低场强MRI诊断脑出血的应用价值

目的探讨低场强MRI诊断脑出血的应用价值。方法对60例脑出血患者MRI影像学表现及血肿内血红蛋白的信号变化进行回顾性分析。结果 14例急性期脑出血患者中,3例症状典型,腰穿有血性脑脊液确诊;1例症状不典型,MRI影像学特点不明显,进行Gd-DTPA增强扫描,血肿轻度强化,结合CT检查确诊;10例MRI影像学特点不典型,结合临床症状及其他检查结果确诊。20例亚急性期脑出血患者,低场强MRI检查中影像学特点典型,且T1WI、T2WI均为高信号。26例慢性期脑出血患者,病变开始阶段T1WI、T2W均为高信号。结论临床医师需要掌握低场强MRI的典型影像学特点及信号演变规律,并结合临床症状和辅助检查确诊。     

22例自发性脊髓出血临床及影像学分析

目的 探讨自发性脊髓出血的病因、临床表现及影像学特征。方法 回顾分析22例经临床、MRI、脑脊液证实的脊髓出血患者的临床及影像学表现。结果 本组患者多表现为突然起病的剧烈神经根痛，随后出现运动感觉及植物神经功能障碍。22例中发现脊髓髓外出血4例，髓内出血18例；脊髓血管畸形15例。结论 脊髓血管畸形为脊髓出血的主要病因。对于MRI、DSA不能发现脊髓血管畸形的脊髓出血，血常规、血脂、血糖、高血压等检查对明确病因有一定的意义。     

脊髓空洞MRI表现与病因分析

目的分析21例不种病因所致脊髓空洞的MRI表现。方法21例脊髓空洞患者均经手术及病理证实，MRI重点观察脊髓及其空洞的部位、形态和信号特点。结果21例脊髓空洞中，脊髓肿瘤性空洞9例，Chiari畸形所致4例．创伤后空洞4例，自发性脊髓空洞2例．脊柱侧弯2例；空洞累及颈髓或胸髓，空洞均位于脊髓中央管，范围从2～13个脊髓节段不等，空洞内信号变化同脑脊液。结论脊髓空洞主要由于脊髓肿瘤、Chiari畸形、创伤、脊柱侧弯、自发性脊髓空洞等引起，不同病因空洞的MRI表现各不相同，籍此可进行鉴别诊断并分析其病因。     

自发性脊髓出血临床及影像学分析

目的 :探讨自发性脊髓出血的病因、临床表现及影像学特征。方法 :回顾分析了 18例经临床、 CT、 MRI或血管造影证实的脊髓出血患者的临床及影像学表现。结果 :本组患者多为突然起病的剧烈神经根痛 ,随后出现运动、感觉及植物神经功能障碍 ;病变在颈段 7例 ,胸段 8例 ,腰段 3例 ;腰穿为血性脑脊液 ;影像学检查尤其是 MRI和DSA能明确病因及部位 ,本组发现脊髓血管畸形 13例 ,血液病 2例 ,其他 3例。结论 :脊髓出血最常见的病因为脊髓血管畸形 ,MRI和 DSA检查有可能在出血前做出病因诊断 ,早期治疗脊髓血管畸形可防止出血发生。     

脊柱放线菌感染并发脊髓压迫症(附3例报告)

目的探讨脊柱放线菌感染并发脊髓压迫症的临床和影像学特点及治疗方法。方法回顾性分析3例经病理检查证实的本病患者的临床资料。结果3例患者均有颈、胸脊椎及软组织感染和脊髓压迫症状;MRI示病变椎体骨质破坏,颈、胸硬膜外软组织肿块,脊髓受压。病理学检查组织病理学检查证实3例均为放线菌感染,2例表现为炎性肉芽组织伴微脓肿形成,另1例表现为硬膜外脓肿。均予以脓肿清除、脊髓减压术,并给予4~8周大剂量青霉素G静脉滴注,后改口服维持4~6个月,术后及随访3例患者均取得显著的疗效。结论脊柱放线菌感染并发脊髓压迫症临床和影像学表现无特征性,其确诊依赖于病理学和微生物学检查。脓肿引流、椎管内减压术和大剂量抗生素治疗有效。     

