线粒体神经胃肠型脑肌病的临床和病理分析

Clinical and pathological analysis of mitochondrial neurogastrointestinal encephalopathy disease

目的探讨线粒体神经胃肠型脑肌病(Mitochondrial Neurogastrointestinal Encephalopathy Disease,MNGIE)的临床和病理特点。方法通过1例临床确诊为线粒体神经胃肠型脑肌病病例的临床表现、影像学检查及病理检查,系统回顾线粒体神经胃肠型脑肌病的发病机制、临床表现、病理特点。结果该患有长期的腹痛、腹泻史,神经系统首发症状为听力障碍,此后出现头晕、走路不稳、记忆力逐渐下降。神经系统检查有眼外肌麻痹、听力障碍、周围神经损害。肌电图:广泛神经源性损害。头部MRI表现为广泛的白质脑病。肌肉活检为HE染色中出现嗜碱的肌纤维,在GT染色中为典型和不典型的RRF,在NADH染色和SDH染色中深染。结论线粒体神经胃肠型脑肌病是一种特殊类型的线粒体肌病,具有上述临床及影像学特点,加上血及(或)脑脊液乳酸水平升高,肌肉活检示组织学线粒体肌病的表现。如果发现血清白细胞中胸苷磷酸化酶活性降低或基因检测发现胸苷磷酸化酶(thymidine phosphorylase,TYMP)基因位点突变更能进一步确诊。

Objective To explore the clinical and pathological features of mitochondrial neurogastrointestinal encephalopathy disease（MNGIE）.Methods Clinical manifestations,imaging,and pathologic examination results of one confirmed case of MNGIE were studied.The pathogenesis,clinical manifestations,and pathological characteristics of MNGIE were systematically reviewed.Results The patient had a long history of chronic abdominal pain and diarrhea.The initial nervous system symptoms were hearing disorder,followed by dizziness,ataxia,and gradual memory impairment.Nervous system examination showed external ophthalmoplegia,hearing impairment,and peripheral nerve damage.Electromyogram showed extensive neurogenic damage.Head MRI showed extensive leukoencephalopathy.HE staining of muscle biopsy specimens showed basophilic muscle fibers,and GT staining revealed typical and atypical ragged red fibers,which were darkly stained in SDH staining and NADH staining.Conclusion MNGIE is a special type of mitochondrial myopathy with the aforementioned clinical and imaging features.In addition,lactate levels in the blood and/or cerebrospinal fluid are elevated,and muscle biopsy shows histological manifestations of mitochondrial myopathy.The disease may be further confirmed if the activity of thymidine phosphorylase（TYMP） in white blood cells is decreased or gene locus mutation of TP is detected by genetic analysis.