Histopathologic findings in 37 cases of functional hemispherectomy.

Hemispherectomy procedures are performed in patients for whom focal cortical resection would be predicted to produce a significant reduction in seizures. The functional hemispherectomy procedure consists of disconnecting the hemispheres while attempting, in some cases, to preserve parenchyma. This study retrospectively reviews the histopathologic findings in 37 cases of functional hemispherectomy performed between 1990 and 1998 at a major epilepsy center. Procedures were performed in 20 males and 17 females who ranged in age from 3 months to 37 years (mean age, 9.6 years). In all but two cases, more than half or all the material submitted for pathologic testing was examined histologically. Cortical dysplasias or hemimegalencephaly were identified in 14 patients. The most common patterns of dysplasia observed included architectural disorganization (n = 13), increased molecular layer neurons (n = 11), and neuronal cytomegaly (n = 11). One patient was known to have epidermal nevus syndrome. Six patients had Sturge-Weber syndrome. Remote infarct/ischemic damage was identified as the etiology of seizures in six patients; four of these patients had mild associated secondary cortical architectural abnormalities. Three patients demonstrated pathology consistent with Rasmussen's encephalitis; one additional patient had chronic encephalitis changes, not otherwise specified. In two cases, changes consistent with hippocampal sclerosis were identified; additionally, hippocampal neuronal loss and gliosis was focally identified in three patients. Most of these patients had coexistent cortical dysplasia or radiographic evidence of remote infarct. One specimen demonstrated areas of infarct following resection of an arteriovenous malformation. In two specimens, significant histopathologic findings were not identified; both of these patients had radiographic evidence of remote infarct. The spectrum of pathologic conditions that may be encountered in the setting of a functional hemispherectomy is varied and in this study most frequently included cortical dysplasia, Sturge-Weber syndrome remote infarct, and Rasmussen's encephalitis.     

Cortical dysplasia in extratemporal lobe intractable epilepsy: a study of 52 cases

Cortical dysplasias or malformations due to abnormalities of cortical development are a well-recognized cause of intractable seizures. This study retrospectively examines the clinicopathologic features of 52 cases of extratemporal cortical dysplasia (from 135 total resections performed over a 16-year period). The study consists of 52 patients (27 males; 25 females) who underwent extratemporal resection for epilepsy at a mean age of 15.1 years (range, 3 months to 44.1 years). Seizure duration before surgery ranged from 7 to 372 months (mean duration, 129 months). Patterns of cortical dysplasia observed included diffuse architectural disorganization (n=48), neuronal cytomegaly (n=32), increased number of molecular layer neurons (n=32), balloon cells (n=19), gray matter heterotopia (n=3), neuronal glial clustering (n=3), and pial glial neuronal tissue (n=2). Five patients had coexistent nodular hamartomas. Coexistent tumors were present in five patients; including three dysembryoplastic neuroepithelial tumors, one ganglioglioma, and one low-grade fibrillary astrocytoma. Two patients had tuberous sclerosis. Follow-up was available in 50 patients (mean follow-up, 29 months). Thirty-eight patients (73%) had complete resolution or significant decrease in seizure frequency, 13 patients (25%) had increased seizures or no change in seizures, and one patient died in the postoperative period. In conclusion, (1). cortical dysplasia was identified in 38.5% of extratemporal resections for epilepsy; (2). the common cortical dysplasia patterns observed included diffuse cortical disorganization, neuronal cytomegaly, and increased molecular layer neurons; (3). 10% of extratemporal cortical dysplasia was associated with tumors; (4). improved seizure control was obtained in approximately three fourths of patients after resection; and (5). seizures associated with balloon cell dysplasia were less successfully managed with surgery.     

