Della Nave Riccardo, Ginestroni Andrea, Tessa Carlo, Salvatore Elena, De Grandis Domenico, Plasmati Rosaria, Salvi Fabrizio, De Michele Giuseppe, Dotti Maria Teresa, Piacentini Silvia, Mascalchi Mario
Radiodiagnostic Section, Department of Clinical Physiopathology, University of Florence, Florence, Viale Morgagni 85, 50134 Florence, Italy.
Neuroimage. 2008 Oct 15;43(1):10-9. doi: 10.1016/j.neuroimage.2008.06.036. Epub 2008 Jul 11.
Neurodegeneration in spinocerebellar ataxia type 1(SCA1) and 2(SCA2) is associated with white matter(WM) damage. Voxel-Based Morphometry(VBM), histogram analysis of mean diffusivity(MD) and Tract-Based Spatial Statistics(TBSS) enable an in vivo quantitative analysis of WM volume and structure. We assessed with these 3 techniques the whole brain WM damage in SCA1 and SCA2.
Ten patients with SCA1, 10 patients with SCA2 and 10 controls underwent MRI with acquisition of T1-weighted and diffusion tensor images. The results were correlated with severity of clinical deficit.
VBM showed atrophy of the brainstem and cerebellar WM without significant differences between SCA1 and SCA2. Focal atrophy of the cerebral subcortical WM was also present. Histogram analysis revealed increased MD in the brainstem and cerebellum in patients with SCA1 and SCA2 which in SCA2 was more pronounced and combined with mild increase of the MD in the cerebral hemispheres in SCA2. In SCA1 and SCA2 TBSS revealed decreased fractional anisotropy(FA) in the inferior, middle and superior cerebellar peduncles, pontine transverse fibres, medial and lateral lemnisci, spinothalamic tracts, corticospinal tracts and corpus callosum. The extent of tract changes was greater in SCA2 patients who also showed decreased FA in the short intracerebellar tracts. In both diseases VBM, histogram and TBSS results correlated with clinical severity.
Brain WM damage featuring a pontocerebeellar atrophy is similar in SCA1 and SCA2 but more pronounced in SCA2. In both diseases it correlates with severity of the clinical deficit.
1型脊髓小脑共济失调（SCA1）和2型脊髓小脑共济失调（SCA2）中的神经退行性变与白质（WM）损伤相关。基于体素的形态学测量（VBM）、平均扩散率（MD）直方图分析和基于纤维束的空间统计学（TBSS）能够对WM体积和结构进行活体定量分析。我们使用这三种技术评估了SCA1和SCA2患者全脑的WM损伤情况。
10例SCA1患者、10例SCA2患者和10名对照者接受了MRI检查，采集了T1加权像和扩散张量图像。结果与临床缺陷的严重程度相关。
VBM显示脑干和小脑WM萎缩，SCA1和SCA2之间无显著差异。大脑皮质下WM也存在局灶性萎缩。直方图分析显示，SCA1和SCA2患者脑干和小脑中MD增加，其中SCA2更为明显，且SCA2患者大脑半球MD轻度增加。在SCA1和SCA2中，TBSS显示小脑下脚、中脚和上脚、脑桥横纤维、内侧丘系和外侧丘系、脊髓丘脑束、皮质脊髓束和胼胝体的各向异性分数（FA）降低。SCA2患者的纤维束变化程度更大，其小脑内短纤维束的FA也降低。在这两种疾病中，VBM、直方图和TBSS结果均与临床严重程度相关。
SCA1和SCA2中以脑桥小脑萎缩为特征的脑WM损伤相似，但SCA2中更明显。在这两种疾病中，它都与临床缺陷的严重程度相关。
