Background: The pathogenesis of adolescent idiopathic scoliosis (AIS), including the role of brain and spinal inhibitory circuits, is still poorly elucidated. The aim of this study was to identify which central inhibitory mechanisms are involved in the pathogenesis of AIS.

Design: A prospective neurophysiological study, using a battery of neurophysiological tests, such as cutaneous (CuSP) and cortical (CoSP) silent periods, motor evoked potentials (MEP) and paired-pulse transcranial magnetic stimulation (ppTMS).

Settings: Neurophysiological laboratory.

Participants: Sixteen patients with AIS (14 females, median age 14.4) and healthy controls.

Outcome measures: MEPs were obtained after transcranial magnetic stimulation (TMS) and recorded from the abductor pollicis muscle (APB). ppTMS was obtained at interval ratios (ISI) of 1, 2, 3, 6, 10, 15 and 20 ms. The cortical silent period (CoSP) was recorded from the APB. The cutaneous silent period (CuSP) was measured after painful stimuli delivered to the thumb while the subjects maintained voluntary contraction of the intrinsic hand muscles. The data were analyzed and compared with those from healthy subjects.

Results: The CoSP duration was significantly prolonged in AIS patients. A significantly higher amplitude of ppTMS for ISI was found in all AIS patients, without remarkable left-right side differences. No significant difference in MEP latency or amplitude nor in the CuSP duration was obtained.

Conclusion: Our observation demonstrates evidence of central nervous system involvement in adolescent idiopathic scoliosis (AIS). Lower intracortical inhibition, higher motor cortex excitability, and preserved spinal inhibitory circuits are the main findings of this study. A possible explanation of these changes could be attributed to impaired sensorimotor integration predominantly at the cortical level.

背景：青少年特发性脊柱侧凸 (AIS) 的发病机制，包括脑和脊髓抑制回路的作用，仍不清楚。本研究的目的是确定哪些中枢抑制机制参与了 AIS 的发病机制。

设计：一项前瞻性神经生理学研究，使用一系列神经生理学测试，例如皮肤 (CuSP) 和皮质 (CoSP) 静默期、运动诱发电位 (MEP) 和配对脉冲经颅磁刺激 (ppTMS)。

设置：神经生理实验室。

参与者： 16 名 AIS 患者（14 名女性，中位年龄 14.4 岁）和健康对照组。

结果测量：经颅磁刺激 (TMS) 后获得 MEP，并从拇展肌 (APB) 记录。ppTMS 是在 1、2、3、6、10、15 和 20 毫秒的间隔比率 (ISI) 下获得的。从 APB 记录皮质静默期 (CoSP)。当受试者保持手部内在肌肉的自主收缩时，在将疼痛刺激传递到拇指后测量皮肤静默期 (CuSP)。对数据进行分析并与健康受试者的数据进行比较。

结果： AIS 患者的 CoSP 持续时间显着延长。在所有 AIS 患者中发现 ISI 的 ppTMS 幅度显着更高，左右侧没有显着差异。在 MEP 潜伏期或幅度以及 CuSP 持续时间方面没有显着差异。

结论：我们的观察证实了青少年特发性脊柱侧凸 (AIS) 中枢神经系统受累的证据。较低的皮质内抑制、较高的运动皮层兴奋性和保留的脊髓抑制回路是本研究的主要发现。对这些变化的可能解释可归因于主要在皮层水平的感觉运动整合受损。