Neuropathology in patients with multiple surgeries for medically intractable epilepsy

Outcomes following surgery for chronic epilepsy are generally good; however, seizures persist/recur following initial surgery in some patients. We hypothesize that in patients who require multiple surgeries for intractable epilepsy, an identifiable pathologic substrate can be found in the subsequent surgical specimen, which accounts for the recurrent seizures. We retrospectively studied 102 patients (56 females) with medically intractable epilepsy who have had at least 2 surgeries more than 60 days apart from 1990-2010. Patient age at time of 1st surgery ranged from 3 months-60 years (mean 18.1 years). Mean duration of seizures prior to 1st surgery was 9.7 years. Time between the 1st and 2nd surgeries ranged from 0.28-15.3 years (mean 4.3 years). The most common pathologies at initial resection included focal cortical dysplasia (45%), tumor (19%), hippocampal sclerosis (16%), and non-specific changes (13%); 10% of patients had multiple significant pathologies. Of the 89 patients that had a significant initial surgical finding, 74 (83.1%) had a significant pathology at 2nd surgery; the same pathology was identified in 49 (66.2%) of these cases. The most commonly identified pathologies at 2nd surgery included remote infarcts (likely postoperative) (N = 51) and focal cortical dysplasia (N = 29). Three out of the 13 patients with initially non-specific findings had a significant finding at 2nd surgery, excluding postoperative infarct. Follow-up after last surgery ranged from 0.5-190 months (mean 48 months); 83% of patients were on anti-convulsive medication and 57% were seizure-free at last known follow-up. In the majority of cases of recurrent epilepsy with at least 2 surgeries (84%), pathologic findings accounting for seizures were found at the 2nd surgery. In most cases with significant initial pathology, a similar pathology was present at 2nd surgery (55%). Post-operative contusional damage may account for persistent seizures following initial surgery in a subset of patients.     

癫痫相关局灶性皮质发育不良的临床病理学研究

目的研究癫痫相关局灶性皮质发育不良（FCD）的临床病理学特征。方法对38例2005年在北京宣武医院接受致痫灶外科手术切除治疗并临床病理诊断为FCD患者的临床资料、神经影像学以及病理学资料进行回顾性分析。结果38例患者的平均发病年龄为9．2岁,平均病程为11．9年,发作形式以复杂部分性发作为主。神经影像学检查有21例可见海马硬化、灰质异常信号等改变。组织学具体分型为：FCDⅠA型3例,FCDⅠB型20例,FCDⅡA型5例以及FCDⅡB型5例,另有5例被诊断为轻微皮质发育不良（mild MCD）。从部位来看,FCDⅡ型病变多见于颞叶以外的脑叶（8／10）,尤以额叶多见（5／8）。具有双重病理改变的5例均为FCDⅠB型。在免疫组织化学染色,巨大神经元、未成熟神经元、形态异常神经元及白质内异位神经元均可由NeuN清晰的标记出来。少数气球细胞呈nestin阳性表达。结论FCD是难治性癫痫的常见病理组织学所见,其中又以FCDIB型最为多见,并且可伴有海马硬化。FCDⅠ型和Ⅱ型有着不同的临床病理学以及细胞病理学形特征。     

Brain tumors in adults with medically intractable epilepsy

Much of the literature on tumors arising in the setting of chronic epilepsy focuses on children. This study reviewed 1 institution's 141-patient experience with tumors in adults arising in this clinical setting. The majority of tumors (71.6%) arose in the temporal lobe. The most common tumor types encountered included ganglioglioma (n = 38), low-grade fibrillary astrocytoma (n = 24), and low-grade oligodendroglioma (n = 22). Coexistent focal cortical dysplasia (type IA) was identified in 15 cases (10.6%). The largest group of tumors in adults were World Health Organization (WHO) grade II neoplasms compared with WHO grade I tumors in children. Gangliogliomas are the most commonly encountered neoplasms. Coexistent focal cortical dysplasia may be observed in a significant minority of tumors, suggesting a possible developmental origin for some of these neoplasms.     

