【摘要】 目的利用静息态分数低频振幅(fractional amplitude of low-frequency fluctuations,fALFF)技术探讨初诊原发性甲状腺功能减退症(甲减)患者脑损害的神经病理生理机制。材料与方法对25名初诊未治疗的甲减患者(甲减组)和19名健康对照(健康对照组)行认知心理量表评定和头颅MRI扫描,用两样本t检验比较全脑fALFF值的组间差异,并与临床变量及认知心理评分行Pearson相关分析。结果甲减组蒙特利尔认知评估量表评分减低(P=0.009),汉密顿抑郁量表-24和汉密顿焦虑量表评分增高(P=0.013;P=0.041),其左侧枕下回、舌回和右侧梭状回、枕上回、脑岛、中央后回的fALFF值减低(GRF校正,体素水平P<0.005,团块水平P<0.05),其中左侧枕下回、舌回和右侧梭状回的fALFF值与认知评分呈正相关(r=0.514,P=0.009;r=0.468,P=0.018;r=0.400,P=0.048)。当体素水平阈值降至P<0.001时,左侧舌回fALFF仍显著减低,且与认知评分呈正相关(r=0.547,P=0.005),另外,甲减组甲状腺素与抑郁评分呈负相关(r=-0.363,P=0.005)。结论甲减患者存在认知功能受损、抑郁及焦虑状态。静息状态下,多个与认知功能及情绪密切相关脑区的自发性神经元活动减低,可能是甲减患者认知功能受损及情绪异常的重要神经病理生理机制。更多还原

【Abstract】 Objective: To explore the neurophysiological mechanisms of the brain damage in naive patients with primary hypothyroidism by using the fractional amplitude of low-frequency fluctuations(fALFF) of the resting-state functional magnetic resonance imaging(rs-fMRI). Meterials and Methods: Twenty-five untreated patient with hypothyroidism(hypothyroidism group) and 19 healthy volunteers(healthy control group) were assessed with cognitive psychological scales and cranial rs-fMRI scan. The two-sample t test was used to compare the difference of whole brain fALFF value between groups and Pearson correlation analysis with clinical variables and cognitive psychological scores. Results: In the hypothyroidism group, the cognitive scores of Montreal Cognitive Assessment(P=0.009),and the scores of Hamilton Depression Scale-24 and Hamilton Anxiety Scale increased(P=0.013; P=0.041). Compared to controls, the fALFF values in the hypothyroidism group were decreased in the left inferior occipital gyrus, lingual gyrus and right fusiform gyrus,superior occipital gyrus,insula, and central posterior gyrus(GRF correction, voxel level P<0.005, mass level P<0.05). Meanwhile, the fALFF values of left inferior occipital gyrus, lingual gyrus and right fusiform gyrus were positively correlated with cognitive scores(r=0.514, P=0.009; r=0.468, P=0.018; r=0.400, P=0.048). When the voxel decreased to P<0.001, the fALFF of the left lingual gyrus still decreased significantly and was positively correlated with Montreal Cognitive Assessment scores(r=0.547, P=0.005). Additionally,thyroxine was negatively correlated with depression scores in hypothyroidism group(r=-0.363, P=0.005). Conclusions: Patients with hypothyroidism have cognitive impairment, depression and anxiety. In the resting state, the spontaneous neuronal activity is decreased in multiple brain regions closely related to cognitive function and emotion, which may be a crucially neurophysiological mechanism of cognitive impairment and emotional abnormality in patients with hypothyroidism.更多还原