自发性硬脊膜外血肿的诊断和治疗策略

目的探讨自发性硬脊膜外血肿的临床特征、治疗及影响预后的因素。方法对16例自发性硬脊膜外血肿患者的临床特征、手术治疗时机以及手术后神经功能恢复情况进行回顾总结,并结合文献分析影响预后的因素。所有自发性硬脊膜外血肿患者均行MRI检查。结果16例患者的硬脊膜外血肿分别位于下颈段（2例）、颈胸段（6例）、胸段（7例）及胸腰段（1例）。MRI检查T1WI表现为等信号或略高信号,T2WI以高信号为主,其中可见混杂低信号。12例施行手术治疗的患者中10例预后良好;4例保守治疗者中3例神经功能完全恢复。结论脊髓MRI检查是诊断自发性硬脊膜外血肿的首选方法,早期诊断和外科手术治疗是恢复神经功能、提高疗效的关键。手术疗效主要与自发性硬脊膜外血肿患者手术前的神经功能缺损程度和手术间隔时间有关;症状较轻者在密切观察下可予以保守治疗,其神经功能的恢复主要取决于神经功能缺损程度。目的探讨自发性硬脊膜外血肿的临床特征、治疗及影响预后的因素。方法对16例自发性硬脊膜外血肿患者的临床特征、手术治疗时机以及手术后神经功能恢复情况进行回顾总结,并结合文献分析影响预后的因素。所有自发性硬脊膜外血肿患者均行MRI检查。结果16例患者的硬脊膜外血肿分别位于下颈段（2例）、颈胸段（6例）、胸段（7例）及胸腰段（1例）。MRI检查T1WI表现为等信号或略高信号,T2WI以高信号为主,其中可见混杂低信号。12例施行手术治疗的患者中10例预后良好;4例保守治疗者中3例神经功能完全恢复。结论脊髓MRI检查是诊断自发性硬脊膜外血肿的首选方法,早期诊断和外科手术治疗是恢复神经功能、提高疗效的关键。手术疗效主要与自发性硬脊膜外血肿患者手术前的神经功能缺损程度和手术间隔时间有关;症状较轻者在密切观察下可予以保守治疗,其神经功能的恢复主要取决于神经功能缺损程度。     

脊髓硬膜外血肿的诊断与治疗

脊髓硬膜外血肿(ｓｐｉｎａｌｅｐｉｄｕｒａｌｈｅｍａｔｏｍａ)临床上很少遇到。我院神经外科从1989年至1998年共收治经手术证实的脊髓硬膜外血肿6例,占同期收治的脊髓压迫症的096%。现报告如下。临床资料1一般资料:男4例,女2例。发病年龄23～49岁,平均356岁。自首发症状至就诊时间平均13天(3～21天)。2临床及影像学检查:6例患者首发症状均是突然后背疼痛,几小时后出现疼痛部位以下运动感觉障碍,产生脊髓压迫症状。5例行腰穿检查梗阻试验阳性,无血性脑脊液。截瘫4例,脊髓半横断2例,大小便功能障碍5例。3例行胸段脊髓ＣＴ扫描,断面可见椎管…     

CT脊髓造影在自发性颅内低压脑脊液漏点检出中的价值

目的 探讨CT脊髓造影在自发性颅内低压脑脊液漏点检出中的价值及影像学表现.方法 6例自发性颅内低压患者,男女各3例,均符合2004年国际头痛分类第2版自发性颅内低压的诊断标准.影像学资料包括5例全脊柱MRI检查和6例全脊柱CT脊髓造影.根据CT脊髓造影发现的脑脊液漏点,选择穿刺部位,透视下注射混合碘造影剂的自体静脉血,随访观察治疗效果.结果 5例全脊柱MRI检查均未发现漏点.6例CT脊髓造影检查均发现了漏点,各例漏点数目为1～7个,总漏点数目25个,平均4.2个,其中颈椎和胸椎各12个,腰椎1个.CT脊髓造影表现包括造影剂线状漏出、椎旁软组织内片状造影剂蓄积及神经根袖呈鸟嘴样扩大等.6例患者经靶向硬膜外血贴治疗后获得临床痊愈.结论 CT脊髓造影是一种有效和精确的自发性脊髓脑脊液漏点定位诊断手段.     

硬膜外血贴治疗自发性低颅压的临床和影像学分析

目的探讨靶向硬膜外血贴治疗自发性低颅压综合征的机制和价值。方法对1例自发性脑脊液漏所致的低颅压患者行MRI脊髓造影,根据MRI脊髓造影发现的脑脊液漏点位置选择穿刺部位,注射自体血至硬膜外椎间隙。结果经硬膜外血贴治疗后,患者临床症状缓解,随访至术后6个月颅内压力恢复正常。结论 MRI脊髓造影漏点精确定位后,硬膜外血贴疗法是一种有效治疗自发性脑脊液漏的方法。     

脊髓空洞症合并吉兰-巴雷综合征一例

目的探讨脊髓空洞症(SM)合并吉兰-巴雷综合征(GBS)的临床特点、影像学及实验室检查特征、诊断标准。方法分析1例SM合并GBS临床资料。结果患者肌电图(EMG)提示周围神经轴索损害,脑脊液(CSF)未出现"蛋白-细胞"分离现象,胸椎MRI示胸7~8椎体水平脊髓内异常信号,考虑SM。结论 GBS脑脊液检查可能不出现"蛋白-细胞"分离现象;SM临床特点结合MRI即可确诊;两者的病因、发病机制均不同,为一合并症。     

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.     

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.     

