磁共振成像对脑静脉畸形的诊断价值

目的 探讨磁共振成像各种方法对脑静脉畸形的诊断价值.方法 收集本院6例脑静脉畸形病例,均进行过磁共振T1WI、T2WI扫描,其中部分病例做过DWI、T2FLAIR、MRA、MRV、T1WI增强扫描及DSA. 结果幕上4例,幕下2例,T1WI、T2WI表现:引流静脉均为流空的低信号,深髓静脉为细条状长T1、长T2信号.其中1例DWI引流静脉及深髓静脉区域低信号;1例T2FLAIR引流静脉流空的低信号,深髓静脉高信号;2例MRA均阴性,但MRV显示深髓静脉汇入引流静脉;2例TIWI增强扫描:深髓静脉呈轮辐状汇入引流静脉;1例DSA:动脉期阴性,静脉期见典型的"海蛇头"征.结论 磁共振能明确诊断脑静脉畸形,T1WI增强扫描及MRV均较敏感,DSA为诊断脑静脉畸形金标准.     

妊娠相关性脑静脉及静脉窦血栓形成和可逆性后部白质脑病的磁共振鉴别

目的探讨MRI和MRV在妊娠相关性脑静脉及静脉窦血栓形成(CVST)和可逆性后部白质脑病综合征(RPLS)鉴别诊断中的价值。方法回顾性分析3例妊娠相关性CVST和6例重度子痫前期、子痫发生RPLS患者的影像学资料。所有患者均行MRI和DSA检查,其中7例患者行MRV检查。结果 3例CVST患者中,1例孤立性大脑上静脉前组血栓形成,MRI表现为相应部位T1WI低、等信号,T2WI、FLAIR等、稍高信号,DWI为等、高信号,ADC图为低、稍高信号;2例横窦血栓形成,表现为双侧枕叶皮质、皮质下白质片状T1WI低信号,T2WI、FLAIR高信号,DWI、ADC高信号,可不对称性地累及顶叶、小脑半球,MRV与DSA检查结果相符。6例RPLS患者MRI显示双侧顶、枕叶皮质、皮质下白质多发性、斑片状、对称性病变,部分严重患者大脑半球呈弥漫性、大片状受累,表现为T1WI低信号,T2WI、FLAIR高信号,DWI、ADC高信号;1例患者MRV检查示左侧横窦未显影,DSA检查示左侧横窦通畅。结论横窦血栓形成和RPLS患者MRI均显示血管源性脑水肿,两者脑水肿主要发生于双侧枕、顶叶,但前者范围较局限,后者范围更广泛,可累及基底节、额叶、颞叶。RPLS患者MRV检查可有假阳性,DSA是鉴别两者的重要检查方法。     

3.0T磁共振磁敏感成像在脑出血性病变中的应用探讨

目的 探讨3.0T磁共振磁敏感加权成像(susceptibility weighted imaging,SWI)在颅脑出血性病变中的应用价值.方法 对临床疑有颅脑出血的56例患者进行检查.其中男32例,女24例.受检者年龄14～72岁,平均45.9岁.设备:飞利浦Achieva3.0T X-series 磁共振扫描仪.全部采用常规T1WI、T2WI、FLAIR、DWI及SWI扫描,有8例患者追加MRA检查.对各扫描序列显示的异常信号,尤其是出血灶的显示及出血灶大小、多少及病灶分布进行分析.同时对脑静脉分支显示进行后处理,以提高脑静脉的显示质量.结果 56例患者脑静脉分支均显示清楚.SWI显示22例有出血灶(22/56),T1WI显示8例有出血灶(8/56),T2WI显示11例有出血灶(11/56),FLAIR显示10例有出血灶(10/56),DWI显示7例有出血灶(7/56).13例脑梗死患者,4例提示治疗后梗死区有低信号出血灶.3例脑血管瘤合并出血者,SWI显示出血灶明显大于和多于常规T1WI及T2WI序列显示.1例CT扫描阴性,SWI显示大脑前动脉畸形并少量蛛网膜下腔出血.结论 3.0T磁共振扫描仪磁敏感序列(SWI)对脑出血的敏感性明显高于其他常规序列,是一种显示少量脑出血及提高出血灶检出率的有效检查方法,值得在临床疑有脑出血性病变的患者检查中运用.     

磁敏感加权成像在脑静脉性血管畸形诊断中的应用

目的探讨磁敏感加权成像(SWI)在脑静脉性血管畸形中的诊断价值。方法回顾性分析21例脑静脉性血管畸形患者的影像学资料,所有患者均行常规MRI平扫与SWI序列扫描,评价SWI序列对脑静脉性血管畸形检出的优越性。结果 SWI发现脑静脉性血管畸形21例,T1WI发现病灶17例,T2WI发现病灶18例,常规MRI扫描序列呈点状或条形流空信号,且只可显示大部分扩张的引流静脉及部分扩张的髓静脉,SWI可以清晰的显示所有扩张的髓静脉及粗大的引流静脉,呈典型"水母头"状。结论 SWI较常规MRI扫描序列对脑静脉性血管畸形的显示更为敏感。     

瘤样炎性脱髓鞘病MRI的临床意义

目的分析瘤样炎性脱髓鞘病(TIDD)临床、影像与病理特点,探讨磁共振(MRI)检查对TIDD的诊断价值。方法对39例TIDD患者进行头颅、脊髓CT和MRI扫描,并分析临床和影像学特点。结果病灶在头颅CT均为低密度,常规MRI扫描呈T1WI低信号、T2WI高信号,T1WI增强扫描44%可见"开环征",发病早期DWI可见高信号,FLAIR较T1WI及T2WI更清晰显示病灶及其范围。结论 DWI能发现TIDD早期病变,FLAIR较常规T1WI、T2WI敏感,"开环征"是磁共振诊断TIDD的重要辅助依据。     

