Oono Yuka, Wang Kelun, Baad-Hansen Lene, Futarmal Simple, Kohase Hikaru, Svensson Peter, Arendt-Nielsen Lars
Center for Sensory-Motor Interaction (SMI), Department of Health Science and Technology, Faculty of Medicine, Aalborg University, Fredrik Bajers Vej 7, Bld. D3, 9220, Aalborg E, Denmark,
Exp Brain Res. 2014 Oct;232(10):3111-9. doi: 10.1007/s00221-014-3997-7. Epub 2014 Jun 5.
The aims were to investigate (1) if temporomandibular disorders (TMD) patients with temporomandibular joint (TMJ) pain had different conditioned pain modulation (CPM) compared with healthy subjects and, (2) if clinical pain characteristics influenced CPM. Sixteen TMD pain patients and 16 age-matched healthy subjects were participated. A mechanical conditioning stimulus (CS) was applied to pericranial muscles provoking a pain intensity of 5/10 on a visual analogue scale. Pressure pain thresholds (PPT) and pressure pain tolerance thresholds (PPTol) were assessed at masseter, forearm and painful TMJ (only PPT) before, during, and 20 min after CS. Data were analyzed with ANOVAs. The correlations between CPM effect and ratings of TMD pain intensity on a numerical rating scale (NRS) or the pain duration were calculated (correlation coefficient; R). The relative PPT and PPTol increases (mean for the three assessment sites) during CS were significantly higher than baseline in healthy subjects (43.0 ± 3.6, 33.0 ± 4.0 %; P < 0.001, P < 0.001) but not in the TMD pain patients (4.9 ± 2.7, -1.4 ± 4.1 %; P = 0.492, P = 1.000) with significant differences between groups (P < 0.001). In the patients, the relative PPT changes during CS were not significantly higher than baseline at TMJ (5.3 ± 3.8 %, P = 0.981) and masseter (-2.8 ± 4.8 %, P = 1.000) but significantly higher at forearm (12.3 ± 4.7 %, P = 0.039). No correlation was detected between TMD pain intensity and CPM effect (R = -0.261; P = 0.337) or between pain duration and CPM effect (R = -0.423; P = 0.103) at painful TMJ. These findings indicate that CPM is impaired in TMD pain patients especially at sites with chronic pain but not at pain-free sites and that the clinical pain characteristics do not influence CPM.
（1）患有颞下颌关节（TMJ）疼痛的颞下颌关节紊乱（TMD）患者与健康受试者相比，是否具有不同的条件性疼痛调制（CPM）；（2）临床疼痛特征是否会影响CPM。16名TMD疼痛患者和16名年龄匹配的健康受试者参与了研究。对颅周肌肉施加机械性条件刺激（CS），使其在视觉模拟量表上产生5/10的疼痛强度。在CS施加前、施加期间和施加后20分钟，分别在咬肌、前臂和疼痛的TMJ（仅测量PPT）处评估压痛阈值（PPT）和压痛耐受阈值（PPTol）。采用方差分析对数据进行分析。计算CPM效应与TMD疼痛强度数字评分量表（NRS）评分或疼痛持续时间之间的相关性（相关系数；R）。在CS期间，健康受试者中相对PPT和PPTol的增加（三个评估部位的平均值）显著高于基线水平（分别为43.0±3.6%，33.0±4.0%；P<0.001，P<0.001），而TMD疼痛患者则不然（分别为4.9±2.7%，-1.4±4.1%；P = 0.492，P = 1.000），两组之间存在显著差异（P<0.001）。在患者中，CS期间TMJ（5.3±3.8%，P = 0.981）和咬肌（-2.8±4.8%，P = 1.000）处的相对PPT变化不显著高于基线水平，但在前臂处显著更高（12.3±4.7%，P = 0.039）。在疼痛的TMJ处，未检测到TMD疼痛强度与CPM效应之间的相关性（R = -0.261；P = 0.337），也未检测到疼痛持续时间与CPM效应之间的相关性（R = -0.423；P = 0.103）。这些发现表明，TMD疼痛患者的CPM受损，尤其是在慢性疼痛部位，但在无疼痛部位则不然，并且临床疼痛特征不会影响CPM。
