Effect of aquatic-treadmill training on cerebrovascular function and gait in community-dwelling stroke survivors: a...

Water-based exercise augments exercise-induced increases in brain blood flow, optimizing a proposed key mechanistic pathway for improved brain health. Aquatic treadmill exercise has been shown to aid gait re-education of stroke survivors, however its potential to enhance cerebrovascular function in this clinical population has not been tested. This pilot study aimed to examine the feasibility and preliminary efficacy of a 4-week aquatic treadmill (ATM) training intervention on cerebrovascular responsiveness and gait function in stroke survivors.

Six community-dwelling stroke survivors (58 ± 11 years, 8 ± 11 years post stroke) completed a 4-week ATM intervention, consisting of 20-30 min sessions, 3 times/week. Pre- and post-intervention measures were taken of cerebrovascular reactivity (CVR), indexed via changes in middle cerebral artery blood velocity (MCAv) to a hypercapnic (5% CO₂ in air) stimulus. Changes in mobility were assessed via 10-metre walk, Timed-Up-And-Go, and 6-minute walk (6MW) tests.

Adherence to the intervention was excellent, with 70 of the 72 (97%) available training sessions completed by participants. CVR increased on average by 44% (95% CI: ±58%; 2.8%-4.0%ΔMCAv/mm Hg ΔPETCO₂) in the stroke-affected hemisphere and 48% (95% CI: ±41%; 3.0%-4.5%ΔMCAv/mm Hg ΔPETCO₂) in the unaffected hemisphere post intervention, although changes did not reach statistical significance (p = 0.218; Friedman's test). Within-group gait improvements were seen in speed and distance, with some changes above clinically meaningful thresholds; although this was not uniformly evident.

This pilot study established ATM training as a feasible option for some patients in stroke rehabilitation. Despite the limited sample size, the study demonstrated promising enhancements in cerebrovascular function, with preliminary evidence suggesting concurrent improvements in gait performance. Well-designed, larger studies are warranted.