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线粒体脑肌病是一组由于线粒体DNA基因和(或)核DNA基因突变导致线粒体结构和(或)功能障碍,主要累及脑部和肌肉系统的多系统受累疾病,线粒体脑肌病伴高乳酸血症和卒中样发作(mitochondrial myopathy, encephalopathy, lactic acidosis, and strokelike episodes,MELAS)是最常见的线粒体脑肌病类型,本病涉及多个系统,临床表现复杂多样,常被误诊为脑梗死、中枢神经系统感染、脑部肿瘤等,导致病人不能及时准确诊断,延误治疗。本研究通过对4例MELAS病人的临床资料进行回顾性总结,结合文献探讨其临床、影像及病理学特点,以提高对MELAS综合征的认识,避免误诊误治。
线粒体脑肌病伴高乳酸血症和卒中样发作综合征的临床、影像及病理学特征
Analysis of the clinical, imaging and pathological features of MELAS
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摘要:
目的探讨线粒体脑肌病伴高乳酸血症和脑卒中样发作综合征(MELAS)的临床、影像及病理学特点。 方法通过4例MELAS综合征病例结合文献回顾性分析MELAS的临床、影像学及病理学特征。 结果以癫痫发作起病1例,头痛起病2例,发热伴意识障碍起病1例;头颅MRI检查示顶、枕叶和(或)颞叶T1WI/T2WI长或稍长信号及FLAIR高信号病灶,呈脑回样改变,均未见强化。3例肌肉活检发现有肌纤维变性,横纹消失或断裂,肌膜下出现不规则的不整红边纤维(RRF);其中1例行基因检测发现有线粒体DNA A3243G位点突变,另有1例曾多次住院未行肌肉活检。 结论MELAS主要表现为卒中样起病伴癫痫发作,可有视听力减退以及认知功能障碍等;影像学特征为病变主要累及双侧大脑半球后部皮质,呈脑回样改变;肌肉活检发现RRF;基因检测可发现线粒体DNA A3243G位点突变。 Abstract:ObjectiveTo investigate the clinical, imaging and pathological features of mitochondrial myopathy, encephalopathy, lactic acidosis, and strokelike episodes syndrome(MELAS). MethodsThe clinical, imaging and pathological data of 4 cases with MELAS were retrospectively analyzed. ResultsThere were 1 case of seizure, 2 cases of headache and 1 case of fever complicated with disturbance of consciousness.The results of cranial MRI showed that the parietal, occipital and/or temporal lobes lesions were long or slightly longer T1WI/T2WI and FLAIR hyperintensity, gyri-like changes, and not enhancement.The disappearance or fracture of transverse striations and irregular red edge fibers(RRF) under the muscle membrane were found in 3 cases detected by muscle biopsies.One case with mitochondrial DNA A3243G site mutation was found by routine gene testing, and the muscle biopsy in 1 case was not be done during the multiple hospitalizations. ConclusionsThe strokelike episodes complicated with seizures, visual and hearing loss, and cognitive impairment are the major performance of MELAS.The imaging features show that the lesions are mainly involved in the posterior cortex of both cerebral hemispheres, and gyri-like changes.The RRF can be found using the muscle biopsy, and the mutations in mitochondrial DNA A3243G can be found using gene testing. -
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