Effect of transcranial direct current stimulation in the initial weeks post-stroke: a pilot randomized study.

Area of Science:

• Neuroscience
• Rehabilitation Medicine
• Neurology

Background:

• Stroke frequently causes upper limb motor impairment.
• Transcranial direct current stimulation (tDCS) is being investigated as a potential therapy to enhance motor recovery.
• Understanding the effects of tDCS on motor pathways and clinical outcomes is crucial.

Purpose of the Study:

• To assess changes in upper limb motor function and brain connectivity after cathodal tDCS in early post-stroke patients.
• To compare the effects of active tDCS versus sham stimulation on motor impairment and neural connectivity.

Main Methods:

• Thirteen early post-stroke patients received six sessions of either active or sham cathodal tDCS targeting the primary motor cortex.
• Upper limb motor impairment was assessed using the Fugl-Meyer Assessment (FMA).
• Resting-state functional connectivity between primary motor cortices and within the unaffected hemisphere's motor network was analyzed.

Main Results:

• More participants in the sham group achieved clinically relevant FMA improvements (≥9 points) than in the active group.
• No statistically significant differences in FMA score changes or connectivity modifications were found between the active and sham groups.
• Increased connectivity between primary motor cortices was observed in more participants receiving active tDCS, but this did not correlate with greater clinical improvement.

Conclusions:

• Early post-stroke application of cathodal tDCS did not yield significant clinical benefits in upper limb motor function.
• Enhanced neural connectivity observed with active tDCS did not translate into superior motor performance compared to sham stimulation.
• Further research with larger cohorts is needed to elucidate the mechanisms and optimize the use of tDCS for stroke rehabilitation.