反复误诊的一例MELAS型线粒体脑肌病的临床病理研究

The Clinical and Pathological Study of A Patient with Multiple Misdiagnosed MELAS

本文报道1例MELAS型线粒体脑肌病,该病人早期发育正常,9岁起病,以反复发作的头痛、腹痛起病,继以局部和全身抽搐发作、四肢无力及反复的卒中样发作,反复发作视物不清和偏盲、逐渐智力减退;血清乳酸增高;MRI示半球额、顶、枕、颞叶多发性长T1和长T2异常信号,呈灶状和层性改变。肌活检组化检查可见破碎红纤维(RRF),电镜发现糖原堆积和异常线粒体。诊断符合MELAS型。本例长期误诊为精神异常、多发性硬化和间脑综合征。本文将对MELAS的临床、病理和影像学所见进行讨论。

One patient with mitochondrial myopathy, encephalopathy, lactic acidosis and strokelike episodes (MELAS) are reported. This patient have normal early development, followed by recurrent headache and recurrent vomiting at 9 years old, and then developed focal or generalized seizures, exercise intolerance, limb weakness, and strokelike episodes; She experienced of recurrent blindness, recurrent homonymous hemianopia and progressive metal retardation; plasma lactate was raised. MRI demonstrated clearly the abnormal longer T1 and T2 weighted signals which distributed in frontal, parietal, occipital and temporal cortex as multiple focal, cystic and laminar necrotic areas; and generalized cerebral atrophy was present. Muscle biopsy showed red ragged fiber and abnormal mitochondria. Electron microscopic examination revealed abnormal accumulations of mitochondria in the skeletal muscle, and abundant glycogen particles are also seen in the myofibrils. This patient had been misdiagnosed mental disorder, multiple sclerosis and diencephalic syndrome for long time. In this paper, we will discuss the clinical, pathology, imaging characteristics of this disease.