麻痹性痴呆患者磁共振波谱与认知障碍的相关研究

目的应用氢质子磁共振波谱(1H-proton magnetic resonance spectroscopy,1H-MRS)技术,探索麻痹性痴呆(general paresis of the insane,GPI)患者海马区代谢物水平特点。方法纳入GPI患者52例,健康中老年对照(normal control,NC)38例进行双侧海马区1H-MRS检查,比较N-乙酰天门冬氨酸(N-acetylaspartate,NAA)/肌酸、胆碱/肌酸,NAA/胆碱,胆碱/NAA和肌醇/肌酸的水平;并同日进行简易精神状态检查(MMSE)、蒙特利尔认知检查量表(Mo CA)量表评定,探索GPI患者海马区代谢物水平与病程严重程度的相关性。结果 GPI和NC两组比较:GPI组的双侧海马区NAA/Cr水平较NC组明显下降,差异有统计学意义(P0.001)。不同痴呆程度的GPI患者比较:重度痴呆组左侧海马区NAA/Cr水平较轻度痴呆组明显下降,差异有统计学意义(P0.001)。重度痴呆组右侧海马区的Cho/Cr和m I/Cr较轻度痴呆组升高(P0.05)。GPI组左侧海马区的NAA/Cr与MMSE、Mo CA呈正相关(P0.001)。结论 GPI患者均存在双侧海马区神经元损伤。且痴呆程度越重,左侧海马神经元损害越严重。     

磁共振波谱对原发性癫痫患者海马病变的诊断价值

目的 探讨磁共振波谱(MRS)对原发性癫痫患者海马病变的诊断价值.方法 对38例原发性癫痫患者(癫痫组)和30例健康志愿者(正常对照组进行EEG、MRI和MRS检查.采用MRS检测双侧海马N-乙酰天门冬氨酸(NAA)、肌酸复合物(Cr)和胆碱复合物(Cho)的水平.结果 正常对照组EEG、MRI、MRS检查均无异常.癫痫组EEG检查发现痫样放电30例(78.9％);MRI检查发现海马异常15例(39.5％),其中双侧异常10例、单侧异常5例;MRS检查发现海马异常35例(92.1％),其中双侧异常30例、单侧异常5例.癫痫组病侧海马Cho/Cr和Cho/NAA显著高于对侧海马及正常对照组(均P＜ 0.001),NAA/(Cho+Cr)显著低于对侧海马及正常对照组(均P＜0.001).癫痫组病侧海马头部的NAA/(Cho+ Cr)明显低于体部及尾部(均P＜0.001).结论 MRS可提高原发性癫痫患者海马病变的检出率,且可显示海马的生化改变,对原发性癫痫具有很高的诊断价值.     

急性脑梗死患者脑组织磁共振波谱研究

目的研究基底节区急性脑梗死患者脑组织磁共振波谱(MRS)的改变。方法应用MRS检测50例一侧基底节区梗死患者(脑梗死组)及50例其他疾病患者(对照组)双侧基底节区的N-乙酰天冬氨酸(NAA)、胆碱复合物(Cho)、肌酸复合物(Cr)和乳酸(Lac)水平及NAA/Cr、Cho/Cr比值。结果脑梗死组病灶侧Cho及Cr水平均显著低于非病灶侧(均P<0.05),NAA、Lac水平及NAA/Cr、Cho/Cr比值的差异无统计学意义。脑梗死组病灶侧及非病灶侧Cho、NAA及Cr水平均明显低于对照组病灶对应区(P<0.001～0.05),而Lac水平明显高于对照组病灶对应区(均P<0.05)。与对照组病灶对应区比较,脑梗死组病灶侧Cho/Cr比值显著升高,非病灶侧NAA/Cr比值显著降低(均P<0.05)。结论基底节区梗死急性期病灶侧及对侧脑组织均有明显的代谢障碍,且病灶区代谢异常较对侧更明显。     

