基于功能性近红外光谱成像技术的脊髓损伤患者脑激活及脑网络改变研究

Changes of brain activation and networks in patients with spinal cord injury based on functional near-infrared spectroscopy

目的探讨脊髓损伤患者脑激活及脑网络连接的变化。方法纳入2021年1-10月山东大学齐鲁医院收治的20例脊髓损伤患者,包括单纯下肢受累8例(截瘫组)、四肢均受累12例(四肢瘫组),并同期纳入基线资料与脊髓损伤组相匹配的10例健康对照者。采用功能性近红外光谱成像(fNIRS)技术收集受试者静息态双侧前额皮质(LPFC/RPFC)、运动皮质(LMC/RMC)和枕叶(LOL/ROL)大脑氧合血红蛋白(HbO_(2))数据,广义线性模型计算静息态HbO_(2)β值以评估不同检测通道覆盖大脑皮质的激活程度,Pearson相关分析和偏相关分析计算不同检测通道HbO_(2)β值之间的相关性[偏相关系数(r)定义为功能连接强度],并以此评估脑网络功能连接。结果(1)脑激活程度:与对照组相比,四肢瘫组静息态通道2(t=-2.482,P=0.020)、通道8(t=-3.315,P=0.003)和通道16(t=-2.738,P=0.011)相应脑皮质HbO_(2)β值增加,通道25相应脑皮质HbO_(2)β值减少(t=2.104,P=0.045),而截瘫组通道8相应脑皮质HbO_(2)β值增加(t=-2.475,P=0.020);与四肢瘫组相比,截瘫组通道17(t=2.552,P=0.017)和通道25(t=2.342,P=0.027)相应脑皮质HbO_(2)β值增加。不同脑区比较,四肢瘫组左侧前额皮质HbO_(2)β值增加且显著高于对照组(t=2.652,P=0.013)。(2)不同通道与脑区之间的功能连接数量:不同组别与运动皮质相关的通道对占比依次为截瘫组占94.12%(32/34)、四肢瘫组占82.76%(24/29),对照组仅占74.36%(29/39)。(3)脑区内功能连接强度:与对照组相比,截瘫组(t=4.572,P=0.000)和四肢瘫组(t=4.822,P=0.000)右侧运动区功能连接强度减弱。结论脊髓损伤后静息态脑激活和脑网络功能连接存在异常,表现为部分脑区局部自发性神经元活动增强、大脑皮质之间及脑区内功能连接异常。

Objective in patients with spinal cord injury(SCI).MethodsA total of 20 patients with SCI were selected from Qilu Hospital of Shandong University from January to October 2021,including 8 patients with simple lower extremity involvement(paraplegia group)and 12 patients with all limbs involvement(tetraplegia group),and10 healthy controls with matched baseline data with the SCI group were included in the same period.Functional near-infrared spectroscopy(fNIRS)was used to collect the data of cerebral oxyhemoglobin(HbO_(2))in the bilateral prefrontal lobe(LPFC/RPFC),motor cortex(LMC/RMC)and occipital lobe(LOL/ROL).The resting HbO_(2)βvalues was calculated by generalized linear model to evaluate the activation degree of the cerebral cortex covered by different detection channels,the correlation between HbO_(2)βvalues was calculated by Pearson correlation analysis and partial correlation to analysis different detection channels[partial correlation coefficient(r)was defined as functional connectivity strength]to evaluate the functional connectivity of the brain network.Results1)Degree of brain activation:compared with the control group,the HbO_(2)βvalues corresponding to channel 2(t=-2.482,P=0.020),channel 8(t=-3.315,P=0.003)and channel 16(t=-2.738,P=0.011)was increased in the tetraplegia group,while the HbO_(2)βvalue corresponding to channel 25 was decreased(t=2.104,P=0.045),andthe HbO_(2)βvalue of channel 8 was increased(t=-2.475,P=0.020)in paraplegia group.Compared with the tetraplegia group,the HbO_(2)βvalues in channel 17(t=2.552,P=0.017)and channel 25(t=2.342,P=0.027)were increased in the paraplegia group.The value of HbO_(2)βin the left prefrontal lobe of tetraplegia group was significantly higher than that of control group(t=2.652,P=0.013).2)The number of functional connections between different channels and cerebral cortex:the proportion of channels related to motor cortex in different groups was 94.12%in the paraplegia group(32/34),82.76%in the tetraplegia group(24/29),and only 74.36%in the control group(29/39).3)Functional connectivity strength in the brain:compared with the control group,the functional connectivity strength in the right motor area was weakened in both the paraplegia group(t=4.572,P=0.000)and the tetraplegia group(t=4.822,P=0.000).ConclusionsThere are abnormalities in resting brain activation and functional connectivity of brain network after SCI,which are manifested as local enhancement of spontaneous neural activity in some brain regions and abnormal functional connectivity in cerebral cortices and brain regions.