Prei Kilian, Kanig Carolina, Osnabruegge Mirja, Langguth Berthold, Mack Wolfgang, Abdelnaim Mohamed, Schecklmann Martin, Schoisswohl Stefan
Department of Psychiatry and Psychotherapy, University of Regensburg, Universitätsstraße 84, 93053 Regensburg, Germany.
Department of Psychiatry and Psychotherapy, University of Regensburg, Universitätsstraße 84, 93053 Regensburg, Germany; Department of Human Sciences, University of the Bundeswehr Munich, Werner-Heisenberg-Weg 39, 85577 Neubiberg, Germany.
Brain Res. 2023 Dec 1;1820:148534. doi: 10.1016/j.brainres.2023.148534. Epub 2023 Aug 14.
The aim of this study was to investigate the reliability of low-frequency and high-frequency repetitive transcranial magnetic stimulation (rTMS) on healthy individuals over the motor cortex. A secondary outcome was the assessment if low-frequency rTMS results in inhibition and high-frequency rTMS results in facilitation.
In this experiment, 30 healthy participants received on four consecutive days one session each with application of 1 Hz or 20 Hz rTMS over the left motor cortex. 1 Hz and 20 Hz were applied in alternating order, whereby the starting frequency was randomized. Motor evoked potentials (MEPs) were measured before and after each session. Reliability measures were intraclass and Pearson's correlation coefficient (ICC and r).
ICCs and r values were low to moderate. Notably, within subgroups of less confounded measures, we found good r values for 20 Hz rTMS. The group-level analysis did not demonstrate a clear low-frequency inhibition and high-frequency facilitation pattern. At the single-subject level, only one participant exhibited significant changes consistent with the expected pattern, with concurrent decreases in MEPs following 1 Hz sessions and increases following 20 Hz sessions.
The investigated neuromodulatory protocols show low to moderate reliability. Results are questioning the low-frequency inhibition and high-frequency facilitation pattern.
Methodological improvements for the usage of rTMS are necessary to increase validity and reliability of non-invasive brain stimulation.
本研究旨在调查健康个体运动皮层上低频和高频重复经颅磁刺激（rTMS）的可靠性。次要结果是评估低频rTMS是否导致抑制，高频rTMS是否导致易化。
在本实验中，30名健康参与者连续四天每天接受一次在左侧运动皮层施加1Hz或20Hz rTMS的治疗。1Hz和20Hz交替施加，起始频率随机。每次治疗前后测量运动诱发电位（MEP）。可靠性测量指标为组内相关系数和皮尔逊相关系数（ICC和r）。
ICC和r值为低到中等。值得注意的是，在混杂因素较少的测量亚组中，我们发现20Hz rTMS的r值良好。组水平分析未显示出明显的低频抑制和高频易化模式。在单受试者水平上，只有一名参与者表现出与预期模式一致的显著变化，即1Hz治疗后MEP下降，20Hz治疗后MEP增加。
所研究的神经调节方案显示出低到中等的可靠性。结果对低频抑制和高频易化模式提出了质疑。
为提高非侵入性脑刺激的有效性和可靠性，有必要对rTMS的使用进行方法学改进。
