André-Obadia Nathalie, Mertens Patrick, Lelekov-Boissard Taïssia, Afif Afif, Magnin Michel, Garcia-Larrea Luis
Neurophysiology & Epilepsy Unit, Neurological Hospital P. Wertheimer, Hospices Civils de Lyon, France; Inserm U 1028, NeuroPain team, Neuroscience Research Center of Lyon (CRNL), Lyon-1 University, France.
Pain Physician. 2014 Jan-Feb;17(1):53-62.
A positive effect of motor cortex stimulation (MCS) (defined as subjective estimations of pain relief ≥ 30%) has been reported in 55 - 64% of patients. Repetitive magnetic cortical stimulation (rTMS) is considered a predictor of MCS effect. These figures are, however, mostly based on subjective reports of pain intensity, and have not been confirmed in the long-term.
This study assessed long-term pain relief (2 - 9 years) after epidural motor cortex stimulation and its pre-operative prediction by rTMS, using both intensity and Quality of Life (QoL) scales.
Analysis of the long-term evolution of pain patients treated by epidural motor cortex stimulation, and predictive value of preoperative response to rTMS.
University Neurological Hospital Pain Center.
Twenty patients suffering chronic pharmaco-resistant neuropathic pain.
All patients received first randomized sham vs. active 20 Hz-rTMS, before being submitted to MCS surgery.
Postoperative pain relief was evaluated at 6 months and then up to 9 years post-MCS (average 6.1 ± 2.6 y) using (i) pain numerical rating scores (NRS); (ii) a combined assessment (CPA) including NRS, drug intake, and subjective quality of life; and (iii) a short questionnaire (HowRu) exploring discomfort, distress, disability, and dependence.
Pain scores were significantly reduced by active (but not sham) rTMS and by subsequent MCS. Ten out of 20 patients kept a long-term benefit from MCS, both on raw pain scores and on CPA. The CPA results were strictly comparable when obtained by the surgeon or by a third-party on telephonic survey (r = 0.9). CPA scores following rTMS and long-term MCS were significantly associated (Fisher P = 0.02), with 90% positive predictive value and 67% negative predictive value of preoperative rTMS over long-term MCS results. On the HowRu questionnaire, long-term MCS-related improvement concerned "discomfort" (physical pain) and "dependence" (autonomy for daily activities), whereas "disability" (work, home, and leisure activities) and "distress" (anxiety, stress, depression) did not significantly improve.
Limited cohort of patients with inhomogeneous pain etiology. Subjectivity of the reported items by the patient after a variable and long delay after surgery. Predictive evaluation based on a single rTMS session compared to chronic MCS.
Half of the patients still retain a significant benefit after 2 - 9 years of continuous MCS, and this can be reasonably predicted by preoperative rTMS. Adding drug intake and QoL estimates to raw pain scores allows a more realistic assessment of long-term benefits and enhance the rTMS predictive value. The aims of this study and its design were approved by the local ethics committee (University Hospitals St Etienne and Lyon, France).
据报道，55% - 64%的患者接受运动皮层刺激（MCS）（定义为疼痛缓解主观估计≥30%）后有积极效果。重复磁皮层刺激（rTMS）被认为是MCS效果的预测指标。然而，这些数据大多基于疼痛强度的主观报告，且尚未得到长期证实。
本研究使用强度和生活质量（QoL）量表评估硬膜外运动皮层刺激术后2至9年的长期疼痛缓解情况及其术前rTMS预测。
分析硬膜外运动皮层刺激治疗的疼痛患者的长期病情演变，以及术前rTMS反应的预测价值。
大学神经医院疼痛中心。
20例患有慢性药物难治性神经性疼痛的患者。
所有患者在接受MCS手术前，先随机接受假刺激与20Hz主动rTMS。
术后6个月评估疼痛缓解情况，之后直至MCS术后9年（平均6.1±2.6年），使用（i）疼痛数字评分量表（NRS）；（ii）综合评估（CPA），包括NRS、药物摄入量和主观生活质量；（iii）一份简短问卷（HowRu），探讨不适、痛苦、残疾和依赖情况。
主动（而非假）rTMS和随后的MCS均显著降低了疼痛评分。20例患者中有10例在原始疼痛评分和CPA方面均从MCS中获得了长期益处。外科医生或第三方通过电话调查获得的CPA结果具有高度可比性（r = 0.9）。rTMS和长期MCS后的CPA评分显著相关（Fisher P = 0.02），术前rTMS对长期MCS结果的阳性预测值为90%，阴性预测值为67%。在HowRu问卷中，与长期MCS相关的改善涉及“不适”（身体疼痛）和“依赖”（日常活动自主性），而“残疾”（工作、家庭和休闲活动）和“痛苦”（焦虑、压力、抑郁）并未显著改善。
疼痛病因不均一的患者队列有限。患者在术后不同且较长延迟后报告项目的主观性。与慢性MCS相比，基于单次rTMS session的预测评估。
半数患者在持续MCS治疗2至9年后仍能显著获益，术前rTMS可合理预测这一情况。在原始疼痛评分中加入药物摄入量和QoL评估，可更实际地评估长期益处并提高rTMS的预测价值。本研究的目的及其设计已获当地伦理委员会（法国圣艾蒂安和里昂大学医院）批准。
