Kazumata Ken, Tha Khin Khin, Narita Hisashi, Kusumi Ichiro, Shichinohe Hideo, Ito Masaki, Nakayama Naoki, Houkin Kiyohiro
From the Departments of Neurosurgery (K.K., H.S., M.I., N.N., K.H.), Radiobiology and Medical Engineering (K.K.T.), and Psychiatry (H.N., I.K.), Hokkaido University Graduate School of Medicine, Sapporo, Japan.
Stroke. 2015 Feb;46(2):354-60. doi: 10.1161/STROKEAHA.114.007407. Epub 2014 Dec 23.
The mechanisms underlying frontal lobe dysfunction in moyamoya disease (MMD) are unknown. We aimed to determine whether chronic ischemia induces subtle microstructural brain changes in adult MMD and evaluated the association of changes with neuropsychological performance.
MRI, including 3-dimensional T1-weighted imaging and diffusion tensor imaging, was performed in 23 adult patients with MMD and 23 age-matched controls and gray matter density and major diffusion tensor imaging indices were compared between them; any alterations in the patients were tested for associations with age, ischemic symptoms, hemodynamic compromise, and neuropsychological performance.
Decrease in gray matter density, associated with hemodynamic compromise (P<0.05), was observed in the posterior cingulate cortex of patients with MMD. Widespread reduction in fractional anisotropy and increases in radial diffusivity and mean diffusivity in some areas were also observed in bilateral cerebral white matter. The fractional anisotropy (r=0.54; P<0.0001) and radial diffusivity (r=-0.41; P<0.01) of white matter significantly associated with gray matter density of the cingulate cortex. The mean fractional anisotropy of the white matter tracts of the lateral prefrontal, cingulate, and inferior parietal regions were significantly associated with processing speed, executive function/attention, and working memory.
In adult MMD, there were more white matter abnormalities than gray matter changes. Disruption of white matter may play a pivotal role in the development of cognitive dysfunction.
烟雾病（MMD）额叶功能障碍的潜在机制尚不清楚。我们旨在确定慢性缺血是否会在成年烟雾病患者中引起细微的脑微观结构变化，并评估这些变化与神经心理学表现之间的关联。
对23例成年烟雾病患者和23例年龄匹配的对照者进行MRI检查，包括三维T1加权成像和扩散张量成像，并比较两者之间的灰质密度和主要扩散张量成像指标；测试患者的任何改变与年龄、缺血症状、血流动力学损害和神经心理学表现之间的关联。
在烟雾病患者的后扣带回皮质中观察到灰质密度降低，与血流动力学损害相关（P<0.05）。在双侧脑白质中也观察到一些区域的各向异性分数普遍降低，径向扩散率和平均扩散率增加。白质的各向异性分数（r=0.54；P<0.0001）和径向扩散率（r=-0.41；P<0.01）与扣带回皮质的灰质密度显著相关。外侧前额叶、扣带回和顶下区域白质束的平均各向异性分数与处理速度、执行功能/注意力和工作记忆显著相关。
在成年烟雾病患者中，白质异常比灰质变化更多。白质破坏可能在认知功能障碍的发展中起关键作用。
