线粒体脑肌病伴高乳酸血症和卒中样发作综合征的临床特点分析

目的探讨线粒体脑肌病伴高乳酸血症和卒中样发作(MELAS)综合征的临床、影像学、肌肉病理及分子生物学特点。方法回顾性分析6例MELAS患者的临床资料。结果首发症状表现为肢体抽搐4例,轻偏瘫1例,失语1例;其他症状包括发作性头痛和视力障碍。合并心脏功能异常2例,ECG提示预激综合征。6例患者行血乳酸运动试验,均为阳性。6例患者MRI检查显示大脑皮质和皮质下与血管分布不一致的长T_1、长T_2病灶。3例伴有脑萎缩,其中2例为小脑萎缩,1例为全脑萎缩。1例患者4个月后复查头颅MRI提示病灶完全消失。磁共振波谱可见病灶内多个体素的乳酸峰值升高,N-乙酰天冬氨酸值降低,乳酸/胆碱比降低。2例患者肌肉组织活检的病理均见到不同程度的萎缩肌纤维,未见到破碎红纤维。5例患者基因检测发现线粒体DNA(mtDNA)A3243G点突变,1例患者发现mtDNA T3271C点突变。结论 MELAS综合征临床表现复杂多样,以头痛、肢体抽搐及反复卒中样发作为突出特点。卒中样发作期影像学主要表现为脑内与供血区分布不一致的病灶;血乳酸运动试验阳性;典型肌肉病理检查MGT染色可见破碎红纤维;分子遗传学检查可发现基因突变。最终确诊有赖于基因检测。     

线粒体脑肌病伴高乳酸血症和卒中样发作综合征的分子生物学特征

目的 探讨线粒体脑肌病伴高乳酸血症和卒中样发作综合征的分子生物学特征.方法 收集2011-01—2020-01郑州大学第五附属医院和郑州大学第一附属医院经肌肉病理和基因测序同时确诊的42例MELAS综合征的临床表现、影像学、肌肉病理和基因测序等资料,对其血液和新鲜尿液的基因测序结果进行回顾性分析.结果 42例患者均发现...     

线粒体脑肌病伴高乳酸血症和卒中样发作综合征的影像学特征及动态演变

目的探讨线粒体脑肌病伴高乳酸血症和卒中样发作(MELAS)综合征的影像学特点及其动态演变过程。方法收集2011年1月-2016年2月我院经肌肉病理确诊的21例MELAS综合征的资料,对他们的头部CT、MRI、增强MRI、MRA和MRS表现进行回顾性分析。结果 19例患者行头部CT,其中8例显示双侧基底节区对称性钙化。卒中样发作急性期头部磁共振主要表现为T_1WI低信号、T_2WI和FLAIR高信号,DWI高信号或等信号,ADC高信号或低信号;增强MRI未见明显强化或线状强化,MRA未见明显异常,MRS可见N-乙酰天门冬氨酸峰(NAA)下降、乳酸峰(Lac)明显升高。19例(90.5%)病灶累及2个及2个以上脑叶,最常累及的部位是枕叶、颞叶和顶叶。病灶呈层状坏死,分布不符合脑血管的支配区域,动态观察具有"可逆性"、"游走性"和"进展性"。结论 MELAS综合征临床表现复杂,神经影像学具有一定的特征性,具有重要诊断价值。充分认识这些特征,有助于早期诊治、减少误诊。     

线粒体脑肌病伴乳酸血症和卒中样发作综合征一例

<正>1病例介绍患者,女,54岁,因头痛1d于2015年1月2日入院。患者于入院前1d无明显诱因出现头痛,眼眶疼痛,伴有恶心、呃逆,自服止痛药物后头痛缓解。发病前8天有"感冒"症状,全身不适,精神状态欠佳。病程中无发热、咳嗽咳痰,无言语不清,无饮水呛咳、吞咽困难,无肢体活动不灵,无肢体抽搐,为进一步治疗入院。既往史及个人史:"糖尿病"病史20年。     

