Prefrontal cortex oxygenation dynamics during dual-task walking in independently ambulatory patients with acute...

Advances in stroke care have led to an increase in the number of patients who regain independent indoor ambulation; however, many still experience limitations when attempting to resume community activities. Altered prefrontal cortex (PFC) activity during dual-task walking (DTW) after stroke has been suggested as a contributing factor to difficulties with community ambulation. The purpose of this study was to compare PFC oxygenation dynamics and walking performance during DTW between independently ambulatory patients with acute stroke and healthy older adults.

A total of 36 independently ambulatory patients with stroke within 14 days of onset (74.8 ± 6.3 years; 44% female) and 17 healthy older adults (71.4 ± 4.1 years; 41% female) were included in this cross-sectional observational study. Each participant performed normal walking as a single task (Walk-ST), serial subtraction as a single task (Serial-7-ST), and DTW tasks. We measured PFC oxygenation by assessing oxyhemoglobin (O₂Hb) and deoxyhemoglobin (HHb) using a wearable near-infrared spectroscopy device and assessed walking speed, cadence, stride length, cognitive accuracy, and number of responses. Two-way repeated-measures analysis of variance was applied to the PFC oxygenation and performance outcomes, and the Hochberg method was used to adjust for multiple testing across related outcomes.

Significant task effects were observed for both O₂Hb and HHb after Hochberg adjustment (both adjusted p < 0.01), whereas no significant group effects were detected. O₂Hb was higher and HHb lower during Serial-7-ST and dual-task walking than during walking alone (all Bonferroni-adjusted p < 0.01), with no significant differences between Serial-7-ST and dual-task walking for either O₂Hb (adjusted p = 0.20) or HHb (adjusted p = 0.15). Walking speed, cadence, and stride length showed significant group and task effects after Hochberg adjustment (all adjusted p < 0.05). No significant group differences were observed in cognitive accuracy or number of responses, although the number of responses showed a significant task effect (adjusted p = 0.04).

Ambulatory patients with acute stroke exhibited poorer walking performance than did healthy older adults, despite showing no significant between-group differences in task-related PFC oxygenation dynamics or cognitive performance.