老年人舌肌训练后运动神经可塑性减弱：一项概念验证研究

文献信息

中文摘要

目的： 低舌压通过损害安全吞咽而导致吞咽困难。虽然抬舌训练在年轻个体中持续诱导皮质运动可塑性，但老年人的神经肌肉效能和运动神经可塑性仍不清楚。这项概念验证研究旨在探讨低舌压老年人在短暂抬舌训练后的中枢和外周运动适应。
方法： 13名低舌压（<30 kPa）老年人（8名女性，平均年龄±标准差：81±4岁）在连续5天内接受每日41分钟的标准抬舌训练。每日在训练前后测量最大舌压。在第1天和第5天进行经颅磁刺激，以评估舌的静息运动阈值（MT）和运动诱发电位（MEP）图谱面积，作为皮质运动兴奋性的指标。采用Friedman检验检查时间对结局参数的影响。
结果： 5天舌训练导致最大舌压显著增加（33.0%；P = 0.005），其变异系数显著降低（-51.5%，P = 0.030），同时舌MT显著降低（-11.3%，P < 0.001）。然而，舌MEP皮质图谱面积没有显著变化（P = 0.853）。
结论： 这些发现为老年人舌肌训练后运动神经可塑性减弱提供了初步证据。尽管如此，舌运动功能和皮质延髓兴奋性的改善表明，神经生理和功能适应的潜力仍然完整。更好地理解这些年龄相关差异可能有助于为口腔功能低下的老年人制定康复策略。

英文摘要

PURPOSE: Low tongue pressure contributes to dysphagia by compromising safe swallowing. While tongue-lift training consistently induces corticomotor plasticity in younger individuals, neuromuscular efficacy and motor neuroplasticity in older adults remain unclear. This proof-of-concept study aimed to investigate central and peripheral motor adaptations following brief tongue-lift training in older adults with low tongue pressure.
METHODS: Thirteen older adults (8 women, mean age ± SD: 81 ± 4 years) with low tongue pressure (<30 kPa) underwent 41-minute standardized daily tongue-lift training over 5 consecutive days. Maximal tongue pressure was measured daily pre- and post-training. Transcranial magnetic stimulation was administered on days 1 and 5 to evaluate the resting motor threshold (MT) and motor-evoked potential (MEP) map areas of the tongue as measures of corticomotor excitability. Friedman tests were conducted to examine effects of time on outcome parameters.
RESULTS: The 5-day tongue training induced a significant increase in maximal tongue pressure (33.0%; P = 0.005) with a significant decrease in its coefficient of variation (-51.5%, P = 0.030), accompanied by a significant decrease in the tongue MT (-11.3%, P < 0.001). However, the tongue MEP cortical map area did not change significantly (P = 0.853).
CONCLUSIONS: These findings provide preliminary evidence for attenuated motor neuroplasticity following tongue-muscle training in older adults. Nevertheless, improved tongue motor function and corticobulbar excitability indicate that the potential for neurophysiological and functional adaptation remains intact. A better understanding of these age-related differences may contribute to the development of rehabilitation strategies for older adults with oral hypofunction.