Managing epilepsy in tuberous sclerosis complex

Epilepsy is very common in tuberous sclerosis complex and occurs in 80 to 90% of affected individuals during their lifetime. Onset usually occurs during childhood, and up to one third of children with tuberous sclerosis complex will develop infantile spasms. Although not completely understood, the incidence of epilepsy is thought to relate to the neuropathologic features of the disorder, including cortical tubers and other dysgenetic features. Individuals with tuberous sclerosis complex frequently have epileptiform features to their electroencephalograms. Treatment of epilepsy in tuberous sclerosis complex is similar to epilepsy resulting from other causes and includes anticonvulsant medications, the vagus nerve stimulator, and the ketogenic diet. Vigabatrin has been shown to be particularly effective in treating infantile spasms in the setting of tuberous sclerosis complex. Epilepsy surgery has a very important role in the management of children and adults with pharmacoresistant epilepsy in tuberous sclerosis complex.     

结节性硬化症与难治性癫痫相关基因的生物信息学分析

目的 用生物信息学方法探讨结节性硬化症与难治性癫痫的发病相关基因,为癫痫的基础研究和临床治疗提供新思路。 方法 从基因芯片公共数据库Gene Expression Omnibus(GEO)中下载结节性硬化症与难治性癫痫相关基因芯片数据,利用String、KEGG、Panther等在线分析软件对差异表达基因进行生物信息学分析。 结果 在100个差异表达基因所编码的蛋白中,有47个蛋白与其他蛋白存在相互作用关系,作用过程涉及多种生物学通路,与多个生物学过程和分子功能相关。 结论 结节性硬化症与难治性癫痫这二者发病是多种基因相互作用的结果,其中与GFAP、ANXA2和S100A 10等关系最为密切。     

Management of epilepsy in tuberous sclerosis complex

Tuberous sclerosis complex (TSC) is an inherited disorder resulting from mutations in one of two genes, TSC1 (Hamartin) and TSC2 (Tuberin). These two proteins form a cytosolic complex that inhibits the mTOR pathway that controls cell growth and proliferation. Pathologically, abnormalities of neuronal migration, cellular differentiation and excessive cellular proliferation all contribute to the formation of the different brain lesions of TSC. Seizure is the most common presenting symptom. Seizures can be present in the first year of life and up to one third of children develop infantile spasms. Seizures usually have a focal or multifocal origin, are often resistant to antiepileptic drugs and have a negative impact on the neurocognitive development. Vigabatrin has proved to be effective against infantile spasms due to TSC. New evidence suggests that it is possible to noninvasively identify using multimodality techniques, TSC children who are likely to become seizure-free following surgical treatment. Understanding the mechanisms of epileptogenesis and the possible role of the mTOR pathway in this process might increase the availability of novel and targeted therapies.     

Low glycemic index treatment for epilepsy in tuberous sclerosis complex

Retrospective chart review of 15 patients with tuberous sclerosis complex (TSC) who initiated the low glycemic index treatment (LGIT) for epilepsy management at Massachusetts General Hospital over a five-year period. Prior to dietary therapy, this cohort (average age: 8.5 years) had tried an average of 5.8 anti-epileptic drugs with incomplete seizure control. At 6 months on the LGIT, 7/15 (47%) patients experienced >50% reduction in seizure frequency.     

手术治疗结节性硬化的疗效观察

目的 探讨手术治疗结节性硬化引起癫痫的疗效.方法 回顾性分析6例患者的临床资料并系统随访18-30个月,综合评估3例导航下行致痫结节切除+皮层低功率热灼术;2例皮层电极植入后,经过监测,行致痫结节切除+皮层热灼术;1例行胼胝体前段切开术的疗效.结果 癫痫发作完全消失2例(Engel Ⅰ级),偶有发作1例(Engel Ⅱ级),发作减轻3例(Engel Ⅲ级).结论 手术可以有效地控制或者减轻结节性硬化引起的癫痫发作.     

Multidrug resistance proteins in tuberous sclerosis and refractory epilepsy

Tuberous sclerosis is an autosomal dominant syndrome characterized by seizures that are refractory to medication in severely affected individuals. The mechanism involved in drug resistance in tuberous sclerosis is unknown. The proteins MDR-1 (multidrug resistance) and MRP-1 (multidrug resistance-associated protein-1) are linked to chemotherapy resistance in tumor cells. However, the relationship between refractoriness to antiepileptic drugs and MDR-1 or MRP-1 brain expression has been poorly studied. We have previously described a case of tuberous sclerosis with refractory epilepsy that expressed multidrug resistance gene (MDR-1) in tuber cells from epileptogenic brain lesion. In this retrospective study, we describe the expression of MDR-1 and MRP-1 in the epileptogenic cortical tubers of three pediatric patients with tuberous sclerosis and refractory epilepsy surgically treated. Monoclonal antibodies for MDR-1 and MRP-1 proteins were used for immunohistochemistry. In epileptogenic cortical tuber brain specimens, MDR-1 and MRP-1 proteins were strongly immunoreactive in abnormal balloon cells, dysplastic neurons, astrocytes, microglial cells, and some blood-brain vessels. A more extensive MDR-1 immunoreactivity was observed. These data suggest that refractory epilepsy phenotype in tuberous sclerosis can be associated with the expression of both multidrug resistance MDR-1 and MRP-1 transporters in epileptogenic cortical tubers.     

