Department of Rehabilitation Medicine, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou 510080, China.
Department of Physical Therapy, University of North Texas Health Science Center, Fort Worth, Texas 76101, USA.
Neural Plast. 2021 Feb 18;2021:6666024. doi: 10.1155/2021/6666024. eCollection 2021.
The transversus abdominis (TVA) and multifidus (MF) muscles are the main segmental spinal stabilizers that are controlled by the primary motor cortex of the brain. However, relocations of the muscle representation in the motor cortex may occur after chronic lower back pain (cLBP); it still needs more evidence to be proven. The current study was aimed at applying transcranial magnetic stimulation (TMS) to investigate the changes of representation of TVA and MF muscles at the cortical network in individuals with cLBP.
Twenty-four patients with cLBP and 12 age-matched healthy individuals were recruited. Responses of TVA and MF to TMS during muscle contraction were monitored and mapped over the contralateral cortex using a standardized grid cap. Maps of the center of gravity (CoG), area, volume, and latency were analyzed, and the asymmetry index was also computed and compared.
The locations of MF CoG in cLBP individuals were posterior and lateral to the CoG locations in healthy individuals. In the healthy group, the locations of TVA and MF CoG were closed to each other in both the left and right hemispheres. In the cLBP group, these two locations were next to each other in the right hemisphere but discrete in the left hemisphere. In the cLBP group, the cortical motor map of TVA and MF were mutually symmetric in five out of eleven (45.5%) subjects and leftward asymmetric in four out of ten (40.0%) subjects.
Neural representations of TVA and MF muscles were closely organized in both the right and left motor cortices in the healthy group but were discretely organized in the left motor cortex in the cLBP group. This provides strong support for the neural basis of pathokinesiology and clinical treatment of cLBP.
腹横肌（TVA）和多裂肌（MF）是主要的节段性脊柱稳定肌，由大脑的初级运动皮层控制。然而，慢性下腰痛（cLBP）后，大脑运动皮层中肌肉代表区可能会发生迁移；这仍需要更多的证据来证明。本研究旨在应用经颅磁刺激（TMS）来研究 cLBP 患者皮质网络中 TVA 和 MF 肌肉代表区的变化。
招募了 24 名 cLBP 患者和 12 名年龄匹配的健康个体。使用标准化网格帽监测和映射 TVA 和 MF 在肌肉收缩过程中对 TMS 的反应，并在对侧皮质上进行映射。分析了重心（CoG）、面积、体积和潜伏期的图，并计算和比较了不对称指数。
cLBP 个体的 MF CoG 位置比健康个体的 CoG 位置更靠后和更靠外。在健康组中，TVA 和 MF CoG 的位置在左右半球都彼此靠近。在 cLBP 组中，这两个位置在右侧彼此相邻，但在左侧离散。在 cLBP 组中，11 名（45.5%）受试者中有 5 名的 TVA 和 MF 皮质运动图是相互对称的，10 名（40.0%）受试者中有 4 名是左侧不对称的。
健康组中左右运动皮层中 TVA 和 MF 肌肉的神经代表紧密组织在一起，但在 cLBP 组中左运动皮层离散组织。这为 cLBP 的病理生理学和临床治疗的神经基础提供了有力支持。