Clinicopathologic findings in patients with infantile hemiparesis and epilepsy

Infantile hemiparesis may be associated with significant morbidity and may have a profound impact on a child's physical and social development. There are little published data evaluating the clinicopathologic features of patients with infantile hemiparesis. The present study retrospectively examines these clinicopathologic features in a surgical series of 21 patients with infantile hemiparesis. The study group was comprised of 21 patients, 13 females and 8 males, ranging in age from 5 to 41 years (mean, 20 years) at the time of surgery. Hemiparesis involved the right side in 16 patients and the left side in 5 patients. Imaging studies identified porencephaly in 8 patients (38%), encephalomalacia in 5 patients (24%), focal cerebral atrophy in 9 patients (43%), ventricular dilatation in 6 patients (29%), and white matter hyperintensities in 4 patients (19%). Concomitant neurologic diseases included medically intractable epilepsy in all 21 patients and visual field defects in 11 patients (52%). Significant perinatal history included prematurity in 7 patients (33%) and cesarean section, forceps delivery, placental abruption, fetal distress, and prolonged rupture of membranes each in 1 patient (5%). The remainder of the patients had an uncomplicated perinatal course (43%). Twelve patients underwent functional hemispherectomy (57%), 8 patients underwent lobectomy (38%) and 1 patient underwent "cyst" resection (5%). Histological evaluation demonstrated lesional (corresponding to radiographic findings) tissue in 15 of the 21 cases (71%). Infarction, malformations due to abnormalities of cortical development (cortical dysplasia) and gliosis with microcalcifications were each found in 6 patients (29%). Infarction and a geographically distinct area of cortical dysplasia were found to coexist in 1 case. Histopathologic findings in the 6 cases in which excised tissue was considered nonlesional included gliosis in all 6 of the cases, hippocampal sclerosis in 2 cases (10%), and neuronal heterotopia in 2 cases (10%). An osteoma was identified in 1 patient. The most common pathological findings observed in our series were infarction and cortical dysplasia, although radiographically, infarct-related changes were the most evident. Hippocampal sclerosis was encountered in 2 patients, suggesting that a subset of cortical dysplasias and hippocampal sclerosis may be caused by an in utero ischemic event.     

Neuropathological Findings in Intractable Epilepsy: 435 Chinese Cases

The number of patients with intractable epilepsy undergoing surgical management in China is increasing rapidly. We retrospectively reviewed 435 consecutive cases of intractable epilepsy receiving surgical resection from 2005 to 2008 in our hospital, looking specifically at the neuropathological findings. The three most common causes of intractable epilepsy were focal cortical dysplasia (FCD; 52.9%), scar lesions (22.8%) and brain tumors (11.7%). Hippocampal sclerosis was identified in 74 cases (17.0%), although most of these were accompanied by dual pathology with FCD (especially Palmini type IB), scar lesions or tumors. Among FCD cases, Palmini type I lesions are the most frequently observed abnormality, with a preferred location in the temporal lobe (60.1%) and often accompanied by dual pathology. In contrast, Palmini type II FCD lesions occurred predominantly in the frontal regions and with a lower age of onset. Most tumors were mixed neuronal–glial tumors, mainly ganglioglioma (19 cases) and dysembryoplastic neuroepithelial tumor (10 cases), with a trend toward a temporal location and usually accompanied by cortical dysplasia in the peritumor area. Our data on the neuropathology of intractable epilepsy in China show that glioneuronal lesions are the most prominent cause of intractable epilepsy, and this is consistent with reports from other countries.     

Composite ganglioglioma and dysembryoplastic neuroepithelial tumor

Both ganglioglioma and dysembryoplastic neuroepithelial tumors are well-recognized glial-neuronal neoplasms associated with chronic epilepsy and cortical dysplasia (neuronal migration abnormalities). The exact relationship between these 2 glial-neuronal tumors continues to be debated. This article reports a case of a composite ganglioglioma and dysembryoplastic neuroepithelial tumor occurring in a 36-year-old woman in the left temporal lobe region. The resection histologically demonstrated distinct areas of ganglioglioma and dysembryoplastic neuroepithelial tumor. A focal area of cortical dysplasia is also identified. The MIB-1 labeling indexes in both components were low (<1% of tumor cell nuclei). The coexistence of these 2 lesions and cortical dysplasia suggest a possible etiologic relationship between these 2 tumors.     

