佩梅病的头颅MRI表现及其与临床、基因分型的关系

目的 探讨佩梅病( PMD)患儿的头颅MRI特点,以及与临床及基因分型的关系.方法 回顾性分析16例经临床诊断为佩梅病患儿的临床和影像资料.患儿均为男性,年龄5个月至9岁8个月.由儿科神经医师对患儿的症状和体征进行检查,将其按照临床症状进行临床分型.由影像科医师对头颅MRI图像的特点进行分析,病灶的位置包括苍白球、锥体束、胼胝体、小脑白质、半卵圆中心,判断大、小脑是否萎缩、是否有“豹纹征”.结果 临床诊断经典型佩梅病8例,中间型7例,先天型1例.16例佩梅病患儿MRI均以广泛的脑白质髓鞘化延迟为特点,病灶累及苍白球13例、锥体束7例、胼胝体11例、小脑白质7例、半卵圆中心12例、脑萎缩5例、小脑萎缩1例,5例有“豹纹征”.锥体束和小脑白质受累在点突变患儿中多见；临床症状较重的中间型及先天型患儿出现小脑白质病变频率较高；“豹纹征”多见于经典型患儿,提示患儿的髓鞘化程度相对较高.结论 佩梅病患儿的头颅MRI具有典型的影像特点,其影像学表现与临床分型和基因突变类型有一定的相关性.

MRI findings of Pelizaeus-Merzbacher disease correlated with phenotypes and genetic mutation

Objective To investigate the correlation of MRI features and phenotypes and genetic mutations in Pelizaeus-Merzbacher disease.Methods Sixteen boys with clinical diagnosis of PelizaeusMerzbacher disease (PMD) were included in this study.Their ages ranged from 22 months to 9 years.They were examined by pediatric neurologists,and clinical classification was made according to the symptoms and physical signs.An experienced radiologist reviewed the cranial MRI images and analyzed the brain involvement,including pallidus globus,pyramidal tract,corpus callosum,cerebellar white matter,semiovale centrum,brain atrophy and ‘ tigroid sign’.Results There were 8 patients with classic form,7 patients with transitional form and one patient with connatal form.They all showed diffuse delayed myelination in the white matter,with involvement of pallidus globus in 13 cases,pyramidal tract in 7 cases,corpus callosum in 11 cases,cerebellar white matter in 7 cases,semiovale centrum in 12 cases.Cerebral atrophy was found in 5 patients and eerebellar atrophy was found in one patient.Five cases depicted ' tigroid sign'.In patients with PLP1 gene point mutation,pyramidal tract and cerebellar white matter involvement showed a high incidence.Cerebellar white matter lesions were relatively frequent in children with transitional form and connatal form.In contrast,‘ tigroid sign' was often related to classic form,which indicated a better myelination and outcome.Conclusion PMD patients show distinct imaging features in their brains,which may be correlated with the phenotype and genetic mutation.