儿童结节性硬化症合并癫痫临床特点分析

目的 探讨儿童结节性硬化症合并癫痫的临床特征。方法 对36例结节性硬化症合并癫痫患儿的临床资料进行分析。结果 所有患儿均以癫痫发作为首发症状,发病年龄〈1岁23例（63.89%）、1-3岁8例（22.22%）、〉3岁5例（13.89%）;发作类型以部分性发作[12例（33.33%）]、全面性发作[5例（13.89%）]、痉挛发作[7例（19.44%）]和混合性发作[12例（33.33%）]为主,其中伴智力低下或发育落后者19例（67.86%）。MRI可见室管膜下结节（30例）,部分病例[26例（86.67%）]伴皮质和皮质下结节、室管膜下巨细胞型星形细胞瘤2例（6.67%）或巨脑回畸形1例（3.33%）。脑电图显示发作间期样放电[34例（94.44%）],表现为多灶性放电[12例（35.29%）]、广泛性放电[8例（23.53%）]、局限性放电[7例（20.59%）]和高度失律[7例（20.59%）];其中8例监测到临床发作,包括痉挛发作（4例）、局灶性发作（3例）、肌阵挛发作（1例）。17例患儿（47.22%）服用1种抗癫痫药物、12例（33.33%）服用2种药物、7例（19.44%）服用3种药物,其中手术治疗1例;随访0.50~10年,无发作7例（19.44%）,有效16例（44.44%）,无效13例（36.11%）。结论 癫痫发作是儿童结节性硬化症最常见的神经系统表现,多在婴儿期发病,主要发作类型为部分性发作和痉挛发作,多数患儿抗癫痫药物治疗有效。     

Current management for epilepsy in tuberous sclerosis complex

PURPOSE OF REVIEW: This article reviews the most significant advances in the field of epilepsy associated with tuberous sclerosis complex, with emphasis on new advances in the knowledge of the pathophysiological mechanisms of epileptogenicity, progress in identifying the epileptogenic zone, and the rationale for surgical management in individuals with intractable seizures. RECENT FINDINGS: Advances in our understanding of the mechanisms and genetics underlying infantile spasms and catastrophic epilepsy associated with tuberous sclerosis complex may facilitate more effective interventions. Early effective seizure control could significantly reduce the adverse developmental effects of chronic epilepsy in tuberous sclerosis. Vigabatrin is the first choice in the short-term treatment of infantile spasms. Some individuals, however, develop seizures that remain highly intractable. The factors that influence the intractability of epilepsy associated with tuberous sclerosis complex remain poorly understood. Multimodality neuroimaging has improved detection of epileptogenic foci, allowing an increased number of individuals to be evaluated for resective surgery. Epilepsy surgery is often associated with significant improvement of the neurologic outcome. SUMMARY: Epilepsy in tuberous sclerosis seems to arise from the interaction between multiple areas, all of which have increased excitability and reduced inhibition. Understanding the mechanisms of epileptogenesis might increase the availability of development of a more specific and efficacious treatment. New evidence suggests that it is possible to noninvasively identify children with tuberous sclerosis who are highly likely to become seizure free following surgical treatment.     

Intractable epilepsy in hemimegalencephaly and tuberous sclerosis complex

Hemimegalencephaly is a rare brain malformation consisting of the enlargement of 1 hemisphere, often associated with abnormal cortical gyration, thick cortex, large neurons, and increased astrocytes. Cranial asymmetry is the first clinical sign usually present at birth; in the most severe cases, hemimegalencephaly may be evident during pregnancy. Hemiparesis, intractable epilepsy, and developmental delay are the typical clinical manifestations. Tuberous Sclerosis Complex is an autosomal dominant disorder affecting about 1 in 6000 live births; the number of spontaneous mutations is remarkable. It is characterized by the development of hamartias, or nongrowing lesions, and hamartomas, which grow as benign tumors and rarely progress to malignancy. These lesions most frequently involve the brain, skin, kidneys, eyes, and heart. The rare association of hemimegalencephaly and tuberous sclerosis complex has been reported in a few cases. The authors report the case of a 4-year-old boy with left hemimegalencephaly, tuberous sclerosis complex genetically confirmed, and intractable epilepsy originating from the nonhemimegalencephalic hemisphere.     

