Motor cortical excitability behavior in chronic spinal cord injury neuropathic pain individuals submitted to transcranial direct current stimulation—case reports

This study explores the use of transcranial direct current stimulation (tDCS) to treat neuropathic pain in individuals with chronic spinal cord injury (SCINP). The main goal was to evaluate how tDCS affects the motor cortex excitability (MCE) in these individuals, as it is believed that their ability to enhance MCE might be impaired. Eleven individuals with chronic SCINP participated, undergoing a 5-day pre-post MCE analysis to see how their brain activity changed after tDCS sessions. The study found that some participants showed negative variations in MCE, while others had positive variations or no significant change. The authors suggest that factors such as pain and injury duration, age, medication use, and maladaptive neuroplasticity may influence how individuals respond to brain stimulation. The results indicate a need for caution when recommending tDCS for chronic SCINP and highlight the importance of identifying individuals who are most likely to benefit from neuromodulation.

• 1
  Four individuals showed a negative variation of motor cortex excitability (MCE) after tDCS, with two reporting a reduction in pain intensity.
• 2
  Three individuals exhibited a positive variation of MCE, but only one reported a small reduction in pain (VAS 0.5) after five days of observation.
• 3
  The remaining four individuals did not present significant variation in MCE after the tDCS sessions.