1H 磁共振波谱分析在评价多发性硬化轴索损害中的临床价值

目的 探讨1H磁共振波谱分析(1H magnetic resonance spectroscopy,1H MRS)在评价多发性硬化(multiple sclerosis,MS)轴索损害中的临床价值.方法 对36例MS患者(MS组)和26例健康志愿者(健康对照组)行头颅MRI及1H MRS检查,计算脑部代谢产物N-乙酰天门冬氨酸(NAA)、肌酸(Cr)、胆碱(Cho)的水平并比较两组间NAA/Cr和Cho/Cr比值的差异.采用扩展的功能障碍分级法(EDSS)对MS患者进行评分并分析其NAA/Cr、Cho/Cr 比值与EDSS评分间的相关性.结果 MS组NAA/Cr比值(1.44±0.44)显著低于对照组(1.89±0.49)(P＜0.05),MS组Cho/Cr比值(1.92±0.80)显著高于对照组(1.48±0.36)(P＜0.05).MS组NAA/Cr 比值与EDSS评分之间呈负相关(r=-0.503,P＜0.05),Cho/Cr比值与EDSS评分之间无相关性(r=0.14,P＞0.05).结论 MS患者脑部病灶NAA/Cr比值下降可提示MS患者轴索损害的程度.     

成人OSAHS患者认知功能障碍影响因素及海马区磁共振波谱成像临床价值研究

目的研究成人阻塞性睡眠呼吸暂停低通气综合征(obstructive sleep apnea-hypopnea syndrome,OSAHS)患者认知功能障碍及影响因素,分析海马区磁共振波谱成像对OSAHS患者认知功能障碍的临床价值。方法纳入71例成年人,根据多导睡眠监测结果分为OSAHS组和非OSAHS组,比较两组基线资料、多导睡眠监测值、蒙特利尔认知评估(montreal cognitive assessment,MoCA)值、海马区磁共振波谱(magnetic resonance spectroscopy,MRS)值;对OSAHS组进行二元Logistic回归分析及MoCA总分与海马区MRS线性回归分析。结果 OSAHS组血红蛋白比非OSAHS组高(P0.05);OSAHS组在视空间与执行、延迟记忆、注意力、MoCA总分均低于非OSAHS组(P0.05);OSAHS组在呼吸暂停低通气指数(apnea-hypopnea index,AHI)、最长暂停时间、平均暂停时间均高于非OSAHS组,而最低血氧饱和度(SaO_2)、平均血氧饱和度(SaO_2)均低于非OSAHS组(P0.05);最低SaO_2可能是认知功能障碍的独立保护因素(P0.05);OSAHS组海马区MRS中N-乙酰天门冬氨酸/肌酸(NAA/Cr)、胆碱/肌酸(Cho/Cr)、N-乙酰天门冬氨酸/胆碱(NAA/Cho)均下降(P0.05);MoCA总分和NAA/Cr呈正相关(调整R2=0.63,P0.05)。结论 OSAHS认知功能障碍主要在视空间与执行、延迟记忆、注意力等方面;最低SaO_2可能是认知功能障碍的独立保护因素;OSAHS组NAA/Cr降低、Cho/Cr、NAA/Cho降低且NAA/Cr值随着MoCA总分降低而降低,说明MRS对客观评估OSAHS患者认知障碍及海马代谢变化方面具有重要的临床价值。     

颞叶癫痫的磁共振波谱学定侧研究

目的　探讨磁共振波谱学 (magneticResonanceSpectroscopy ,MRS)在颞叶癫痫术前定位中的作用。方法　取 18例接受手术治疗的顽固性颞叶癫痫患者为研究对象 ,其术前已接受EEG、MRI和PET等检查获得定位。接受双侧颞叶内侧的MRS检查 ,测定其N -乙酰天门冬氨酸 (NAA)、肌酐 (Cr)和胆碱 (Cho)含量 ,并计算NAA/(Cr Cho)的比值 ;以NAA/(Cr Cho) <0 .6 8和双侧NAA/(Cr Cho)比值的差别 >7%为标准。结果　在18例病例中 16例患侧颞叶MRS检查结果异常 ,其中 9例为患侧MRS异常 ,7例为双侧MRS异常 ,以患侧为重 ,2例患者的比值正常 ;MRS的敏感性高于MR(15 /18) ,与MR结合 ,可对 17例患者进行术前定侧。结论　MRS对颞叶癫痫的定侧诊断有较高的准确性 ,为颞叶癫痫的定位诊断提供新的手段 ;与MRI、PET等手段结合使用 ,可进一步提高对颞叶癫痫诊断的敏感性和准确性     

