Koob Mériam, Rousseau François, Laugel Vincent, Meyer Nicolas, Armspach Jean-Paul, Girard Nadine, Dietemann Jean-Louis
1 Service de Radiopédiatrie/Imagerie 2, CHU de Strasbourg, Hôpital de Hautepierre, Strasbourg, France.
2 Laboratoire ICube, UMR 7357/FMTS/Université de Strasbourg-CNRS, Strasbourg, France.
Br J Radiol. 2016 Nov;89(1067):20151033. doi: 10.1259/bjr.20151033. Epub 2016 Sep 19.
Cockayne syndrome (CS) is a rare disorder characterized by severe brain atrophy, white matter (WM) hypomyelination and basal ganglia calcifications. This study aimed to quantify atrophy and WM abnormalities using diffusion tensor imaging (DTI) and volumetric analysis, to evaluate possible differences between CS subtypes and to determine whether DTI findings may correspond to a hypomyelinating disorder.
14 patients with CS and 14 controls underwent brain MRI including DTI and a volumetric three-dimensional T weighted sequence. DTI analysis was made through regions of interest within the whole brain to obtain fractional anisotropy (FA) and apparent diffusion coefficient (ADC) values and in the left centrum semiovale to obtain DTI eigenvalues. The Student's t-test was used to compare patients and controls, and CS subtypes. Given the small number of patients with CS, they were pooled into two groups: moderate (CS1/CS3) and severe (CS2/cerebro-oculo-facio-skeletal syndrome).
Total brain volume in CS was reduced by 57%, predominantly in the infratentorial area (68%) (p < 0.001). Total brain volume reduction was greater in the severe group, but there was no difference in the degree of infratentorial atrophy in the two groups (p = 0.7). Mean FA values were lower, whereas ADC was higher in most of the WM in patients with CS (p < 0.05). ADC in the splenium of the corpus callosum and the posterior limb of the internal capsule and FA in the cerebral peduncles were significantly different between the two groups (p < 0.05). Mean ADC values corresponded to a hypomyelinating disorder. All DTI eigenvalues were higher in patients with CS, mainly for transverse diffusivity (+51%) (p < 0.001).
DTI and volumetric analysis provide quantitative information for the characterization of CS and may be particularly useful for evaluating therapeutic intervention. Advances in knowledge: DTI combined with volumetric analysis provides additional information useful for not only the characterization of CS and distinction of clinical subtypes but also monitoring of therapeutic interventions.
科凯恩综合征（CS）是一种罕见疾病，其特征为严重脑萎缩、白质（WM）髓鞘形成不足及基底节钙化。本研究旨在使用扩散张量成像（DTI）和容积分析对萎缩和WM异常进行量化，评估CS各亚型之间可能存在的差异，并确定DTI结果是否可能与髓鞘形成不足性疾病相符。
14例CS患者和14名对照者接受了脑部MRI检查，包括DTI和容积三维T加权序列。通过全脑内的感兴趣区域进行DTI分析，以获取分数各向异性（FA）和表观扩散系数（ADC）值，并在左侧半卵圆中心获取DTI特征值。采用学生t检验比较患者与对照者以及CS各亚型。鉴于CS患者数量较少，将他们分为两组：中度（CS1/CS3）和重度（CS2/脑眼面骨综合征）。
CS患者的全脑体积减少了57%，主要在幕下区域（68%）（p < 0.001）。重度组的全脑体积减少更为明显，但两组幕下萎缩程度无差异（p = 0.7）。CS患者大多数WM区域的平均FA值较低，而ADC较高（p < 0.05）。两组之间胼胝体压部和内囊后肢的ADC以及大脑脚的FA存在显著差异（p < 0.05）。平均ADC值与髓鞘形成不足性疾病相符。CS患者的所有DTI特征值均较高，主要是横向扩散率（+51%）（p < 0.001）。
DTI和容积分析为CS的特征描述提供了定量信息，可能对评估治疗干预特别有用。知识进展：DTI与容积分析相结合不仅为CS的特征描述和临床亚型区分提供了有用的额外信息，还为治疗干预监测提供了有用信息。
