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Refractory Epilepsy (refractory + epilepsy)
Selected AbstractsHemispheric Surgery in Children with Refractory Epilepsy: Seizure Outcome, Complications, and Adaptive FunctionEPILEPSIA, Issue 1 2007Sheikh Nigel Basheer Summary:,Purpose: To describe seizure control, complications, adaptive function and language skills following hemispheric surgery for epilepsy. Methods: Retrospective chart review of patients who underwent hemispheric surgery from July 1993 to June 2004 with a minimum follow-up of 12 months. Results: The study population comprised 24 children, median age at seizure onset six months and median age at surgery 41 months. Etiology included malformations of cortical development (7), infarction (7), Sturge-Weber Syndrome (6), and Rasmussen's encephalitis (4). The most frequent complication was intraoperative bleeding (17 transfused). Age <2 yr, weight <11 kg, and hemidecortication were risk factors for transfusion. Postoperative complications included aseptic meningitis (6), and hydrocephalus (3). At median follow-up of 7 yr, 79% of patients are seizure free. Children with malformations of cortical development and Rasmussen's encephalitis were more likely to have ongoing seizures. Overall adaptive function scores were low, but relative strengths in verbal abilities were observed. Shorter duration of epilepsy prior to surgery was related significantly to better adaptive functioning. Conclusions: Hemispheric surgery is an effective therapy for refractory epilepsy in children. The most common complication was bleeding. Duration of epilepsy prior to surgery is an important factor in determining adaptive outcome. [source] Temozolomide Treatment of Refractory Epilepsy in a Patient with an OligodendrogliomaEPILEPSIA, Issue 7 2006Ly Ngo Summary:, A 40-year-old man with a left frontotemporal grade II oligodendroglioma developed seizures that were refractory to 14 antiepileptic medications, the ketogenic diet, and epilepsy surgery. With temozolomide therapy, his seizure frequency gradually changed from 30 partial seizures per day to a single simple partial seizure in 6 months. No additional therapeutic measures were introduced during this time. This reduction in seizure frequency appears attributable solely to temozolomide therapy. [source] Cardiac Autonomic Control in Patients with Refractory Epilepsy before and during Vagus Nerve Stimulation Treatment: A One-Year Follow-up StudyEPILEPSIA, Issue 3 2006Eija Ronkainen Summary:,Purpose: To elucidate possible effect of vagus nerve stimulation (VNS) therapy on interictal heart rate (HR) variability in patients with refractory epilepsy before and after 1-year VNS treatment. Methods: A 24-hour electrocardiogram (ECG) was recorded at the baseline and after 12 months of VNS treatment in 14 patients with refractory epilepsy, and once in 28 healthy age- and sex-matched control subjects. Time and frequency domain measures, along with fractal and complexity measures of HR variability, were analyzed from the ECG recordings. Results: The mean value of the RR interval (p = 0.008), standard deviation of N-N intervals (SDNN) (p < 0.001), very-low frequency (VLF) (p < 0.001), low-frequency (LF) (p = 0.001), and high-frequency (HF) (p = 0.002) spectral components of HR variability, and the Poincaré components SD1 (p = 0.005) and SD2 (p < 0.001) of the patients with refractory epilepsy were significantly lower than those of the control subjects before VNS implantation. The nocturnal increase in HR variability usually seen in the normal population was absent in patients with refractory epilepsy. VNS had no significant effects on any of the HR-variability indexes despite a significant reduction in the frequency of seizures. Conclusions: HR variability was reduced, and the nocturnal increase in HR variability was not present in patients with refractory epilepsy. One-year treatment with VNS did not have a marked effect on HR variability, suggesting that impaired cardiovascular autonomic regulation is associated with the epileptic process itself rather than with recurrent seizures. [source] Efficacy and Tolerability of the New Antiepileptic Drugs, II: Treatment of Refractory Epilepsy.EPILEPSIA, Issue 11 2004QSS Subcommittees of the American Academy of Neurology, Report of the TTA, the American Epilepsy Society No abstract is available for this article. [source] Malignant Refractory Epilepsy in Identical Twins Mosaic for a Supernumerary Ring Chromosome 19EPILEPSIA, Issue 8 2004Amre Shahwan Summary:, We report identical twins with supernumerary ring chromosome 19 mosaicism, who had severe refractory epilepsy at an early age. The epilepsy was dominated largely by severe life-threatening tonic seizures. Both twins died, likely as a consequence of their severe epilepsy. They displayed no dysmorphic features. Eight cases of ring chromosome 19 have been reported in the literature, all to our knowledge without epilepsy. The clinical picture of these twins emphasizes the importance of carrying out a karyotype study on patients with early-onset epilepsy even in the absence of dysmorphic features. [source] Topiramate in Patients with Learning Disability and Refractory EpilepsyEPILEPSIA, Issue 4 2002Kevin Kelly Summary: ,Purpose: Management of seizures in learning disabled people is challenging. This prospective study explored the efficacy and tolerability of adjunctive topiramate (TPM) in patients with learning disability and refractory epilepsy attending a single centre. Methods: Sixty-four patients (36 men, 28 women, aged 16,65 years) were