Peripheral arterial disease (PAD), commonly caused by atherosclerosis, reduces blood flow to the extremities, resulting in muscle ischemia and intermittent claudication. Aerobic training is an effective strategy for treating individuals with PAD, and high-definition transcranial direct current stimulation (HD-tDCS) has been studied as an adjunct therapy due to its positive effects on exercise endurance, perceived effort, and functional capacity (FC).

To identify the effects of combining aerobic exercise and transcranial neurostimulation on quality of life (QoL), FC, peripheral muscle metabolism, and subjective perception of effort in individuals with PAD.

This case study was conducted with four volunteers diagnosed with PAD. FC was assessed using the Incremental Shuttle Walking Test (ISWT), muscle metabolism through Near-Infrared Spectroscopy (NIRS), QoL using the Short Form 36 (SF-36), and subjective perception of effort through the Modified Borg Scale. Assessments were conducted before and after 12 weeks of intervention. Participants were divided into two groups: the intervention group (IG) and the control group (CG), with two volunteers in each. The IG received active stimulation on the left dorsolateral prefrontal cortex (DLPFC-L) during exercise on a cycle ergometer, while the CG received placebo stimulation, both for 30 minutes.

Regarding QoL, only the two IG participants were reassessed, as the CG participants declined to participate in the reassessment. An improvement in QoL was observed in Volunteer 1 (V1) in the following domains: general health perception (55/100), vitality (95/100), social function (100/100), and mental health (92/100); and in Volunteer 2 (V2) in the domains of physical functioning (60/100), emotional role limitation (67/100), bodily pain (68/100), general health perception (70/100), and mental health (80/100). In terms of subjective perception of effort, both volunteers reported an effort level of "too light" (Borg = 1) at the beginning, end, and recovery phases of the exercise test. FC showed a clinically significant minimal difference in three cases (?V2 = 500m; ?V3 = 110m; ?V4 = 70m). No significant differences were observed between the CG and IG regarding improvements in muscle metabolism after the intervention, except for resistance time (?V1 = 31.6s; ?V2 = 225.2s; ?V3 = 26.4s; ?V4 = 101.6s) in both the occlusion maneuver and the ISWT and lower-limb cycle ergometer tests.

The combination of HD-tDCS and aerobic exercise may contribute to increased QoL and FC in individuals with PAD. Additionally, an improvement in subjective perception of effort and walking distance in the ISWT was observed in the IG. However, no significant changes were noted in tissue oxygenation behavior.

These findings highlight the need for further robust studies and emphasize the importance of additional research on HD-tDCS as an adjunct therapy for PAD treatment, aiming for its integration into clinical practice. Despite limitations, this intervention may contribute to symptom mitigation and functional capacity restoration.