用辅酶Q_(1O) 治疗Kearns-Sayer综合症

Kearns-Sayer综合症(KSS)是一种以眼肌麻痹,视网膜变性和心脏传导功能障碍为特征的线粒体神经肌病。本文报导5例KSS病人,用辅酶Q_(10)(CoQ)治疗取得良好效果。作者对CoQ的代谢及其作用机理进行了研究。本组病例表现为眼肌麻痹、睑下垂、视网膜变性、听力丧失和肌无力。脑脊液(CSF)蛋白含量增加。肌肉活检电镜检查提示红肌纤维形态破碎,异常线粒体数目增加。心电图有传导系统障碍,运动后ST段下降或心律紊乱。心肌活检提示线粒体数目增加,但无形态改变。运动后静脉血中乳酸+丙酮酸盐的含量或乳酸/丙酮酸盐的比率增加。一例智能障碍,一例共济失调。4例正中神经感觉诱发电位(MN-SEP)潜伏期延长。2例血清叶酸含量降低,叶酸在CSF/血清中含量比率降低。除例5外,横纹肌线粒体电子转运系统活性均正常。由于病人     

周围神经病、共济失调、视网膜色素变性综合征的临床和病理学特点(附1例报告)

目的探讨表现为周围神经病、共济失调、视网膜色素变性综合征(NARP)的线粒体病的临床、病理及基因突变特点。方法回顾性分析一个线粒体病家系中表现为NARP综合征患者的临床、病理及基因检测资料。结果该患者首发症状为多饮多尿、记忆减退,客观检查发现腱反射消失和小脑体征。头颅MRI提示明显的小脑萎缩。EMG提示运动感觉神经传导速度减慢、诱发电位波幅降低。眼底荧光造影见到"胡椒与盐"样改变。肌肉活检Gomori染色可见破碎红纤维。全基因测序提示线粒体基因3243AG杂合突变。结论线粒体基因3243AG突变也可表现糖尿病和NARP综合征,临床上早期识别至关重要。     

MELAS型线粒体脑肌病1例临床病理

目的分析1例MELAS型线粒体脑肌病的临床病理特点。方法对该患者的临床、实验室、影像学及肌肉病理特点进行回顾性分析。结果血和脑脊液乳酸高,头颅CT、MRI显示病灶局限于颞顶枕部,肌肉活检证实患者的骨骼肌存在大量典型的不整边红纤维。结论对年轻患者反复表现为卒中样发作、局限性或全面性癫痫,病灶局限于颞顶枕部,应行肌肉活检,避免误诊。     

眼咽肌型肌营养不良一例

眼咽肌型肌营养不良(oculopharyngeal musculardystrophy,OPMD)是一原发于肌肉的遗传性变性疾病,为进行性肌营养不良的一种特殊类型,主要临床特征为缓慢进展的眼外肌和吞咽肌麻痹,临床较少见。此文报道一例经病理确诊的OPMD有关资料。1临床资料患者男,20岁,农民。因双上睑下垂,视物成双5年,吞咽困难、构音障碍、四肢无力3年入院。现病史:15岁时出现双上睑轻度下垂,视物模糊、视物成双影,稍感说话费力;2年后渐出现吞咽困难,复视、言语不清较前加重,同时出现四肢无力,肌肉疼痛,伴有肌肉萎缩。入院查体:神志清楚,构音障碍,双上睑下垂,双眼…     

16例MELAS临床、神经影像与肌肉病理研究

目的探讨线粒体脑肌病并乳酸血症与卒中样发作(MELAS)的临床、影像学及肌肉病理特点。方法对16例MELAS患者的临床表现、影像学及肌肉病理特点进行分析。结果患者主要临床表现为卒中样癫发作(87.5%),其次为头痛、呕吐和智能减退等;头颅MRI提示脑实质片状异常信号,不按血管供应区分布;肌肉活检见破碎红纤维(RRF)。结论MELAS是一种具有特殊临床、影像学表现的线粒体脑肌病,其诊断依赖于肌肉活检病理和基因诊断。     