begun on adjunctive TPM after a 3-month prospective baseline on unchanged medication. Efficacy end points were reached when a consistent response was achieved over a 6-month period at optimal TPM dosing. These were seizure freedom or ,50% seizure reduction (responder). Appetite, behaviour, alertness, and sleep were assessed by caregivers throughout the study. Results: Sixteen (25%) patients became seizure free with adjunctive TPM. There were 29 (45%) responders. A further 10 (16%) patients experiencing a more modest improvement in seizure control continued on treatment at the behest of their family and/or caregivers. TPM was discontinued in the remaining nine (14%) patients, mainly because of side effects. Final TPM doses and plasma concentrations varied widely among the efficacy outcome groups. Many patients responding well to adjunctive TPM did so on ,200 mg daily. Mean carer scores did not worsen with TPM therapy. Conclusions: TPM was effective as add-on therapy in learning-disabled people with difficult-to-control epilepsy. Seizure freedom is a realistic goal in this population. [source] Blood,brain barrier damage and brain penetration of antiepileptic drugs: Role of serum proteins and brain edemaEPILEPSIA, Issue 4 2009Nicola Marchi Summary Purpose:, Increased blood,brain barrier (BBB) permeability is radiologically detectable in regions affected by drug-resistant epileptogenic lesions. Brain penetration of antiepileptic drugs (AEDs) may be affected by BBB damage. We studied the effects of BBB damage on brain distribution of hydrophilic [deoxy-glucose (DOG) and sucrose] and lipophilic (phenytoin and diazepam) molecules. We tested the hypothesis that lipophilic and hydrophilic drug distribution is differentially affected by BBB damage. Methods:, In vivo BBB disruption (BBBD) was performed in rats by intracarotid injection of hyperosmotic mannitol. Drugs (H3-sucrose, 3H-deoxy-glucose, 14C-phenytoin, and C14-diazepam) or unlabeled phenytoin was measured and correlated to brain water content and protein extravasation. In vitro hippocampal slices were exposed to different osmolarities; drug penetration and water content were assessed by analytic and densitometric methods, respectively. Results:, BBBD resulted in extravasation of serum protein and radiolabeled drugs, but was associated with no significant change in brain water. Large shifts in water content in brain slices in vitro caused a small effect on drug penetration. In both cases, total drug permeability increase was greater for lipophilic than hydrophilic compounds. BBBD reduced the amount of free phenytoin in the brain. Discussion:, After BBBD, drug binding to protein is the main controller of total brain drug accumulation. Osmotic BBBD increased serum protein extravasation and reduced free phenytoin brain levels. These results underlie the importance of brain environment and BBB integrity in determining drug distribution to the brain. If confirmed in drug-resistant models, these mechanisms could contribute to drug brain distribution in refractory epilepsies. [source] Taurine deficiency is a cause of vigabatrin-induced retinal phototoxicity,ANNALS OF NEUROLOGY, Issue 1 2009Firas Jammoul MD Objective Although vigabatrin irreversibly constricts the visual field, it remains a potent therapy for infantile spasms and a third-line drug for refractory epilepsies. In albino animals, this drug induces a reduction in retinal cell function, retinal disorganization, and cone photoreceptor damage. The objective of this study was to investigate the light dependence of the vigabatrin-elicited retinal toxicity and to screen for molecules preventing this secondary effect of vigabatrin. Methods Rats and mice were treated daily with 40 and 3mg vigabatrin, respectively. Retinal cell lesions were demonstrated by assessing cell function with electroretinogram measurements, and quantifying retinal disorganization, gliosis, and cone cell densities. Results Vigabatrin-elicited retinal lesions were prevented by maintaining animals in darkness during treatment. Different mechanisms including taurine deficiency were reported to produce such phototoxicity; we therefore measured amino acid plasma levels in vigabatrin-treated animals. Taurine levels were 67% lower in vigabatrin-treated animals than in control animals. Taurine supplementation reduced all components of retinal lesions in both rats and mice. Among six vigabatrin-treated infants, the taurine plasma level was found to be below normal in three patients and undetectable in two patients. Interpretation These results indicate that vigabatrin generates a taurine deficiency responsible for its retinal phototoxicity. Future studies will investigate whether cotreatment with taurine and vigabatrin can limit epileptic seizures without inducing the constriction of the visual field. Patients taking vigabatrin could gain immediate benefit from reduced light exposures and dietetic advice on taurine-rich foods. Ann Neurol 2009;65:98,107 [source] Vagus nerve stimulation for treatment of epilepsy in Rett syndromeDEVELOPMENTAL MEDICINE & CHILD NEUROLOGY, Issue 8 2006Angus A Wilfong MD, Assistant Professor This case series presents the outcomes of seven females with Rett syndrome and medically refractory epilepsy who were treated with adjunctive vagus nerve stimulation (VNS) therapy for a minimum of 12 months. Patients ranged in age from 1 to 14 years (median age 9y) at the time of implantation, had experienced seizures for a median period of approximately 6 years, and had failed at least two trials of antiepileptic drugs