Botelho Leonardo, Angoleri Letícia, Zortea Maxciel, Deitos Alicia, Brietzke Aline, Torres Iraci L S, Fregni Felipe, Caumo Wolnei
Post-Graduate Program in Medical Sciences, School of Medicine, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil.
Laboratory of Pain and Neuromodulation, Hospital de Clínicas de Porto Alegre, Porto Alegre, Brazil.
Front Hum Neurosci. 2018 Oct 16;12:388. doi: 10.3389/fnhum.2018.00388. eCollection 2018.
There is limited evidence concerning the effect of intramuscular electrical stimulation (EIMS) on the neural mechanisms of pain and disability associated with chronic Myofascial Pain Syndrome (MPS). To provide new insights into the EIMS long-term effect on pain and disability related to chronic MPS (primary outcomes). To assess if the neuroplasticity state at baseline could predict the long-term impact of EIMS on disability due to MPS we examined the relationship between the serum brain-derived-neurotrophic-factor (BDNF) and by motor evoked potential (MEP). Also, we evaluated if the EIMS could improve the descending pain modulatory system (DPMS) and the cortical excitability measured by transcranial magnetic stimulation (TMS) parameters. We included 24 right-handed female with chronic MPS, 19-65 years old. They were randomically allocated to receive ten sessions of EIMS, 2 Hz at the cervical paraspinal region or a sham intervention ( = 12). A mixed model analysis of variance revealed that EIMS decreased daily pain scores by -73.02% [95% confidence interval (CI) = -95.28 to -52.30] and disability due to pain -43.19 (95%CI, -57.23 to -29.39) at 3 months of follow up. The relative risk for using analgesics was 2.95 (95% CI, 1.36 to 6.30) in the sham group. In the EIMS and sham, the change on the Numerical Pain Scale (NPS0-10) throughout CPM-task was -2.04 (0.79) vs. -0.94 (1.18), respectively, ( = 0.01). EIMS reduced the MEP -28.79 (-53.44 to -4.15), while improved DPMS and intracortical inhibition. The MEP amplitude before treatment [(Beta = -0.61, (-0.58 to -0.26)] and a more significant change from pre- to post-treatment on serum BDNF) (Beta = 0.67; CI95% = 0.07 to 1.26) were predictors to EIMS effect on pain and disability due to pain. These findings suggest that a bottom-up effect induced by the EIMS reduced the analgesic use, improved pain, and disability due to chronic MPS. This effect might be mediated by an enhancing of corticospinal inhibition as seen by an increase in IC and a decrease in MEP amplitude. Likewise, the MEP amplitude before treatment and the changes induced by the EIMS in the serum BDNF predicted it's long-term clinical impact on pain and disability due MPS. : NCT02381171.
关于肌内电刺激（EIMS）对慢性肌筋膜疼痛综合征（MPS）相关疼痛和功能障碍神经机制的影响，证据有限。为了深入了解EIMS对慢性MPS相关疼痛和功能障碍的长期影响（主要结果）。为了评估基线时的神经可塑性状态是否可以预测EIMS对MPS所致功能障碍的长期影响，我们研究了血清脑源性神经营养因子（BDNF）与运动诱发电位（MEP）之间的关系。此外，我们评估了EIMS是否可以改善下行疼痛调节系统（DPMS）以及通过经颅磁刺激（TMS）参数测量的皮质兴奋性。我们纳入了24名年龄在19至65岁之间的右利手女性慢性MPS患者。她们被随机分配接受10次EIMS治疗，频率为2Hz，刺激颈旁脊柱区域，或接受假干预（每组n = 12）。方差混合模型分析显示，在随访3个月时，EIMS使每日疼痛评分降低了-73.02%[95%置信区间（CI）=-95.28至-52.30]，疼痛所致功能障碍降低了-43.19（95%CI，-57.23至-29.39）。假治疗组使用镇痛药的相对风险为2.95（95%CI，1.36至6.30）。在EIMS组和假治疗组中，整个CPM任务期间数字疼痛量表（NPS 0-10）的变化分别为-2.04（0.79）和-0.94（1.18），（P = 0.01）。EIMS使MEP降低了-28.79（-53.44至-4.15），同时改善了DPMS和皮质内抑制。治疗前的MEP波幅[（β=-0.61，（-0.58至-0.26）]以及血清BDNF治疗前后更显著的变化（β = 0.67；95%CI = 0.07至1.26）是EIMS对疼痛和疼痛所致功能障碍影响的预测指标。这些发现表明，EIMS诱导的自下而上的效应减少了镇痛药的使用，改善了慢性MPS所致的疼痛和功能障碍。这种效应可能是由皮质脊髓抑制增强介导的，表现为IC增加和MEP波幅降低。同样，治疗前的MEP波幅以及EIMS诱导的血清BDNF变化预测了其对MPS所致疼痛和功能障碍的长期临床影响。试验注册号：NCT02381171。