Mild Malformation of Cortical Development with Oligodendroglial Hyperplasia in Frontal Lobe Epilepsy: A New Clinico‐Pathological Entity

The histopathological spectrum of human epileptogenic brain lesions is widespread including common and rare variants of cortical malformations. However, 2–26% of epilepsy surgery specimens are histopathologically classified as nonlesional. We hypothesized that these specimens include also new diagnostic entities, in particular when presurgical magnetic resonance imaging (MRI) can identify abnormal signal intensities within the anatomical region of seizure onset. In our series of 1381 en bloc resected epilepsy surgery brain specimens, 52 cases could not be histopathologically classified and were considered nonlesional (3.7%). An increase of Olig2‐, and PDGFR‐alpha‐immunoreactive oligodendroglia was observed in white matter and deep cortical layers in 22 of these patients (42%). Increased proliferation activity as well as heterotopic neurons in white matter were additional histopathological hallmarks. All patients suffered from frontal lobe epilepsy (FLE) with a median age of epilepsy onset at 4 years and 16 years at epilepsy surgery. Presurgical MRI suggested focal cortical dysplasia (FCD) in all patients. We suggest to classify this characteristic histopathology pattern as “mild malformation of cortical development with oligodendroglial hyperplasia (MOGHE).” Further insights into pathomechanisms of MOGHE may help to bridge the diagnostic gap in children and young adults with difficult‐to‐treat FLE.     

Intimal thickening of meningeal arteries after serial corticectomies for Rasmussen encephalitis

Rasmussen encephalitis is a rare cause of intractable epilepsy in children. Between 2008 and 2010, 4 patients had second cortical resections performed after a primary corticectomy for Rasmussen encephalitis. In each case, we observed some degree of vessel wall change in leptomeningeal arteries, consisting of moderate to moderately severe intimal hyperplasia. The intervals between original resection and second operation ranged from 8 months to 10 years. Ages of the patients ranged from 9 to 12 years at their first resection and from 10 to 19 years at the time of revision. Four other Rasmussen encephalitis cases operated upon in the years 2006 to 2010 and 2 surgical revisions for severe cortical dysplasia, 1 for mild cortical dysplasia and 1 for recurrent dysembryoplastic neuroepithelial tumor, did not show significant vascular abnormalities (with surgical intervals of 10 months to 16 years). Leptomeningeal intimal hyperplasia appears to develop in the interval between repeated cortical resections for Rasmussen encephalitis, an inflammatory disorder. The pathogenesis of this vascular change may be related to meningeal inflammation in Rasmussen encephalitis. This finding in children undergoing surgical resection for Rasmussen encephalitis may itself lead to "secondary" ischemic change that contributes to worsening of epilepsy.     

Composite ganglioglioma/dysembryoplastic neuroepithelial tumor: a clinicopathologic study of 8 cases

Ganglioglioma and dysembryoplastic neuroepithelial tumor are both low-grade glioneuronal neoplasms that most commonly occur in association with chronic epilepsy. Rare cases of tumors with composite features of ganglioglioma and dysembryoplastic neuroepithelial tumor have been reported. We retrospectively reviewed the clinicopathologic features of 8 composite tumors (7 were female; median age, 20 years). All patients had chronic epilepsy and had tumors in either the temporal or the frontal lobe. Six patients are currently seizure-free (follow-up: median, 90 months). All tumors were multinodular. Some nodules had distinct features of each tumor type (range, 5%-85% of the tumor). Seven tumors contained nodules with mixed features of both tumor types. Five of 7 evaluable tumors demonstrated adjacent focal cortical dysplasia (Palmini type I). Mitotic activity, vascular proliferation, or necrosis was not observed in any of the tumors. Three tumors demonstrated focal meningeal extension. Composite tumors commonly arise in the temporal lobe in young patients with chronic epilepsy; they appear to behave as a World Health Organization grade I neoplasm. Histologically, these multinodular tumors appear to maintain distinct areas with features of each tumor and foci where the 2 patterns are merged. A subset of composite tumors are associated with adjacent focal cortical dysplasia.     

