Pain Medicine最新文献

Background: Non-invasive brain stimulation (NIBS) has been investigated increasingly as a means of treating pain. The effectiveness of NIBS in the treatment of pain has traditionally focused upon protocols targeting the primary motor cortex (M1). However, over time, the effectiveness of M1 NIBS has been attributed to effects on interconnected cortical and subcortical sites rather than M1 itself. While previous reviews have demonstrated the effectiveness of non-M1 NIBS in improving subjective reports of pain intensity, the neurophysiological mechanisms underlying these effects remain incompletely understood. As chronic pain is associated with pain hypersensitivity and impaired endogenous descending pain modulation, it is plausible that non-M1 NIBS promotes analgesic effects by influencing these processes.

Objective: The aim of this systematic review and meta-analysis was therefore to evaluate the effect of NIBS over non-M1 sites on quantitative sensory testing measures in clinical pain populations.

Methods: A systematic search of electronic databases was conducted from inception to January 2024. Included articles (13trials, n = 565 participants) were appraised using PEDro and GRADE and a random effects model was used to meta-analyse outcomes where possible.

Results: A small number of studies found that NIBS applied to DLPFC may improve pain modulation in patients with fibromyalgia, and that stimulation of the posterior superior insula and prefrontal cortex could improve pain sensitivity in chronic neuropathic and osteoarthritic pain, respectively. However, findings varied between studies and there remains a paucity of primary research.

Conclusion: This review indicates that current literature does not provide clear evidence that NIBS over non-M1 sites influences pain processing.

Objective: Priming the neural circuity likely targeted by pain neuroscience education (PNE), using transcranial direct current stimulation (tDCS) may enhance the efficacy of PNE. The aim of this study was to compare the effects of active tDCS + PNE to sham tDCS + PNE on measures of pain, pain behaviors, and cognitive function in participants with chronic low back pain (CLBP) and high pain catastrophizing.

Methods: 20 participants were recruited and randomly allocated into the active tDCS + PNE (n = 10) or sham tDCS + PNE (n = 10) groups. All participants received five sessions of their assigned interventions over a 2-week period. The active tDCS + PNE group received 20 minutes of 2 mA, anodal current applied to the left dorsolateral prefrontal cortex.

Results: Within groups, both interventions demonstrated significant improvement in NPRS, PCS, and TSK. The active tDCS + PNE group also demonstrated significant improvement on the SCWT, CTMT2-Inhibitory, and CTMT2-Set Shifting. Between groups, the active tDCS + PNE group showed significantly greater improvement on the PCS, SCWT, and CTMT2-Inhibitory.

Conclusions: The results of this pilot study suggest that active tDCS + PNE appeared to provide greater improvement than sham tDCS + PNE on levels of pain catastrophizing and attentional interference in participants with CLBP and high pain catastrophizing, consistent with both interventions targeting brain regions involved in those processes. Considering the differences between groups, tDCS appears to provide a priming effect on PNE.

Objective: Exercise induces a hypoalgesic response and improves affect. However, some individuals are unable to exercise for various reasons. Motor imagery, involving kinesthetic and visual imagery without physical movement, activates brain regions associated with these benefits and could be an alternative for those unable to exercise. Virtual reality also enhances motor imagery performance because of its illusion and embodiment. Therefore, we examined the effects of motor imagery combined with virtual reality on pain sensitivity and affect in healthy individuals.

Design: Randomized crossover study.

Setting: Laboratory.

Subjects: Thirty-six participants (women: 18) were included.

Methods: Each participant completed three 10-min experimental sessions, comprising actual exercise, motor imagery only, and motor imagery combined with virtual reality. Hypoalgesic responses and affective improvement were assessed using the pressure-pain threshold and the Positive and Negative Affect Schedule, respectively.

Results: All interventions significantly increased the pressure-pain threshold at the thigh (P < .001). Motor imagery combined with virtual reality increased the pressure-pain threshold more than motor imagery alone, but the threshold was similar to that of actual exercise (both P ≥ .05). All interventions significantly decreased the negative affect of the Positive and Negative Affect Schedule (all P < .05).

Conclusions: Motor imagery combined with virtual reality exerted hypoalgesic and affective-improvement effects similar to those of actual exercise.

Clinical trials registration: The study was enrolled in the UMIN Clinical Trials Registry (registration number: UMIN000046095). The website for registration information is https://center6.umin.ac.jp/cgi-open-bin/ctr_e/ctr_view.cgi?recptno=R000052614.