Background: There is currently a lack of studies that evaluate the effects of matrix electrode neuromodulation on acute pain. In this prospective and randomized cross-over study, we investigated the efficacy of 4 Hz-matrix stimulation on venipuncture-induced pain in 30 healthy subjects.
Methods: We compared two conditions of neurostimulation: in EC1 (experimental condition 1), we performed venipuncture during stimulation, with 2.5 min of prestimulation with 600 stimuli; in EC2 (experimental condition 2), the length of stimulation was 5 min, at 1200 stimuli, with subsequent venipuncture. A group with no stimulation was used as control condition.
Results: The EC2 group did not only show a 77% reduction in puncture pain when compared to the control group (p < 0.001; effect size [ES] d = 1.45), but also had a significant effect compared with EC1 (p < 0.001; ES d = 1.33). EC1, on the other hand, did not demonstrate a significant difference to the control group. The status of the veins was evaluated based on visibility and did not differ significantly between the conditions.
Conclusion: The results of this study showed for the first time that pre-emptive matrix stimulation could be an effective way to reduce acute pain. The duration of stimulation seems to play a key role in the effectiveness of the neurophysiological mechanism of action. Matrix stimulation is a therapeutic intervention with very few side effects, which could, in the future, expand our pain-management options for the treatment of acute pain.
Keywords: Acute pain; Long-term depression (LTD); Matrix stimulation; Neuromodulation.