Focal dysplasia of the cerebral cortex and infantile spasms associated with somatic 1q21.1‐q44 duplication including the AKT3 gene

Somatic and germline duplications or activating mutations of AKT3 have been reported in patients with hemimegalencephaly and megalencephaly. We performed array comparative genomic hybridization on brain tissue and blood in 16 consecutive patients with symptomatic epilepsy due to focal or multilobar malformations of cortical development who underwent surgical treatment of epilepsy. One patient with infantile spasms and a dysplastic left frontal lobe harboured a somatic trisomy of the 1q21.1‐q44 chromosomal region, encompassing the AKT3 gene, in the dysplastic brain tissue but not in blood and saliva. Histopathology revealed severe cortical dyslamination, a thin cortex in the premotor area with microgyri and microsulci, immature neurons with disoriented dendrites and areas of cortical heterotopia in the sub‐cortical white matter. These cytoarchitectural changes are close to those defining type Ib focal cortical dysplasia. Immunohistochemistry in brain specimens showed hyperactivation of the PI3K/AKT/mTOR pathway. These findings indicate that AKT3 upregulation may cause focal malformations of cortical development. There appears to be an etiologic continuum between hemimegalencephaly and focal cortical dysplastic lesions. The extent of brain malformations due to AKT3 upregulation may be related to the embryonic stage when the post‐zygotic gene alteration occurs.     

Utilization of frozen sections in the evaluation of chronic epilepsy–related cases

The role of frozen section consultation in the evaluation of chronic epilepsy–associated surgical excisions of brain tissue has not been previously examined. The study retrospectively reviews 335 cases in which a frozen section consultation was obtained in the setting of a resection for chronic epilepsy. In most cases (n = 323), 3 or fewer frozen sections were performed. The most commonly identified pathologies on final diagnosis included tumor or tumorlike lesions (79.1% of cases) and focal cortical dysplasia (20.9% of cases). Frozen section diagnoses discrepant with final diagnoses due to sampling error or misinterpretation were noted in 39 cases and most commonly involved a diagnosis of gliosis or tumor in the setting of a focal cortical dysplasia or diagnosis of gliosis in the setting of a low-grade tumor. In conclusion, frozen section consultation may be particularly useful in the evaluation of neoplasms arising in the setting of chronic epilepsy. Some epilepsy-associated pathology, such as focal cortical dysplasia, may be difficult to diagnose at the time of frozen section and such cases may not be an ideal target for intraoperative frozen section consultation.     

Frozen section discrepancy in the evaluation of nonneoplastic central nervous system samples

Frozen section (FS) for intraoperative evaluation of central nervous system (CNS) lesions provides the neurosurgeon with a rapid preliminary pathologic diagnosis. Diagnosis of nonneoplastic lesions is particularly challenging in this venue. To highlight common diagnostic pitfalls, we sought to identify discrepancies between FS and final diagnoses among nonneoplastic CNS samples via a retrospective review of 303 FS cases encountered from 1997 to 2006. Thirty-nine (12.9%) discrepant diagnoses were identified, of which 27 were clinically suspected tumors. Final diagnoses in the discrepant group included the following: inflammatory lesions (n = 8, 20.5%), malformation of cortical development-cortical dysplasia (n = 5, 12.8%), gliosis (n = 5, 12.8%), vascular malformations (n = 5, 12.8%), demyelination/progressive multifocal leukoencephalopathy (n = 3, 7.7%), infarct (n = 3, 7.7%), hemorrhage/blood clot (n = 3, 7.7%), and no pathologic changes (n = 3, 7.7%). The remaining 4 (10.2%) discrepant cases involved one case each of amyloid angiopathy, nonspecific vasculopathy, vasculitis, and meningioangiomatosis. Nonneoplastic lesions are often more challenging than neoplastic lesions at FS, particularly because they are less commonly sampled for FS and, therefore, less familiar to pathologists.     