抑郁症首次发病患者海马磁共振质子波谱成像的研究

目的 探讨抑郁症首次发病患者海马的磁共振质子波谱(1H-MRS)代谢物质的变化.方法 对99例首次发病的抑郁症患者和26例健康对照组行磁共振常规扫描及1H-MRS检查,测量双侧海马N-乙酰天门冬氨酸(NAA)、胆碱复合物(Cho)和肌酸(Cr)三种代谢物质,计算NAA/Cr和Cho/Cr比值.结果 抑郁症患者海马NAA/Cr左右侧比值(1.23±0.16;1.16±0.16)低于对照组NAA/Cr左右侧比值(1.38±0.23;1.31±0.26),差异有显著性(P<0.05);抑郁症患者海马体部Cho/Cr左右侧比值(1.19±0.14;1.18±0.12)高于对照组Cho/Cr左右侧比值(1.14±0.12;1.11±0.14),差异有显著性(P<0.05).对照组左右侧NAA/Cr和Cho/Cr比较差异无显著性(P>0.05).抑郁症组右侧NAA/Cr低于左侧,差异显著(P<0.05);左侧Cho/Cr高于右侧,差异不明显(P>0.05).结论 抑郁症患者可能存在双侧海马神经细胞代谢功能障碍,右侧神经细胞功能障碍较左侧明显.     

轻度阿尔茨海默病患者磁共振成像及磁共振氢质子波谱研究

目的　探讨磁共振成像 (magneticresonanceimaging,MR)及磁共振氢质子波谱 (1H magneticresonancespectroscopy ,1H MRS)对轻度阿尔茨海默病 (Alzheimerdisease ,AD)患者的早期诊断。方法　对 18例临床确诊轻度AD患者和 2 0名正常对照者的MR及1H MRS进行分析 :MR上观察两组的海马回钩间距 (AB)及同层颅腔左右径 (CD)并计算两者间 (AB/CD)的比值 ;对两组额、颞叶区行1H MRS检测 ,得到N 乙酰天门冬氨酸 (N acetylaspartate ,NAA)峰、肌酸 (creatine ,Cr)峰、胆碱 (choline ,Cho)峰的积分值及计算NAA/Cr、NAA/ (Cr Cho)。对 2组检测值 ( x±s)行t检验。结果　AD组的AB =(2 7 5 3± 2 1)mm ,AB/CD =(0 2 2± 0 0 5 )mm及额、颞叶的NAA分别是 32 74± 4 72和35 38± 3 5 2 ,颞叶的NAA/Cr=2 4 6± 0 4 3,与正常对照组比较均有统计学差异 (P <0 0 5 )。用ROC法找出诊断阈值并联合应用诊断早期AD ,敏感性为 87% ,特异性为 94 %。结论　海马回钩间距及其与同层颅腔左右径比值的增大 ;额、颞叶NAA的减少 ,尤其是颞叶NAA的减少有助于对轻度AD患者的早期诊断。     

氢质子磁共振波谱对Alzheimer病神经生化改变的分析

目的研究Alzheimer病(Alzheimerdisease,AD)的氢质子磁共振波谱分析改变,并与认知正常的老年志愿者(normalcognition,NC)进行比较。方法对AD组21例及NC组20名被观察者行磁共振波谱分析,测定双侧海马、颞顶叶联合区的N乙酰天门冬氨酸(N acetylaspartate,NAA)、胆碱(choline,Cho)和肌醇(myo inositol,mI)与肌酸(creatine,Cr)的比值。采用SPSS11.5软件进行统计分析。结果AD组和NC组双侧海马和颞顶联合区的NAA/Cr差异有显著性(P<0.05),双侧海马和左侧颞顶叶联合区的mI/Cr差异有显著性(P<0.05),双侧海马和颞顶叶联合区的Cho/Cr差异无显著性(P<0.05)。只有左侧海马的NAA/Cr水平下降与AD的严重程度呈正相关(r=0.470,P<0.05)。结论磁共振波谱分析可发现AD海马及颞顶联合区的NAA/Cr、mI/Cr改变,左侧海马NAA/Cr的减低可帮助评价AD的严重程度。     

