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van Vliet E, Aronica E, Gorter J. Role of blood–brain barrier in temporal lobe epilepsy and pharmacoresistance. Neuroscience 2014; 277:455-73. [DOI: 10.1016/j.neuroscience.2014.07.030] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2014] [Revised: 07/17/2014] [Accepted: 07/21/2014] [Indexed: 12/14/2022]
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152
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Nikalje APG, Shaikh SI, Mulay A, Khan FAK, Sangshetti JN, Shaikh S. Ultrasound-Assisted Synthesis, Anticonvulsant Activity, and Docking Study of Indole-Appended Thiazolidin-4-ones. Arch Pharm (Weinheim) 2014; 347:756-67. [DOI: 10.1002/ardp.201400148] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2014] [Revised: 05/24/2014] [Accepted: 05/26/2014] [Indexed: 11/11/2022]
Affiliation(s)
- Anna Pratima G. Nikalje
- Department of Pharmaceutical Chemistry; Y.B. Chavan College of Pharmacy; Dr. Rafiq Zakaria Campus Rauza Bagh Aurangabad Maharashtra India
| | - Sameer I. Shaikh
- Department of Pharmaceutical Chemistry; Y.B. Chavan College of Pharmacy; Dr. Rafiq Zakaria Campus Rauza Bagh Aurangabad Maharashtra India
| | - Abhineet Mulay
- Department of Pharmaceutical Chemistry; Y.B. Chavan College of Pharmacy; Dr. Rafiq Zakaria Campus Rauza Bagh Aurangabad Maharashtra India
| | - Firoz A. K. Khan
- Department of Pharmaceutical Chemistry; Y.B. Chavan College of Pharmacy; Dr. Rafiq Zakaria Campus Rauza Bagh Aurangabad Maharashtra India
| | - Jaiprakash N. Sangshetti
- Department of Pharmaceutical Chemistry; Y.B. Chavan College of Pharmacy; Dr. Rafiq Zakaria Campus Rauza Bagh Aurangabad Maharashtra India
| | - Shoaib Shaikh
- Wockhardt Research Centre; D-4 Chikalthana MIDC Aurangabad Maharashtra India
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153
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Salar S, Maslarova A, Lippmann K, Nichtweiss J, Weissberg I, Sheintuch L, Kunz WS, Shorer Z, Friedman A, Heinemann U. Blood-brain barrier dysfunction can contribute to pharmacoresistance of seizures. Epilepsia 2014; 55:1255-63. [PMID: 24995798 DOI: 10.1111/epi.12713] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/30/2014] [Indexed: 11/28/2022]
Abstract
OBJECTIVE We tested the hypothesis that interstitial albumin can contribute to pharmacoresistance, which is common among patients with focal epilepsies. These patients often present with an open blood-brain barrier (BBB), resulting in diffusion of drug-binding albumin into the brain interstitial space. METHODS Seizure-like events (SLEs) induced by 100 μm 4-aminopyridine (4-AP) were monitored using extracellular field potential recordings from acute rat entorhinal cortex-hippocampus slices. Effects of standard antiepileptic drugs (phenytoin, valproic acid, carbamazepine, and phenobarbital) were studied in the presence of albumin applied acutely or by intraventricular injection. Unbound antiepileptic drugs (AEDs) were detected by ultrafiltration and high-performance liquid chromatography (HPLC). RESULTS Contrary to the absence of albumin, conventional AEDs failed to suppress SLEs in the rat entorhinal cortex in the presence of albumin. This effect was partially caused by buffering of phenytoin and carbamazepine (CBZ) by albumin. Increasing CBZ concentration from 50 μm to 100 μm resulted in block of SLEs. In slices obtained from animals that were pretreated with intraventricular albumin application 24 h prior to experiment, CBZ suppressed SLEs similar to control slices. We also found that application of serum-like electrolytes transformed SLEs into late recurrent discharges (LRDs), which were no longer responding to CBZ. SIGNIFICANCE A dysfunctional BBB with acute extravasation of serum albumin into the brain's interstitial space could contribute to pharmacoresistance. In such instances, choice of an AED with low albumin binding affinity may help in seizure control.