before receiving VNS. The median number of seizures per month was 150 (range 12,3600). At 12 months, six females had ,50% reduction in seizure frequency. VNS was safe and well tolerated, with no surgical complications and no patients requiring explantation of the device. Quality of life outcomes of note among these patients included reports at 12 months of increased alertness among all seven patients. No change in mood or communication abilities was noted. [source] Continuous local intrahippocampal delivery of adenosine reduces seizure frequency in rats with spontaneous seizuresEPILEPSIA, Issue 9 2010Annelies Van Dycke Summary Purpose:, Despite different treatment options for patients with refractory epilepsy such as epilepsy surgery and neurostimulation, many patients still have seizures and/or drug-related cerebral and systemic side effects. Local intracerebral delivery of antiepileptic compounds may represent a novel strategy with specific advantages such as the option of higher local doses and reduced side effects. In this study we evaluate the antiepileptic effect of local delivery of adenosine in the kainic acid rat model, a validated model for temporal lobe epilepsy. Methods:, Fifteen rats, in which intraperitoneal kainic acid injection had induced spontaneous seizures, were implanted with a combination of depth electrodes and a cannula in both hippocampi. Cannulas were connected to osmotic minipumps to allow continuous hippocampal delivery. Rats were freely moving and permanently monitored by video-EEG (electroencephalography). Seizures were scored during 2 weeks of local hippocampal delivery of saline (baseline), followed by 2 weeks of local adenosine (6 mg/ml) (n = 10) or saline (n = 5) delivery (0.23 ,l/h) (treatment). In 7 of 10 adenosine-treated rats, saline was also delivered during a washout period. Results:, During the treatment period a mean daily seizure frequency reduction of 33% compared to the baseline rate was found in adenosine-treated rats (p < 0.01). Four rats had a seizure frequency reduction of at least 50%. Both nonconvulsive and convulsive seizures significantly decreased during the treatment period. In the saline-control group, mean daily seizure frequency increased with 35% during the treatment period. Conclusions:, This study demonstrates the antiseizure effect of continuous adenosine delivery in the hippocampi in rats with spontaneous seizures. [source] Epilepsy with dual pathology: Surgical treatment of cortical dysplasia accompanied by hippocampal sclerosisEPILEPSIA, Issue 8 2010Dong W. Kim Summary Purpose:, The presence of two or more epileptogenic pathologies in patients with epilepsy is often observed, and the coexistence of focal cortical dysplasia (FCD) with hippocampal sclerosis (HS) is one of the most frequent clinical presentations. Although surgical resection has been an important treatment for patients with refractory epilepsy associated with FCD, there are few studies on the surgical treatment of FCD accompanied by HS, and treatment by resection of both neocortical dysplastic tissue and hippocampus is still controversial. Methods:, We retrospectively recruited epilepsy patients who had undergone surgical treatment for refractory epilepsy with the pathologic diagnosis of FCD and the radiologic evidence of HS. We evaluated the prognostic roles of clinical factors, various diagnostic modalities, surgical procedures, and the severity of pathology. Results:, A total of 40 patients were included, and only 35.0% of patients became seizure free. Complete resection of the epileptogenic area (p = 0.02), and the presence of dysmorphic neurons or balloon cells on histopathology (p = 0.01) were associated with favorable surgical outcomes. Patients who underwent hippocampal resection were more likely to have a favorable surgical outcome (p = 0.02). Conclusions:, We show that patients with complete resection of epileptogenic area, the presence of dysmorphic neurons or balloon cells on histopathology, or resection of hippocampus have a higher chance of a favorable surgical outcome. We believe that this observation is useful in planning of surgical procedures and predicting the prognoses of individual patients with FCD patients accompanied by HS. [source] Impact of severe epilepsy on development: Recovery potential after successful early epilepsy surgeryEPILEPSIA, Issue 7 2010Eliane Roulet-Perez Summary Purpose:, Epilepsy surgery in young children with focal lesions offers a unique opportunity to study the impact of severe seizures on cognitive development during a period of maximal brain plasticity, if immediate control can be obtained. We studied 11 children with early refractory epilepsy (median onset, 7.5 months) due to focal lesion who were rendered seizure-free after surgery performed before the age of 6 years. Methods:, The children were followed prospectively for a median of 5 years with serial neuropsychological assessments correlated with electroencephalography (EEG) and surgery-related variables. Results:, Short-term follow-up revealed rapid cognitive gains corresponding to cessation of intense and propagated epileptic activity [two with early catastrophic epilepsy; two with regression and continuous spike-waves during sleep (CSWS) or frontal seizures]; unchanged or slowed velocity of progress in six children (five with complex partial seizures and frontal or temporal cortical malformations). Longer-term follow-up showed stabilization of cognitive levels in the impaired range in most children and slow progress up to borderline level in two with initial