METHODS: Four databases (Medline, Embase, PsycINFO and Scopus) were searched from inception to February 7, 2023. Studies investigating age group comparisons and associations between age and neuroplasticity induction from NBS paradigms were included. Only studies delivering neuroplasticity paradigms to the primary motor cortex and responses measured via motor-evoked potentials (MEPs) in healthy adults were considered.
RESULTS: 39 studies, encompassing 40 experiments and eight NBS paradigms were included: paired associative stimulation (PAS; n = 12), repetitive transcranial magnetic stimulation (rTMS; n = 2), intermittent theta burst stimulation (iTBS; n = 8), continuous theta burst stimulation (cTBS; n = 7), transcranial direct and alternating current stimulation ((tDCS; n = 7; tACS; n = 2)), quadripulse stimulation (QPS; n = 1) and i-wave periodic transcranial magnetic stimulation (iTMS; n = 1). Pooled findings from PAS paradigms suggested older adults have reduced post-paradigm responses, although there was considerable heterogeneity. Mixed results were observed across all other NBS paradigms and post-paradigm timepoints.
CONCLUSIONS: Whilst age-dependent reduction in corticospinal excitability is possible, there is extensive inter- and intra-individual variability both within and between studies, making it difficult to draw meaningful conclusions from pooled analyses.
方法:四个数据库(Medline,Embase,PsycINFO和Scopus)从成立之初到2023年2月7日进行了搜索。包括调查年龄组比较以及年龄与NBS范式中神经可塑性诱导之间关联的研究。仅考虑将神经可塑性范例传递到初级运动皮层的研究以及通过健康成年人的运动诱发电位(MEP)测量的反应。
结果:39项研究,包括40个实验和8个NBS范例:配对联想刺激(PAS;n=12),重复经颅磁刺激(rTMS;n=2),间歇性theta爆发刺激(iTBS;n=8),连续theta爆发刺激(cTBS;n=7),经颅直接和交流电流刺激((tDCS;n=7;tACS;n=2)),四脉冲刺激(QPS;n=1)和i波周期经颅磁刺激(iTMS;n=1)。PAS范式的汇总结果表明,老年人的范式后反应减少,尽管存在相当大的异质性。在所有其他NBS范式和范式后时间点中观察到混合结果。
结论:虽然皮质脊髓兴奋性的年龄依赖性降低是可能的,研究内部和研究之间都存在广泛的个体间和个体内差异,这使得很难从汇总分析中得出有意义的结论。