Microvascular Reactivity to Cutaneous Local Heating in the Paretic and Non-Paretic Legs of Chronic Stroke Survivors-A...

Cutaneous microvascular reactivity was investigated in chronic stroke survivors by comparing vasodilatory responses in the paretic and non-paretic legs to matched controls. It was hypothesized that vasodilatory responses would be blunted in the paretic leg of stroke survivors vs. the non-paretic leg and controls.

Cutaneous vascular conductance to local heating was measured in 20 stroke survivors and 20 controls using laser-Doppler flowmetry probes with integrated heaters. Probes were placed on both legs of stroke survivors and the dominant leg of controls. After 15 min rest, the skin was subjected to gradual (1°C/5 min) or rapid heating (0.1°C/s) to 39°C, then increased to 43°C to induce maximal vasodilation.

Vasodilation to gradual heating did not differ between the paretic and non-paretic legs of stroke survivors (p = 0.07) and controls (p = 0.82). Neurogenic axon-mediated responses to rapid heating showed no differences across groups (paretic vs. non-paretic, p = 1.00; paretic vs. control, p = 0.23).

Cutaneous vasodilatory responses to gradual and rapid heating were comparable between stroke survivors and controls. Future studies combining local heating with dermal microdialysis should explore specific vasodilatory pathways, as limb-specific changes may not be evident by measuring vasodilatory magnitude alone.