半侧巨脑畸形临床及磁共振成像特点分析

Clinical and MRI Features of Hemimegalencephaly

目的分析半侧巨脑畸形(HME)的临床及磁共振成像(MRI)特点,以提高对HME的认识。方法回顾性分析2008—2012年河北医科大学第一医院收治的HME患者的临床及MRI表现。结果 6例HME临床表现为癫痫4例,偏侧肢体肥大3例,精神运动发育迟滞2例。MRI平扫均表现为一侧大脑半球增大,大脑皮质增厚,灰白质交界模糊,病变位于左侧大脑半球4例,右侧大脑半球2例。病变侧侧脑室均表现为明显扩大,其中1例以侧脑室后角扩大为主,2例表现为侧脑室前角伸直,指向前上方。3例病变侧脑白质内出现斑片状T2加权像(T2WI)高信号。1例患儿行弥散张量成像(DTI)检查,显示通过胼胝体膝部及压部的半球间脑白质纤维束在双侧额叶及枕叶分布不对称。结论 HME典型的临床表现为癫痫及精神运动发育迟滞;MRI表现具有特征性,表现为一侧大脑半球弥漫性增大,侧脑室扩大,脑皮质增厚,脑白质内可见长T2异常信号。

Objective To investigate clinical and MRI features of hemimegalencephaly （ HME ）, thus the understanding of HME can be improved. Methods The clinical and MRI findings of HME patients in the First Hospital of Hebei Medical University from 2008 to 2012 were retrospectively analyzed. Results The clinical manifestation of 6 HME patients was epilepsy（ 4 cases）,hemihypertrophy of limb（ 3 cases）,and mental retardation（ 2 cases）,respectively. MRI showed enlargement of unilateral cerebral hemisphere with apparent thickening of the grey matter,and the boundary between grey matter and white matter was not clear. Lesions of four cases were located in left cerebral hemisphere,and lesions of two cases were located in right cerebral hemisphere. Enlargement of lateral ventricle of the lesion side was found in all cases,the main manifestation of 1 case was enlargement of rear corner of lateral ventricle,the main manifestation of 2 cases was straight front corner of lateral ventricle which pointed upward and forward. Three cases had patchy high signal on T2WI in white matter of the lesion side. According to DTI for a child patients,the interhemisphere fiber tracts（FTs）passing through the genu and splenium of the corpus callosum were distributed to different area in each frontal lobe and occipital lobe. Conclusion The typical clinical manifestation of HME is epilepsy and mental retardation. HME has characteristic MRI findings,MRI demonstrates enlargement of diffuse unilateral cerebral hemisphere with thickened cortex,enlargement of lateral ventricle,and abnormal T2 signals in the white matter.