弥散峰度成像对儿童阻塞性睡眠呼吸暂停综合征脑微结构变化的研究

Microstructural changes of white matter in obstructive sleep apnea syndrome on diffusional kurtosis imaging study

目的分析阻塞性睡眠呼吸暂停综合征(obstructive sleep apnea syndrome,OSAS)患者脑微观结构的改变,探索OSAS患者认知功能下降的神经生理。方法对19例OSAS患者、23例正常对照组使用美国GE Medical Systems Discovery MR750 3.0T磁共振仪进行磁共振弥散峰度成像(diffusional kurtosis imaging,DKI)扫描,采用FSL软件对两组被试者进行基于纤维束空间统计学(tract-based spatial statistics,TBSS)分析和与临床参数的相关性分析。结果与正常对照组比较,OSAS患儿在右侧内囊前肢、右侧丘脑辐射、穹窿、胼胝体部分各向异性(fractional anisotropy,FA)值下降,在左后放射冠、右上纵行纤维束、右侧外囊、右侧内囊前肢、胼胝体压部峰度部分各向异性(kurtosis fractional anisotropy,KFA)值下降。右侧内囊前肢、左顶叶的KFA值与最低血样饱和度(lowest oxygen saturation,LSa O2)呈正相关,胼胝体压部、右后放射冠、左侧中央后回、左前顶叶DKI参数值FA、KFA与血氧饱和度<90%所占比例、低通气指数呈负相关。结论 OSAS患者在多个脑区KFA值存在异常,且与缺氧存在关系,可能是OSAS患者认知功能下降的机制。

Objective To analyze the microstructural changes of white matter(WM)in obstructive sleep apnea syndrome(OSAS),and to explore neurophysiological mechanisms of cognitive impairment in patients with OSAS.Methods We used tract-based spatial statistics(TBSS)analysis to compare diffusion and kurtosis parameters in 19 OSAS children and 23 age and gender matched healthy children.Results Compared to healthy controls,the diffusion parameter fractional anisotropy(FA)decreased in WM regions(anterior limb of internal capsule,anterior thalamic radiation,fornix,inferior longitudinal fasciculus and corpus callosum)with coherent fiber arrangement,while the kurtosis parameter kurtosis fractional anisotropy(KFA)decreased in WM regions(superior longitudinal fasciculus and posterior corona radiata)with complex fiber arrangement.The two parameters were sensitive to reveal abnormality of WM in OSAS children.There are multiple abnormal brain lobes in OSAS patients.The KFA values in the right forelimb of internal capsule and the left parietal lobe were positively correlated with lowest oxygen saturation(LSaO 2).The values FA,KFA of DKI parameters in the corpus callosum,right posterior coronaries,left post central and left anterior parietal lobes were negatively correlated with SaO 2<90%and hypoventilation index.Conclusion The abnormal KFA value existed in multiple brain lobes in OSAS patients,which showed significant positive correlations with hypoxia,which may be mechanism of cognitive impairment for OSAS children.