缺血性卒中后抑郁状态患者弥散张量成像的初步研究

Manifestations of diffusion tensor imaging in patients with post-stroke depression

目的通过弥散张量成像(DTI)功能MRI检查观察急性缺血性卒中后抑郁状态(PSD)患者脑内不同区域功能变化,探索PSD的发病机制。方法对38例急性缺血性脑卒中患者(其中PSD 21例,非PSD 17例)行DTI功能MRI检查,测量感兴趣区的各项异性分数(FA),比较两组患者脑内8个解剖部位FA值、梗死灶中心区FA值、FA下降百分比和脑梗死侧FA差值百分比及偏侧化指数(LI),并分析与汉密尔顿抑郁量表(HAMD)评分的相关性。结果(1)PSD组两侧额中回白质的FA值均较非PSD组降低(均P<0.05),其他解剖部位两组间的差异无统计学意义(均P>0.05);组内比较时PSD组左侧内囊前肢FA值较右侧低(P<0.05),其余解剖部位(除外胼胝体膝部和压部)的双侧FA值无统计学差异(均P>0.05)。(2)两组间内囊前肢的LI值有统计学差异(P<0.05),其余5个解剖部位(除外胼胝体膝部和压部)的LI值无统计学差异(均P>0.05)。(3)两组患者梗死灶中心区FA值、FA下降百分比和脑梗死侧FA差值百分比均无统计学差异(均P>0.05)。(4)两组患者8个解剖部位的FA值、梗死灶中心区FA值、脑梗死侧FA差值百分比和FA下降百分比与HAMD评分无明显相关性(均P>0.05)。结论DTI显示PSD组患者存在双侧额中回白质结构异常,双侧内囊前肢白质结构异常有不对称性,提示前额叶背外侧白质损害破坏了前额叶-边缘系统环路可能对PSD的发生有重要作用,左侧内囊前肢白质结构异常可能参与了PSD的发病。

Objective To analyze the manifestation of diffusion tensor imaging(DTI)in patients with post-stroke depression(PSD).Methods Thirty eight patients with first-onset acute ischemic stroke were enrolled,including 21 cases with PSD(PSD group)and 17 cases without PSD(non-PSD group).All patients underwent DTI scan,the fractional anisotropy(FA)of the region of interest(ROI)was measured.The FA values of 8 anatomic parts in the brain,FA value of central infarct area,percentage of FA decrease,percentage of FA difference on the infarct side and the laterality index(LI)were compared between the two groups,and the correlation of above indicators with the Hamilton Rating Scale for Depression(HAMD)score was analyzed.Results The FA value of white matter in bilateral middle frontal gyrus in PSD group was lower than that in non-PSD group(P<0.05),while there was no significant difference in other anatomic sites between two groups.In PSD group,the FA value of left anterior limb of internal capsule was lower than that of right side(P<0.05),but there was no significant difference in bilateral FA values of other anatomic sites(except genu and splenium of corpus callosum).There was significant difference in LI value of anterior limbs of internal capsule between two groups(P<0.05),but there was no significant difference in LI value of other five anatomic sites(except genu and splenium of corpus callosum).There was no significant difference in FA value of central infarct area,percentage of FA decrease,percentage of FA difference on the infarct side between two groups.The HAMD scores of two groups were not correlated with FA value of 8 anatomic sites,FA value of central area of infarct,percentage of FA decrease and percentage of FA difference on the infarct side.Conclusion DTI reveals that the white matter structure of bilateral middle frontal gyrus is abnormal in PSD patients,and the white matter structure of anterior limb of bilateral internal capsule is asymmetrical.It suggests that the destruction of the prefrontal-limbic circuit by the damage of the dorsolateral prefrontal lobe may play an important role in the pathogenesis of PSD,and the abnormal white matter structure of anterior limb of left internal capsule may be in volved in the pathogenesis of PSD.