线粒体脑肌病伴高乳酸血症和卒中样发作综合征:1例报告及文献复习

目的:提高临床对线粒体脑肌病伴高乳酸血症和卒中样发作(mitochondrial myopathy,encephalopathy,lactic acidosis,and stroke-like episode,MELAS)综合征的认识。方法:报道1例MELAS综合征患者的临床表现和诊疗经过,并结合文献复习对MELAS综合征的发病机制、临床表现、诊断和治疗进行探讨。结果:MELAS综合征是线粒体疾病的一种类型,主要累及脑和肌肉组织并伴有卒中样发作,在临床上应与脑炎和脑梗死进行鉴别。早期诊断和治疗有助于阻止病情的进一步发展。结论:MELAS综合征的临床表现复杂多样,远期预后较差,死亡率较高,因此早期诊断和治疗对于改善患者的预后和生活质量均具有重要的临床意义。     

线粒体脑肌病伴高乳酸血症和卒中样发作的发病机制、诊断和治疗研究进展

线粒体脑肌病伴高乳酸血症和卒中样发作(MELAS)是线粒体脑肌病(ME)中最常见的一种类型。其发病机制尚不明确,多考虑是基因突变、能量缺乏、血管病变和NO缺乏等多种因素相互作用的结果。MELAS可累及以脑和肌肉组织为主的全身多个系统,临床表现复杂多样,其诊断依据尚无统一标准,且缺乏根治的方法,极易误诊、漏诊,预后差。本文就MELAS的发病机制、诊断及治疗进展进行综述。     

线粒体脑肌病伴高乳酸血症和卒中样发作的发病机制、诊断和治疗研究进展

线粒体脑肌病伴高乳酸血症和卒中样发作（MELAS）是线粒体脑肌病（ME）中最常见的一种类型。其发病机制尚不明确，多考虑是基因突变、能量缺乏、血管病变和NO缺乏等多种因素相互作用的结果。MELAS可累及以脑和肌肉组织为主的全身多个系统，临床表现复杂多样，其诊断依据尚无统一标准，且缺乏根治的方法，极易误诊、漏诊，预后差。本文就MELAS的发病机制、诊断及治疗进展进行综述。     

线粒体脑肌病伴高乳酸血症和卒中样发作综合征与一种新的线粒体DNA基因突变

目的 检测1例线粒体脑肌病伴高乳酸血症和卒中样发作综合征(MELAS)患者脑组织和外周血线粒体DNA(mtDNA)的基因突变类型。方法 应用聚合酶链反应-限制性片段长度多态性(PCR—RFLP)方法对这例MELAS患者脑组织和外周血mtDNA的A3243G点突变进行检测，对检测过程中发现的异常扩增产物进行DNA测序分析。结果 该例MELAS患者脑组织和外周血白细胞PCR扩增产物行聚丙烯酰胺凝胶电泳时产生了两条带，一条为494bp，另一条为218bp。494bp的扩增产物是目的片段，而218bp的片段是一种异常扩增产物。我们对218bp的PCR扩增产物进行测序，发现在mtDNA3314—3589之间有276bp的碱基缺失。结论 mtDNA3314-3589位点之间276bp的碱基缺失可能是导致MELAs的一种新的基因突变类型。     

3例线粒体脑肌病伴高乳酸血症及卒中样发作患者的临床分析

目的探讨线粒体脑肌病伴高乳酸血症及卒中样发作(mitochondrial encephalomyopathy with lactic acidosis and stroke-like episodes,MELAS)患者的临床特征、影像学及分子遗传学特点。方法回顾性分析3例MELAS患者的临床及影像学特征、分子遗传检测结果以及临床治疗效果,进而总结MELAS患者的临床特点。结果3例患者均表现为头痛、卒中样发作、运动不耐受、症状性癫痫、血乳酸运动负荷试验阳性,其中2例患者存在感音性耳聋,1例患者同时患心肌病,1例患者表现精神异常、痴呆及糖尿病。头部MRI可见与主要脑血管分布不相应的梗死灶,MRS病变区可见乳酸峰。3例患者均经分子遗传检测证明为m. 3243A G突变。结论 MELAS是线粒体脑肌病最常见的类型,多在青少年起病,起病症状复杂多样,常见的有头痛、卒中样发作、癫痫,有时可伴发听力下降、心肌病、发育迟缓、糖尿病等。尽早完成分子遗传学检测有助于早期明确诊断,早期干预可获得一定疗效并改善预后。     