慢性进行性眼外肌麻痹-线粒体脑肌病CEPO型1例报告

线粒体脑肌病是一组由线粒体DNA或核DNA缺陷导致线粒体结构和功能障碍、ATP合成不足所致的多系统疾病。目前国内报道较少,现报道1例如下。1病例报告患者,男,59岁,因"进行性双眼上睑下垂3年"于2006年6月19日到吉林大学白求恩第一医院神经内科入院。患者缘于入院前3年发现右眼上睑下垂,逐渐加重,并出现左眼上睑     

乳酸血症和脑卒中样发作为主要临床表现的线粒体脑肌病(附1例报道)

目的报道线粒体脑肌病伴高乳酸血症和脑卒中样发作(MELAS)病1例,进行相关文献复习,探讨其临床表现、生化、影像学和组织病理学检查在该疾病诊断中作用。方法对线粒体脑肌病伴高乳酸血症和脑卒中样发作(MELAS)患者的临床表现、辅助检查、影像学、组织病理学、免疫组化等情况进行分析。结果 MELAS患者的主要临床表现为发作性头痛、脑卒中样发作、高乳酸血症;脑MRI示病灶位于顶叶、枕叶、颞叶脑回处;肌肉活检见肌纤维变性、破碎样改变以及异常线粒体。结论血乳酸、影像学及肌肉活检在诊断MELAS时有重要的诊断价值,但都缺乏特异表现,需要结合临床和各种检查结果而确诊。     

局部应用萘甲唑啉治疗肌病性上睑下垂

肌病性上睑下垂(myopathic ptosis,MP)是由于影响了提上睑肌或其神经肌肉连接所引起。其它辅助提上睑的肌肉是M(?)ller氏平滑肌。作者局部应用萘甲唑啉(naphazoline)试图选择性地增加M(?)ller氏肌的收缩力,缓解肌病性上睑下垂。 研究的12例MP病人中,男5例,年龄18～72岁。肌强直性营养不良(myotonic dystrophy)3例;常染色体显性遗传性眼咽肌营养不良(oculopharyngeal muscular dystrophy)的同胞3人;重症肌无力5例;以上睑下垂、眼麻痹、肌病、神经病、白质脑病和胃肠功能障碍为特征的多系统线粒体病(MNGIE综合征)1例。17只下垂眼每只滴入0.1％     

线粒体脑肌病伴高乳酸血症和卒中样发作三例

目的分析3例线粒体脑肌病伴高乳酸血症和卒中样发作(MELAS)患者的临床表现影像学特点并探讨其发病机制。方法对3例MELAS患者的临床资料进行分析。结果 3例患者均以卒中样发作为主要表现,伴有内分泌、循环系统等多系统症状。患者头颅影像学有异常表现,肌肉活检示破碎红纤维。结论MELAS的初步诊断主要依据临床表现和影像学特点,肌肉活检可以为进一步明确诊断提供重要的依据。     

线粒体脑肌病治疗进展

线粒体脑肌病(mitochondrial encephalomyopathy,ME)是一组由线粒体DNA(mtDNA)突变导致的线粒体结构和功能异常,从而累及中枢神经系统和肌肉组织的疾病,其神经系统主要表现有卒中样发作、癫痫、肌阵挛、眼外肌麻痹及视神经损害等,肌肉损害主要表现为以近端为主的肌萎缩和肌无力,其它表现可有心脏传导阻滞、心肌病、糖尿病和身材矮小等,实验室检查可发现血清和脑脊液中乳酸水平升高,肌肉活检可见破碎红纤维(ragged red fiber,RRF),分子生物学研究发现ME的发生与mtDNA遗传缺陷密切相关[1].     

Basal ganglia calcification in Kearns-Sayre syndrome

The Kearns-Sayre syndrome (KSS) appears to be a distinctive disorder characterized by progressive external ophthalmoplegia, pigmentary degeneration of the retina, heart block, and elevated CSF protein levels. Recent reports have suggested that abnormalities of muscle mitochondria may also be a consistent finding in KSS. We recently examined a patient with KSS whose skeletal muscle contained abnormal mitochondria. In addition, a computerized tomographic scan of the head showed cerebellar and brain stem atrophy, as well as calcification in the region of the basal ganglia.     

