Antal Andrea, Lang Nicolas, Boros Klara, Nitsche Michael, Siebner Hartwig R, Paulus Walter
Department of Clinical Neurophysiology, Georg-August University, 37073 Göttingen, Germany.
Cereb Cortex. 2008 Nov;18(11):2701-5. doi: 10.1093/cercor/bhn032. Epub 2008 Mar 27.
Preconditioning of the human primary motor cortex (M1) with transcranial direct current stimulation (tDCS) can shape the magnitude and direction of excitability changes induced by a subsequent session of repetitive transcranial magnetic stimulation (rTMS). Here, we examined this form of metaplasticity in migraine patients with visual aura and healthy controls. In both groups, facilitatory preconditioning of left M1 with anodal tDCS increased the mean amplitudes of motor-evoked potentials (MEPs) elicited in the contralateral hand, whereas inhibitory preconditioning with cathodal tDCS produced a decrease in amplitude. Following cathodal tDCS, a short train of low-intensity 5-Hz rTMS antagonized the suppression of the mean MEP amplitude in both groups. In contrast, the homeostatic effects of 5-Hz rTMS differed between groups when rTMS was given after anodal tDCS. In controls 5-Hz rTMS induced a marked decrease in MEP amplitudes, whereas in migraineurs rTMS induced only a modest decrease in MEP amplitudes, which were still facilitated after rTMS when compared with baseline amplitudes. These findings indicate that short-term homeostatic plasticity is altered in patients with visual aura between the attacks.
经颅直流电刺激（tDCS）对人类初级运动皮层（M1）进行预处理，可以塑造随后重复经颅磁刺激（rTMS）所诱导的兴奋性变化的幅度和方向。在此，我们研究了有视觉先兆的偏头痛患者和健康对照者中的这种形式的可塑性变化。在两组中，用阳极tDCS对左侧M1进行易化性预处理可增加对侧手部诱发的运动诱发电位（MEP）的平均幅度，而用阴极tDCS进行抑制性预处理则使幅度降低。在阴极tDCS之后，短串低强度5Hz的rTMS拮抗了两组中平均MEP幅度的抑制。相比之下，当在阳极tDCS之后给予rTMS时，5Hz rTMS的稳态效应在两组之间有所不同。在对照组中，5Hz rTMS诱导MEP幅度显著降低，而在偏头痛患者中，rTMS仅诱导MEP幅度适度降低，与基线幅度相比，rTMS后MEP幅度仍有易化。这些发现表明，发作间期有视觉先兆的患者短期稳态可塑性发生了改变。
