that in control group (Z = ⁃ 4.853, P = 0.000), and the forward APAs peak was lower than that in control group (Z = ⁃ 5.253, P = 0.000). The cut⁃off value of APAs duration was 0.440 s, the area under the curve (AUC) was 0.947 (95%CI: 0.885-1.000, P = 0.000), the sensitivity was 95%, the specificity was 77.30%, and the Youden index was 0.723. The cut⁃off value of forward APAs peak was 0.445 m/s2, the AUC was 0.974 (95%CI: 0.936-1.000, P = 0.000), the sensitivity was 85%, the specificity was 95.50%, and the Youden index was 0.805. The cut⁃off value of the combination was 0.540, the AUC was 0.974 (95%CI: 0.936-1.000, P = 0.000), the sensitivity was 90%, the specificity was 90.10%, and the Youden index was 0.801. Conclusions The APAs in the initial step stage is abnormal in patients with early PD, the related parameters have high sensitivity and specificity, which can assist clinicians in early screening of diseases.