Tonic Cold Pain Temporal Summation and Translesional Cold Pressor Test-Induced Pronociception in Spinal Cord Injury: Association with Spontaneous and Below-Level Neuropathic Pain

This study investigates how people with spinal cord injuries (SCI) and neuropathic pain (NP) experience cold pain, and how their bodies regulate pain signals, compared to those without NP. The researchers used a cold pressor test (CPT) to induce pain and measured the pain response. The study found that individuals with SCI-NP, especially those with below-level pain, showed increased sensitivity to cold pain and altered pain regulation compared to those without NP. These findings suggest that the way the body processes and modulates pain is different in individuals with SCI-NP. The results highlight the role of central sensitization, spontaneous pain intensity, and spinothalamic tract hyperexcitability in SCI-NP, particularly in those with below-level NP. These findings could potentially lead to better diagnostic and treatment strategies for neuropathic pain in individuals with spinal cord injuries.

• 1
  Temporal summation of pain (TSP) in response to the foot CPT was higher in subacute compared to chronic incomplete SCI-NP, while TSP to the hand CPT was significantly higher in chronic compared to the subacute complete SCI-NP group.
• 2
  The hand CPT induced widespread pronociception (lower PPT), which correlated with 7-day non-evoked (spontaneous) pain intensity in individuals with incomplete SCI-NP.
• 3
  Individuals with below-level NP, but not at-level NP, showed higher TSP during the foot CPT and greater hand CPT-induced L4 dermatome pronociception.