Neurorehabilitation Research Department, Hammel Neurorehabilitation and Research Centre, Hammel, Denmark.
Prog Brain Res. 2009;177:191-200. doi: 10.1016/S0079-6123(09)17713-0.
Transcranial magnetic stimulation (TMS) is a noninvasive means of investigating the function, plasticity, and excitability of the human brain. TMS induces a brief intracranial electrical current, which produces action potentials in excitable cells. Stimulation applied over the motor cortex can be used to measure overall excitability of the corticospinal system, somatotopic representation of muscles, and subsequent plastic changes following injury. The facilitation and inhibition characteristics of the cerebral cortex can also be compared using the modulatory effect of a conditioning stimulus preceding a test stimulus. So called paired-pulse protocols have been used in humans and animals to assess GABA (gamma-amino-butyric acid)-ergic function and may have a future role directing therapeutic interventions. Indeed, repetitive magnetic stimulation, where intracranial currents are induced by repetitive stimulation higher than 1 Hz, has been shown to modulate brain responses to sensory and cognitive stimulation. Here, we summarize information gathered using TMS with patients in coma, vegetative state, and minimally conscious state. Although in the early stages of investigation, there is preliminary evidence that TMS represents a promising tool by which to elucidate the pathophysiological sequelae of impaired consciousness and potentially direct future therapeutic interventions. We will discuss the methodology of work conducted to date, as well as debate the general limitations and pitfalls of TMS studies in patients with altered states of consciousness.
经颅磁刺激（TMS）是一种非侵入性的手段，用于研究人类大脑的功能、可塑性和兴奋性。TMS 会在颅内产生短暂的电流，从而在可兴奋细胞中产生动作电位。在运动皮层上施加刺激可用于测量皮质脊髓系统的整体兴奋性、肌肉的躯体代表区以及受伤后的后续可塑性变化。通过在测试刺激之前施加条件刺激，可以比较大脑皮层的易化和抑制特性。所谓的双脉冲方案已在人类和动物中使用，以评估 GABA（γ-氨基丁酸）能功能，并且可能在未来具有指导治疗干预的作用。实际上，重复磁刺激（其中通过高于 1 Hz 的重复刺激来产生颅内电流）已被证明可以调节大脑对感觉和认知刺激的反应。在这里，我们总结了在昏迷、植物状态和最小意识状态的患者中使用 TMS 收集的信息。尽管处于早期研究阶段，但有初步证据表明 TMS 是一种很有前途的工具，可以阐明意识障碍的病理生理后果，并有可能指导未来的治疗干预。我们将讨论迄今为止进行的工作的方法学，并讨论在意识改变状态的患者中进行 TMS 研究的一般局限性和陷阱。