Treatment Considerations in Anticonvulsant Monotherapy

Summary: The long-standing practice of polypharmacy in treating epilepsy is giving way to use of monotherapy. Monotherapy can improve seizure control as well as reduce the risk of serious idiosyncratic reactions, dose-related side effects, and complex drug interactions. Monotherapy also offers improved compliance and cost-effectiveness. The basis of monotherapy is accurate diagnosis and assessment of the patient's seizure type(s), followed by selection of a single appropriate anticonvulsant drug. Many patients currently treated with multiple anticonvulsants can be successfully converted to monotherapy with a carefully monitored program in which troublesome and redundant drugs are gradually withdrawn from the therapeutic regimen.     

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.     

Dextromethorphan: Cellular Effects Reducing Neuronal Hyperactivity

Summary: Dextromethorphan is a dextrorotary morphinan without affinity for opioid receptors, commonly used as an antitussive medication. During the past 5 years, interest in the compound and its demethylated derivative, dextrorphan, has been revived because additional neuroprotective and an-tiepileptic properties were found in in vitro studies, animal experiments, and a few clinical cases. Both morphinans are able to inhibit N -methyl-D-aspartate (NMDA) receptor channels and voltage-operated calcium and sodium channels with different potencies. The inhibition of the NMDA receptor is believed to be the predominant mechanism of action responsible for the anticonvulsant and neuroprotective properties of the compounds.     

Anticonvulsant Drugs and Cognitive Function: A Review of the Literature

Summary: Alterations of cognitive function are separate from disturbances of behavior seen in association with epilepsy. The nature of the cognitive disability may to a certain extent depend on the seizure type. Partial seizures, mainly derived from a temporal lobe focus, impair memory tasks, while generalized seizures seem to have more effect on attentional abilities. A number of studies, reviewed in this paper, suggest that anticonvulsant drugs further impair cognitive function. Maximal impairments are seen in patients receiving polytherapy: rationalization of polytherapy improves cognitive abilities. Studies in children and adults have allowed differentiation of the effects of various commonly used antiepileptic agents. Maximal cognitive deficits are seen with. phenytoin, while phenobarbital and sodium valproate induce moderate disturbances, and carbamazepine seems relatively free from such toxicity. Further research is needed on the interrelationship between types of seizure disorders, types of anticonvulsant medications, and cognitive function.     

Effects of NMD A- and AMPA-Receptor Antagonists on Different Forms of Epileptiform Activity in Rat Temporal Cortex Slices

Summary: Lowering extracellular magnesium induces different patterns of epileptiform activity in rat hippocampus and entorhinal cortex. Short recurrent epileptiform discharges in the hippocampus are stable over time, whereas seizurelike events (SLEs) in the entorhinal cortex, the subiculum, and the neighboring neocortex develop into late recurrent discharges which are not blocked by clinically employed antiepileptic drugs. We tested the sensitivity of the different epileptiform discharge patterns to. /V-methyl-D-aspartate (NMDA)- and non-NMDA-receptor antagonists. As NMDA-receptor antagonist we used dextrorphan, ket-amine, and 2-aminophosphonovalerate (2APV); as α-amino-3-hydroxy-5-methyl-4-isoxazole-propionic acid (AMPA)-receptor antagonist we employed the quinoxaline derivative glutamate 6-cyano-7-nitroquinoxaline-2,3-dione (CNQX). The findings show that the different patterns of epileptiform activity, including the late recurrent discharges, are sensitive to all NMDA-receptor antagonists. However, when dextrorphan was employed to suppress seizure-like events, later recurrent discharges did not develop during the remaining time course of the experiment. CNQX reversibly suppressed recurrent discharges in the hippocampus and SLEs in the entorhinal cortex. However, late recurrent discharges become insensitive to CNQX, even at a high concentration of 60 μM m. This finding suggests a prominent role for NMDA receptors in the generation of late recurrent discharges.     

Pediatric Epilepsy Surgery

Summary: The use of implantable arrays of epidural electrodes has made it possible to carry out extraoperative electrocorticography (ECoG) and functional localization in the awake child. This has permitted cortical excisions that are determined by criteria similar to those obtained during surgical procedures performed under local anesthesia in adults. In addition, the method also permits simultaneous ECoG and video monitoring during the child's symptomatic seizures, providing additional important localizing information that is impractical to obtain in operations under local anesthesia. We report our experience with 75 children, ages 5 months to 15 years, whom we have managed with epidural electrode arrays. The method of extraoperative ECoG is described and illustrative cases are presented to demonstrate its feasibility and utility in children. In addition, we call attention to gliomas as a common cause of chronic focal seizures in children. Of 49 children undergoing resection and followed for from 1 to 14 years (mean of 5.8 years), 32 (65%) are either seizure free or have had a significant reduction in seizure frequency that has unambiguously improved their quality of life. The results are analyzed further by relating the surgical outcome to each of the pathologic entities that caused the seizures. This analysis reveals the variety of neurological conditions that commonly cause intractable focal seizure disorder in children and distinguishes those pathologic entities in which the seizure disorder is apt to respond to surgical intervention from those that will not.