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Affiliation(s)
- Seda Salar
- Institute of Neurophysiology, Charite-University Medicine Berlin, Berlin, Germany
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154
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Cheng JW, Zhang LJ, Hou YQ, Zhao Q, Zhang XJ, Chen XF, Bai Y. Association between MDR1 C3435T polymorphism and refractory epilepsy in the Chinese population: a systematic review and meta-analysis. Epilepsy Behav 2014; 36:173-9. [PMID: 24953225 DOI: 10.1016/j.yebeh.2014.05.007] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/29/2014] [Revised: 04/08/2014] [Accepted: 05/06/2014] [Indexed: 12/31/2022]
Abstract
The association between the C3435T polymorphism in the MDR1 gene and refractory epilepsy remains controversial. The association appears to be influenced by ethnicity and region. We have performed a systematic review and meta-analysis to assess the link between the MDR1 C3435T polymorphism and refractory epilepsy in the Chinese population. We searched the Cochrane Library, MIDLINE, EMBASE, CBM disc, CNKI, VIP, and WANFANG databases for literature published through August 2013 for case-control studies that evaluated the association between the MDR1 C3435T polymorphism and refractory epilepsy. Twenty-one case-control studies involving 4269 patients (1863 cases in the group with drug-resistant epilepsy and 2406 in the group with drug-responsive epilepsy) were included in the systematic review and meta-analysis. The analysis showed that there were significantly more cases with the MDR1 3435 CC genotype in the group with drug-resistant epilepsy than in the group with drug-responsive epilepsy [odds ratio (OR)=1.50, 95% confidence interval (CI)=1.09-2.06, P=0.01]. In a subanalysis of patients from the southern regions of China, the correlation was not significant [odds ratio (OR)=1.2, 95% confidence interval (CI)=0.89-1.64, P=0.24]. The relationship established in a subset of the Chinese population between the MDR1 C3435T polymorphism and refractory epilepsy will guide epilepsy treatment and development of new AEDs.
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Affiliation(s)
- Ji-Wei Cheng
- Department of Neurology, Putuo Hospital, Shanghai University of Traditional Chinese Medicine, Shanghai 200062, China
| | - Li-Jun Zhang
- Department of Neurology, Putuo Hospital, Shanghai University of Traditional Chinese Medicine, Shanghai 200062, China
| | - Yu-Qing Hou
- Department of Neurology, Putuo Hospital, Shanghai University of Traditional Chinese Medicine, Shanghai 200062, China
| | - Qing Zhao
- Department of Neurology, Putuo Hospital, Shanghai University of Traditional Chinese Medicine, Shanghai 200062, China
| | - Xiao-Jing Zhang
- Department of Neurology, Putuo Hospital, Shanghai University of Traditional Chinese Medicine, Shanghai 200062, China
| | - Xue-Fen Chen
- Department of Preventive Medicine and Health Statistics of Shanghai University of Traditional Chinese Medicine, Shanghai 201203, China
| | - Yu Bai
- Department of Neurology, Putuo Hospital, Shanghai University of Traditional Chinese Medicine, Shanghai 200062, China.
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155
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Singh E, Pillai KK, Mehndiratta M. Characterization of a Lamotrigine-Resistant Kindled Model of Epilepsy in Mice: Evaluation of Drug Resistance Mechanisms. Basic Clin Pharmacol Toxicol 2014; 115:373-8. [DOI: 10.1111/bcpt.12238] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2013] [Accepted: 03/10/2014] [Indexed: 12/31/2022]
Affiliation(s)
- Ekta Singh
- Department of Pharmacology; Faculty of Pharmacy; Jamia Hamdard (Hamdard University); New Delhi India
| | - Krishna K. Pillai
- Department of Pharmacology; Faculty of Pharmacy; Jamia Hamdard (Hamdard University); New Delhi India
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156
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Ren H, Shi YJ, Lu QC, Liang PJ, Zhang PM. The role of the entorhinal cortex in epileptiform activities of the hippocampus. Theor Biol Med Model 2014; 11:14. [PMID: 24656055 PMCID: PMC3994397 DOI: 10.1186/1742-4682-11-14] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2014] [Accepted: 03/17/2014] [Indexed: 01/24/2023] Open
Abstract
BACKGROUND Temporal lobe epilepsy (TLE) is the commonest type of epilepsy in adults, and the hippocampus is indicated to have a close relationship with TLE. Recent researches also indicate that the entorhinal cortex (EC) is involved in epilepsy. To explore the essential role that the EC may play in epilepsy, a computational model of the hippocampal CA3 region was built, which consisted of pyramidal cells and two types of interneurons. By changing the input signals from the EC, the effects of EC on epileptiform activities of the hippocampus were investigated. Additionally, recent studies have found that the antiepileptic drug valproate (VPA) can block ictal discharges but cannot block interictal discharges in vitro, and the mechanism under this phenomenon is still confusing. In our model, the effects of VPA on epileptiform activities were simulated and some mechanisms were explored. RESULTS Interictal discharges were induced in the model without the input signals from the EC, whereas the model with the EC input produced ictal discharges when the EC input contained ictal discharges. The GABA-ergic connection strength was enhanced and the NMDA-ergic connection strength was reduced to simulate the effects of VPA, and the simulation results showed that the disappearance of ictal discharges in the model mainly due to the disappearance of ictal discharges in the input signals from the EC. CONCLUSIONS Simulation results showed that ictal discharges in the EC were necessary for the hippocampus to generate ictal discharges, and VPA might block the ictal discharges in the EC, which led to the disappearance of ictal discharges in the hippocampus.
