Inter-session reliability of short-interval intracortical inhibition measured by threshold tracking TMS
Inter-session reliability of short-interval intracortical inhibition measured by threshold tracking TMS
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DOI：
10.1016/j.neulet.2018.02.065
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发表时间：
2018-05-01
影响因子：
2.5
通讯作者：
Kiernan, Matthew C.
中科院分区：
文献类型：
--
作者：
Matamala, Jose Manuel;Howells, James;Kiernan, Matthew C.
使用固定测试刺激的配对脉冲经颅磁刺激（TMS）存在运动诱发电位（MEP）幅度的显着变化性。阈值跟踪TMS（TT-TMS）的引入，以克服这个问题。这项工作的目的是描述使用TT-TMS的短间隔皮质内抑制（SICI）的绝对和相对可靠性。对26名健康受试者进行了三次皮层兴奋性研究（两次记录在同一天，一次间隔7天），记录了拇短展肌的MEP。通过计算测量值的标准误（SEm）、最小可检测变化（MDC）和组内相关系数（ICC）建立可靠性。静息运动阈值和平均SICI表现为最低的SEm和最高的ICC。1 ms时的SICI比3 ms时的SICI显示出更高的SEm，这表明不同的生理过程，但在多个间隔上平均SICI大大增加了再现性。与在同一天进行的测试相比，在相隔7天的同一时间进行的测试的变异性较低，并且在两种情况下，平均SICI的ICC均>= 0.81。如果受试者数量从1例增加到11例，平均SICI的MDC从6.7%降低到2%。总之，平均SICI是配对脉冲TT-TMS测量中最可重复的变量，显示出出色的ICC。建议在纵向研究中，在一天中的同一时间进行测试，并应测量皮层兴奋性的变化，并在多个刺激间隔内取平均值，以尽量减少变异性。
Paired-pulse transcranial magnetic stimulation (TMS) using fixed test stimuli suffers from marked variability of the motor evoked potential (MEP) amplitude. Threshold tracking TMS (TT-TMS) was introduced to overcome this problem. The aim of this work was to describe the absolute and relative reliability of short-interval intracortical inhibition (SICI) using TT-TMS. Cortical excitability studies were performed on twenty-six healthy subjects over three sessions (two recordings on the same day and one seven days apart), with MEPs recorded over abductor pollicis brevis. Reliability was established by calculating the standard error of the measurements (SEm), minimal detectable change (MDC) and intraclass correlation coefficient (ICC). Resting motor threshold and averaged SICI presented the lowest SEm and highest ICCs. SICI at 1 ms showed a higher SEm than SICI at 3 ms, suggesting different physiological processes, but averaging SICI over a number of intervals greatly increases the reproducibility. The variability was lower for tests undertaken at the same time of day seven days apart compared to tests performed on the same day, and in both instances the ICC for averaged SICI was >= 0.81. The MDC in averaged SICI was reduced from 6.7% to 2% if the number of subjects was increased from one to eleven. In conclusion, averaged SICI is the most reproducible variable across paired-pulse TT-TMS measures, showing an excellent ICC. It is recommended that, in longitudinal studies, testing be performed at the same time of day and that changes in cortical excitability should be measured and averaged over a number of interstimulus intervals to minimise variability.