gains. Discussion:, Cessation of epileptic activity after early surgery can be followed by substantial cognitive gains, but not in all children. In the short term, lack of catch-up may be explained by loss of retained function in the removed epileptogenic area; in the longer term, by decreased intellectual potential of genetic origin, irreversible epileptic damage to neural networks supporting cognitive functions, or reorganization plasticity after early focal lesions. Cognitive recovery has to be considered as a "bonus," which can be predicted in some specific circumstances. [source] Relationship between adverse effects of antiepileptic drugs, number of coprescribed drugs, and drug load in a large cohort of consecutive patients with drug-refractory epilepsyEPILEPSIA, Issue 5 2010Maria Paola Canevini Summary Purpose:, To evaluate the adverse effects (AEs) of antiepileptic drugs (AEDs) in adults with refractory epilepsy and their relationship with number of coprescribed AEDs and AED load. Methods:, Patients with refractory epilepsy were enrolled consecutively at 11 tertiary referral centers. AEs were assessed through unstructured interview and the Adverse Event Profile (AEP) questionnaire. AED loads were calculated as the sum of prescribed daily dose (PDD)/defined daily dose (DDD) ratios for each coprescribed AED. Results:, Of 809 patients enrolled, 709 had localization-related epilepsy and 627 were on polytherapy. AED loads increased with increasing number of AEDs in the treatment regimen, from 1.2 ± 0.5 for patients on monotherapy to 2.5 ± 1, 3.7 ± 1.1, and 4.7 ± 1.1 for those on two, three, and ,4 AEDs, respectively. The number of spontaneously reported AEs correlated with the number of AEs identified by the AEP (r = 0.27, p < 0.0001). AEP scores did not differ between patients with monotherapy and patients with polytherapy (42.8 ± 11.7 vs. 42.6 ± 11.2), and there was no correlation between AEP scores and AED load (r = ,0.05, p = 0.16). Conclusions:, AEs did not differ between monotherapy and polytherapy patients, and did not correlate with AED load, possibly as a result of physicians' intervention in individualizing treatment regimens. Taking into account the limitations of a cross-sectional survey, these findings are consistent with the hypothesis that AEs are determined more by individual susceptibility, type of AEDs used, and physicians' skills, than number of coprescribed AEDs and AED load. [source] Placebo-corrected efficacy of modern antiepileptic drugs for refractory epilepsy: Systematic review and meta-analysisEPILEPSIA, Issue 1 2010Stefan Beyenburg Summary Although adjunctive treatment with modern antiepileptic drugs (AEDs) is standard care in refractory epilepsy, it is unclear how much of the effect can be attributed directly to the AEDs and how much to the beneficial changes seen with placebo. Therefore, we performed a systematic review and meta-analysis of the evidence to determine the placebo-corrected net efficacy of adjunctive treatment with modern AEDs on the market for refractory epilepsy. Of 317 potentially eligible articles reviewed in full text, 124 (39%) fulfilled eligibility criteria. After excluding 69 publications, 55 publications of 54 studies in 11,106 adults and children with refractory epilepsy form the basis of evidence. The overall weighted pooled-risk difference in favor of AEDs over placebo for seizure-freedom in the total sample of adults and children was 6% [95% confidence interval (CI) 4,8, z = 6.47, p < 0.001] and 21% (95% CI 19,24, z = 17.13, p < 0.001) for 50% seizure reduction. Although the presence of moderate heterogeneity may reduce the validity of the results and limit generalizations from the findings, we conclude that the placebo-corrected efficacy of adjunctive treatment with modern AEDs is disappointingly small and suggest that better strategies of finding drugs are needed for refractory epilepsy, which is a major public health problem. [source] Outcome after hemispherectomy in hemiplegic adult patients with refractory epilepsy associated with early middle cerebral artery infarctsEPILEPSIA, Issue 6 2009Arthur Cukiert Summary Purpose:, To study the outcome after hemispherectomy (HP) in a homogeneous adult patient population with refractory hemispheric epilepsy. Methods:, Fourteen adult patients submitted to HP were studied. Patients had to be at least 18 years old, and have refractory epilepsy, clearly focal lateralized seizures and unilateral porencephalus consistent with early middle cerebral artery infarct on magnetic resonance imaging (MRI). All patients were submitted to functional hemispherectomy. We analyzed age of seizure onset, age by the time of surgery, gender, seizure type and frequency, interictal and ictal electroencephalography (EEG) findings, MRI and IQ scores preoperatively; seizure frequency, drug regimen, and IQ outcome were studied postoperatively. Results:, Mean follow-up was 64 months. All patients had frequent daily seizures preoperatively. All patients had unilateral simple partial motor seizures (SPS); 11 patients had secondarily generalized tonic,clonic (GTC) seizures and five patients had complex partial seizures (CPS), preoperatively. All patients had hemiplegia and hemianopsia. Twelve patients had unilateral EEG findings, and in two epileptic discharges were seen exclusively over the apparently normal hemisphere. Twelve patients were seizure-free after surgery and two patients had at least 90% improvement in seizure frequency. Pre- and postoperative mean general IQ was 84 and 88, respectively. Five of the twelve Engel I patients were