经颅聚焦超声单次刺激初级运动皮层对健康女性疼痛敏感性及脑电活动的影响

关键词：经颅聚焦超声刺激  初级运动皮层  热痛阈值  压痛阈值  静息态脑电图  疼痛调节

Keywords:transcranial focused ultrasound stimulation  primary motor cortex  heat pain threshold  pressure pain threshold  resting-state EEG  pain modulation

摘要：

      摘要 目的：观察单次靶向初级运动皮层（M1）的经颅聚焦超声刺激（tFUS）对健康女性实验性疼痛敏感性的即刻影响，并探索相关静息态脑电活动变化。 方法：采用随机、双盲、假刺激对照的交叉探索性设计，纳入11名健康女性，分别接受真实刺激与假刺激。于干预前后评估热痛阈值（HPT）、压痛阈值（PPT）、情绪指标及静息态脑电图（EEG），并于每次干预后进行盲法评价。行为学指标采用双侧配对置换检验进行比较，并基于校正后P值或q值进行统计判断。EEG最终纳入9名通过质量控制的受试者。 结果：真实刺激后疼痛阈值整体升高，其中HPT总体在Holm校正后仍具有显著性意义（P=0.005）；PPT总体在Holm校正后亦达到显著性意义（P=0.049），但其效应量和结果稳定性均弱于HPT总体。情绪指标及盲法评价经校正后均未见显著差异。EEG全头皮通道层面未见校正后显著结果。探索性ROI-行为学分析显示，PPT相关候选信号主要集中于右后顶区低频活动，其中总体PPT差值与右后顶区theta频段交互效应值之间的负相关最强（ρ=﹣0.867，结局内q=0.061），但未通过全局q值校正。 结论：单次靶向M1的tFUS对健康女性实验性疼痛阈值具有即刻调节作用，其中HPT总体升高较为稳定。

Abstract:

      Abstract Objective: To examine the immediate effects of single-session transcranial focused ultrasound stimulation (tFUS) targeting the primary motor cortex (M1) on experimental pain sensitivity in healthy women and to explore related resting-state electroencephalographic (EEG) changes. Method: This randomized, double-blind, sham-controlled crossover exploratory study included 11 healthy women who received both real and sham stimulation. We assessed heat pain threshold (HPT), pressure pain threshold (PPT), affective measures, and resting-state EEG before and after each intervention, and collected blinding ratings after each intervention. Behavioral outcomes were analyzed using two-sided paired sign-flipping permutation tests, with corrected P or q values as the inference criterion. EEG analyses included 9 participants who met prespecified quality-control criteria. Result: Real stimulation increased pain thresholds overall. Overall HPT remained significant after Holm correction (P=0.005). Overall PPT also reached statistical significance after Holm correction (P=0.049), although its effect size and result stability were weaker than those of overall HPT. No corrected differences were found for affective measures or blinding ratings. No corrected whole-scalp EEG effects were observed. Exploratory ROI analyses suggested that PPT-related candidate signals were concentrated in low-frequency activity in the right posterior parietal region, with the strongest association observed between overall PPT change and right posterior parietal theta activity (ρ=?0.867, within-outcome q=0.061), although this did not survive global correction. Conclusion: Single-session M1-targeted tFUS may increase experimental pain thresholds in healthy women, with a more stable effect on HPT than on PPT.