结节性硬化症癫痫的术前评估及手术方式的选择

目的 总结结节性硬化症所致癫痫患者的术前评估及手术方式,观察术后疗效.方法 回顾性分析北京三博脑科医院2004年6月至2011年6月手术治疗的20例结节性硬化症患者临床资料并系统随访1～5年.结果 经过综合评估,单纯致痫结节切除术8例;电极植入后致痫结节切除术1例;脑叶切除术4例;致痫结节切除+致痫皮层热灼术2例;脑叶切除+离断术1例;迷走神经刺激术2例;胼胝体全段切开术2例.术后随访Engel Ⅰ级11例,Ⅱ级2例,Ⅲ级5例,Ⅳ级2例,有效率达90％ (18/20).结论 经过精确术前评估,选择合适的手术方式,可以有效地控制或减轻结节性硬化引起的癫痫发作.     

Long-term outcomes of epilepsy surgery in tuberous sclerosis complex

Approximately 50% of patients with tuberous sclerosis complex (TSC) present intractable epilepsy, and surgery is an option for those patients. Hereby, we analyze long-term seizure control and neuropsychological outcomes of epilepsy surgery in patients with TSC. Clinical data were retrospectively collected from 66 patients with TSC and epilepsy followed up over 5 years, 51 of whom underwent epilepsy surgery between 2001 and 2011. Reductions in the number of seizures were analyzed at 1-year (1FU), 5-year (5FU), and 10-year (10FU) follow-ups visits after the operation. Influential factors on postoperative seizure free and intelligence quotient (IQ) and quality-of-life (QOL) outcomes were evaluated at 5FU. Resective procedures included 26 tuber resections, 15 lobectomies, and 10 tuber resections and lobectomies. Corpus callosotomies were performed as the adjunctive approach in 11 cases with low IQ. The percentages of seizure-free cases were 74.5% at 1FU, 58.8% at 5FU, and 47.8% at 10FU, and the predictive factor for long-term postoperative seizure freedom was the history of preoperative seizures and preoperative full-scale IQ. Significant improvements were found in performance IQ, full-scale IQ, and QOL in patients from the surgery group, particularly those who were seizure free after the operation. Our study showed that epilepsy surgery in TSC with epilepsy rendered improvements in seizure control, full-scale IQ, and QOL. Satisfactory long-term seizure control was often achieved with an early operation and without mental retardation, and improvements in QOL and IQ were frequently observed in postoperative patients who remained seizure free.     

The natural history of epilepsy in tuberous sclerosis complex

Background : Although epilepsy affects most patients with tuberous sclerosis complex (TSC), little is known about the natural history of epilepsy in this genetic disease. Methods : A retrospective chart review of all patients with TSC seen between January 2002 and October 2008. Charts were reviewed for a history of infantile spasms (IS), seizure other than IS, refractory epilepsy, Lennox‐Gastaut syndrome (LGS), anticonvulsant medication use, ages of seizure onset, last seizure, last clinic visit, clinical seizure phenotype(s), cognitive impairment, and genetic mutation. Results : Two hundred ninety‐one patients were included. Among these patients, 37.8% had a history of IS; 85.2% had a history of seizure; 54.1% developed multiple seizure types, not including IS; 63.2% had seizure onset in the first year of life; and 12.1% of adults without a seizure history developed epilepsy. Of epilepsy patients, 62.5% developed refractory epilepsy and 33.5% achieved epilepsy remission; 37.5% of these patients achieved medication freedom. IS was a risk factor for refractory epilepsy (p<0.0001) and LGS (p<0.0001). History of seizure, IS, age at seizure onset, and refractory epilepsy each correlated with poor cognitive outcome (p<0.0001). Epilepsy remission correlated with better cognitive outcome (p<0.0001). TSC2 was a risk factor for IS and epilepsy; patients without an identified mutation were more likely to achieve remission. Conclusion : Most patients with TSC develop epilepsy and most develop multiple seizure types. Onset typically occurs in the first year of life; however, adults remain at risk. Although refractory epilepsy is common, many patients achieve seizure control. Many features of seizure history are predictive of cognitive and epilepsy outcome.     

Developmental outcome of epilepsy surgery in tuberous sclerosis complex.