receiving no drugs at last follow-up. There was no mortality or major morbidity. Conclusions:, Our results suggest that well-selected adult patients might also get good results after HP. Although good results were obtained in our adult series, the same procedure yielded a much more striking result if performed earlier in life. [source] Sleep staging and respiratory events in refractory epilepsy patients: Is there a first night effect?EPILEPSIA, Issue 12 2008Linda M. Selwa Summary Purpose:, We performed this analysis of possible first night effects (FNEs) on sleep and respiratory parameters in order to evaluate the need for two serial night polysomnograms (PSGs) to diagnose obstructive sleep apnea (OSA) in epilepsy patients. Methods:, As part of a pilot multicenter clinical trial investigating the effects of treating sleep apnea in epilepsy, two nights of PSG recording were performed for 40 patients with refractory epilepsy and OSA symptoms. Sleep architecture was examined in detail, along with respiratory parameters including apnea/hypopnea index (AHI) and minimum oxygen saturation. Analysis included two-tailed t -tests, Wilcox sign rank analysis, and Bland Altman measures of agreement. Results:, Total sleep time differed between the two nights (night 1,363.8 min + 59.4 vs. 386.3 min + 68.6, p = 0.05). Rapid eye movement (REM) sleep and percentage of REM sleep were increased during night two (night 1: 12.3% + 5.9 vs. night 2: 15.5% + 6.2, p = 0.007), and the total minutes of slow-wave sleep (SWS) were increased (night 1: 35.6 + 60.7 vs. night 2: 46.4 + 68.1, p = 0.01). No other sleep or respiratory variables differed between the two nights. Given an AHI inclusion criterion of five apneas per hour, the first PSG identified all but one patient with OSA. Discussion:, Respiratory parameters showed little variability between the first and second nights. Sleep architecture was mildly different between the first and second PSG night. Performing two consecutive baseline PSGs to diagnose OSA may not be routinely necessary in this population. [source] Medium-chain triglyceride (MCT) ketogenic therapyEPILEPSIA, Issue 2008Yeou-mei Christiana Liu Summary The medium-chain triglyceride diet (MCTD) is a variant of the classic 4:1 ketogenic diet (KD) introduced in 1971 by Huttenlocher as an attempt to improve the palatability of the KD by allowing more carbohydrates yet preserving ketosis. Although initially found to be equally effective as the classic KD, use of the MCTD declined because of frequent gastrointestinal side effects such as cramps, diarrhea, and vomiting. Recently, we have used the MCTD in more than 50 patients. We have found excellent seizure control, similar to the classic KD, and with careful monitoring, we have encountered minimal side effects. The MCTD should remain a viable dietary option for children with refractory epilepsy who have large appetites, can tolerate more calories, or cannot accept the restrictions of the classic KD. [source] The contribution of norepinephrine and orexigenic neuropeptides to the anticonvulsant effect of the ketogenic dietEPILEPSIA, Issue 2008David Weinshenker Summary The ketogenic diet (KD) is a high-fat, low-carbohydrate, low-protein diet used to treat refractory epilepsy. Despite its efficacy and many years of investigation, the mechanism by which the KD exerts its anticonvulsant effect remains controversial and poorly understood. The purpose of this article is to review the available data considering two classes of molecules that may contribute to the anticonvulsant effect of the KD: norepinephrine and the orexigenic neuropeptides galanin and neuropeptide Y. [source] Association of ABCB1 genetic variants 3435C>T and 2677G>T to ABCB1 mRNA and protein expression in brain tissue from refractory epilepsy patientsEPILEPSIA, Issue 9 2008Igor Mosyagin Summary Purpose: There is evidence from studies in rodents that P-glycoprotein (P-gp) overexpression is implicated in the causation of refractory epilepsy. Genetic variants in the human ABCB1 (MDR1) gene were shown to affect the expression levels of the transporter in various tissues and to be associated with refractory epilepsy. However, the effect of the genetic variants on the P-gp level in epileptogenic brain tissue is poorly investigated. In the present study, we examined the impact of putatively functional polymorphisms 3435C>T and 2677G>T in the ABCB1 gene on the ABCB1 mRNA expression and P-gp content in human brain tissue from epileptogenic foci of the patients with refractory epilepsy. Methods: Fresh brain tissue specimens were obtained from therapy-refractory epilepsy patients during neurosurgery of the epileptogenic focus. We determined the ABCB1 mRNA expression in 23 samples using 5, exonuclease-based real-time polymerase chain reaction (PCR) as well as the P-gp content in 32 samples determined by immunohistochemistry, genotyping was performed by PCR/restriction fragment length polymorphism (RFLP). Results: There was lack of association of 3435C>T and 2677G>T as well as diplotype configurations on ABCB1 mRNA expression and P-gp content in epileptogenic brain tissues. Conclusions: We cannot exclude an association of ABCB1 variants on P-gp function, but our results suggest that brain ABCB1 mRNA and protein expression is not substantially influenced by major ABCB1 genetic variants thus explaining in part results from case-control studies obtaining lack of association of ABCB1 polymorphisms to the risk of refractory epilepsy. [source] Mechanisms of Epileptogenesis in Tuberous Sclerosis Complex and Related Malformations