轻度认知障碍和阿尔茨海默病的边缘系统氢质子磁共振波谱特点

目的探讨海马和扣带回后部氢质子磁共振波谱(’H-MRS)改变在轻度认知障碍(MCI)和阿尔茨海默病(AD)早期诊断中的作用。方法应用’H-MRS技术检测15名健康老年人、15例MCI患者及15例AD患者脑内边缘系统的代谢物水平,对检测的N-乙酰天门冬氨酸(NAA)、胆碱复合物(Cho)、肌酸复合物(Cr)和肌醇(mI)波谱数据进行比较分析。结果 AD组与健康对照组和MCI组相比,海马部位的mI/Cr均升高(均P0.05),NAA/mI降低(均P0.05);随病情进展,扣带回后部的mI/Cr呈递增趋势(P0.05),NAA/mI呈递减趋势(P0.05);AD组和MCI组扣带回后部的NAA/mI与健康对照组的差别程度大于海马部位(P=0.001,P=0.019)。结论扣带回后部的mI/Cr和NAA/mI有助于鉴别健康老人和AD患者;海马部位的NAA/mI有助于鉴别痴呆和非痴呆;MRS在诊断AD和MCI方面有一定辅助作用。     

Diagnostic Difficulties and Treatment Implications

Summary: Differentiation between types of epileptic seizures has been aided in recent years by the introduction of intensive neurodiagnostic techniques and the development of increasingly detailed classification systems. Paradoxically, these developments have not simplified the task of matching the appropriate antiepileptic drug to a particular seizure type. It is reasonable to assume that anticonvulsant drugs will have different effects on different types of seizures, but faulty, circular reasoning can enter the picture if one also assumes that responses of seizures to different drugs signify different seizure types. There are several examples of differential diagnoses that can fall prey to this problem, including the diagnosis between partial seizures with secondary generalization and generalized tonic-clonic seizures, and the diagnosis between complex partial seizures and absence seizures with automatisms, among others. Considerations of etiology in future classification systems can further complicate the problem: should one then choose an anticonvulsant drug on the basis of individual seizure type or on the basis of the type of epilepsy? Ramifications of this issue extend even to the drug approval process. Official sanction is not given for use of a drug for a seizure type not included in the original efficacy studies, even if later scientific evidence shows that seizure type to be related to a type that is included. New trials must be undertaken. These problems arise from how we choose to classify seizures.     

Cognitive Dysfunction Associated with Antiepileptic Drug Therapy

Summary: Epilepsy is frequently associated with cognitive dysfunction. However, the reasons for this correlation are unclear. Possible influential factors include patient age; duration, frequency, etiology, and type of seizures; hereditary factors; psychosocial issues; and antiepileptic drug (AED) therapy. Whereas many of these factors are beyond the physician's control, AED therapy is one element that can be addressed in treatment decisions by recognizing the potential cognitive effects of particular AEDs. For example, phenobarbital impairs memory and concentration; phenytoin affects attention, problem solving ability, and performance of visuomotor tasks. In contrast, carbamazepine may affect concentration, while valproate would appear to have minimal effects on cognition. Moreover, cognitive effects of AEDs are amplified with coadministration of multiple anticonvulsants (polytherapy). A review of studies on the cognitive effects of monotherapy with AEDs, as opposed to those of polytherapy, provides evidence that drug-related cognitive dysfunction can be reversed if patients are switched to a simpler therapeutic regimen. Future research should be directed toward developing reliable measures for assessing and monitoring cognition, and understanding the particular cognitive side effects of each AED. Physicians also need to revise their opinions about which side effects are "tolerable" for epileptic patients.     

