Haakana P, Holopainen K, Nätkynmäki A, Kirveskari E, Tarvainen M P, Shulga A
BioMag Laboratory, HUS Diagnostic Center, Helsinki University Hospital, University of Helsinki and Aalto University School of Science, Helsinki, Finland.
Motion Analysis Laboratory, New Children's Hospital, Helsinki University Hospital and University of Helsinki, Helsinki, Finland.
Front Rehabil Sci. 2023 Jul 26;4:1200958. doi: 10.3389/fresc.2023.1200958. eCollection 2023.
A novel protocol for paired associative stimulation (PAS), called high PAS, consists of high-intensity transcranial magnetic stimulation (TMS) and high-frequency peripheral nerve stimulation (PNS). High PAS was developed for spinal cord injury rehabilitation and targets plastic changes in stimulated pathways in the corticospinal tract, which improves motor function. As therapy interventions can last many weeks, it is important to fully understand the effects of high PAS, including its effect on the cardiovascular system. Heart rate variability (HRV) has been used to measure changes in both sympathetic and parasympathetic systems.
We used short-term HRV measurements to evaluate the effects of one 20-min session of high PAS on 17 healthy individuals. HRV was recorded for 5 min before (PRE), during (STIM), immediately after (POST), 30 min after (POST30), and 60 min after (POST60) the stimulation. Five participants repeated the HRV setup with sham stimulation.
A significant decrease in low-frequency (LF) power (n.u.) ( = 0.002), low-frequency to high-frequency (HF) ratio ( = 0.017), in Poincaré plot [the standard deviation of RR intervals perpendicular to (SD1) and along (SD2) the line of identity SD2/SD1 ratio < 0.001], and an increase in HF power (n.u.) ( = 0.002) were observed between PRE and STIM conditions; these changes were fully reversible immediately after stimulation. PRE to POST by 3% ( = 0.015) and continued to decline until POST60 by 5% ( = 0.011). LF power (ms) ( = 0.017) and SD2 ( = 0.015) decreased from PRE to STIM and increased from PRE to POST ( = 0.025 and = 0.017, respectively). The results from sham PAS exhibited a trend similar to active high-PAS stimulation.
High PAS does not have sustained effects during 60-min follow-up on cardiovascular functions, as measured by HRV. None of the short-term results indicates activation of the sympathetic nervous system in healthy individuals. Observed changes in HRV indicate higher parasympathetic activity during stimulation, which is reversible, and is plausibly explained by the fact that the participants spend 20 min without moving, talking, or using phones while being stimulated.
一种名为高配对联想刺激（PAS）的新型配对联想刺激方案，由高强度经颅磁刺激（TMS）和高频外周神经刺激（PNS）组成。高PAS是为脊髓损伤康复而开发的，其目标是皮质脊髓束中受刺激通路的可塑性变化，从而改善运动功能。由于治疗干预可能持续数周，充分了解高PAS的效果，包括其对心血管系统的影响非常重要。心率变异性（HRV）已被用于测量交感神经系统和副交感神经系统的变化。
我们使用短期HRV测量来评估一次20分钟的高PAS对17名健康个体的影响。在刺激前（PRE）、刺激期间（STIM）、刺激后立即（POST）、刺激后30分钟（POST30）和刺激后60分钟（POST60）记录HRV，共5分钟。五名参与者在假刺激下重复HRV设置。
在PRE和STIM条件之间观察到低频（LF）功率（n.u.）显著降低（ = 0.002）、低频与高频（HF）比值显著降低（ = 0.017）、庞加莱图[垂直于RR间期标准差（SD1）并沿同一性线（SD2）的RR间期标准差SD2/SD1比值<0.001]，以及HF功率（n.u.）显著增加（ = 0.002）；这些变化在刺激后立即完全可逆。从PRE到POST下降了3%（ = 0.015），并持续下降直到POST60下降了5%（ = 0.011）。LF功率（ms）（ = 0.017）和SD2（ = 0.015）从PRE到STIM降低，从PRE到POST增加（分别为 = 0.025和 = 0.017）。假PAS的结果显示出与主动高PAS刺激相似的趋势。
通过HRV测量，高PAS在60分钟的随访期间对心血管功能没有持续影响。短期结果均未表明健康个体的交感神经系统被激活。观察到的HRV变化表明刺激期间副交感神经活动增强，这是可逆的，可能的解释是参与者在刺激期间20分钟内不移动、不说话或不使用手机。
