基于海马-全脑功能连接探讨重复经颅磁刺激对缺血性脑卒中患者记忆功能的影响及神经影像学机制

关键词：重复经颅磁刺激  缺血性脑卒中  记忆功能  海马  功能连接

Keywords:repetitive transcranial magnetic stimulation  ischemic stroke  memory  functional connectivity

摘要：

      摘要 目的：基于海马-全脑功能连接观察重复经颅磁刺激（repetitive transcranial magnetic stimulation， rTMS）对缺血性脑卒中患者记忆功能的影响。 方法：49例缺血性脑卒中患者按临床中实际接受的干预方式，被分为rTMS组和对照组。对照组仅接受常规康复治疗，rTMS组在对照组基础上整合低频rTMS。分别于治疗前及治疗2周后采用行为记忆功能评定表（Rivermead behavioral memory test， second edition， RBMT-Ⅱ）评估患者的记忆功能及静息态功能磁共振成像技术观察患者海马-全脑功能连接的变化。 结果：①记忆功能变化：RBMT-Ⅱ分维度指标—回忆被藏物品评分存在显著的组—时间交互效应（P<0.05）和时间效应（P<0.05），且rTMS组的回忆被藏物品评分的差值显著高于对照组（P<0.05）。②海马-全脑功能连接变化：与对照组相比，rTMS组的患侧海马-患侧顶下缘角回、患侧海马-患侧中央前回、患侧海马-健侧颞上回、患侧海马-健侧额中回，以及双侧海马-健侧中央沟盖的功能连接强度增强（P<0.05）。③偏相关分析结果显示，rTMS组患侧海马-患侧中央前回与RBMT-Ⅱ的分维度指标—回忆被藏物品评分呈正相关（P<0.05）。结构方程模型分析显示，rTMS在间接影响患侧海马-患侧中央前回的功能连接，进而提高患者的RBMT-Ⅱ的分维度指标—回忆被藏物品评分方面具有边缘显著性（P<0.1）。 结论：在常规康复治疗的基础上，整合rTMS干预可能对患者前瞻性记忆功能的改善效果更佳，可能与rTMS影响患者的海马与额叶、颞叶及顶叶等多个脑区的功能连接有关。

Abstract:

      Abstract Objective： To observe the effects of repetitive transcranial magnetic stimulation （rTMS） on memory function in patients with ischemic stroke, based on functional connectivity analysis between hippocampus and the whole-brain. Method： Forty-nine eligible participants were assigned to either the control or rTMS group according to the rehabilitation intervention received in routine clinical practice. The control group received conventional rehabilitation therapy only， while the rTMS group received additional low-frequency (1Hz) rTMS. Rivermead Behavioral Memory Test， Second Edition （RBMT-Ⅱ）, and resting-state functional magnetic resonance imaging (rs-fMRI) were performed before and after the 2-week intervention. Functional connectivity (FC) analyses were conducted using the ipsilesional, contralesional, and bilateral hippocampus as seed regions. Result： The result showed a significant group-time interaction effects and time effects in the RBMT-Ⅱ’s subtest belongings（P<0.05）and the improvement in this subscore in the rTMS group was significantly higher（P<0.05）. Compared with the control group, the rTMS group showed significantly increased FC between the ipsilesional hippocampus and ipsilateral inferior parietal lobule and precentral gyrus，as well as enhanced FC between the ipsilesional hippocampus and contralateral superior temporal gyrus and middle frontal gyrus, and between bilateral hippocampus and contralesional rolandic operculum in rTMS group（P<0.05）. There was a positive correlation between FC of the ipsilateral hippocampus-ipsilateral precentral gyrus and RBMT-Ⅱ belongings score in rTMS group（P<0.05）. Structural equation modeling analysis indicates a marginally significant indirect effect of rTMS on improving RBMT-Ⅱ belongings performance through modulation of ipsilateral hippocampus-precentral gyrus connectivity(P<0.1）. Conclusion： Compared with conventional rehabilitation alone, adjunctive rTMS may provide greater benefits for prospective memory function in patients with ischemic stroke， which may be mediated by rTMS-induced modulation of FC between the hippocampus， frontal lobe， temporal lobe， and parietal lobe.