Hepatic Considerations in the Use of Antiepileptic Drugs

Summary: Virtually all of the major antiepileptic drugs (AEDs) can cause hepatotoxicity, although fatal hepatic reactions are rare. The mechanisms, incidences, and risk profiles for such reactions differ from drug to drug. With carbamazepine and phenytoin, hepatotoxicity may be due to drug hypersensitivity. Although the profiles of patients at risk have not been well-defined for these two antiepileptic drugs, it would appear from reports in the literature that older adolescents and adults are at higher risk than children of developing serious or fatal hepatotoxicity. Once hepatotoxicity develops, mortality rates are 10–38% with phenytoin and 25% for carbamazepine. The risk profile for valproate fatal hepatotoxicity has been more clearly defined. Those at primary risk of fatal hepatic dysfunction are children under the age of 2 years who are receiving multiple anticonvulsants and also have significant medical problems in addition to severe epilepsy. The risk is considerably lower for patients over the age of 2 years on valproate monotherapy. In contrast to the risk profile with other AEDs, adults receiving valproate as monotherapy have the lowest risk of hepatotoxicity. Fatal hepatic dysfunction coincident with valproate may be the result of aberrant drug metabolism. Concomitant use of AEDs that induce microsomal P450 enzymes (e.g., phenytoin and phenobarbital) may enhance the production of a toxic metabolite, and hence the greater risk of hepatotoxicity with polypharmacy.     

Vascular Malformations and Epilepsy: Clinical Considerations and Basic Mechanisms

Summary: Vascular malformations (VMs) are associated with epilepsy. The natural history of the various VMs, clinical presentation, and tendency to provoke epilepsy determine treatment strategies. Investigations have probed the mechanisms of epileptogenesis associated with these lesions. Electrophysiologic changes are associated with epileptogenic cortex adjacent to VMs. Putative pathophysiologic mechanisms of epileptogenesis include neuronal cell loss, glial proliferation and abnormal glial physiology, altered neurotransmitter levels, free radical formation, and aberrant second messenger physiology.     

Carbamazepine Efficacy in Adults With Partial and Generalized Tonic-Clonic Seizures

Summary: Carbamazepine and phenytoin are drugs of choice in initial monotherapy for adult partial and secondarily generalized tonic-clonic seizures. These designations reflect the results of the Veterans Administration Epilepsy Cooperative Study Group of 1985. An earlier comparative study of carbamazepine and phenytoin by Ramsay and associates found both drugs equally effective in controlling new-onset seizures. Among the advantages of carbamazepine is that it causes relatively few cognitive and dysmorphic side effects. Its disadvantages are its unavailability in parenteral formulation and its metabolic autoinduction. The latter must be compensated for by planned dosage increases to maintain therapeutic plasma steady-state levels during the first 2 or 3 months of treatment. Carbamazepine is judged a drug of choice in the treatment of these secondarily generalized tonic-clonic seizures, and the drug of choice in children, adolescents, and women susceptible to the dysmorphic side effects associated with other anticonvulsant agents.     

Etiologic and Preventive Aspects of Epilepsy in the Child–Bridging the Gap Between Laboratory and Clinic

Summary: Four broad categories of basic phenomena are pertinent to developing ways to prevent epilepsy. These include mechanisms of epileptogenesis, ictal initiation and temporary entrainment by the seizure discharge of normally functioning brain, seizure propagation, and control mechanisms that function both to restrain the cascade of epileptic events culminating in a seizure and to arrest the epileptic event and restore the interictal state. In newborns and children, hypoxia-ischemia is a major factor leading to epileptogenesis, and several schemes are proposed to classify, quantify, and prevent hypoxic-ischemic encephalopathy. Control mechanisms must be better understood in order to develop prophylactic recommendations for epilepsy, and an experimental model of "kindling antagonism" may increase our understanding of these. Programs of prevention of seizures in children will evolve only if basic researchers and clinicians work productively together to develop an adequate understanding of factors important in epileptogenesis and antiepileptogenic control mechanisms.     

Epilepsy and anomalies of neuronal migration: MRI and clinical aspects

Neuronal migration disorders are the result of disturbed brain development. In such disorders, neurons are abnormally located. In diagnosing these conditions, magnetic resonance imaging is superior to any other imaging technique. This enables us to improve our knowledge of the clinical correlates of neuronal migration. With reference to migrational disorder, a retrospective study of all 303 patients with epileptic seizures referred for magnetic resonance imaging during a 3-year period was performed, 13 patients (aged 12-41, mean age 27) were identified. They represent 4.3% of the entire study group. Of the patients with known epilepsy, 6.7% and of the mentally retarded, 13.7% had migrational disorders. Four patients had schizencephaly as the dominant finding, one was classified as hemimegalencephaly, 2 had isolated heterotopias, and 6 had localized pachy- and/or poly-microgyria. The clinical pictures are complex. Ectopias of grey matter are recognised foci of epilepsy, but from an epileptological and a clinical viewpoint little attention has been given to these disorders. The present study shows that malmigration is not rare in epilepsy patients, especially not in the mentally retarded.     

