白质消融性白质脑病临床分析

Clinical characteristics of cases with leukoencephalopathy with vanishing white matter

目的分析白质消融性白质脑病的临床特点及诊断方法。方法对9例临床诊断为该病的患儿的临床及头颅影像学特点、实验室检查等进行分析,结合病例对该病进行综述介绍。结果(1)临床表现:9例中8例出现神经系统症状和体征,1例仅有 MRI 异常。发病时间为生后6个月～3岁;5例家族史阳性,病前智力运动发育多正常;多以运动症状起病,下肢为著。6例发病前或每遇病情加重前有呼吸道感染史,3例病前有轻微头部外伤史;到目前为止,有症状的7例呈进行性加重病程,其中4例同时有发作性加重现象。所有病例智力受损相对轻。7例头围正常,8例有上运动单元病变体征,4例有共济失调体征。3例双侧视神经萎缩。(2)头颅 MRI:表现为双侧对称弥漫性深部白质长 T_1长 T_2信号,可累及皮层下白质,额、顶叶为主,Flair 像为对称性白质高信号伴部分白质低信号甚至囊性变或大部分白质低信号仅存少量线状稍高信号,为此症特征性改变。(3)其他遗传性白质脑病相关酶学或生化检查均正常。结论以运动障碍起病、运动障碍重于智力障碍、神经影像学改变显著重于临床表现、MRI 表现为双侧对称弥漫性深部白质长 T_1长 T_2病变伴早期出现白质消融征象是本症的临床特点,临床诊断还需除外其他遗传性及获得性脑白质病。找到相应基因的致病突变可最终确诊。

Objective To analyze and review the characteristics of leukoencephalopathy with vanishing white matter （VWM）. Methods The clinical features including clinical manifestations, neurologic signs, cranial MRI and laboratory tests in 9 patients with the diagnosis of YWM were analyzed and the characteristics of the disease were reviewed. Results Clinical manifestations： 8 cases had symptoms involving central nervous system, 1 case only showed abnormal cranial MRI findings. The onset of the disease occurred between 6 months to 3 years of age. Family history was positive in 5 cases. Almost all cases had normal psychomotor development before the onset of the disease. The initial symptom was usually movement disorder with predominant involvement of lower limbs. The onset or deterioration of the disease was followed by respiratory tract infection in 6 cases and minor head trauma preexisted in 3 cases The course of the disease was progressive in 7 cases and there was episodic deterioration in 4 cases. Mental abilities were relatively better preserved. Head circumference was normal in 7 cases. Positive upper motor unit signs were found in 8 cases and ataxia in 4 cases Bilateral optic nerve atrophy was found in 3 cases Cranial MRI indicated diffuse and symmetrical involvement of deep white matter which showed long T1 and T2 signal. Subcorfical white matter was also involved with predominance in frontal and parietal lobes. Flair image showed symmetrical high signal intensity in cerebral white matter with low signal intensity similar to that of CSF in partial area or low signal in most area of white matter with only meshwork of higher signal preserved. The results of all the laboratory tests including the enzyme and biochemical test specific for some well-known leukoencephalopathy were normal Conclusions The clinical features of VWM include： I. Initial symptom is usually movement disorder; 2. Movement disorder is more prominent compared to mental retardation ; 3. Cranial MRI shows symmetrical abnormal T1 and T2 signal in deep white matter with signs of vanishing white matter. Exclusion of other hereditary and acquired leukoencephalopathy is necessary for diagnosis. Final diagnosis should be made on the basis of genetic evidence.