磁敏感加权成像对脑静脉性血管畸形的诊断价值

目的 探讨磁敏感加权成像(SWI)对脑静脉性血管畸形的临床诊断价值.方法 回顾分析23例脑静脉性血管畸形患者SWI特点,并与常规MRI和全脑血管造影检查结果进行对比分析.结果 常规MRI扫描显示.23例患者中20例呈单发病灶,4例伴海绵状血管瘤;3例为多发病灶.T1WI呈点状或片状稍低信号改变.T2WI呈短条形或条形低信号改变;增强扫描呈明显放射状线样强化改变.全脑血管造影检查于静脉期显示扩张的髓静脉及引流静脉.SWI可见扩张的髓静脉和粗大的引流静脉.与MRI和全脑血管造影检查相比.其病灶显示范围更全面、广泛,且图像更加清晰.结论 SWI诊断脑静脉性血管畸形快捷、无创,可替代全脑血管造影作为脑静脉性血管畸形的筛查及手术前评价方法.     

外伤性颅内静脉窦血栓形成的MRI诊断

目的探讨磁共振成像(MRI)结合磁共振静脉成像(MRV)在外伤性颅脑静脉窦血栓形成中的诊断价值。方法回顾性分析28例经临床及影像学诊断为外伤性颅脑静脉窦血栓形成的 MRI与MRV资料。磁共振均行常规SE序列T1WI、T2WI以及液性衰减反转恢复序列(FLAIR)扫描,并全部行二维时间飞跃法静脉成像(2d-TOF MRV)检查。结果外伤性静脉窦血栓形成最常累及上矢状窦、下矢状窦、横窦,表现为受累静脉窦流空效应消失,为不同信号的血栓所阻断。MRV则表现为受累静脉窦管腔的狭窄、中断以及属支的迂曲扩张。结论 MRI结合MRV能无创性的同时显示外伤性颅脑静脉窦血栓形成与脑挫裂伤,为外伤性颅脑静脉窦血栓形成的首选检查方法。     

脑发育性静脉畸形的MRI诊断

目的探讨MRI对脑发育性静脉畸形的诊断价值。方法对8例脑发育性静脉畸形患者MRI资料进行回顾性分析,均行MRI常规平扫、磁敏感加权成像(SWI)及增强扫描。结果额叶4例,颞叶1例,小脑3例,引流静脉显示长T1短T2低信号流空影,显示的部分髓静脉呈稍长T1长T2信号。增强扫描及SWI显示全部的引流静脉及髓静脉,呈典型"海蛇头"样表现。结论 MRI能明确诊断DVA,增强扫描及SWI序列较敏感,其中SWI无需注射对比剂,能清晰显示DVA及伴发的隐匿性血管畸形,可作为DVA诊断的常规序列。     

可复性后部脑病综合征的影像学诊断

目的探讨可复性后部脑病综合征（PRES）的影像学表现.方法回顾性分析了12例PRES病人的临床和影像学资料,其中9例为子痫/先兆子痫,2例为高血压脑病,1例为环孢菌素A（CSA）的神经毒性.12例均行MRI检查,其中7例同时行钆喷替酸葡甲胺（Gd-DTPA）增强扫描,4例行磁共振血管造影（3D-TOF MRA）检查,1例行弥散加权成像（DWI）.7例行CT平扫检查,2例行脑血管造影（DSA）检查.结果MRI显示病灶基本上呈双侧对称性分布,多数病灶位于顶、枕叶脑实质内,T1WI呈等或略低信号,T2WI呈高信号,FLAIR像显示皮层和皮层下白质明显高信号影,较T1WI、T2WI更加清楚.注射Gd-DTPA后多无明显异常对比增强.1例DWI显示双侧顶、枕叶及额叶皮层内弥散受限呈高信号,ADC图显示邻近的皮层下白质呈高信号.4例CT显示双侧顶、枕叶及额叶对称性斑片状低密度影,3例CT未见异常.经对症处理后复查示所有病灶几乎完全吸收消失.结论PRES的影像学表现具有特征性.MRI应作为诊断本病的首选手段.     

SWI 技术在脑血管疾病诊断中的应用

目的：探讨磁共振磁敏感加权成像技术在脑血管疾病诊断中的临床应用价值。方法回顾分析我院2012-09-2013-12收治的74例脑血管疾病患者的常规序列 T1WI、T2WI、DWI、FLAIR及SWI、增强 T1WI、MRA图像,评价SWI序列显示小出血灶、小静脉、海绵状血管瘤、脑内铁钙异常沉积等方面的优越性。结果 SWI可鉴别海绵状血管瘤出血与血管,发现更多的小出血灶,发现常规序列扫描不能发现的小静脉畸形并显示向大静脉的引流,显示脑外伤平扫时难以发现的更多小出血灶和脑梗死伴发的小出血灶。结论 SWI是显示脑部低流量血管畸形、小静脉的结构,多发小灶性出血以及铁钙沉积十分敏感的脉冲序列,作为M RI常规序列的重要补充,对脑血管疾病的诊断和鉴别诊断具有重要意义。     

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.     

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.     

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.     

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.     

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.     

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.