of Cortical Development with Abnormal Glioneuronal ProliferationEPILEPSIA, Issue 1 2008Michael Wong Summary Malformations of cortical development (MCDs) are increasingly recognized as causes of medically intractable epilepsy. In order to develop more effective, rational therapies for refractory epilepsy related to MCDs, it is important to achieve a better understanding of the underlying mechanisms of epileptogenesis, but this is complicated by the wide variety of different radiographic, histopathological, and molecular features of these disorders. A subset of MCDs share a number of characteristic cellular and molecular abnormalities due to early defects in neuronal and glial proliferation and differentiation and have a particularly high incidence of epilepsy, suggesting that this category of MCDs with abnormal glioneuronal proliferation may also share a common set of primary mechanisms of epileptogenesis. This review critically analyzes both clinical and basic science evidence for overlapping mechanisms of epileptogenesis in this group of disorders, focusing on tuberous sclerosis complex, focal cortical dysplasia with balloon cells, and gangliogliomas. Specifically, the role of lesional versus perilesional regions, circuit versus cellular/molecular defects, and nonneuronal factors, such as astrocytes, in contributing to epileptogenesis in these MCDs is examined. An improved understanding of these various factors involved in epileptogenesis has direct clinical implications for optimizing current treatments or developing novel therapeutic approaches for epilepsy in these disorders. [source] Severe Epilepsy in X-Linked Creatine Transporter Defect (CRTR-D)EPILEPSIA, Issue 6 2007Maria Margherita Mancardi Disorders of creatine synthesis or its transporter resulting in neurological impairment with mental retardation and epilepsy have only been recognized in recent years. To date, the epileptic disorder observed in creatine transporter deficiency (CRTR-D) has been described as a mild phenotype with infrequent seizures and favorable response to common antiepileptic drugs. We report on a 5 year-old boy with known speech delay who presented with severe and refractory epilepsy. After extensive investigations, metabolite analysis and brain 1H-MRS suggested CRTR-D, which was confirmed by the detection of a known pathogenic mutation in the SLC6A8 gene (c.1631C>T; p.Pro544Leu). [source] Hemispheric Surgery in Children with Refractory Epilepsy: Seizure Outcome, Complications, and Adaptive FunctionEPILEPSIA, Issue 1 2007Sheikh Nigel Basheer Summary:,Purpose: To describe seizure control, complications, adaptive function and language skills following hemispheric surgery for epilepsy. Methods: Retrospective chart review of patients who underwent hemispheric surgery from July 1993 to June 2004 with a minimum follow-up of 12 months. Results: The study population comprised 24 children, median age at seizure onset six months and median age at surgery 41 months. Etiology included malformations of cortical development (7), infarction (7), Sturge-Weber Syndrome (6), and Rasmussen's encephalitis (4). The most frequent complication was intraoperative bleeding (17 transfused). Age <2 yr, weight <11 kg, and hemidecortication were risk factors for transfusion. Postoperative complications included aseptic meningitis (6), and hydrocephalus (3). At median follow-up of 7 yr, 79% of patients are seizure free. Children with malformations of cortical development and Rasmussen's encephalitis were more likely to have ongoing seizures. Overall adaptive function scores were low, but relative strengths in verbal abilities were observed. Shorter duration of epilepsy prior to surgery was related significantly to better adaptive functioning. Conclusions: Hemispheric surgery is an effective therapy for refractory epilepsy in children. The most common complication was bleeding. Duration of epilepsy prior to surgery is an important factor in determining adaptive outcome. [source] Cardiac Autonomic Control in Patients with Refractory Epilepsy before and during Vagus Nerve Stimulation Treatment: A One-Year Follow-up StudyEPILEPSIA, Issue 3 2006Eija Ronkainen Summary:,Purpose: To elucidate possible effect of vagus nerve stimulation (VNS) therapy on interictal heart rate (HR) variability in patients with refractory epilepsy before and after 1-year VNS treatment. Methods: A 24-hour electrocardiogram (ECG) was recorded at the baseline and after 12 months of VNS treatment in 14 patients with refractory epilepsy, and once in 28 healthy age- and sex-matched control subjects. Time and frequency domain measures, along with fractal and complexity measures of HR variability, were analyzed from the ECG recordings. Results: The mean value of the RR interval (p = 0.008), standard deviation of N-N intervals (SDNN) (p < 0.001), very-low frequency (VLF) (p < 0.001), low-frequency (LF) (p = 0.001), and high-frequency (HF) (p = 0.002) spectral components of HR variability, and the Poincaré components SD1 (p = 0.005) and SD2 (p < 0.001) of the patients with refractory epilepsy were significantly lower than those of the control subjects before VNS implantation. The nocturnal increase in HR variability usually seen in the normal population was absent in patients with refractory epilepsy. VNS had no significant effects on any of the HR-variability indexes despite a significant reduction in the frequency of seizures. Conclusions: HR variability was reduced, and the nocturnal increase in HR variability was not present in patients with refractory epilepsy. One-year treatment with