多模式MRI对线粒体脑肌病的诊断价值

目的探讨线粒体脑肌病多模式MRI影像学特点。方法对21例线粒体脑肌病患者的脑MRI、MRA、MRS影像资料进行分析。结果 MRI：线粒体脑肌病病灶多位于颞、枕、顶叶,病灶具有不符合脑动脉分布及游走性的特点;4例患者病灶对称性累及豆状核、丘脑和（或）尾状核;2例患者大脑、小脑、脑干萎缩,脑室增大,脑沟增宽。病灶均呈T1低信号、T2高信号,陈旧性病灶T2信号稍高;MRA：10例新发病灶处脑动脉及其远端分支较对侧相应脑动脉增粗,信号增强;MRS：14例新鲜病灶可检出倒置的乳酸双峰波及NAA/Cr降低。结论线粒体脑肌病的多模式MR影像学特点有一定的特异性,对线粒体脑肌病的诊断有一定价值。     

Applications of magnetic resonance spectroscopy to diagnosis and monitoring of mitochondrial disease

Magnetic resonance spectroscopy (MRS) can now be performed on routine high-field clinical magnetic resonance imaging systems. Over the last decade it has provided several useful insights into the pathophysiology of mitochondrial disorders. More recently, the feasibility of applications to clinical diagnosis and monitoring have been demonstrated. Exciting new work suggests that carefully supervised physical conditioning in conjunction with sodium dichloroacetate administration can markedly enhance both biochemical measures of aerobic metabolism and functional performance of patients with mitochondrial myopathies.

---

Sommario La risonanza magnetica spettroscopica (MRS) può oggi essere effettuata di routine in apparecchi clinici di risonanza magnetica. Nell'ultima decade essa ha fornito importanti informazioni nella patofisiologia dei disordini mitocondriali. Più recentemente sono state dimostrate le sue possibilità di applicazione nella diagnosi clinica e nel monitoraggio di pazienti neurologici. Nuovi ed interessanti studi suggeriscono che un allenamento attentamente supervisionato in congiunzione con trattamento con dicloroacetato è capace di migliorare i parametri biochimici e la performance di pazienti con miopatie mitocondriali.

     

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.     

Stroke-like episodes in familial mitochondrial encephalomyopathy: clinical and biochemical aspects

Summary Acute episodes of focal neurological dysfunction are a well-recognized complication of the mitochondrial encephalomyopathies. Because of rapid remission, biochemical tests and other diagnostic procedures are mostly performed after the acute phase. We report the case of a patient suffering from mitochondrial disease manifesting primarily with seizures, progressive deafness and dementia, who experienced multiple stroke-like episodes. Other members of the family with evidence of mitochondrial dysfunction are presented briefly. EEG and biochemical findings in the acute stage are correlated with clinical symptoms, showing characteristics distinct from the chronic illness. The possible involvement of dietary factors in the provocation of stroke-like episodes is discussed and regulation of glucose intake suggested as a strategy in the prevention of stroke-like episodes.     

线粒体脑肌病的MR诊断与鉴别诊断:附4例报告并文献复习

目的:探讨线粒体脑肌病(ME)的MR诊断与鉴别诊断。方法:分析4例线粒体脑肌病患者的临床`实验室及MRI表现,其中4例行常规MRI扫描,1例行MRA扫描。结果:3例病变主要累及两侧大脑皮层和皮层下,1例主要表现为白质内改变,均表现为长T1长T2信号,2例合并脑萎缩,MRA示1例未见明显改变。结论:MRI对线粒体脑肌病的脑内病变敏感,当年轻患者出现非典型性脑梗死表现,应考虑到线粒体脑肌病的可能。     

线粒体脑肌病的临床、MRI及病理学诊断

目的探讨成人线粒体脑肌病（ME）的临床、MRI及病理学诊断方法。方法回顾性分析5例ME患者的临床表现、影像学和组织病理学特征，5例患者均行MRI检查、脑电图、肌肉活检及病理检查，其中2例行脑活检。结果患者主要临床表现为以抽搐为主要特征的癫痫样发作、运动不耐受及发作性头痛和呕吐、视听障碍等。脑电图为广泛中、重度异常。血乳酸水平升高。肌肉活检可见不整红边纤维。脑活检可见大量神经细胞空泡变性、减少和脱失。MRI检查示广泛的大脑皮层及皮层下长T1、长T2异常信号，呈灶状、囊状改变伴有脑萎缩，或者灰质核团对称性长T1、长T2信号，病变均未见强化。结论根据ME的临床及影像学特点，结合肌肉活检可对该病做出早期诊断。     

