基于功能性近红外光谱成像技术探究脑老化对老年人步行任务的影响机制

The effect of brain aging on the brain′s walking network as revealed by functional near infrared spectroscopy

目的基于功能性近红外光谱成像(fNIRS)技术探究脑老化对老年人步行任务的影响机制。方法招募20例健康老年人和22例健康年轻人,分别对2组受试者进行简明智力状态检查量表(MMSE)评分、站立步行试验(TUGT)、快速和自选速度10 m步行试验(10MWT)以及GaitRite步态参数采集和步行同步功能性近红外光谱成像(fNIRS)试验,分析和比较2组受试者的前额叶认知区(PFC)和运动区初级运动皮质(MC)功能连接强度以及步态参数之间的差异。结果在步态分析参数中,老年组的步频较青年组明显增高(Z=-2.067,P=0.039)。在脑网络数据中,老年组在同源ROI中RPFC的FC值低于青年组(t=2.65,P<0.05),且老年组在异源ROI中的RMC-RPFC(t=2.62,P=0.04)和RPFC-LPFC(t=2.69,P=0.04)FC值亦低于青年组,且差异均有统计学意义(P<0.05)。结论老年人正常步行时出现RPFC及其相关脑区的FC值减少,可能属于脑老化早期脑网络激活模式。

Objective To explore any effect of brain aging on the brain′s walking network and its mechanism.Methods Twenty healthy elderly people and 22 healthy young adults formed an elderly group and a youth group.All were evaluated using the Mini-Mental State Examination(MMSE),the Timed Up and Go test(TUGT),the 10-metre walk test(10MWT),the functional near infrared spectroscopy walking synchrony test and GaitRite gait parameters.The intensity of functional connections and the gait parameters of the prefrontal cortex(PFC)and the primary motor cortex(MC)were compared between the two groups.Results Compared with the youth group,the average cadence of the elderly group was significantly faster.The FC value of the RPFC in the homologous ROI,as well as those of the RMC-RPFC and RPFC-LPFC in the heterologous ROI of the elderly group were significantly lower than in the youth group.Conclusions Lower FC values in the RPFC and its associated brain regions in the elderly during normal walking may be what activates the brain′s walking network in the early stage of brain aging.