Brunberg James A, Jacquemont Sebastien, Hagerman Randi J, Berry-Kravis Elizabeth M, Grigsby Jim, Leehey Maureen A, Tassone Flora, Brown W Ted, Greco Claudia M, Hagerman Paul J
Department of Radiology, University of California, Davis, School of Medicine, Sacramento, CA 95817, USA.
AJNR Am J Neuroradiol. 2002 Nov-Dec;23(10):1757-66.
Our purpose was to characterize the findings of MR imaging of the brain of adult male fragile X premutation carriers with a recently identified disorder characterized by ataxia, tremor, rigidity, and cognitive dysfunction.
MR imaging studies of the brain of 17 male patients were characterized for signal intensity and for size of ventricles, cerebral and cerebellar sulci, and brain stem. Comparison was made with age- and sex-matched control participants. Southern blot and/or polymerase chain reaction methods were used to analyze CGG trinucleotide repeats in the fragile X mental retardation 1 gene.
Fifteen of 17 patients showed symmetrically decreased T1 and increased T2 signal intensity in cerebellar white matter lateral, superior, and inferior to the dentate nuclei. Fourteen of 17 had similar signal intensity alterations in the middle cerebellar peduncles. Cerebellar cortical atrophy was present in 16 of 17 and cerebral atrophy in 17 of 17. Evan's Index as a measure of ventricular size averaged 0.35 (range, 0.25-0.46), with that for age-matched control participants averaging 0.28 (range, 0.24-0.31) (P <.005). The mean third ventricle width was 11 mm (for control participants, 6 mm; P <.01). Corpus callosum was thinned in 14 of 16 participants. Middle cerebellar peduncles were atrophic when compared with those of control participants (P <.005). Pontine transverse dimension was 25 mm (for control participants, 31 mm; P <.005), and rostral-caudal length averaged 26 mm (for control participants, 29 mm; P <.005). CGG repeats clustered in the low to mid premutation range (86 +/- 10 CGG repeats) in the 17 patients.
MR imaging findings in symptomatic male fragile X premutation carriers are characteristic of this disorder. Recognition of these alterations may support a specific diagnosis and may have implications for the potential occurrence of fragile X syndrome in the children of reproductive age female relatives.
我们的目的是描述成年男性脆性X前突变携带者脑部磁共振成像（MR成像）的表现，这些携带者患有最近发现的一种以共济失调、震颤、僵硬和认知功能障碍为特征的疾病。
对17例男性患者的脑部进行MR成像研究，观察其信号强度以及脑室、大脑和小脑沟回、脑干的大小。与年龄和性别匹配的对照参与者进行比较。采用Southern印迹法和/或聚合酶链反应方法分析脆性X智力低下1基因中的CGG三核苷酸重复序列。
17例患者中有15例在齿状核外侧、上方和下方的小脑白质中显示出对称的T1信号减低和T2信号增强。17例中有14例在小脑中脚有类似的信号强度改变。17例中有16例存在小脑皮质萎缩，17例均有脑萎缩。作为脑室大小测量指标的埃文斯指数平均为0.35（范围为0.25 - 0.46），年龄匹配的对照参与者平均为0.28（范围为0.24 - 0.31）（P <.005）。第三脑室平均宽度为11毫米（对照参与者为6毫米；P <.01）。16例参与者中有14例胼胝体变薄。与对照参与者相比，小脑中脚萎缩（P <.005）。脑桥横向尺寸为25毫米（对照参与者为31毫米；P <.005），前后长度平均为26毫米（对照参与者为29毫米；P <.005）。17例患者的CGG重复序列聚集在低至中前突变范围内（86 ± 10个CGG重复序列）。
有症状的男性脆性X前突变携带者的MR成像表现是这种疾病的特征。认识到这些改变可能有助于做出特定诊断，并可能对育龄女性亲属的子女中潜在发生脆性X综合征有影响。
