Unraveling the stride: exploring the influence of neurogenic orthostatic hypotension on gait and balance in Parkinson's disease

Purpose: Neurogenic orthostatic hypotension (nOH) and gait impairment are frequent sources of disability in Parkinson’s disease (PD). However, the impact of nOH on balance and gait features remains unclear. This cross-sectional study aimed to assess the influence of nOH on postural and gait parameters in a cohort of patients with PD by means of wearable inertial sensors. Methods: Gait and balance were assessed using Opal inertial sensors. nOH was defined as sustained systolic blood pressure (BP) drop ≥ 20 mmHg or diastolic BP drop ≥ 10 mmHg within 3 min of standing, with a ΔHR/ΔSBP ratio ≤ 0.5 bpm/mmHg. Analysis of covariance was performed to evaluate differences in gait/balance features between patients with and without nOH, adjusting for age, cognitive status, and motor disability. Moreover, we performed the same analysis considering the presence of hemodynamically relevant nOH (orthostatic mean BP ≤ 75 mmHg). Results: A total of 82 patients were enrolled, 26 with nOH (31.7%), of which 13 presented with hemodynamically relevant nOH. After correcting for confounders, nOH was independently associated with lower gait speed (p = 0.027), shorter stride length (p = 0.033), longer time for postural transitions (p = 0.004), and increased postural sway (p = 0.019). These differences were even more pronounced in patients with hemodynamically relevant nOH. Higher postural sway was associated with a 7.9-fold higher odds of falls (p = 0.040). Conclusions: Our study presents an objective demonstration of the independent negative impact of nOH on gait and balance in PD, emphasizing the need for careful detection and management of nOH to mitigate gait and balance disturbances in PD.