脊髓小脑共济失调2个家系的临床表现、影像学和基因型分析

目的 分析脊髓小脑共济失调(SCA)2个家系的临床表现、影像学特点和基因型及三者之间的联系.方法 描述SCA 2个家系部分成员的临床表现、总结其特点,对部分患者行头部磁共振检查,同时抽取2 ml外周血对其进行基因检测.结果 家系Ⅰ经基因检测证实为SCA2,先证者、先证者母亲、哥哥的CAG重复数目分别为44、36、38次,磁共振显示脑干、小脑萎缩,脑桥"十字征"、"纵线征";家系Ⅱ经基因检测证实为SCA1,先证者、先证者姑姑、先证者表弟的CAG重复数目分别为60、51、52,磁共振显示小脑明显萎缩.结论 SCA亚型临床表现相似,仅靠临床症状和影像学检查难以确诊,最终诊断需依赖于基因检测.     

脊髓小脑共济失调17型临床特征和基因突变分析

目的 探讨脊髓小脑共济失调17型(spinocerebellar ataxia 17,SCA17)患者的临床特征和基因突变的特点.方法 对708个常染色体显性遗传SCA家系的先证者和另外119例临床拟诊SCA的散发患者进行常规基因检测,按照患病率不同依次筛选:SCA3、SCA1、SCA2、SCA6、SCA7、SCA8、SCA12、SCA17、齿状核-红核-苍白球-路易体萎缩致病基因三核苷酸重复动态突变分析.其中SCA17致病基因检测采用聚合酶链反应扩增TATA结合蛋白(TBP)基因CAG重复序列,琼脂糖凝胶电泳检测扩增产物;对出现2个电泳条带的样品应用毛细管电泳片段分析方法进行TBP基因CAG重复次数检测,并对其临床表型、神经影像学特征以及表型与基因型相关性进行细致分析.结果 通过上述检测及分析,发现5例患者具有TBP基因CAG重复扩展突变.片段分析显示CAG重复次数分别为37/50、36/45、38/52、38/53、36/54次,长片段重复次数已达到异常范围.5例患者的临床表型各异,以共济失调、记忆力减退为主要症状.结论 在827例共济失调病例中仅发现5例SCA17,说明该病在中国人群中较为罕见;通过对5例患者的临床表型进行分析,初步认为国人SCA17存在临床变异.     

痉挛性截瘫并共济失调表型的家系基因分析

以该院门诊收治的5例具有痉挛性截瘫合并共济失调表型的家系先证者为研究对象,运用高通量测序芯片结合毛细管电泳技术对这些家系先证者进行致病基因动态突变检测。发现了一个家系先证者携带有ATXN3/MJD1基因CAG重复84次,其妹妹CAG重复82次,其父CAG重复73次,该家系拟诊为遗传性脊髓小脑共济失调3型(SCA3/MJD)家系,并具有明显的临床异质性及遗传早现现象。建议对于兼有痉挛性截瘫及小脑性共济失调表型的患者,特别是具有显性遗传家族史的患者,应进行SCA3致病基因的动态突变检测,同时对家系内表型正常的成员应仔细查体,以防漏诊。     

脊髓小脑共济失调3型临床变异型特征及突变分析

目的 探讨脊髓小脑共济失调3型临床变异型特征.方法 应用CEQ8000核酸分析仪对1个表型为变形性肌张力障碍家系和2个表型为痉挛性截瘫家系的SCA3/MJD基因胞嘧啶-腺嘌呤-鸟嘌呤(CAG)重复序列进行基因片段分析.结果 基因学检查证实3个家系均为SCA3/MJD基因CAG重复扩增突变致病.结论 我国脊髓小脑共济失调3型存在变形性肌张力障碍和痉挛性截瘫的临床变异型.脊髓小脑共济失调3型的多种临床变异类型为调节因素假说提供了进一步的证据,并且提示在临床工作中应注意避免遗漏阳性家系.     

宁夏地区回、汉族脊髓小脑共济失调家系SCA3/MJD基因突变研究

目的通过对宁夏地区临床诊断为脊髓小脑共济失调的3个家系(2个汉族家系、1个回族家系)进行SCA3/MJD基因检测,探讨脊髓小脑共济失调的发病机制与临床特点,以为临床应用提供依据。方法对3家系受试者进行神经系统检查和系谱调查,部分行头部MRI和肌电图检查,以及SCA3/MJD基因胞嘧啶-腺嘌呤-鸟嘌呤(CAG)重复数目检测。结果3家系中共计8例脊髓小脑共济失调患者(汉族家系1中6例、汉族家系2中1例和回族家系中1例),符合常染色体显性遗传特点,以共济失调与构音障碍为主要表现,其次为眼外肌麻痹、眼球震颤、慢眼动、锥体束征等。其中汉族家系1和回族家系明确诊断为SCA3/MJD家系,两家系中7例患者(汉族家系1中6例、回族家系中1例)及2例临床表型正常亲属(两家系中各1例)检测出SCA3/MJD异常等位基因,其CAG重复数目为66～81次。汉族家系2中1例患者及汉族家系1中4例临床表型正常亲属SCA3/MJD基因CAG重复数目为20～33次。正常等位基因与异常等位基因CAG重复数目差异有统计学意义(t=5.309,P=0.000)。结论宁夏地区回、汉族脊髓小脑共济失调患者中存在SCA3/MJD基因型,基因检测分析有利于明确诊断脊髓小脑共济失调且能够检出症状前患者。     

