大脑中动脉供血区皮质下梗死后海马早期继发性改变与记忆损害研究

Early secondary changes and memory impairment of hippocampus after subcortical infarction in middle cerebral artery

目的观察大脑中动脉供血区急性皮质下梗死后海马结构的动态改变,探讨这些改变与语义记忆功能改变的关系。方法22例急性皮质下梗死患者在卒中后1 w、4 w和12 w分别进行认知功能评估、结构磁共振成像(magnetic resonance imaging,MRI)和弥散张量成像(diffusion tensor imaging,DTI)检测。22名年龄和风险因素匹配的人群作为健康对照组。结果随访期间患者的双侧海马体积并没有显著改变。Spearman相关性结果表明,即时和延迟语义记忆分数的下降百分比与同侧海马平均弥散度(mean diffusivity,MD)值的升高百分比呈显著负相关(即时记忆,rs=-0.683,P=0.006;延迟记忆,rs=-0.602,P=0.013)。结论大脑中动脉供血区皮质下梗死早期,海马宏观结构未改变之前其微结构的完整性可能受到破坏,且这些变化可能与语义记忆能力下降有关。

Objective To observe the dynamic changes of hippocampus microstructure in patients with cerebral infarction within the territory of the middle cerebral artery(MCA)with cortex involvement,thus exploring the relationship between these changes and the changes in semantic memory function.Methods Twenty-two patients with acute subcortical infarction were assessed for cognitive function,structural magnetic resonance imaging(MRI)and diffusion tensor imaging(DTI)at 1,4,and 12 weeks(W)respectively.A total of 22 gender and age matched subjects were enrolled as healthy controls.Results Bilateral hippocampal volume did not change significantly during the entire follow-up period.Spearman’s rank correlations showed that percent decreases in immediate recall and long-delay recall scores correlated negatively with percent increases in mean diffusivity(MD)values in the ipsilateral hippocampus(immediate,rs=-0.683,P=0.006;long-delay,rs=-0.602,P=0.013).Conclusion In patients with cerebral infarction within the territory of the MCA with cortex involvement,the microstructural integrity of the hippocampus may be damaged before the macrostructure changes,and these changes may be related to the decline of semantic memory.