Institute of Neuroscience, Newcastle University, Framlington Place, Newcastle upon Tyne, UK.
School of Dental Sciences, Newcastle University, Framlington Place, Newcastle upon Tyne, UK.
JDR Clin Trans Res. 2020 Jul;5(3):224-232. doi: 10.1177/2380084419872135. Epub 2019 Aug 28.
Dysfunction of the autonomic nervous system (ANS) is seen in chronic fatigue syndrome (CFS) and temporomandibular disorders (TMDs). Both conditions have poorly understood pathophysiology. Several brain structures that play a role in pain and fatigue, such as the insular cortex and basal ganglia, are also implicated in autonomic function.
ANS dysfunction may point to common neurophysiologic mechanisms underlying the predominant symptoms for CFS and TMD. No studies to date have investigated the combination of both conditions. Thus, our aim was to test whether patients with CFS with or without TMD show differences in brain responses to autonomic challenges.
In this exploratory functional imaging study, patients with CFS who screened positive for TMD (n = 26), patients who screened negative for TMD (n = 16), and age-matched control participants (n = 10) performed the Valsalva maneuver while in a 3-T magnetic resonance imaging scanner. This maneuver is known to activate the ANS.
For all 3 groups, whole-brain F test showed increased brain activation during the maneuver in the superior and inferior frontal gyri, the left and right putamen and thalamus, and the insular cortex. Furthermore, group contrasts with small-volume correction showed that patients with CFS who screened positive for TMD showed greater activity in the left insular cortex as compared with patients who screened negative and in the left caudate nucleus as compared with controls.
Our results suggest that increased activity in the cortical and subcortical regions observed during autonomic challenges may be modulated by fatigue and pain. ANS dysfunction may be a contributing factor to these findings, and further work is required to tease apart the complex relationship among CFS, TMD, and autonomic functions.
Brain activity related to activation of the autonomic nervous system in patients with chronic fatigue syndrome who screened positive for painful temporomandibular disorder was greater than in patients who screened negative; activity was seen in brain regions associated with autonomic functions and pain. These findings suggest that autonomic dysfunction may play a role in the pathophysiology of both conditions, explain some of the apparent comorbidity between them, and offer avenues to help with treatment.
自主神经系统（ANS）功能障碍可见于慢性疲劳综合征（CFS）和颞下颌关节紊乱（TMD）。这两种疾病的病理生理学都知之甚少。一些在疼痛和疲劳中起作用的大脑结构，如脑岛皮层和基底神经节，也与自主功能有关。
ANS 功能障碍可能指向 CFS 和 TMD 主要症状的共同神经生理机制。迄今为止，尚无研究调查这两种疾病的合并情况。因此，我们的目的是测试 CFS 患者无论是否存在 TMD，其对自主挑战的大脑反应是否存在差异。
在这项探索性的功能成像研究中，筛查出 TMD 的 CFS 患者（n=26）、筛查出 TMD 的 CFS 患者（n=16）和年龄匹配的对照组参与者（n=10）在 3T 磁共振成像扫描仪中进行瓦尔萨尔瓦动作。众所周知，这种动作会激活 ANS。
对于所有 3 组，全脑 F 检验显示在动作期间大脑在前额上、下回、左侧和右侧壳核和丘脑以及脑岛皮层的激活增加。此外，小体积校正的组对比显示，筛查出 TMD 的 CFS 患者与筛查出 TMD 的患者相比，左脑岛和左侧尾状核的活动增加；与对照组相比，左脑岛和左侧尾状核的活动增加。
我们的结果表明，在自主挑战期间观察到的皮质和皮质下区域的活性增加可能与疲劳和疼痛有关。ANS 功能障碍可能是这些发现的一个促成因素，需要进一步的工作来梳理 CFS、TMD 和自主功能之间复杂的关系。
在筛查出疼痛性 TMD 的慢性疲劳综合征患者中，与自主神经系统激活相关的大脑活动强于筛查出阴性结果的患者；活动见于与自主功能和疼痛相关的大脑区域。这些发现表明，自主神经功能障碍可能在这两种疾病的病理生理学中起作用，解释了它们之间一些明显的共病性，并为治疗提供了途径。