In Tuberous sclerosis complex (TSC), neurological dysfunction, usually in association with epilepsy, is responsible for the greatest degree of disease-related disability. Epilepsy surgery is increasingly recognized as a therapeutic option given the often medication-resistant nature of the disease. Seven subjects with medically refractory epilepsy associated with TSC, who underwent surgery at a tertiary care epilepsy center and in whom both preoperative and postoperative neuropsychological data were available, were examined. The Vineland Adaptive Behavior Scales, and in one case, the WISC-III were utilized. Postoperatively, the composite standard scores declined in six of the seven subjects, although for the most part this decline was quite modest (8 points or less in 5/6 subjects). The mean overall developmental/intellectual quotients were comparable across assessments (preoperative M = 55, SD = 20.3; postoperative M = 49 SD = 16.6). Good outcomes appeared to be related to seizure relief. Age estimates of developmental level indicated developmental progress in the majority of subjects in the current sample, and may yield greater clinical information for individuals with developmental delay than do standard scores.     

Long-term neurological outcome in children with early-onset epilepsy associated with tuberous sclerosis

In tuberous sclerosis complex, early seizure onset is associated with high risk of intractable epilepsy and cognitive/behavioral impairment. We retrospectively evaluated the long-term outcome of 44 infants presenting with seizures in the first 12 months who received vigabatrin, and were followed up for at least 3.5 years. At the final evaluation 55% of patients were still having seizures, 80% had intellectual disability, and 30% had autism. Sixty-five percent of children who had been treated earlier with vigabatrin after seizure onset achieved seizure freedom, compared with 24% of subjects who received vigabatrin treatment later (P < 0.01). Intellectual disability was present in 61% of the children treated early (group A) and in 100% of the children treated later (group B). Nine percent of group A and 52% of group B had autism (P ≈ 0.001).A shorter gap between seizure onset and start of treatment could reduce the risk of epileptic encephalopathy, minimizing the deleterious effect of seizures, but is not able to completely reverse the tuberous sclerosis complex-associated cognitive impairment.     

Long-term neurological outcome in children with early-onset epilepsy associated with tuberous sclerosis

In tuberous sclerosis complex, early seizure onset is associated with high risk of intractable epilepsy and cognitive/behavioral impairment. We retrospectively evaluated the long-term outcome of 44 infants presenting with seizures in the first 12 months who received vigabatrin, and were followed up for at least 3.5 years. At the final evaluation 55% of patients were still having seizures, 80% had intellectual disability, and 30% had autism. Sixty-five percent of children who had been treated earlier with vigabatrin after seizure onset achieved seizure freedom, compared with 24% of subjects who received vigabatrin treatment later (P < 0.01). Intellectual disability was present in 61% of the children treated early (group A) and in 100% of the children treated later (group B). Nine percent of group A and 52% of group B had autism (P ≈ 0.001).A shorter gap between seizure onset and start of treatment could reduce the risk of epileptic encephalopathy, minimizing the deleterious effect of seizures, but is not able to completely reverse the tuberous sclerosis complex-associated cognitive impairment.     

Bilateral temporal arachnoid cysts associated with tuberous sclerosis complex

The association between tuberous sclerosis complex and intracranial abnormalities such as hemimegalencephaly, schizencephaly, intracranial arterial aneurysms, and corpus callosum agenesis/dysplasia has been reported in the recent literature. However, the association between tuberous sclerosis complex and bilateral temporal arachnoid cysts has not been reported. A case of an 8-year-old boy with a mental impairment and epileptic seizures that began 5 years earlier is presented. The neuro-radiological findings are consistent with tuberous sclerosis complex associated with bitemporal arachnoid cysts. His epileptic seizures were treated with antiepileptic medications. To the authors' knowledge, this is the first reported case of tuberous sclerosis complex associated with bilateral arachnoid cysts of the temporal region. In such cases, arachnoid cysts may exacerbate the clinical picture.     

Proton spectroscopic findings in children with epilepsy owing to tuberous sclerosis complex

Tuberous sclerosis complex is an autosomal dominant disorder that often causes refractory seizures. The presence of multiple lesions makes it difficult to identify a single lesion responsible for the epilepsy. Our purpose is to assess the single-voxel proton spectroscopic findings of the tubers in 11 children with tuberous sclerosis complex. Prior to age 4 years, all of the patients had presented with epileptic seizures and multiple bilateral tubers in magnetic resonance images. Single-voxel proton spectroscopy was performed from the tubers especially showing epileptogenic activity using both the long and short echo time and in 14 controls. The results were analyzed using the Mann-Whitney U-test. Compared with the control group, the spectroscopic findings of tubers were characterized by decreased N-acetylaspartate to creatine ratios (1.43 +/- 0.33; P < .001) in both the long and short echo time spectra, increased choline to creatine ratios (0.91 +/- 0.082; P < .05), and myo-inositol to creatine ratios (0.97 +/- 0.19; P < .01) in the short echo time spectra. A lactate peak was detected in the regions corresponding to an epileptic focus on electroencephalography in six patients. Single-voxel proton spectroscopy could be a useful noninvasive method to evaluate epileptogenic tubers.