[Gait characteristics in patients with persistent postural-perceptual dizziness]

Objective:To investigate gait characteristics under different walking conditions in patients with persistent postural-perceptual dizziness （PPPD） and to examine their correlation with dizziness and balance scales. Methods:This study included 45 patients diagnosed with PPPD and 45 healthy controls recruited from the Department of Neurology, Xi'an Third Hospital, Northwest University, between January 2024 and March 2025. Gait parameters were assessed using a portable gait analysis system during single-task free walking and dual-task walking （while viewing and naming sequentially displayed fruit images on a mobile phone）. Participants also completed the Dizziness Handicap Inventory （DHI） and Activities-specific Balance Confidence （ABC） Scale. Gait parameters were compared between groups and across tasks, and correlations between gait parameters and scale scores were analyzed. Receiver operating characteristic （ROC） curve analysis was used to evaluate the predictive efficacy of gait parameters for PPPD. Results:Compared to healthy controls, patients with PPPD exhibited significantly shorter stride length, slower gait speed, wider stride width, and longer stance phase percentage during both single-and dual-task walking （all P<0.01）. These abnormalities were further exacerbated under dual-task conditions （all P<0.01）. ROC analysis revealed that dual-task stance phase （%） had the highest predictive value for PPPD （AUC=0.83; 95%CI 0.75-0.92）, followed by dual-task gait speed （AUC=0.80; 95%CI 0.70-0.89） and single-task stance phase （%） （AUC = 0.75; 95%CI 0.65-0.85）. A combined model incorporating dual-task gait speed and dual-task stance phase demonstrated superior diagnostic performance （AUC=0.895; 95%CI 0.83-0.961; Youden index=0.689）, significantly outperforming dual-task stance phase alone （P<0.05）. Single-task gait speed showed a strong positive correlation with ABC scores （r=0.598, P<0.01）, No significant correlations were found between DHI scores and gait parameters （including velocity, stride length, step length, stride width, or stance phase percentage） under either walking conditions （P>0.05）. Conclusion:Individuals with PPPD demonstrate reduced stride length, slower walking speed and rhythm, a broader base of support, and an increased proportion of time spent in the stance phase. A combined metric incorporating dual-task stance phase percentage and dual-task walking speed enhances differentiation between PPPD patients and healthy individuals.