A 31P-magnetic resonance spectroscopy and biochemical study of the movbr mouse: Potential model for the mitochondrial encephalomyopathies

³¹P-magnetic resonance spectroscopy (³¹P-MRS) provides new biochemical information on mitochondrial disorders affecting brain and muscle. To elucidate the mechanisms of mitochondrial abnormalities, however, animal models are needed. We assessed the mo^vbr (mottled viable brindled) mouse for its value in studying (1) energetics of a mitochondrial disorder and (2) ³¹P-MRS changes associated with mitochondrial abnormalities in vivo. The maximal activity of succinate-cytochrome c reductase was significantly reduced in mo^vbr muscle compared to controls, whereas cytochrome oxidase activity was only reduced in mo^vbr brain. ³¹P-MRS of mo^vbr brain showed an increased pH, but no changes in any metabolite ratios. The phosphocreatine (PCr) recovery rate after exercise was reduced in muscles from mo^vbr mice, indicating impairment of oxidative metabolism. We conclude that mo^vbr brain and muscle tissue have biochemical abnormalities consistent with mitochondrial impairment. The PCr recovery rate, measured by ³¹P-MRS, was sensitive to the muscle abnormality. This strain is best described as having chronic mitochondrial dysfunction. © 1997 John Wiley & Sons, Inc. Muscle Nerve 20: 1352–1359, 1997     

Intraoperative magnetic resonance imaging in epilepsy surgery: A systematic review and meta-analysis

This systematic review investigated the added value of intraoperative magnetic resonance imaging (iMRI)-guidance in epilepsy surgery, compared to conventional non-iMRI surgery, with respect to the rate of gross total resection (GTR), postoperative seizure freedom, neurological deficits, non-neurological complications and reoperations. A comprehensive literature search was conducted using Medline, Embase, PubMed, and Cochrane Reviews databases. Randomized control trials, case control or cohort studies, and surgical case series published from January 1993 to February 2021 that reported on iMRI-guided epilepsy surgery outcomes for either adults or children were eligible for inclusion. Studies comparing iMRI-guided epilepsy surgery to non-iMRI surgery controls were selected for meta-analysis using random-effects models. Forty-two studies matched the selection criteria and were used for qualitative synthesis and ten of these were suitable for meta-analysis. Overall, studies included various 0.2–3.0 Tesla iMRI systems, contained small numbers with heterogenous clinical characteristics, utilized subjective GTR reporting, and had variable follow-up durations. Meta-analysis demonstrated that the use of iMRI-guidance led to statistically significant higher rates of GTR (RR = 1.31 [95% CI = 1.10–1.57]) and seizure freedom (RR = 1.44 [95% CI = 1.12–1.84]), but this was undermined by moderate to significant statistical heterogeneity between studies (I² = 55% and I² = 71% respectively). Currently, there is only level III-2 evidence supporting the use of iMRI-guidance over conventional non-iMRI epilepsy surgery, with respect to the studied outcomes.     

Superior temporal gyrus and P300 in schizophrenia: a combined ERP/structural magnetic resonance imaging investigation

Decrement of the auditory P300 component of the event-related potentials (ERP) is a robust finding in schizophrenic patients and seems to be most pronounced in the left temporal region. Structural MRI studies support the hypothesis that regional structural brain differences in this patient group include reduced volume in temporal lobe structures. The aim of the presented study was to investigate the possible gray matter volume reductions in the left posterior superior temporal gyrus (STG) and the P300 reduction and left 相似文献   

Early-onset encephalomyopathy associated with tissue-specific mitochondrial DNA depletion: A morphological,biochemical and molecular-genetic study

