Transcranial direct current stimulation for upper limb neuropathic pain: A double-blind randomized controlled trial

Area of Science:

• Neuroscience
• Pain Management
• Neurology

Background:

• Mixed findings exist regarding the efficacy of transcranial direct current stimulation (tDCS) for chronic pain management.
• Upper limb neuropathic pain presents a significant clinical challenge.

Purpose of the Study:

• To evaluate the effect of anodal tDCS on pain and function in individuals with upper limb neuropathic pain.
• To assess the impact of tDCS on nociceptive system function via quantitative sensory testing (QST).

Main Methods:

• A double-blinded, randomized controlled trial was conducted with 30 participants.
• Participants received 5 days of active or sham anodal tDCS (1 mA) over the primary motor cortex.
• Pain, function, and QST measures were assessed at baseline and at 1, 3, and 8 weeks post-intervention.

Main Results:

• Group analyses revealed no significant improvements in pain, function, or QST measures over time for either the active or sham tDCS groups.
• A significantly higher number of individual responders (≥30% pain reduction) were observed in the active tDCS group compared to the sham group at the final follow-up.
• A positive correlation was found in the active group between higher baseline pain and greater pain relief.

Conclusions:

• Group-level analyses did not provide evidence for the efficacy of 1 mA anodal tDCS for upper limb neuropathic pain.
• Individualized treatment effects suggest that tDCS may offer lasting pain relief for a subset of patients.
• Early responders to active tDCS experienced sustained pain relief, indicating potential for personalized treatment strategies.