儿童线粒体脑肌病伴乳酸血症和卒中样发作(附Ⅰ例报告)

临床资料 :方×× ,女性 ,7岁 ,因双眼睑下垂 ,四肢无力 3年 ,左侧口角抽搐发作 6天。于 2 0 0 1年 2月 8日第一次住院。患儿入院前 3年开始出现四肢萎软无力 ,不耐疲劳 ,上肢抬举费劲 ,下蹲起立或上楼梯困难 ,不能久立 ,行走慢 ,不耐走远路 ,不能跑步 ,伴双眼睑下垂 ,无视物模糊或成双现象。 6天前出现左侧口角频繁抽搐发作 ,伴两目上翻、小便失禁 ,但神志清醒 ,啼哭不安 ,易激惹。患儿自出生以来智能、语言发育较同龄儿明显滞后 ,身体矮小。系足月顺产 ,无头部外伤、手术史 ,无发热惊厥史 ,家庭成员中无类似病史 ,但其外祖母系近亲结婚。 …     

MELAS综合征的临床、病理和动态影像学表现

目的 探讨线粒体脑肌病伴乳酸血症和脑卒中发作(MELAS综合征)的临床、病理和动态影像学表现特点. 方法 回顾性分析经肌肉活检病理证实的10例MELAS综合征患者的临床、病理及动态影像学资料. 结果 MELAS综合征患者的主要临床表现为头痛、癫痫、恶心呕吐、眼球震颤、视力障碍.CT显示病变较差,MR能清晰显示病变,病变多位于颞叶、顶叶、枕叶皮层及皮层下,呈脑回状,具有多灶性、非对称性、游走性、不按血管分布特点,MRA多无明显血管狭窄,病变区呈现高灌注和血管源性水肿,MRS可见乳酸(Lac)峰.肌肉病理活检光镜下显示破碎红纤维、强阳性血管,电镜下见线粒体数量增多、大小和形态异常. 结论 MELAS综合征的临床和影像学表现具有一定特点,结合肌肉病理活检可对该病进行早期诊断和鉴别诊断.     

10例误诊为线粒体脑肌病伴高乳酸血症及卒中样发作的青年卒中患者的临床分析

目的线粒体脑肌病伴高乳酸血症及卒中样发作(MELAS)是最常见的线粒体脑肌病类型之一,具有明显的临床和遗传异质性。MELAS最显著的核心症状是卒中样发作,容易与缺血性脑卒中混肴。方法通过分析10例曾误诊为MELAS的青年脑梗死患者的临床表现和辅助检查,并与MELAS患者相对比。同时结合文献复习,分析卒中发作与卒中样发作的相同与不同之处。结果所有10例患者均出现一次以上卒中发作,以偏侧肢体无力最常见,其次为偏侧肢体麻木、偏盲、失语等。其中8例患者存在一种以上血管病相关的危险因素。头部MRI发现皮质和皮质下白质病变,均累及多个脑叶,数月后复查可见软化灶形成。所有患者均同时存在基底节和/或深部白质病变。MRA均发现动脉闭塞或狭窄。结论本组患者卒中发作以偏瘫最常见。影像学上以皮质受累为主,同时常出现深部白质和/或基底节病变,后期可形成软化灶。     

Alzheimer-type pathology in a patient with mitochondrial myopathy,encephalopathy, lactic acidosis and stroke-like episodes (MELAS)

