阿尔茨海默病~(18)F-FDG PET显像诊断的研究

目的 探讨阿尔茨海默病（AD）脑葡萄糖代谢及其18F-脱氧葡萄糖正电子发射计算机断层扫描（18F-FDG PET）显像的影像学特征和PET诊断标准。方法 静脉注射18F-FDG后行脑断层显像,检查13例 AD、13例非AD痴呆及13例正常人。获得纹状体、丘脑、黑质、顶叶、颞叶、额叶、枕叶、海马单位面积放射性计数与小脑计数的比值（Rcl/cb）,进行半定量分析,并与MR进行对照。结果AD患者PET异常率为100％,MR异常者占10/13。PET显像特征:①对称性双侧颞顶叶及海马伴额叶或枕叶代谢减低占9例（9/13）;②双侧颞叶对称性代谢减低伴海马或额叶代谢下降占3例（3/13）;③双顶叶对称性代谢降低1例（1/13）。12例（12/13）非AD痴呆表现为不对称、多发性代谢降低,降低区位于黑质、纹状体、丘脑及脑皮质区,MR异常率为11/13。结论 在除外脑内结构特异性损害基础上,PET发现对称性双颞顶叶、海马或颞叶、顶叶,伴或不伴枕叶、额叶代谢下降,可诊断AD。PET对AD早期诊断及鉴别诊断具有临床意义。     

不同类型痴呆脑代谢改变图型:~(18)F-FDG PET显像

目的探讨不同类型痴呆患者基于像素水平的脑代谢图型特点。方法对最终临床诊断为阿尔茨海默病(20例)、额颞叶痴呆(20例)、路易体痴呆(10例)、进行性核上性麻痹(7例)、原发性进行性失语(3例)、皮质基底节变性(1例)和多系统萎缩(1例)等认知功能障碍患者的18F-FDG PET显像资料进行回顾分析,描述各种神经变性疾病脑代谢降低区域和程度。结果 SPM分析表明,各种神经变性疾病引起的痴呆18F-FDG PET显像均表现为皮质代谢降低,但其代谢图型变化明显不同:阿尔茨海默病组以双侧颞顶叶和额叶皮质代谢降低为主,基本感觉运动皮质、枕叶、基底节和丘脑活性保留;额颞叶痴呆组额叶和颞叶皮质不对称性代谢降低,伴部分顶叶皮质和基底节、丘脑等皮质下核团不同程度代谢降低;路易体痴呆组枕叶、视皮质和双侧颞上回前部代谢降低;进行性核上性麻痹组双侧前额叶背外侧、颞叶前外侧、中脑和双侧尾状核代谢降低;原发性进行性失语组左侧额叶Broca区、左侧颞叶皮质(除左侧颞上回后部)和右侧颞叶内侧皮质代谢降低;皮质基底节变性组双侧中央沟周围额顶叶皮质(右侧显著)、右侧基底节代谢降低;多系统萎缩组双侧小脑背外侧皮质和左侧壳核代谢降低。结论神经变性疾病所致痴呆在18F-FDG PET显像中表现出各自特征性脑代谢降低图型,18F-FDG PET显像有可能成为痴呆鉴别诊断的一种辅助手段。     

阿尔茨海默病18F-FDG PET显像诊断的研究☆

目的探讨阿尔茨海默病(AD)脑葡萄糖代谢及其18F-脱氧葡萄糖正电子发射计算机断层扫描(18F-FDGPET)显像的影像学特征和PET诊断标准.方法静脉注射18F-FDG后行脑断层显像,检查13例AD、13例非AD痴呆及13例正常人.获得纹状体、丘脑、黑质、顶叶、颞叶、额叶、枕叶、海马单位面积放射性计数与小脑计数的比值(Rcl/cb),进行半定量分析,并与MR进行对照.结果AD患者PET异常率为100%,MR异常者占10/13.PET显像特征①对称性双侧颞顶叶及海马伴额叶或枕叶代谢减低占9例(9/13);②双侧颞叶对称性代谢减低伴海马或额叶代谢下降占3例(3/13);③双顶叶对称性代谢降低1例(1/13).12例(12/13)非AD痴呆表现为不对称、多发性代谢降低,降低区位于黑质、纹状体、丘脑及脑皮质区,MR异常率为11/13.结论在除外脑内结构特异性损害基础上,PET发现对称性双颞顶叶、海马或颞叶、顶叶,伴或不伴枕叶、额叶代谢下降,可诊断AD.PET对AD早期诊断及鉴别诊断具有临床意义.     