Sturge–Weber Syndrome Is Associated with Cortical Dysplasia ILAE Type IIIc and Excessive Hypertrophic Pyramidal Neurons in Brain Resections for Intractable Epilepsy

Sturge–Weber syndrome (SWS) is a rare syndrome characterized by capillary‐venous malformations involving skin and brain. Many patients with SWS also suffer from drug‐resistant epilepsy. We retrospectively studied a series of six SWS patients with epilepsy and extensive neurosurgical resections. At time of surgery, the patients' age ranged from 11 to 35 years (with a mean of 20.2 years). All surgical specimens were well preserved, which allowed a systematic microscopical inspection utilizing the 2011 ILAE classification for focal cortical dysplasia (FCD). Neuropathology revealed dysmorphic‐like neurons with hypertrophic cell bodies reminiscent to those described for FCD type IIa in all cases. However, gross architectural abnormalities of neocortical layering typical for FCD type IIa were missing, and we propose to classify this pattern as FCD ILAE type IIIc. In addition, our patients with earliest seizure onset also showed polymicrogyria (PMG; n = 4). The ictal onset zones were identified in all patients by subdural electrodes, and these areas always showed histopathological evidence for FCD type IIIc. Four out of five patients had favorable seizure control after surgery with a mean follow‐up period of 1.7 years. We concluded from our study that FCD type IIIc and PMG are frequently associated findings in SWS. FCD type IIIc may play a major epileptogenic role in SWS and complete resection of the associated FCD should be considered a prognostic key factor to achieve seizure control.     

难治性癫痫相关脑肿瘤的临床病理学研究

目的 探讨难治性癫痫相关脑肿瘤的临床病理学特征.方法 选择 2005年1月至2008年4月期间在首都医科大学宣武医院接受难治性癫痫致痫灶手术切除治疗并经病理诊断为脑肿瘤患者的临床、影像以及病理学资料35例进行回顾性分析.结果 35例患者的癫痫平均发病年龄为14.3岁,平均病程8.6年,94.3%(33/35)的患者经头颅核磁共振(MRI)检查可见异常信号表现.组织学分型:神经节细胞胶质瘤19例(WHO Ⅰ级13例,WHOⅡ级6例),胚胎发育不良性神经上皮瘤3例(WHO Ⅰ级),多形性黄色瘤型星形细胞瘤3例(WHO Ⅱ级),弥漫性星形细胞瘤(WHO Ⅱ级)、少突星形细胞瘤(WHO Ⅱ级)、血管中心性胶质瘤(WHO Ⅰ级)和脑膜血管瘤病各1例,另有6例病变的组织学形态介于胶质神经元错构性病变和混合性神经元-胶质肿瘤之间.上述肿瘤多位于颞叶(27/35),多数同时伴有局灶性皮质发育不良的双重病理改变.免疫组织化学染色可见CD34显著表达于神经节细胞胶质瘤等病例.结论 表现为难治性癫痫的脑肿瘤多为位于颞叶且生长缓慢的混合性神经元-胶质肿瘤.观察到一组形态学上介于错构性病变和混合性神经元-胶质肿瘤之间的具有过渡特征的病变,这些错构性病变和肿瘤在组织形态学上体现的连续性以及良好的生物学行为提示了它们具有相同或相似的发生来源和发病机制,由此提出胶质神经元混合性病变的疾病谱概念.     

Usefulness of Diffusion Tensor Tractography in Pediatric Epilepsy Surgery

Purpose

This study was conducted to assess the clinical relevance of diffusion tensor tractography (DTT) in pre- and post-operative evaluations of childhood epilepsy surgery.

Materials and Methods

Seventy-two patients who received epilepsy surgery between March 2004 and July 2008 were retrospectively analyzed (M : F=40 : 32, ages of 3 months to 24 years, mean age=8.9 years). DTT was performed using a 3.0 T scanner and single-shot spin-echo echo-planar imaging with 32-different diffusion gradient directions. We reviewed the data focusing on the type of surgery, final pathological diagnosis, and how the DTT data were clinically used.

Results

The most common form of childhood epilepsy surgery was complete resection of an epileptogenic lesion (n=52, 72.2%). The reported etiologies included cortical dysplasia (n=32, 44.4%), hippocampal sclerosis (n=9, 12.5%), brain tumors (n=7, 9.7%), and non-pathologic lesions (n=4, 5.6%) in the final diagnoses. Twenty-one dysplastic cortexes and four brain tumors involved an approximal relationship with the corticospinal tract (n=18), optic radiation (n=2), and arcuate fasciculus (n=5). Additionally, although DTT demonstrated white matter tracts clearly, DTT in the hippocampal sclerosis did not provide any additional information. In cases of callosotomy (n=18, 25%), post-operative DTT was utilized for the evaluation of complete resection in all patients. DTT information was not used in functional hemispherectomy (n=2, 2.8%).

