TORIE-DTI: Transient white matter changes under sevoflurane anesthesia

Cognitive dysfunction after surgery under general anesthesia is a well-recognized clinical phenomenon in the elderly. Physiological effects of various anesthetic agents have been studied at length. Very little is known about potential effects of anesthesia on brain structure. In this study we used Diffusion Tensor Imaging to compare the white matter microstructure of healthy control subjects under sevoflurane anesthesia with their awake state. Fractional Anisotropy, a white mater integrity index, transiently decreases throughout the brain during sevoflurane anesthesia and then returns back to baseline. Other DTI metrics such as mean diffusivity, axial diffusivity and radial diffusivity were increased under sevoflurane anesthesia. Although DTI metrics are age dependent, the transient changes due to sevoflurane were independent of age and sex. Volumetric analysis shows various white matter volumes decreased whereas some gray matter volumes increased during sevoflurane anesthesia. These re...全身麻醉术后认知功能障碍是老年人群中公认的临床现象。目前已针对各类麻醉药物的生理效应开展了广泛深入的研究，但对于麻醉对大脑结构的潜在影响，目前仍所知有限。本研究采用扩散张量成像（Diffusion Tensor Imaging，DTI），对比健康对照受试者在七氟烷麻醉状态与清醒状态下的白质微结构差异。作为白质完整性评价指标的各向异性分数（Fractional Anisotropy，FA），在七氟烷麻醉期间会在全脑范围内短暂下降，随后恢复至基线水平。其余DTI指标，如平均扩散率（mean diffusivity，MD）、轴向扩散率（axial diffusivity，AD）与径向扩散率（radial diffusivity，RD），在七氟烷麻醉期间均出现升高。尽管DTI指标本身存在年龄依赖性，但七氟烷诱导的短暂变化并不受年龄与性别的影响。体积分析结果显示，七氟烷麻醉期间多项白质体积出现下降，而部分灰质体积则有所升高。上述研究的相关内容尚未完整呈现。