VNS did not have a marked effect on HR variability, suggesting that impaired cardiovascular autonomic regulation is associated with the epileptic process itself rather than with recurrent seizures. [source] Characterization of the Tetanus Toxin Model of Refractory Focal Neocortical Epilepsy in the RatEPILEPSIA, Issue 2 2005Karen E. Nilsen Summary:,Purpose: To characterize in detail a model of focal neocortical epilepsy. Methods: Chronic focal epilepsy was induced by injecting 25,50 ng of tetanus toxin or vehicle alone (controls) into the motor neocortex of rats. EEG activity was recorded from electrodes implanted at the injection site, along with facial muscle electromyographic (EMG) activity and behavioral monitoring intermittently for up to 5 months in some animals. Drug responsiveness was assessed by using the antiepileptic drugs (AEDs) diazepam (DZP) and phenytoin (PHT) delivered systemically, while 1,2,3,4-tetrahydro-6-nitro-2,3-dioxo-benzo[f]quinoxaline-7-sulfonamide (NBQX), a competitive antagonist at AMPA receptors, was administered directly to the brain to investigate the potential benefits of focal drug delivery. Results: Tetanus toxin induced mild behavioral seizures that persisted indefinitely in all animals. EEG spiking activity, occurring up to 80% of the time, correlated with clinical seizures consisting of interrupted behavioral activity, rhythmic bilateral facial twitching, and periods of abrupt motor arrest. Seizures were refractory to systemic administration of DZP and PHT. However, focal delivery of NBQX to the seizure site reversibly reduced EEG and behavioral seizure activity without detectable side effects. Conclusions: This study provides a long-term detailed characterisation of the tetanus toxin model. Spontaneous, almost continuous, well-tolerated seizures occur and persist, resembling those seen in neocortical epilepsy, including cortical myoclonus and epilepsia partialis continua. The seizures appear to be similarly resistant to conventional AEDs. The consistency, frequency, and clinical similarity of the seizures to refractory epilepsy in humans make this an ideal model for investigation of both mechanisms of seizure activity and new therapeutic approaches. [source] High-resolution MRI Enhances Identification of Lesions Amenable to Surgical Therapy in Children with Intractable EpilepsyEPILEPSIA, Issue 8 2004Monisha Goyal Summary:,Purpose: Many children with refractory epilepsy can achieve better seizure control with surgical therapy. An abnormality on magnetic resonance imaging (MRI), along with corroborating localization by other modalities, markedly increases chances of successful surgical outcome. We studied the impact of high-resolution MRI on the surgical outcome of intractable epilepsy. Methods: High-resolution MRI using four-coil phased surface array was obtained as part of the comprehensive presurgical protocol for children with focal onset intractable seizures evaluated by our epilepsy center during the first half of 2002. Results: Thirteen consecutive children, ages 5 to 18 years, entered this prospective study. For four patients with a lesion on a recent MRI examination with a standard head coil, management did not change with high-resolution MRI. Standard MRI in the other nine patients did not identify a lesion. However, high-resolution MRI with the phased-array surface coil found previously undiagnosed focal abnormalities in five of nine patients. These abnormalities included hippocampal dysplasia, hippocampal atrophy, and dual pathology with frontal cortical dysplasia. In four of nine patients, no identifiable lesion was identified on the high-resolution MRI. All patients underwent invasive monitoring. In three of five patients, newly diagnosed lesions correlated with EEG abnormalities, and resection was performed. Conclusions: In our center, high-resolution MRI identified lesions not detected by standard MRI in more than half the children (56%). Technical advances such as four-coil phased surface array MRI can help identify and better delineate lesions, improving the diagnosis of patients who are candidates for surgical treatment of refractory epilepsy. [source] Malignant Refractory Epilepsy in Identical Twins Mosaic for a Supernumerary Ring Chromosome 19EPILEPSIA, Issue 8 2004Amre Shahwan Summary:, We report identical twins with supernumerary ring chromosome 19 mosaicism, who had severe refractory epilepsy at an early age. The epilepsy was dominated largely by severe life-threatening tonic seizures. Both twins died, likely as a consequence of their severe epilepsy. They displayed no dysmorphic features. Eight cases of ring chromosome 19 have been reported in the literature, all to our knowledge without epilepsy. The clinical picture of these twins emphasizes the importance of carrying out a karyotype study on patients with early-onset epilepsy even in the absence of dysmorphic features. [source] Levetiracetam and Partial Seizure Subtypes: Pooled Data from Three Randomized, Placebo-controlled TrialsEPILEPSIA, Issue 12 2003Ilo E. Leppik Summary:,Purpose: To determine the effect of levetiracetam (LEV) on partial seizure subtypes (simple partial, complex partial, and secondarily generalized seizures) in patients with refractory epilepsy. Methods: Pooled results from three placebo-controlled trials were analyzed. Results: A statistically significant reduction in the frequency of all partial seizures and all seizure subtypes was observed in the LEV group (p < 0.001 vs. placebo). The proportion of patients in whom secondarily generalized seizures could be prevented