Conclusion

Preoperatively, DTT was a useful technique in cases of cortical dysplasia and brain tumors, and in cases with callosotomy, postoperatively. DTT should be included among the routine procedures performed in management of epilepsy.     

Heterotopias,cortical dysplasias and glioneural tumors participate in cognitive processing in patients with temporal lobe epilepsy

Focal brain lesions such as cortical dysplasia and glioneural tumors generate epileptic activity and thus may be synaptically connected with normal cortex. To test this hypothesis, we compared event-related potentials recorded directly from the medial temporal lobe (MTL) and a dysplastic lesion in eight patients with intractable temporal lobe epilepsy. The P3 component, related to visual target detection, showed different peak latencies in four patients and a larger intralesional amplitude compared to established anterior-MTL-generators in two patients. Semantic processing was identified by the N400 component and showed a different latency in four patients and larger intralesional amplitudes in two patients. These results are compatible with the hypothesis that cortical lesions interact with synaptic pathways related to cognitive functions such as visual target detection, and verbal processing.     

Neurodevelopmental disorders as a cause of seizures: neuropathologic, genetic, and mechanistic considerations

This review will consider patterns of developmental neuropathologic abnormalities—malformations of cortical development (MCD)—encountered in infants (often with infantile spasms), children, and adults with intractable epilepsy. Treatment of epilepsy associated with some MCD, such as focal cortical dysplasia and tubers of tuberous sclerosis, may include cortical resection performed to remove the “dysplastic” region of cortex. In extreme situations (eg, hemimegalencephaly), hemispherectomy may be carried out on selected patients. Neuropathologic (including immunohistochemical) findings within these lesions will be considered. Other conditions that cause intractable epilepsy and often mental retardation, yet are not necessarily amenable to surgical treatment (eg, lissencephaly, periventricular nodular heterotopia, double cortex syndrome) will be discussed. Over the past 10 years there has been an explosion of information on the genetics of MCD. The genes responsible for many MCD (eg, TSC1, TSC2, LIS‐1, DCX, FLN1) have been cloned and permit important mechanistic studies to be carried out with the purpose of understanding how mutations within these genes result in abnormal cortical cytoarchitecture and anomalous neuroglial differentiation. Finally, novel techniques allowing for analysis of patterns of gene expression within single cells, including neurons, is likely to provide answers to the most vexing and important question about these lesions: Why are they epileptogenic?     

成人缺血型烟雾病临床特点的回顾性分析

目的:分析成人缺血型烟雾病的临床特点。方法:对53例成人缺血型烟雾病患者的临床表现和影像学资料进行回顾性分析。结果:53例成人缺血型烟雾病患者年龄分布不均衡(P0.05),平均(44.92±13.41)岁,以41~60岁者居多(25例,47.17%);男性患者多于女性(1∶0.43,P0.01)。53例患者首发症状的分布差异无统计学意义(P0.05)。53例患者中新发脑梗死31例(58.49%)、陈旧性脑梗死22例(41.51%);双侧梗死32例(60.38%)、单侧梗死21例(39.62%);新发脑梗死以急性症状为主,陈旧性脑梗死以慢性症状为主;单、双侧脑梗死与首发症状为急性和慢性无明显关联(P0.05)。53例患者脑缺血部位共157处,依次为额叶、颞叶、脑室旁、顶叶、枕叶,各部位发生率差异有统计学意义(P0.01)。单纯前循环病例(n=34)与合并后循环病例(n=19)的脑卒中评分(NIHSS)差异无统计学意义(P0.05)。结论:成人缺血型烟雾病临床表现复杂,缺乏特异性,确诊需借助颅内血管影像学技术如经颅多普勒(TCD)、头颅磁共振血管成像(MRA)、全脑数字减影血管造影(DSA)等检查,以指导临床治疗。