A male infant, born from consanguineous parents, suffered from birth with a progressive neuromuscular disorder characterized by psychomotor delay, hypotonia, muscle weakness and wasting, deep-tendon areflexia and spastic posture. High levels of lactic acid in blood and cerebrospinal fluid suggested a mitochondrial respiratory chain defect. Muscle biopsy revealed raggedred and cytochromec oxidase-negative fibres, lipid accumulation and dystrophic changes. Multiple defects of respiratory complexes were detected in muscle homogenate, but cultured fibroblasts, myoblasts and myotubes were normal. Southern blot analysis showed markedly reduced levels of mitochondrial DNA (mtDNA) in muscle, while lymphocytes, fibroblasts and muscle precursor cells were normal. Neither depletion of mtDNA nor abnormalities of the respiratory complexes were observed in innervated muscle fibres cultured for as long as 4 months. No mutations were observed in two candidate nuclear genes,mtTFA andmtSSB, retro-transcribed, amplified and sequenced from the proband's mRNA. Sequence analysis of the mtDNA D-loop and of the origin of replication of the mtDNA light strand failed to identify potentially pathogenic mutations of these replicative elements in the proband's muscle mtDNA. Our findings indicate that mtDNA depletion is due to a nuclear encoded gene and suggest that the abnormality underlying defective mtDNA propagation must occur after muscle differentiation in vivo.     

肌萎缩侧索硬化38例弥散张量成像及磁共振波谱表现

目的 研究肌萎缩侧索硬化(ALS)的弥散张量成像(DTI)和磁共振波谱(MRS)特点,并对ALs的病理生理机制进行初步探讨.方法 ALS患者38例,单纯下运动神经元受累疾病患者8例,混合型颈椎病5例和健康对照34名,行常规头颅MRI、DTI和1H-MRS测定.结果 21%(8/38)的ALS患者可见T2 FLAIR序列双侧锥体束走行异常高信号,强度高于皮质灰质.ALS组和健康对照组相比,中央前回(ALS组0.492±0.059,健康对照组0.552 4-0.045,F=17.150,P<0.01)、内囊后肢(分别为0.679 ±0.048、0.727±0.031,F=19.481,P<0.01)、大脑脚(左侧0.740±0.038、0.761±0.024,F=4.290;右侧0.720±0.044、0.746±0.034,F=3.264,均P<0.01)的部分各向异性(FA值)显著降低;ALS组上述部位的N-乙酰大冬氨酸/肌酸(NAA/Cr)值和健康对照组相比亦存在显著降低.AKS组各部位FA值降低百分率分别为10.9%、6.6%、2.8%～3.5%,以中央前回处最为显著;内囊前肢、枕叶处的FA值亦有不同程度降低.结论 DTI和MRS枪测不仪有助于ALS患者:运动神经元高位受累的确认和ALS的诊断和鉴别诊断,而且还可促进对ALS病理机制和病损分布的了解.     

磁共振多体素波谱技术对颞叶癫痫的定位研究

目的评价磁共振多体素波谱扫描技术对颞叶癫痫的定位诊断价值。方法选择具有明显颞叶癫痫表现,并经脑电图检查定位诊断明确的单侧颞叶癫痫患者30例作为研究对象;排除M R I检查存在颅脑肿瘤、脑血管畸形等症状性癫痫患者。患者均行常规M RI及双侧海马区多体素波谱扫描,完成检查后将以代谢物峰值含量为灰阶的伪彩图与倾斜冠状重度T2W I图像进行融合,测量双侧海马区N-乙酰天冬氨酸、胆碱峰值含量和胆碱/N-酰天冬氨酸比值,并直观分析双侧海马区两代谢物的分布情乙况。结果患侧N-乙酰天冬氨酸峰值含量为(13587.61±3913.99)M R units,健侧为(17683.10±5610.61)M R units,患侧低于健侧差异有显著性意义(t=6.728,P<0.001);患侧胆碱/N-乙酰天冬氨酸比值为(1.26±0.11),健侧比值为(1.01±0.14),患侧高于健侧差异亦有显著性意义(t=7.883,P<0.001)。将两代谢物含量及比值伪彩图与常规M RI图像进行融合,可直观发现双侧海马区N-乙酰天冬氨酸峰值含量及胆碱/N-酰天冬氨酸比值存在明显差异。结论磁共振多体素波谱技术不仅可以通过对某些代谢物含量乙的定量分析进行癫痫灶的定位、定侧诊断,还可通过常规M RI图像与多体素磁共振波谱图像的融合图像直观评价代谢物分布状态,描记癫痫灶的大致轮廓,为制定手术方案提供依据。     