A 53-year-old Japanese woman with a point mutation in mitochondrial DNA (tRNA^Leu(UUR), nt3243) consistent with mitochondrial myopathy, encephalopathy, lactic acidosis and stroke-like episodes (MELAS) and Alzheimer-type brain pathology is reported. This woman had suffered myopathy and psychosis without any clinical evidence of, stroke-like episodes during the last 10 years of her life, and had died after an accident. At autopsy 30 h post mortem, a part of the brain was snap frozen for biochemical and histochemical studies, and the remaining part was processed for a routine examination and electron microscopy. In the brain there were no ischemic lesions. Instead, primitive/diffuse senile plaques were found throughout the brain, predominantly in the frontal and temporal lobes, while Alzheimer neurofibrillary tangles were found only in the parahippocampal gyrus. These plaques were positive for β-protein and mostly negative for tau protein, ubiquitin, neurofilaments, α-choline acetyltransferase, and acetylcholinesterase. Mutations in codon 331 of the ND2 gene as well as codons 693, 713 and 717 of the β-amyloid precursor protein gene, known to be responsible for some cases of familial Alzheimer disease, were not found. Furthermore, coincidental Down syndrome was ruled out by chromosome analysis. The results suggest a possible correlation between this mitochondrial DNA abnormality and Alzheimer-type pathology. Received: 30 January 1996 / Revised, accepted: 26 March 1996     

MELAS型线粒体脑肌病的脑部MRI表现(附三例报道)

目的 总结分析MELAs型线粒体脑肌病的脑部MRI表现.方法 回顾性分析3例MELAS型线粒体脑肌病患者的临床资料和MRI表现.结果 MRI显示MELAS型线粒体脑肌病表现为以颞叶、顶、枕叶为主的皮层及皮层下白质病变,病变多呈双侧非对称性分布,部分患者以累及基底节为主要表现,T2WI和液体衰减翻转恢复序列对病变的显示有独特的作用,DWI、ADC图及增强扫描能够诊断及鉴别诊断线粒体脑肌病及卒中,MRS对其诊断可以起到辅助作用.结论 MELAS型线粒体脑肌病在MRI图像上具有特征性,MRI影像表现结合临床资料对本病多能作出正确的诊断.     

MELAS: a neuropsychological and radiological follow-up study. Mitochondrial encephalomyopathy,lactic acidosis and stroke

We report on a patient with long standing, full-blown mitochondrial encephalomyopathy, lactic acidosis and stroke-like episodes (MELAS). In contrast to earlier publications, detailed neuropsychological assessment revealed no dementia but a pattern of distinct cognitive deficits with marked impairment of visuo-constructive and executive functions. Focal lesions and progressing atrophy mainly of the basal ganglia and the temporo-parieto-occipital area with preservation of hippocampal and entorhinal structures were present. Furthermore, a 4-year follow-up assessment revealed an increasing deterioration of distinct cognitive functions, including phasic alertness, tactile functions and the discrimination of tone pitch and rhythm. This may be because of chronic regional metabolic disturbances, as there was no further stroke-like episode in that period of time.     

肌肉活检未见显著异常的MELAS综合征：3例病理病例分析

目的：探讨肌肉活检未见显著线粒体异常病理改变的MELAS综合征的临床、神经影像及分子病理学特点。方法：3例患者（1男,2女）,发病年龄13-18岁,1例以癫痫首发,2例以头痛呕吐首发。3例均有家族史,符合母系遗传方式。主要临床表现包括：癫痫发作(3/3例),视物下降(3/3例),发作性头痛(2/3例),听力减退 (2/3例),身材矮小（2/3例）,智能减退 (2/3例),精神异常(1/3例)。3例患者均进行肱二头肌活检。应用限制性片段长度多态方法对患者尿液mtDNA A3243G位点突变进行分析。结果：3例患者血清肌酸激酶正常,空腹血乳酸增高。肌电图检查正常。头颅MRI示T2异常高信号,枕叶3例,颞叶2例,顶叶2例,动态检查卒中样病灶呈迁徙样改变者1例。肌活检在3例患者均可见个别SDH深染的肌间小血管,未见破碎红肌纤维和COX阴性肌纤维。3例患者mtDNA基因突变分析发现均存在A3243G点突变。结论：MELAS综合征的临床异质性明显,肌无力症状可以不突出,而且肌肉活检可以没有破碎红肌纤维和COX阴性肌纤维,SDH深染的小血管可能有重要提示价值。     