中晚期帕金森病患者的脑功能影像研究

目的　探讨晚期帕金森病(PD)患者静止期18F 脱氧葡萄糖(FDG)正电子发射断层扫描(PET)脑代谢显像的影像学特征及其意义。方法　11例中晚期帕金森病患者,其中男5例,女6例;平均年龄(63 .5±3 .7)岁;Hoehn Yahr分级4. 1±0. 5;以11名年龄匹配的健康人为对照,经静脉注射FDG后行脑断层显像,获得两组人的脑局部葡萄糖代谢率,通过SPM99统计学软件进行数据分析,比较两组脑内代谢的差异。结果　与健康人相比,帕金森病患者丘脑、豆状核代谢增加(P<0 .05);双侧运动前区(BA6)、额中回及顶叶代谢减低(P<0. 05)。结论　帕金森病患者丘脑、豆状核代谢增加,其相应的运动区皮质代谢减低,帕金森病的这一脑内代谢特点有助于帕金森病的辅助诊断及对其发病机制的探讨。     

~(18)F-FDG PET显像鉴别阿尔茨海默病与额颞叶痴呆临床价值

目的探讨18F-FDG PET显像在阿尔茨海默病与额颞叶痴呆鉴别诊断中的应用价值。方法对临床明确诊断的阿尔茨海默病(20例)和行为异常型额颞叶痴呆(20例)患者的18F-FDG PET显像资料进行回顾,分析两组患者皮质代谢降低脑区间的差异。结果视觉分析显示,两组患者均表现为皮质代谢降低,阿尔茨海默病患者以双侧颞顶叶和后扣带回代谢降低明显,以及部分额叶皮质代谢降低,而基底节和丘脑不受累,18/20患者双侧大脑半球皮质代谢降低范围和程度基本对称;额颞叶痴呆患者额叶和前颞叶皮质代谢均降低,其中11例同时伴部分顶叶皮质和基底节、丘脑等皮质下核团不同程度降低,16/20患者双侧大脑半球代谢降低程度和范围明显不对称,4例以右侧为主、12例以左侧为主。结论由于18F-FDG PET显像所显示的阿尔茨海默病和额颞叶痴呆患者之皮质代谢降低图型不同,故具有较好的鉴别诊断价值。     

不同严重程度帕金森病患者脑葡萄糖代谢变化特点的临床研究

目的:探讨早、晚期帕金森病（PD）患者不同脑区葡萄糖代谢变化的特点,寻求PD严重度的新型生物学标志物。方法:19例早期PD（H-YⅠ～Ⅱ级）组、14例中晚期PD（H-YⅢ～V级）组患者及50名年龄匹配的健康对照组接受静脉注射¹⁸F-FDG PET脑断层显像,应用参数图分析法进行数据分析,比较各组间受试者脑内葡萄糖代谢变化的差异和特点。结果:与健康对照组比较,早期PD患者的丘脑、豆状核、小脑葡萄糖代谢增高;中晚期双侧丘脑、豆状核、小脑代谢增高,双侧顶叶葡萄糖代谢减低。结论:PD患者存在双侧丘脑、豆状核、小脑葡萄糖代谢增高,双侧顶叶葡萄糖代谢减低的代谢异常模式,且随着病情严重度的不同而变化,应用于PD严重度的客观评价,值得进一步研究。     