over and above the reduction of partial seizures was significantly greater in the LEV group as compared with placebo, with an odds ratio of 1.83 [95% confidence interval (CI), 1.10,3.05]. Conclusions: LEV reduces frequency of simple and complex partial seizures. In addition, it demonstrates a specific, independent reduction of secondarily generalized seizures. [source] Topiramate in Patients with Learning Disability and Refractory EpilepsyEPILEPSIA, Issue 4 2002Kevin Kelly Summary: ,Purpose: Management of seizures in learning disabled people is challenging. This prospective study explored the efficacy and tolerability of adjunctive topiramate (TPM) in patients with learning disability and refractory epilepsy attending a single centre. Methods: Sixty-four patients (36 men, 28 women, aged 16,65 years) were begun on adjunctive TPM after a 3-month prospective baseline on unchanged medication. Efficacy end points were reached when a consistent response was achieved over a 6-month period at optimal TPM dosing. These were seizure freedom or ,50% seizure reduction (responder). Appetite, behaviour, alertness, and sleep were assessed by caregivers throughout the study. Results: Sixteen (25%) patients became seizure free with adjunctive TPM. There were 29 (45%) responders. A further 10 (16%) patients experiencing a more modest improvement in seizure control continued on treatment at the behest of their family and/or caregivers. TPM was discontinued in the remaining nine (14%) patients, mainly because of side effects. Final TPM doses and plasma concentrations varied widely among the efficacy outcome groups. Many patients responding well to adjunctive TPM did so on ,200 mg daily. Mean carer scores did not worsen with TPM therapy. Conclusions: TPM was effective as add-on therapy in learning-disabled people with difficult-to-control epilepsy. Seizure freedom is a realistic goal in this population. [source] Lamotrigine Therapy of Epilepsy in Tuberous SclerosisEPILEPSIA, Issue 7 2001David Neal Franz Summary: ,Purpose: Lamotrigine (LTG), a newer antiepileptic drug (AED), has activity against both partial-onset and generalized seizures. Its reported benefits for behavior, and its effectiveness in Lennox,Gastaut syndrome and other forms of refractory epilepsy, make it a logical choice for treatment of epilepsy in tuberous sclerosis complex (TSC). We present our experience with LTG therapy of epilepsy in 57 patients with TSC. Methods: Patients fulfilled the diagnostic criteria for clinically definite TSC. LTG was initiated and increased until improvement in seizure frequency was noted, intolerable side effects occurred, or maximal doses were reached. Seizure frequency and behavioral changes were recorded during LTG therapy and compared with those prior to the introduction of LTG. Results: Twenty-four (42%) were seizure free, and 21 (37%) had a >50% reduction in seizure frequency. Eighteen (32%) had subjectively improved behavior and/or alertness with daily activities. Thirty-eight (67%) had no change in this regard, whereas one (2%) became worse. Responders were more likely to not have a history of infantile spasms, and to have experienced only partial seizures (p < 0.05). Otherwise no phenotypic correlations with response were apparent. Conclusions: Among patients with TSC and epilepsy, LTG was effective and well tolerated, including as initial monotherapy. Improved alertness and behavior were apparent in many patients. The incidence of side effects is similar to that reported for other pediatric populations with symptomatic partial epilepsy. The usefulness of LTG in TSC may relate to an underlying defect of glutamatergic neurotransmission in partial epilepsy. [source] The Role of Vigabatrin in Childhood Seizure Disorders: Results from a Clinical AuditEPILEPSIA, Issue 1 2001Asuri N. Prasad Summary: ,Purpose: The emergence of visual field defects attributed to vigabatrin (VGB) treatment and intramyelinic edema in animal experiments has raised concerns about its future role in the treatment of childhood seizures. Methods: We evaluated our experience with this antiepileptic agent with retrospective analysis of database and chart audit. Results: Of 73 patients, 43 girls and 33 boys were treated with VGB over a 7-year period. The mean age of patients at the introduction of VGB was 87 months (range, 5,257 months). In 12 of 73 cases, VGB was used as monotherapy; in 61 of 73 cases, it was used as an add-on drug. Seizure types included secondarily generalized seizures (21), mixed seizures (21), partial seizures (18), and generalized seizures (13). Seizure etiology was idiopathic/cryptogenic in 22 patients, symptomatic in 50, and undetermined in a single patient. The mean duration of therapy was 16 months (median, 10 months; range, 1,144 months). VGB was effective in 30 (seven seizure free, 23 with >90% reduction in seizures), partially effective in four (50,90% reduction in seizures), and ineffective in 38 (<50% reduction in seizures). Nearly 50% of patients with infantile spasms responded to VGB. All patients underwent ophthalmic evaluation; two (16%) of 12 patients who could undergo static threshold perimetry were demonstrated to have the characteristic visual field constriction. Conclusions: VGB is effective in producing a significant reduction in seizure frequency in nearly half the patients with childhood seizures, including refractory epilepsy. Despite emerging concerns regarding visual side effects, this drug retains an important role in the medical management of childhood epilepsy. [source] | |||||||||||||||||||||||||