Abstract:
Patients with complex regional pain syndrome suffer from chronic neuropathic pain and also show a decrease in sensorimotor performance associated with characteristic central and peripheral neural system parameters. In the brain imaging domain, these comprise altered functional sensorimotor representation for the affected hand side. With regard to neurophysiology, a decrease in intracortical inhibition for the sensorimotor cortex contralateral to the affected hand has been repetitively verified, which might be related to increased primary somatosensory cortex functional activation for the affected limb. Rare longitudinal intervention studies in randomized controlled trials have demonstrated that a decrease in primary somatosensory cortex functional MRI activation coincided with pain relief and recovery in sensorimotor performance. By applying a randomized wait-list control crossover study design, we tested possible associations of clinical, imaging and neurophysiology parameters in 21 patients with complex regional pain syndrome in the chronic stage (>6 months). In more detail, we applied graded motor imagery over 6 weeks to relieve movement pain of the affected upper limb. First, baseline parameters were tested between the affected and the non-affected upper limb side and age-matched healthy controls. Second, longitudinal changes in clinical and testing parameters were associated with neurophysiological and imaging parameters. During baseline short intracortical inhibition, as assessed with transcranial magnetic stimulation, was decreased only for hand muscles of the affected hand side. During movement of the affected limb, primary somatosensory cortex functional MRI activation was increased. Hand representation area size for somatosensory stimulation in functional MRI was smaller on the affected side with longer disease duration. Graded motor imagery intervention but not waiting, resulted in a decrease of movement pain. An increase of somatosensory hand representation size over graded motor imagery intervention was related to movement pain relief. Over graded motor imagery intervention, pathological parameters like the increased primary somatosensory cortex activation during fist movement or decreased short intracortical inhibition were modified in the same way as movement pain and hand performance improved. No such changes were observed during the waiting period. Overall, we demonstrated characteristic changes in clinical, behaviour and neuropathology parameters applying graded motor imagery in patients with upper limb complex regional pain syndrome, which casts light on the effects of graded motor imagery intervention on biomarkers for chronic neuropathic pain.
摘要:
患有复杂区域疼痛综合征的患者患有慢性神经性疼痛,并且还显示出与特征性中枢和周围神经系统参数相关的感觉运动性能降低。在大脑成像领域,这些包括受影响的手部的功能感觉运动表现改变。关于神经生理学,对患手对侧感觉运动皮层的皮质内抑制的减少已得到反复验证,这可能与受影响肢体的原发性体感皮层功能激活增加有关。随机对照试验中罕见的纵向干预研究表明,原发性体感皮层功能性MRI激活的减少与疼痛缓解和感觉运动表现的恢复相吻合。通过应用随机等待列表对照交叉研究设计,我们测试了可能的临床关联,21例复杂区域疼痛综合征慢性期(>6个月)患者的影像学和神经生理学参数。更详细地说,我们在6周内应用分级运动想象来减轻受影响上肢的运动疼痛。首先,在受影响和未受影响的上肢侧和年龄匹配的健康对照之间测试基线参数.第二,临床和检测参数的纵向变化与神经生理学和影像学参数相关.在基线短皮质内抑制期间,经颅磁刺激评估,仅在受影响的手部肌肉中减少。在受影响的肢体运动期间,原发性体感皮质功能MRI激活增加。功能性MRI中体感刺激的手部代表面积在患侧较小,疾病持续时间较长。分级运动图像干预但不等待,导致运动疼痛的减少。与分级运动图像干预相比,体感手表征大小的增加与运动疼痛缓解有关。过度分级运动想象干预,以与运动疼痛和手部表现改善相同的方式修改病理参数,例如拳头运动期间原发性体感皮层激活增加或皮质内短暂抑制减少。在等待期间没有观察到这样的变化。总的来说,我们证明了临床上的特征性变化,在上肢复杂区域疼痛综合征患者中应用分级运动想象的行为和神经病理学参数,阐明了分级运动想象干预对慢性神经性疼痛生物标志物的影响。