脑静脉窦血栓形成患者磁共振成像与磁共振静脉血管成像联合诊断的价值

目的：探讨脑静脉窦血栓（cerebral venous sinus thrombosis ,CVST ）形成患者磁共振成像与磁共振静脉血管成像联合诊断的价值。方法选取脑静脉窦血栓患者40例进行分析。诊断过程中,全体患者均接受磁共振（magnetic resonance venography ,MR）平扫,数字减影血管造影（digital subtraction angiography ,DSA）检查12例,MRV检测6例,增强扫描22例。结果单一横窦受累6例,上矢状窦、乙状窦及横窦受累8例,单一乙状窦受累16例,横窦和上矢状窦联合受累10例。所有患者磁共振成像（magnetic resonance venography ,MRI）及磁共振静脉成像（magnetic resonance venography ,MRV）均表现出信号改变。22例患者增强扫描显示脑静脉非正常强化,但静脉窦内部血栓未强化。M RV检查6例患者及DSA 12例患者的结果显示其受累静脉窦不明显、狭小、不规则,且出现侧支血管形成现象。结论 M RI与M RV联合诊断对于脑静脉窦血栓形成的诊断具有较好效果。     

癫痫患儿头颅氢质子磁共振波谱改变的研究

目的 探讨癫痫患儿头颅氢质子磁共振波谱(1H-MRS)影像学改变特点及临床意义.方法 选取自2008年3月至2011年3月在广东省人民医院就诊的癫痫患儿64例(癫痫组)及对照组10例(门诊体检健康儿童)为观察对象,癫痫组根据头颅MR有无结构异常再分为MR正常组和MR异常组.全部观察对象行头颅海马区1H-MRS检查.选取N-乙酰天门冬氨酸/(胆碱+肌酸)[NAA/(Cho+Cr)]为观察指标,比较3组之间的差别. 结果 3组成员左右侧海马NAA/(Cho+Cr)比较差异均无统计学意义(P＞0.05);组间NAA/(Cho+Cr)比较差异有统计学意义(P＜0.05).其中对照组与MR正常组、对照组与MR异常组间差异有统计学意义(P＜0.05),但MR正常组与MR异常组间差异无统计学意义(P＞0.05). 结论 癫痫患儿的1H-MRS改变较MR敏感,MRS可早于MR发现癫痫异常改变.     

线粒体脑肌病伴高乳酸血症和卒中样发作的诊断

目的 分析总结线粒体脑肌病伴高乳酸血症和卒中样发作(MELAS)的临床表现和辅助检查结果,探讨在MELAS诊断中存在的问题,提出MELAS早期临床诊断的可行性.方法 归纳总结34例MELAS患者的临床表现,寻找对MELAS患者相对特异的症状组合.同时总结分析各项辅助检查结果,结合文献复习解读血和脑脊液的乳酸水平、神经影像、肌肉活体组织检查(活检)和基因检查对于MELAS诊断的意义和局限性.结果 本组患者最常见的临床表现依次为:癫癎发作、头痛、智能下降、卒中样发作、发育异常、四肢无力和易疲劳、眼肌麻痹.血空腹乳酸或运动后乳酸升高23例(67.6%).32例头颅MRI异常的患者最常见的受累部位依次为枕叶、顶叶、颞叶、基底节、额叶、小脑和深部白质.32例患者行肌肉活检,有阳性发现的共24例(75%),阴性的8例(25%).14例患者行基因检查,9例发现A3243G位点突变,5例未发现该位点突变.结论 认识MELAS的各种临床表现,争取在卒中样发作出现前早期诊断是完全可行的.     

Study of chronic schizophrenics using 31P magnetic resonance chemical shift imaging.

Phosphorus-31 chemical shift imaging showed regional abnormalities of in vivo 31P NMR spectra in the brains of chronic schizophrenic patients. In the left temporal region, the level of % phosphodiesters (PDE) was increased and the level of % gamma alpha beta-ATP (obtained by summation of gamma-ATP, alpha-ATP, and beta-ATP) was decreased. In the basal ganglia, the levels of % PDE were decreased and the level of % phosphomonoesters was increased. The levels of % gamma alpha beta-ATP were increased in the right basal ganglia. The level of % phosphocreatine was decreased in the frontoparietal region. These findings may represent different patterns of dysfunction of membrane phospholipid bilayers and high-energy phosphate metabolism in the specific cerebral regions.     

