School of Psychiatry, University of New South Wales, Sydney, Australia.
Clin Neurophysiol. 2012 Nov;123(11):2220-6. doi: 10.1016/j.clinph.2012.03.081. Epub 2012 May 18.
To examine the effects of theta burst stimulation (TBS) and paired associative stimulation (PAS) on excitability in the human motor cortex.
Sixteen healthy young participants received intermittent TBS (iTBS) or PAS to the primary motor cortex on two testing occasions, at least a week apart. Ten of the participants also received iTBS or PAS after conditioning with continuous TBS on two other occasions. Cortical excitability was assessed with single TMS pulses to the motor cortex. Motor evoked potentials (MEPs) were measured from the first dorsal interosseus (FDI) muscle before TBS or PAS stimulation, and every 10min for 60min after stimulation. Changes in excitability were compared against the potential for motor learning, assessed with the rotor pursuit task.
After the PAS protocol MEP amplitudes were significantly increased. This increase was greater than after intermittent TBS, which did not change MEPs significantly. Conditioning with continuous TBS showed no significant effect. Participants' responses were not correlated across protocols and were not correlated with rotor pursuit learning.
PAS was the only protocol which induced significant increases in MEP amplitude.
PAS is robust in inducing excitatory cortical change. This makes it a suitable protocol for testing plasticity in healthy and patient groups.
考察 theta 爆发刺激（TBS）和成对关联刺激（PAS）对人类运动皮层兴奋性的影响。
16 名健康年轻参与者在至少相隔一周的两次测试中接受初级运动皮层的间歇性 TBS（iTBS）或 PAS 刺激。其中 10 名参与者还在另外两次接受连续 TBS 条件作用后接受 iTBS 或 PAS 刺激。使用单次 TMS 脉冲刺激运动皮层来评估皮层兴奋性。在 TBS 或 PAS 刺激前测量第一背骨间肌（FDI）的运动诱发电位（MEP），并在刺激后每 10 分钟测量一次，持续 60 分钟。将兴奋性变化与转子追踪任务评估的运动学习潜力进行比较。
在 PAS 方案后，MEP 幅度显著增加。这种增加大于间歇性 TBS，后者对 MEP 没有显著影响。连续 TBS 条件作用没有显示出显著的效果。参与者的反应在不同方案之间没有相关性，也与转子追踪学习没有相关性。
PAS 是唯一能显著增加 MEP 幅度的方案。
PAS 可有效诱导兴奋性皮层变化。这使其成为测试健康和患者群体中可塑性的合适方案。
