儿童线粒体脑肌病的脑部MRI表现与诊断

目的探讨儿童线粒体脑肌病的脑部MRI表现及其诊断价值。方法搜集1996年1月至2002年12月经病理与实验室检查证实的16例儿童线粒体脑肌病及其脑部MRI表现，并进行回顾性分析。结果16例患儿脑MRI均有多发对称性片状略长T1和长T2异常信号，其中单纯脑深部灰质受累9例，大脑皮质和深部灰质同时受累6例，单纯白质受累l例。临床主要表现为进行性智力减退(12例)和肌力减退(10例)。骨骼肌活检病理检查可见破碎样红纤维及异常线粒体。结论进行性智力和肌力减退是儿童线粒体脑肌病最常见的临床表现；脑深部灰质多发对称性斑片状异常信号是儿童线粒体脑肌病脑部MRI的主要表现；脑MRI是诊断儿童线粒体脑肌病的重要手段，但儿童线粒体脑肌病的确诊有赖于肌肉活检和基因检查。

MRI appearances and diagnosis of mitochondrial encephalomyopathy in children

Objective To explore the MRI appearances and diagnostic value of mitochondrial encephalomyopathy in children. Methods MRI manifestations in 16 children patients with mitochondrial encephalomyopathy, confirmed by pathology and laboratory examination from January of 1996 to December of 2002, were retrospectively analyzed. Results Cerebral foci of mitochondrial encephalomyopathy showed as multiple and symmetrical abnormal slight long T 1 and long T 2 signals in all 16 cases. Deep grey matter was only invaded in 9 of 16 cases, both cerebral cortex and deep grey matter were involved in 6 cases, and white matter was only invaded in 1 case, respectively. Their main clinical manifestations were progressive declination of the intelligence (n=12) and muscle force (n=10). The biopsy in the skeletal muscle showed ragged red fiber and abnormal mitochondria. Conclusion Gradual declination of intelligence and muscle force is the common clinical manifestations of mitochondrial encephalomyopathy in children. The main MRI findings were multiple symmetrical abnormal signal intensities in the deep grey matter, and MRI is an important way to show the cerebral lesions and benefit to the diagnosis of mitochondrial encephalomyopathy. But the definite diagnosis of mitochondrial encephalomyopathy depends on skeletal muscle biopsy and gene examination.