Kumar Rajesh, Macey Paul M, Woo Mary A, Alger Jeffry R, Harper Ronald M
Department of Neurobiology, David Geffen School of Medicine at UCLA, Los Angeles, California 90095-1763, USA.
J Magn Reson Imaging. 2006 Dec;24(6):1252-8. doi: 10.1002/jmri.20759.
To investigate whether mean diffusivity (MD) values are altered in brain areas underlying cardiovascular and respiratory control in congenital central hypoventilation syndrome (CCHS).
Conventional and diffusion tensor imaging were performed in 15 CCHS and 30 control subjects, using a 3.0-Tesla MRI unit. Mean diffusivity maps were calculated from diffusion-weighted images, spatially normalized, smoothed, and compared between groups using analysis of covariance at each voxel with age as covariate. Global mean MD values of gray and white matter were determined in individual subjects and compared between groups and with age.
Increased MD values appeared in CCHS over control subjects within multiple areas influencing breathing and cardiovascular control, including the midbrain, pons, and dorsal and ventral medulla. Other altered sites included cerebellar cortex and deep nuclei, basal ganglia, basal forebrain, and temporal and frontal cortices. Global mean MD values for gray and white matter did not differ between groups; however, gray matter MD values significantly increased with age (P < 0.02) in CCHS patients only.
Increased MD values suggest regional alterations or injury; affected areas include brainstem sites classically associated with autonomic and respiratory control. Other altered regions mediate additional physiological characteristics impaired in CCHS.
研究先天性中枢性低通气综合征（CCHS）中，心血管和呼吸控制相关脑区的平均扩散率（MD）值是否发生改变。
使用3.0特斯拉磁共振成像（MRI）设备，对15例CCHS患者和30例对照者进行常规成像和扩散张量成像。从扩散加权图像计算平均扩散率图，进行空间归一化、平滑处理，以年龄作为协变量，在每个体素处使用协方差分析对组间进行比较。确定个体受试者灰质和白质的整体平均MD值，并在组间以及与年龄进行比较。
在多个影响呼吸和心血管控制的区域，包括中脑、脑桥以及延髓背侧和腹侧，CCHS患者的MD值高于对照者。其他发生改变的部位包括小脑皮质和深部核团、基底神经节、基底前脑以及颞叶和额叶皮质。两组间灰质和白质的整体平均MD值无差异；然而，仅在CCHS患者中，灰质MD值随年龄显著增加（P < 0.02）。
MD值升高提示区域改变或损伤；受影响区域包括经典的与自主神经和呼吸控制相关的脑干部位。其他发生改变的区域介导了CCHS中受损的其他生理特征。