Automated morphometric magnetic resonance imaging analysis for the detection of periventricular nodular heterotopia

Purpose: To describe a novel magnetic resonance imaging (MRI) postprocessing technique for the detection of periventricular nodular heterotopia (PNH) and to evaluate its diagnostic value. The method is a further development of voxel‐based morphometric analysis with focus on a region of interest around the lateral ventricles to increase the sensitivity and specificity for automated detection of abnormally located gray matter in this area. Methods: T₁‐weighted MRI volume data sets were normalized and segmented in statistical parametric mapping (SPM 5 software), and the distribution of gray matter was compared to a normal database. As a new approach, individual masks derived from segmentation of the lateral ventricles were used to restrict the search for ectopic gray matter to the periventricular area. PNH were automatically detected by localizing the maximum deviation from the normal database in this area, provided that the z‐score exceeded a certain threshold. The optimal z‐score threshold for maximum sensitivity and specificity was determined by a receiver operating characteristic (ROC) curve analysis. The method was applied in 40 patients with PNH and 400 controls. Key Findings: PNH were detected in 37 of 40 patients, and false positives were found in 34 of 400 controls, amounting to 92.5% sensitivity and 91.5% specificity. In 17 of the patients in whom PNH could be identified, these lesions had been overlooked in the past, and in 8 patients even in the high‐resolution MRI subsequently used for postprocessing. Significance: The results suggest that automated morphometric MRI analysis with focus on ectopic gray matter in the periventricular areas facilitates the evaluation of MRI data and increases the sensitivity for the detection of PNH.     

Standardization of amygdalohippocampectomy with intraoperative magnetic resonance imaging: preliminary experience

PURPOSE: Intraoperative magnetic resonance imaging (IMRI) is an extremely useful neurosurgical tool in surgeries in which the extent of resection is known to have a significant impact on outcome. Residual hippocampus is the most common cause of recurrent seizures after temporal lobectomy for medial temporal lobe epilepsy. Although the risk/benefit ratio of a policy of universal radical hippocampal resection is not known, we hypothesized that IMRI would aid in the intraoperative assessment of the extent of hippocampal resection and assist in accomplishing a complete hippocampectomy. METHODS: Five consecutive patients with medically intractable medial temporal lobe epilepsy underwent a radical amygdalohippocampectomy as part of the their surgery for epilepsy. IMRI was used before surgery and after an initial resection. The quality of images was assessed. Postoperative MR images were evaluated by a radiologist to determine the extent of resection of the amygdala, hippocampus, and parahippocampal gyrus. RESULTS: There were no perioperative infections. After a mean follow-up of 10 months, all patients are seizure free. T(1)-weighted coronal intraoperative images were judged adequate at visualizing the medial structures in all patients. T(2) and fluid-attenuated inversion recovery (FLAIR) images did not provide useful information. Postoperative MR images indicated that a complete hippocampectomy had been achieved in all patients. CONCLUSIONS: IMRI is a useful adjunct in the surgical treatment of medial temporal lobe epilepsy and perhaps the most reliable method of standardizing a complete hippocampectomy. T(1)-weighted coronal images are the most helpful sequence.     

Conventional MRI and MR spectroscopy in nonclassical mitochondrial disease: report of three patients with mitochondrial DNA deletion

Objects The objectives were to present magnetic resonance imaging (MRI) and magnetic resonance spectroscopy (MRS) findings in three patients with deletion on mitochondrial DNA (mtDNA) and nonclassical mitochondrial disorders (NCMD), correlating these findings with the percentage of deleted mtDNA.Results Our study confirms the high prevalence of white matter (WM), basal ganglia, and posterior fossa lesions in NCMD, ranging from mild to severe involvement. The subcortical WM, caudate, thalamus, globus pallidus, and dorsal brain stem were more frequently affected. A lactate peak was the most frequent finding at the MRS. We found a correlation between the percentage of mtDNA deletion and degree of MRS abnormalities.Conclusions Our findings showed that MRS is a useful investigational tool in patients with NCMD. Supplementary studies are necessary to elucidate the correlation of quantitative mtDNA deletion and neuroimaging phenotype.