Carbamazepine Efficacy and Utilization in Children

Summary: Carbamazepine is effective for preventing partial and generalized tonic-clonic seizures in children. Although absence epilepsies are more common in children than adults, an estimated 80% of children with epilepsy have seizure types or epilepsies that are potentially responsive to carbamazepine. The differential diagnosis of ictal staring is an especially important issue in children because absence and atypical absence seizures are more prevalent in children than adults. Age-related pharmacokinetic differences and drug interactions are major considerations in children. On average, children have higher clearance rates of carbamazepine, shorter half-lives, and higher ratios of carbamazepine-10, 11-epoxide to carbamazepine than adults. In addition, children with severe epilepsy are more likely to require multiple-drug therapy, which can lead to complex drug interactions. When carbamazepine is administered along with valproate, drug protein binding interactions can cause intermittent side effects.     

Predisposing and Causative Factors in Childhood Epilepsy

Summary: We review information from large studies of defined populations, examining the role of known factors and especially of prenatal and perinatal factors in contributing to nonfebrile seizure disorders of early childhood. We depend especially, but not exclusively, on the recently completed analyses from the Collaborative Perinatal Project of the National Institute of Neurological and Communicative Disorders and Stroke, the NCPP. About 4% of children in the NCPP who had at least one non-febrile nonsymptomatic seizure by the age of 7 years had a previous seizure during acute neurologic illness, such as meningitis or during the acute illness after trauma. Many such seizures should potentially be preventable. Of children with seizures, 10% had had a neonatal seizure and 13% had had a febrile seizure. Among the hundreds of prenatal and perinatal factors explored as predictors of childhood seizure disorders, the principal predictors identified were congenital malformations of the fetus, cerebral and noncerebral; family history of certain neurologic disorders; and neonatal seizures. In agreement with the British National Child Development Study, labor and delivery factors in the NCPP appeared to contribute very little to childhood seizure disorders. Maldevelopment, rather than damage at birth to an initially intact nervous system, appeared to be the more common mechanism. Most seizure disorders of early childhood remained unexplained by the large set of prenatal and perinatal characteristics examined.     

Classification of methods in transcranial Electrical Stimulation (tES) and evolving strategy from historical approaches to contemporary innovations

Transcranial Electrical Stimulation (tES) encompasses all methods of non-invasive current application to the brain used in research and clinical practice. We present the first comprehensive and technical review, explaining the evolution of tES in both terminology and dosage over the past 100 years of research to present day. Current transcranial Pulsed Current Stimulation (tPCS) approaches such as Cranial Electrotherapy Stimulation (CES) descended from Electrosleep (ES) through Cranial Electro-stimulation Therapy (CET), Transcerebral Electrotherapy (TCET), and NeuroElectric Therapy (NET) while others like Transcutaneous Cranial Electrical Stimulation (TCES) descended from Electroanesthesia (EA) through Limoge, and Interferential Stimulation. Prior to a contemporary resurgence in interest, variations of transcranial Direct Current Stimulation were explored intermittently, including Polarizing current, Galvanic Vestibular Stimulation (GVS), and Transcranial Micropolarization. The development of these approaches alongside Electroconvulsive Therapy (ECT) and pharmacological developments are considered. Both the roots and unique features of contemporary approaches such as transcranial Alternating Current Stimulation (tACS) and transcranial Random Noise Stimulation (tRNS) are discussed. Trends and incremental developments in electrode montage and waveform spanning decades are presented leading to the present day. Commercial devices, seminal conferences, and regulatory decisions are noted. We conclude with six rules on how increasing medical and technological sophistication may now be leveraged for broader success and adoption of tES.