Bi-hemispheric effects on corticospinal excitability induced by repeated sessions of imagery versus observation of actions
Bi-hemispheric effects on corticospinal excitability induced by repeated sessions of imagery versus observation of actions
复制标题
DOI：
10.3233/rnn-2012-120241
复制
发表时间：
2012-01-01
影响因子：
2.8
通讯作者：
Rossi, Simone
中科院分区：
文献类型：
--
作者：
Bianco, Giovanni;Feurra, Matteo;Rossi, Simone
目的：调查重复的运动想象和动作观察是否会随着时间的推移调节皮质脊髓兴奋性 (CE)，这些过程是否容易受到任何训练效果的影响，以及这种效果对于优势半球和非优势半球是否可能有所不同。方法：11 名受试者接受了 3 次间隔 5-7 天的左右初级运动皮层单脉冲经颅磁刺激 (TMS)。受试者被要求想象或观察任意一只手的捏握动作。从第一背侧骨间肌 (FDI) 双侧记录运动诱发电位 (MEP)，在精确握力过程中充当主要激动剂。结果：无论半球偏侧化和单独的测试会话如何，运动想象在动作观察方面始终增强 CE。然而，运动想象仅在相对于第一个会话的第三个会话期间在非优势半球上进行测量时才增加CE。在第一节中由动作观察引起的 CE 增加在其余两个节中没有进一步修改，无论是在哪个半球。结论：结果表明，运动想象是由仅对非优势半球易受训练影响的皮层网络维持的。这种效应缺乏行动观察，可能是因为这些机制的固有性。结果可能对康复目的有影响。
Purpose: To investigate whether repeated sessions of motor imagery and action observation modulate corticospinal excitability (CE) over time, whether these processes are susceptible of any training effect and if such effect might be different for the dominant and non dominant hemisphere.Methods: 11 subjects underwent three sessions, spaced 5-7 days, of single-pulse Transcranial Magnetic Stimulation (TMS) of right and left primary motor cortex. Subjects were asked to imagine or observe pinch-grip actions with either hand. Motor evoked potentials (MEPs) were recorded bilaterally from the First Dorsal Interosseus muscle (FDI), acting as main agonist during precision grip.Results: Motor imagery consistently enhanced CE with respect to action observation, regardless of hemispheric lateralization and of separate testing sessions. However, motor imagery increased CE only when measured over the non-dominant hemisphere, during the third session with respect to the first one. The increase of CE induced by action observation in the first session was not further modified throughout the remaining two sessions, in either hemisphere.Conclusions: Results suggest that motor imagery is sustained by a cortical network susceptible to training effects only for the non-dominant hemisphere. Such an effect was lacking for action observation, likely because of the innateness of these mechanisms. Results might have implications for rehabilitative purposes.