遗传性脊髓小脑型共济失调7型遗传学诊断及临床特征

目的研究中国人遗传性脊髓小脑型共济失调(SCA)7型(SCA7)的基冈突变和临床特征。方法应用聚合酶链反应(PCR)、聚丙烯酰胺凝胶电泳(PAGE)等技术对临床表现为SCA的92个家系112例患者和16例散发SCA患者的SCA7基因内CAG三核苷酸重复序列进行检测,对异常等位基因片段进行DNA测序,分析基因型和表型之间的关系,并与表型正常的家系成员和健康人对照。结果在1个SCA7家系的6位成员中检测出2例患者的SCA7等化基因内CAG重复数目为71;临床表现主要为共济失调、视力下降、黄蓝色盲及视网膜色素变性。该家系内表型正常的4位成员SCA7等位基因CAG重复数目为7～9,另126例临床表现为SCA的患者、71名表型正常的家系成员及60名健康对照者SCA7等位基因内CAG三核甘三酸重复数为6—21。结论CAG过度扩增为SCA7的致病原因,分子遗传学分析有助于SCA7的诊断;视网膜色素变性为SCA7的重要特征。     

脊髓小脑性共济失调1型一家系谱分析

目的探讨分子基因学及临床特点对脊髓小脑共济失调1型(spinocerebellar ataxia type1,SCA1)家系诊断的临床意义。方法采集一SCA1患者家系共8人,其中4例为临床症状阳性患者,4人为无临床症状者,分析患者家系成员的临床表现、影像学及电生理检查结果特点,采用PCR-STR分析法对8位家系成员进行ATXN1基因CAG序列检测。结果该家系中8人均存在ATXN1基因CAG序列异常扩增。4例患者首发症状均为小脑共济失调,主要表现进行性步态不稳,并伴有构音障碍、饮水呛咳、双眼上视不充分。MRI检查结果示小脑萎缩。神经电生理检查显示不同程度的异常,4例临床症状阳性患者尤为突出。结论 SCA1临床表现为进展性的小脑共济失调及脑干功能损害,临床症状阳性结合基因检测可诊断。     

脊髓小脑共济失调2型、3型患者10例基因突变与临床表型分析

目的探讨脊髓小脑共济失调（SCA）2型、3型患者的基因突变特点及临床表型。方法总结4个SCAs家系的9例患者和1例散发患者的临床表现，对全部患者、43名家系成员及60名健康对照，采用PCR、荧光PCR、毛细管电泳等技术检测分析SCA2、3基因内CAG三核苷酸重复序列的长度及拷贝数。结果3个家系中的6例患者、1例散发患者存在SCA3／MJD（CAG）n扩展突变，CAG重复数为68—75次；1个家系的3例患者存在SCA2（CAG）n扩展突变，CAG重复数为39—41次。两型患者的临床表现有重叠之处，但在发病年龄、病程进展、神经系统受累部位等方面有明显差异。结论SCA3／MJD型与SCA2型在临床表现上存在一定差异性，有助于鉴别和分型，但基因检测是明确诊断的惟一方法。     

两遗传性脊髓小脑型共济失调7型家系的临床特征和基因突变研究

目的 探讨遗传性脊髓小脑型共济失调(SCA)7型(SCA7)的临床特征和基因突变.方法 采用聚合酶链反应(PCR)和琼脂糖凝胶电泳(AGE)等技术,检测临床诊断为SCA的5个家系26例患者和37例表型正常的家系成员的SCA7基因内CAG三核苷酸重复次数,对异常等位基因片段进行DNA测序,分析临床表现和基因突变的关系. 结果 2个SCA7家系患者的SCA7等位基因内CAG重复数目为44～50次;临床表现主要为共济失调、视力下降及视网膜色素变性.该家系内表型正常的家系成员SCA7等位基因CAG重复数目为10～30. 结论 CAG过度扩增为SCA7的致病原因,分子遗传学分析有助于SCA7的诊断.     

脊髓小脑性共济失调12型一家系的临床特征和基因突变分析

目的研究1个遗传性共济失调12型(spinocerebellar ataxia type 12 SCA12)家系的临床特征与基因突变特点。方法应用聚合酶链反应、毛细管电泳等方法对1个临床诊断为遗传性共济失调的家系进行SCA基因检测。结果确定该家系为遗传性共济失调SCA12型家系。共确诊7例现证患者,患者异常CAG的重复次数为51⁵5次。结论上肢震颤,逐渐出现共济失调、延髓麻痹,病理征阳性为SCA12型相对独特的临床表现。先证者异常片段CAG重复为55次,第3代患者Ⅲ2 CAG重复次数54次,发病年龄提前,可能存在遗传早现现象。SCAs核苷酸突变扩展的数目与年龄呈负相关,与症状严重程度呈正相关的特点可能也存在于SCA12型中。     

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.     

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.     

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.     

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.     

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.