Bilateral Motor Cortex tDCS Effects on Post-Stroke Pain and Spasticity: A Three Cases Study

Area of Science:

• Neuroscience
• Rehabilitation Medicine
• Neurology

Background:

• Stroke frequently leads to chronic limb pain and spasticity, with limited established treatments.
• Transcranial direct current stimulation (tDCS) is a non-invasive brain stimulation method known to modulate cortical excitability.
• Previous research indicates motor cortex tDCS can alleviate pain and potentially reduce spasticity in post-stroke patients, with multiple sessions inducing lasting neuroplastic changes.

Purpose of the Study:

• To investigate the efficacy of multiple anodal transcranial direct current stimulation (atDCS) sessions on upper limb pain and spasticity in stroke patients.
• To assess the safety and tolerability of the atDCS intervention in this patient population.

Main Methods:

• A within-subject, crossover, sham-controlled pilot study design was employed.
• Three stroke patients with similar brain damage extent but varying locations received 5 consecutive daily sessions of atDCS or sham stimulation.
• Pain was assessed using the Adaptive Visual Analog Scales (AVAS), and spasticity was measured with the Fugl-Meyer scale.

Main Results:

• Five consecutive sessions of atDCS significantly reduced pain and spasticity compared to sham stimulation.
• Two patients experienced complete pain relief or marked reduction following verum atDCS.
• Significant spasticity improvement was observed in one patient, though inter-individual variability in response was noted.

Conclusions:

• Multiple sessions of atDCS appear to be a safe and potentially effective intervention for alleviating upper limb pain and spasticity in stroke patients.
• The observed inter-individual variability highlights the need for further research with larger sample sizes and individualized protocols.
• Future studies should include longer follow-up periods to confirm the long-term efficacy and safety of atDCS for post-stroke limb symptoms.