阿尔茨海默病的18F-FDG PET脑显像特征及意义

目的探讨轻、中、重度阿尔茨海默病(AD)患者的脑~(18)F-FDG正电子发射断层显像(PET/CT)特点。方法对10例AD患者和10例健康对照的脑~(18)F标记的脱氧葡萄糖正电子发射断层显像(~(18)F-FDG PET)进行视觉分析,测量感兴趣区的FDG标准化摄取值(SUV),并通过计算获得其与同侧小脑FDG的SUV的比值,比较组间是否有显著性差异。结果轻度AD患者的FDG摄取代谢降低区为后扣带回及楔前叶,且呈双侧不对称性,中度AD患者的颞叶、顶叶FDG代谢降低双侧对称且降低明显,重度AD患者全脑皮质代谢明显降低。结论 AD患者的~(18)F-FDG PET脑显像特征反映认知功能的损害程度,是临床诊断和评估AD的有力工具。     

帕金森病的脑部葡萄糖代谢特征分析

目的 观察帕金森病(Parkinson's disease,PD)的18F-脱氧葡萄糖(18F-labeled 2-deoxyglucose,18F-FDG)正电子发射断层成像(positron emission tomography,PET/CT)显像特征,并分析利用其代谢变化特点进行辅助诊断的方法.方法收集经临床确诊的PD患者15例,对其分别进行18F-FDG PET/CT显像;利用SPM分析软件分析PD患者组的代谢模式,并统计各位患者各自的代谢改变特点.健康对照组10名,分析方法同患者组.结果 与对照组相比,PD组表现为豆状核、脑干、小脑的相对高代谢,以及额叶运动前区及顶叶的相对低代谢 (P ＜ 0.01).对个体数据分析发现:15例患者中13位表现为小脑相对高代谢,8例表现为脑干相对高代谢,8例表现为壳核相对高代谢,10例表现为苍白球相对高代谢,以上区域均为观察到相对低代谢表现 (P ＜ 0.01);同时12例表现为顶叶相对低代谢改变,11例表现为运动前区相对低代谢改变 (P ＜ 0.01),上述两个区域均未观察到相对高代谢改变.结论 与正常人群相比,帕金森患者脑部代谢改变主要表现为小脑、纹状体区代谢相对增高,同时伴有顶叶和运动前区代谢相对减低.     

[~(18)F]FDG脑代谢联合[~(11)C]CFT脑多巴胺转运体PET显像对帕金森病的临床研究

目的探讨[18F]FDG脑代谢联合[11C]CFT脑多巴胺转运体(DAT)正电子发射断层显像(PET)对帕金森病(PD)诊断及病情严重度评估的应用价值。方法对30例PD患者(PD组)进行[18F]FDG脑代谢显像和[11C]CFT脑DAT PET显像检查,同时采用帕金森病统一评分量表第三部分(UPDRSⅢ)的运动评分和Hoehn-Yahr(H-Y)分期对纳入研究PD患者的临床症状进行评分,分析[18F]FDG PET、[11C]CFT PET和临床评分之间的相关性。选取年龄匹配的健康受试者10名为对照组。结果 [18F]FDG PET提示PD组普遍存在苍白球、丘脑、脑干、小脑、感觉运动皮质区代谢增强和运动前皮质、顶枕区代谢减弱的PD相关代谢模式(PDRP),PDRP评分与发病年龄和H-Y分期评分存在显著正相关。[11C]CFT PET提示PD组存在尾状核、壳核DAT摄取值较对照组下降,纹状体DAT摄取值和UPDRSⅢ评分、H-Y分期和PDRP评分存在显著负相关。结论 [11C]CFT与[18F]FDG PET显像联合检查有助于PD诊断和病情严重度的评估。     

