The association between sleepiness and cognitive dysfunction and brain micro-morphological change in obstructive sleep apnea syndrome

我们测量了重度阻塞性睡眠呼吸暂停综合征（sOSAS）患者的认知和情绪障碍，并探讨了这些认知和情绪障碍与睡眠时呼吸指数的相关性。此外，我们采用基于体素的spm8 -回归方法对FA/ADC图和灰质/白质图像进行统计，估计睡眠期间sOSAS脑微结构变化与呼吸指数的相关性。因此，主观的白天嗜睡只与动机有关，只有最低的SpO2对认知障碍有影响。影像学研究显示，在FA/ADC图和白质图像上，最低SpO2与对高级认知功能重要的内侧额叶和下额叶区域以及含有多核维持觉醒功能的脑干呈正相关。海马旁灰质浓度也与最低SpO2呈正相关。综上所述，低SpO2（缺氧侵袭）可能导致认知功能障碍，而认知功能障碍可能是由缺氧侵袭引起的神经轴突微结构改变引起的。

We measured cognitive and emotional impairment of the patients suffered severe obstructive sleep apnea syndrome(sOSAS), and investigated the correlation between these cognitive and emotional impairment and respiratory index during sleep. Additionally, we applied the voxel-based statistic approach by SPM8-regression for FA/ADC maps and gray/white matter images to estimate the correlation between brain microstructural changes of sOSAS and respiratory index during sleep. As a results, subjective daytime sleepiness was only associated with motivation and only lowest SpO2 affected on cognitive impairment. In imaging study, lowest SpO2 showed positive correlation with medial and inferior frontal area where are important for higher cognitive function and brain-stem containing many nuclei for arousal maintaining function in FA/ADC maps and white matter image. The gray matter concentration in parahippocampal area was also affected positive correlation with lowest SpO2. As a conclusion, lower SpO2 (hypoxia invasion) might cause the cognitive impairment and this impairment would be caused by neural axonal microstructural changes by hypoxia invasion.