脑卒中后运动功能障碍与连接半球间同位脑区的胼胝体结构损伤相关

Structural damage of the corpus callosum connecting interhemispheric homologous areas correlated with motor dysfunction after subcortical stroke

目的探究单侧皮质下脑卒中半球间同位脑区经胼胝体结构连接变化与临床运动功能障碍的关系。材料与方法招募34例单侧皮质下脑卒中患者和43例健康人并采集磁共振弥散张量成像数据。利用高分辨经胼胝体纤维束模板(trancallosal tract template,TCATT)计算并比较卒中组与健康对照组通往半球间同位脑区(包括感觉运动区、前额叶、顶叶、颞叶和枕叶)的32条经胼胝体神经纤维束的各向异性分数(fractional anisotropy,FA)的差异,进一步与皮质脊髓束(corticospinal tract,CST)的FA比率(FA ratio,rFA)和上肢运动功能评分(fugl-meyer assessment of upper extremity,FM-UE)进行相关性分析。结果与健康对照组相比,卒中组半球间同位脑区的32条经胼胝体神经纤维束在中矢状面区域的FA值均降低,其中差异有统计学意义的有29条(不包括直回、中央旁小叶和内侧眶回的同位脑区经胼胝体纤维束)。这29条经胼胝体神经纤维束在中矢状面区域的FA值与rFA(CST)、FM-UE均存在显著正相关(P<0.05)。卒中组rFA(CST)与FM-UE评分亦呈显著正相关(r=0.596,P=0.0004)。结论本研究证实皮质下脑卒中的胼胝体微结构受损与病灶同侧CST损伤密切相关。继发性跨半球结构连接损伤对皮质下脑卒中运动功能障碍具有同样重要的影响。

Objective:To investigate the relationship between the transcallosal tracts abnormality of interhemispheric homotopic regions and motor impairment in unilateral subcortical stroke.Materials and Methods:Diffusion tensor imaging data of 34 patients with unilateral subcortical stroke and 43 healthy subjects were collected.Using the high-resolution transcallosal tract template(TCATT),the fractional anisotropy(FA)of 32 transcallosal tracts connecting the interhemispheric homologous brain areas(including sensory motor area,prefrontal lobe,parietal lobe,temporal lobe and occipital lobe)in the stroke group and healthy control group were calculated and compared;furthermore,correlation analysis was conducted with the FA ratio(rFA)of corticospinal tract(CST)and the Fugl-Meyer assessment of upper extremity(FM-UE),respectively.Results:Compared with the healthy controls,FA values of all the 32 transcallosal tracts in the midsagittal plane decreased in the stroke group,of which 29 showed significant differences(except three transcallosal tracts connecting homotopic regions of gyrus rectus,medial orbital and paracentral lobule).FA values of the 29 transcallosal tracts in the midsagittal plane were positively correlated with rFA(CST)and FM-UE in the stroke group.There was also a significant positive correlation between rFA(CST)and FM-UE(r=0.596,P=0.0004).Conclusions:This study confirms that the damage of corpus callosum microstructure in subcortical stroke is closely related to the damage of ipsilesional CST.The secondary structural injury of the corpus callosum also have an important effect on the motor impairment following subcortical stroke.