~(11)C-CFT PET显像评价帕金森病与多系统萎缩P型患者脑内多巴胺转运体分布特点的研究

目的基于~(11)C-CFT正电子发射计算机断层(PET)显像评价帕金森病(PD)与多系统萎缩P型(MSA-P)患者脑内多巴胺转运体(DAT)分布特点,评估~(11)C-CFT PET显像在PD与MSA-P鉴别诊断中的价值。方法回顾性分析年龄、性别和疾病严重程度匹配的32例MSA-P患者(MSA-P组)和56例PD患者(PD组)的临床资料以及~(11)C-CFT PET影像资料;另选择年龄匹配的健康对照者20例为对照组。应用感兴趣区技术获得3组研究对象的尾状核、前壳核和后壳核的DAT分布半定量值,对各感兴趣区的DAT分布半定量值、相互比值和不对称性进行对比研究。建立受试者工作特征曲线(ROL),利用曲线下面积评估基于~(11)C-CFT PET显像所得相关参数对PD和MSA-P的鉴别能力。结果与PD组比较,MSA-P组患者病程更短、进展速度更快(P0.000 1)。与对照组比较,PD组和MSA-P组尾状核、前壳核和后壳核的DAT分布半定量值均显著减低(P0.000 1),且后壳核降低最为显著。PD组和MSA-P组尾状核、前壳核和后壳核的DAT分布半定量值及其不对称指数比较均差异无显著性。PD组和MSA-P组纹状体各感兴趣区DAT分布半定量值中,前壳核/尾状核比值(AP/C)、后壳核/前壳核比值(PP/AP)均差异无显著性;但MSA-P组后壳核/尾状核比值(PP/C)PD组(P0.05),两组PP/C比值的ROL曲线下面积为0.696(P=0.002);以0.611作为PP/C比值的临界值,其对MSA-P和PD鉴别诊断的灵敏度和特异度分别为71.9%和62.5%。结论 ~(11)C-CFT PET显像可以精准显示MSA-P及PD患者脑内多巴胺能神经元的突触前功能损害,但尚不能有效鉴别两种疾病。     

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.     

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.     

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.     

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.     

Neonatal Seizures: Problems in Diagnosis and Classification

Summary: The clinical identification of neonatal seizures is critical for the recognition of brain dysfunction; however, diagnosis is often difficult because of the poorly organized and varied nature of these behaviors. Current classification systems are limited in their ability to communicate motor, autonomic, and electroencephalo-graphic features of seizures precisely and to provide a basis for uniform effective diagnosis, therapy, and determination of prognosis. Recent investigations of neonates, utilizing bedside electroencephalographic/polygraphic/ video monitoring techniques, have provided the basis for improved diagnosis and classification of seizures in the newborn. These studies have demonstrated that not all clinical phenomena currently considered to be seizures require electrocortical epileptiform activity for their initiation or elaboration. In addition, the specific clinical character of the phenomena considered to be seizures, the clinical state of the infant, and the character of the EEG indicate the probable pathophysiological mechanisms involved and suggest probable etiologies, prognosis, and therapy. Similarities between animal models that demonstrate reflex physiology and neonates with motor automatisms and tonic posturing suggest that these clinical behaviors may not be epileptic in origin but, rather, primitive movements of progression and posture mediated by brainstem mechanisms. Although not all clinical behaviors currently considered to be neonatal seizures may have similar pathophysiological mechanisms, they are clinically significant because they all indicate brain dysfunction.     

Valproate Monotherapy in the Management of Generalized and Partial Seizures

Summary: For decades, therapeutic tradition has promoted the concept of polypharmacy in the management of epilepsy. In recent years, however, studies have shown that, for most patients, monotherapy can provide comparable or better seizure control than administration of multiple anticonvulsants, while diminishing the potential for adverse reactions, drug interactions, and poor compliance. Valproate is an important monotherapeutic agent that is highly effective in the control of idiopathic primary and secondarily generalized epilepsies, and partial seizures that do not generalize. Comparative studies have found that valproate is at least as effective as phenytoin and carbamazepine in the treatment of generalized and partial seizures. Given the similar efficacy, other factors such as pharmacokinetics and side effects may therefore determine anticonvulsant selection for monotherapy.     

Un nouveau cadre conceptuel de travail pour la psychiatrie

In an attempt to place psychiatric thinking and the training of future psychiatrists more centrally into the context of modern biology, the author outlines the beginnings of a new intellectual framework for psychiatry that derives from current biological thinking about the relationship of mind to brain. The purpose of this framework is twofold. First, it is designed to emphasize that the professional requirements for future psychiatrists will demand a greater knowledge of the structure and functioning of the brain than is currently available in most training programs. Second, it is designed to illustrate that the unique domain which psychiatry occupies within academic medicine, the analysis of the interaction between social and biological determinants of behavior, can best be studied by also having a full understanding of the biological components of behavior.