Neuroimaging of stroke-like episodes in MELAS

Mitochondrial myopathy, encephalopathy, lactic acidosis and stroke-like episodes (MELAS) shows sudden neurological deficits that are called ‘stroke-like episodes’. With regard to the pathophysiology of stroke-like episodes, so-called mitochondrial angiopathy and cytopathy theories have been proposed, but the subject is still controversial. To clarify this matter and to contribute to the development of a treatment for MELAS, we review here current neuroimaging research and consider the pathophysiology of stroke-like lesions. With regard to diffusion-weighted imaging findings, early reports often showed an elevated apparent diffusion coefficient (ADC) in stroke-like lesions; this was considered to be mainly vasogenic edema in the acute phase and is a different pattern than that in stroke. However, there has recently been an increase in the number of reports of a decrease in ADC; these cases are considered to be cytotoxic edema in the acute phase, which is compatible with stroke. With regard to ¹H-magnetic resonance spectroscopy findings in stroke-like lesions, a decrease in N-acetylaspartate and an increase in lactate have been reported. With regard to single photon emission computed tomography findings for stroke-like lesions in MELAS, an overall trend is hyperperfusion in the acute stage (within 1 month) of stroke-like episodes and hypoperfusion in the chronic stage (several months later). With regard to positron emission tomography, nearly all of these reports are consistent with the mitochondrial cytopathy theory. With regard to neuropathology in MELAS, the most common findings during the chronic stage of stroke-like episodes include foci of necrosis and peculiar vascular changes (abnormalities of mitochondria in small arteries). Concerning the pathology of the acute stage of stroke-like episodes, extensive petechial hemorrhage along the gyri of the cortex corresponding to acute stroke-like lesions has been reported. To clarify the true pathophysiology of stroke-like episodes, we offer three suggestions. First, we must define the precise onset of stroke-like episodes. Second, current studies are limited by the difficulty of imaging just before and just after (within a few minutes) the onset of stroke-like episodes. Third, we hope to establish an experimental animal model. We should conduct a simultaneous multimodal imaging and histological study just before and just after (within a few minutes) the onset of stroke-like episodes in an experimental animal model.     

线粒体脑肌病伴高乳酸血症和卒中样发作综合征的线粒体DNA突变特点

目的 探讨线粒体脑肌病伴高乳酸血症和卒中样发作（MELAS综合征）的分子遗传学特点。方法 用聚合酶链反应-限制片段长度多态性（PCR-RFLP）方法检测来自7个家庭的9例MELAS患者及其部分母系亲属的肌肉和（或）外周血细胞的mtDNA的A3243G和T3271C点突变,并进行突变型mtDNA的定量。结果 在9例患者和1例亲属的肌肉和（或）外周血细胞中检测到A3243G点突变,未检测到T3271C突变。在这10例A3243G阳性标本中,外周血细胞（9例）的突变型mtDNA的比例为26.8%-50.3%;肌肉组织（4例）的突变型mtDNA的比例为46.8%-61.0%;对3例患者同时进行了肌肉和血细胞标本的检测,突变型mtDNA的比例肌肉组织均高于血细胞。对6个家庭的部分母系亲属的血细胞研究表明：只有1例先证者的同胞有此突变;另外3例先证者的母亲及2例先证者的同胞均未检测到此突变。另外有2例先证者的儿子临床表现符合MELAS,血中也检测到此突变。结论 mtDNA A3243G突变在本组MELAS综合征中的发生率较高,并且可在不同组织中检测到此突变,与国外文献报道一致;但国外报道多为母系遗传,而我们的病例以散发的居多,推测是由于新生突变所致。