Anodal tDCS of the lower limb M1 does not acutely affect clinical blood pressure and heart rate in healthy and post stroke individuals.

Transcranial direct current stimulation (tDCS) is a non-invasive brain stimulation technique increasingly investigated an adjunct modality to enhance the effects of motor therapy. Although the safety of tDCS in relation to cognition, sensation and perception has been well reviewed, there still exists limited information regarding its effects on blood pressure and heart rate. As tDCS is being largely used in conjunction with stroke rehabilitation, it is important that we understand the effects of tDCS on autonomic function in the stroke population. In this retrospective study, we examined the acute effects of tDCS of the lower limb motor cortex in healthy and post stroke individuals using clinical measurements of blood pressure and heart rate. Fifteen minutes of 1 mA anodal tDCS did not cause any clinically detectable changes in blood pressure or heart rate. This is the first study to report the cardiovascular autonomic effects of tDCS of the lower limb M1 in healthy and post stroke individuals. Further studies are needed to examine if these safety effects are preserved during repeated applications of tDCS.