Disinhibitory shift of recovery curve of somatosensory-evoked response in elderly: A magnetoencephalographic study
Disinhibitory shift of recovery curve of somatosensory-evoked response in elderly: A magnetoencephalographic study
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DOI：
10.1016/j.clinph.2014.09.018
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发表时间：
2015-06-01
影响因子：
4.7
通讯作者：
Hirayama, Masaaki
中科院分区：
文献类型：
--
作者：
Goto, Sae;Fujisawa, Yoshiro;Hirayama, Masaaki
目的：本研究的目的是探讨青年和老年人体感诱发磁皮层场（SEF）N20 m和P30 m成分的功能差异。使用160通道全头部MEG测量磁场。分别对200个无伪影MEG信号时期的单脉冲和成对脉冲刺激进行平均。结果：老年组N20m峰潜伏期较青年组延长，而P30m峰潜伏期组间差异无统计学意义。老年组60、80 ms的N20 m比值显著高于青年组（60 ms：P < 0.05，80 ms：P < 0.001）。在刺激间期（ISI）为80和100 ms时，老年组的P30 m去抑制率均高于青年组（P < 0.05）。青年组P30m和N20m恢复曲线呈显著负相关（R = 0.72，P < 0.05）。在恢复功能中发生的与年龄相关的变化是N20m成分抑制的减少和P30m成分恢复的增加，表明N20m和P30m组分在与年龄相关的恢复变化中具有不同的作用。我们的研究结果表明，在ISI为80 ms时，老年组的N20 m比率显著增加，表明第二刺激诱发的SEF在ISI为80 ms时受到初始刺激的抑制较小，这表明不应性效应较小或去抑制作用增加。(C)2014年国际临床神经生理学联合会。由Elsevier爱尔兰有限公司出版。保留所有权利。
Objective: The aim of the study was to investigate the functional differences between N20m and P30m components of somatosensory-evoked magnetic cortical field (SEF) in young and senior subjects.Methods: Twenty-nine healthy subjects, 13 younger (mean age: 21.8 years) and 16 senior (63.8 years), participated. Magnetic fields were measured using a 160-channel, whole head MEG. Single-and paired-pulse stimulations of 200 artifact-free MEG signal epochs were averaged separately. We calculated how aging affects recovery function of SEFs.Results: The senior showed a prolonged N20m peak latency compared to the younger, although the P30m peak latency was not significantly different between groups. The N20m ratios at 60 and 80 ms in the senior were significantly increased compared to the ratios in the younger (60 ms: P < 0.05, 80 ms: P < 0.001). The P30m ratios at inter-stimulus interval (ISI) of 80 and 100 ms showed even disinhibition in the senior than in the younger (P < 0.05). The younger also showed a significantly negative correlation between P30m and N20m components' recovery curves (R = 0.72, P < 0.05).Conclusion: Aging-related changes that occurred in recovery functioning were the decrease in N20m component suppression and the increase in P30m component recovery, indicating that the N20m and P30m components have different functions in aging-related recovery changes.Significance: Our results show that the N20m ratio at an ISI of 80 ms was significantly increased in the senior group, indicating that the second stimulus-evoked SEF was less inhibited by the initial stimulus at this ISI, suggesting less refractory effect or increased disinhibition. (C) 2014 International Federation of Clinical Neurophysiology. Published by Elsevier Ireland Ltd. All rights reserved.