头颅降温对高温环境下人脑局部一致性的影响

目的 探讨高温环境下头颅降温对人脑神经活动的影响及其保护机制.方法 16名被试者分别在常温(25℃)、高温(50℃)、头颅降温(舱温:50℃、降温帽:5℃)3组条件下暴露1 h,并采集静息态功能磁共振成像(rs-fMRI)数据.采用REST2.0软件对3组被试者全脑局部一致性(ReHo)值进行单因素方差分析,进一步提取差异显著脑区的ReHo值利用SPSS18.0进行单因素方差分析,并进行事后检验,明确任意2组各脑区神经活性的差异.结果 3组条件下的差异脑区位于右侧眶回、左侧额中回、双侧杏仁核、左侧颞中回、左侧海马、双侧顶下缘角回、左侧中央前回.与常温组相比,头颅降温组ReHo值增大的脑区有右侧眶回,降低的脑区有左侧中央前回、左侧额中回、左侧角回,未见变化的脑区有双侧杏仁核、左侧颞中回、左侧海马、右侧角回.与高温组比较,头颅降温组ReHo值增大的脑区有左侧颞中回、左侧海马、右侧角回,降低的脑区有双侧杏仁核、左侧角回,未见变化的脑区有右侧眶回、左侧中央前回、左侧额中回.结论 头颅降温组ReHo的特异性变化,表明头颅降温可以部分消除高温对大脑ReHo的影响,且与情绪功能存在密切联系.

The impact of head cooling on regional homogeneity during passive hyperthermia

Objective To explore the impact and protective mechanisms of head cooling on neural activity during passive hyperthermia.Methods Sixteen subjects were randomly exposed for 1 h to three different conditions: normal (25℃), hot (50℃) and head cooling (chamber:50℃,cold packs:5℃),after environment exposure, rs-fMRI were performed.Regional homogeneity(ReHo) datum at three different conditions were analyzed by REST2.0 to obtain brain areas with statistical difference.Brain voxel with statistical difference were selected as ROIs to ReHo values and were analyzed by One-Way ANOVA with SPSS18.0.Neural activity of brain areas with statistical difference were compared in any two groups by Post hoc.Results The brain regions showing differences among three groups included right orbital frontal cortex,left middle frontal gyrus,bilateral amygdala,left middle temporal gyrus,left hippocampus,bilateral parietal inferior, left precentral gyrus.Compared with normal group, ReHo increased in right orbital frontal cortex, and decreased in left precentral gyrus,left middle frontal gyrus,left parietal inferior,but no changed in bilateral amygdala,left middle temporal gyrus,left hippocampus,right parietal inferior in head cooling group.Compared with hot group,head cooling group showed increased ReHo in left middle temporal gyrus,left hippocampus,right parietal inferior,and decreased ReHo in bilateral amygdala,left parietal inferior,unchanged ReHo in right orbital frontal cortex, left precentral gyrus, left middle frontal gyrus.Conclusion The specified alterations of ReHo may reflect that the head cooling could partially eliminate the impact of passive hyperthermia, and is closely linked with emotional function.