Diagnosis of mitochondrial diseases: clinical and histological study of sixty patients with ragged red fibers

BACKGROUND: Mitochondrial diseases are caused by mutations in mitochondrial or nuclear genes, or both and most patients do not present with easily recognizable disorders. The characteristic morphologic change in muscle biopsy, ragged-red fibers (RRFs) provides an important clue to the diagnosis. MATERIALS AND METHODS: Demographic data, presenting symptoms, neurological features, and investigative findings in 60 patients with ragged-red fibers (RRFs) on muscle biopsy, seen between January 1990 and December 2002, were analyzed. The authors applied the modified respiratory chain (RC) diagnostic criteria retrospectively to determine the number of cases fulfilling the diagnostic criteria of mitochondrial disease. RESULTS: The most common clinical syndrome associated with RRFs on muscle biopsy was progressive external ophthalmoplegia (PEO) with or without other signs, in 38 (63%) patients. Twenty-six patients (43%) had only external ophthalmoplegia, 5 (8%) patients presented with encephalomyopathy. Specific syndromes were the presenting feature in 8 (13%), Kearns-Sayre syndrome (KSS) in 4 and myoclonus epilepsy with ragged-red fibers (MERRF) in 4. Myopathy was the presenting feature in 5 (8%) and 4 presented with infantile myopathy. Of the 60 patients, 18 (30%) had proximal muscle weakness. Two patients with KSS and one patient with myopathy had complete heart block necessitating pace making. When the modified RC diagnostic criteria were applied, only 26 (43%) patients had one other major criterion in addition to RRFs for the diagnosis of mitochondrial diseases. The remaining 34 (57%) patients with RRFs on muscle biopsy had only some clinical features suggestive of RC disorder but did not fulfill the clinical criteria (of the modified diagnostic criteria) for the diagnosis of mitochondrial diseases. CONCLUSION: In patients with clinical features suggestive of RC disorder, demonstration of RRFs on muscle biopsy helps in confirming the diagnosis of mitochondrial disease in only a subgroup of patients.     

Unusual clinical presentation of a patient carrying a novel single 1.8 kb deletion of mitochondrial DNA

Kearns-Sayre syndrome (KSS) is a mitochondrial encephalomyopathy characterized by progressive external ophthalmoplegia (PEO), pigmentary retinopathy and onset before the age of 20 years. Cerebellar ataxia, as well as short stature and increased protein content in the cerebrospinal fluid, are frequent additional symptoms. A single large mitochondrial (mt) DNA deletion of 4,977 bp is the most common molecular defect in KSS. Recently, different mutations have also been associated with incomplete, KSS-like phenotypes. We describe the unusual clinical presentation of a patient carrying a novel 1,814-bp deletion of mtDNA. In contrast with typical KSS, the clinical picture of this patient did not include either palpebral ptosis or PEO and was dominated by an ataxic syndrome.     

Exercise intolerance in Kearns-Sayre syndrome

Exercise intolerance is a common finding in mitochondrial diseases, including Kearns-Sayre syndrome (KSS), characterised by progressive external ophthalmoplegia, cardiac conduction defects and atypical pigmentary degeneration of the retina. Exercise studies were performed in a 32 year old woman with KSS who had received an atrio-ventricular sequential pacemaker because of continuing breathlessness, having presented with complete heart block requiring a fixed rate demand pacemaker 6 years earlier. Minute ventilation, oxygen consumption, and carbon dioxide production were measured at different workloads on 3 consecutive days by collecting expired air. Compared to controls, after exercise at a subanaerobic workload, heart rate and ventilation were exaggerated relative to both oxygen consumption and carbon dioxide production. The findings are consistent with the hypothesis that, in mitochondrial disorders, impaired oxidative phosphorylation leads to uncoupling of cardiac ouput and ventilation relative to muscle metabolic rate.     

Kearns-Sayre syndrome and complex II deficiency

A 25-year-old woman with Kearns-Sayre syndrome (KSS) had complete external ophthalmoplegia, short stature, ataxia, cardiac conduction defects, and pigmentary retinopathy. Muscle biopsy revealed ragged-red fibers. Electron microscopy showed increased numbers of mitochondria with disordered structure and paracrystalline inclusions. Enzymatic analysis revealed a deficiency of complex II of the mitochondrial respiratory chain, and, more specifically, a deficiency of succinic dehydrogenase, although both subunits of this enzyme proved to be present by immunologic analysis. Therapy with vitamin cofactors did not result in short-term improvement. This appears to be the first report of complex II deficiency in a patient with KSS.     

Mitochondrial DNA deletion in oculoskeletal myopathy

The case of a patient showing bilateral ophthalmoplegia with proximal limb weakness, severe dysphagia and short stature, without family history, is described. The diagnosis of Kearns-Sayre syndrome was excluded because of the absence of pigmentary retinopathy and of all other common manifestations except short stature. The analysis of mitochondrial DNA of the patient's muscle revealed a deleted form accounting for 65% of the total mitochondrial DNA. The deletion, undetectable in the mitochondrial DNA of peripheral blood leukocytes, was apparently indistinguishable from that already described by others in a far more severe form of classic Kearns-Sayre syndrome.     

Severe mitochondrial cytopathy with complete A-V block,PEO, and mtDNA deletions

We describe a 17-year-old male with neurologic and cardiovascular disorders characterized by complete atrioventricular block and a mitochondrial cytopathy with clinical, structural, biochemical, and molecular features shared by chronic progressive external ophthalmoplegia and Kearns-Sayre syndrome. The patient's manifestations included progressive external ophthalmoplegia, bilateral ptosis, muscle weakness, delayed development, and progressive hearing loss with multiple mitochondrial DNA deletions, including an abundant 11-kb novel deletion and reduced specific activities of respiratory complexes I, III, and IV present in skeletal muscle. Ultrastructural analysis of biopsied muscle revealed a heterogenous mixture of normal and abnormal mitochondria with unusual cristae. This unique mitochondrial DNA deletion, which eliminates the origin of mitochondrial DNA replication for the light strand, may be responsible for generating an intermediate clinical phenotype.     

Unusual presentation of Kearns-Sayre syndrome in early childhood

Congenital glaucoma and insulin-dependent diabetes mellitus were the predominant presenting signs in a patient with Kearns-Sayre syndrome. Thereafter, he developed short stature, pigmentary retinopathy, progressive external ophthalmoplegia, and ataxia. The diagnosis was confirmed by detecting a deletion of mitochondrial DNA in muscle, thus demonstrating that Kearns-Sayre syndrome can have the unusual presenting signs described above.     

Overexpressions of myoglobin and antioxidant enzymes in ragged-red fibers of skeletal muscle from patients with mitochondrial encephalomyopathy

To determine the relationship between myoglobin (Mb) and the defense system against reactive oxygen species in various myopathies, we performed immunohistochemical analyses of Mb and various antioxidant enzymes, including manganese superoxide dismutase (Mn-SOD), copper zinc SOD (CuZn-SOD), catalase (CAT), and glutathione peroxidase (GSH-Px). Biopsied muscle specimens were obtained from patients with chronic progressive external ophthalmoplegia (CPEO), Kearns-Sayre syndrome (KSS), Duchenne muscular dystrophy (DMD), and polymyositis (PM). In patients with CPEO/KSS, stainings of Mb, SOD, CAT, and GSH-Px in nonatrophic ragged-red fibers (RRFs) were more intense than those in non-RRFs. These pronounced stainings corresponded to ragged-red lesions. The staining intensities of these antioxidant enzymes were significantly correlated with that of Mb (P < 0.001). Atrophic RRFs in specimens from patients with CPEO/KSS showed intense stainings of these antioxidant enzymes but not intense staining of Mb. In specimens from patients with DMD/PM, the antioxidant enzymes but not Mb were overexpressed in degenerative fibers. These results suggest that oxidative stress is associated with Mb expression specifically in mitochondrial diseases. The antioxidant enzymes seem to be upregulated to protect against muscle damage in nonatrophic RRFs. However, the Mb-mediated oxidative damage may become more extensive and result in further mitochondrial dysfunction and progressive atrophy of RRF with impaired upregulation of Mb.