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Affiliation(s)
| | | | | | | | - Pu-Ming Zhang
- School of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai 200240, China.
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157
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Haerian BS, Baum L, Kwan P, Tan HJ, Raymond AA, Mohamed Z. SCN1A, SCN2A and SCN3A gene polymorphisms and responsiveness to antiepileptic drugs: a multicenter cohort study and meta-analysis. Pharmacogenomics 2014; 14:1153-66. [PMID: 23859570 DOI: 10.2217/pgs.13.104] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
AIM Approximately a third of newly diagnosed epilepsy patients do not respond to antiepileptic drugs (AEDs). Evidence suggests that low penetrance variants in the genes of drug targets such as voltage-gated sodium channels may be involved in drug responsiveness. To examine this hypothesis, we compared data from two epilepsy cohorts from Malaysia and Hong Kong, as well as a meta-analysis from published data. MATERIALS & METHODS Genotype analysis of 39 polymorphisms located in the SCN1A, SCN2A and SCN3A genes was performed on 1504 epilepsy patients from Malaysia and Hong Kong who were receiving AEDs. Meta-analysis was performed for pooled data of SCN1A rs3812718 and rs2298771, and SCN2A rs17183814 polymorphisms. RESULTS Our data from the Hong Kong and Malaysia cohorts showed no significant allele, genotype and haplotype association of polymorphisms in the SCN1A, SCN2A, and SCN3A genes with drug responsiveness in epilepsy. This finding was supported by a meta-analysis for SCN1A rs3812718 and rs2298771, and for SCN2A rs17183814 polymorphisms. CONCLUSION Our comprehensive study suggests that common polymorphisms in SCN1A, SCN2A and SCN3A do not play major roles in influencing response to AEDs. Original submitted 11 March 2013; Revision submitted 31 May 2013.
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Affiliation(s)
- Batoul Sadat Haerian
- Pharmacogenomics Laboratory, Department of Pharmacology, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia.
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158
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Sun G, Sun X, Guan L. Association of MDR1 gene C3435T polymorphism with childhood intractable epilepsy: a meta-analysis. J Neural Transm (Vienna) 2014; 121:717-24. [PMID: 24553780 DOI: 10.1007/s00702-014-1169-3] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2013] [Accepted: 01/29/2014] [Indexed: 12/30/2022]
Abstract
Drug-resistant epilepsy is also referred to as intractable, medically refractory, or pharmacoresistant epilepsy. Approximately, one-third of patients with epilepsy have recurrent seizures despite therapy. Multidrug resistance 1 (MDR1) gene may play a role in drug-resistance in epilepsy. To assess the association between MDR1 C3435T polymorphism and the response to anticonvulsants in childhood intractable epilepsy, we conducted a systematic review and meta-analysis. Studies were obtained from the electronic database of PubMed, Medline, Embase and CNKI up to September 2013. All the case-control association researches evaluating the role of MDR1 C3435T polymorphism in childhood epilepsy to antiepileptic drugs were identified. The odds ratios (ORs) with 95% confidence intervals (CIs) were calculated for comparisons of the alleles and genotypes with co-dominant (C/C vs. T/T, C/T vs. T/T), dominant (C/C + C/T vs. T/T), and recessive (C/C vs. C/T + T/T) models in overall and in ethnicity subgroups to measure the strength of genetic association. A total of 8 related studies, including 634 drug-resistant patients, 615 drug-responsive patients and 1,052 healthy controls were pooled in this meta-analysis. The allelic association of MDR1 C3435T with risk of drug-resistance was not significant (OR 1.03, 95% CI 0.87-1.22, P = 0.73; OR 1.00, 95% CI 0.86-1.16, P = 0.98) in overall and in the subgroup analysis by ethnicity (Asian: OR 0.95, 95% CI 0.77-1.18, P = 0.67; Caucasian: OR 1.18, 95% CI 0.89-1.57, P = 0.25). Neither association was found in other genetic models. Our results did not show a significant association between MDR1 C3435T polymorphism and response to anticonvulsant drugs, suggesting that this polymorphism may not be a risk factor to childhood intractable epilepsy.
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Affiliation(s)
- Guilian Sun
- Department of Pediatrics, The First Affiliated Hospital of China Medical University, No. 155 Nanjing North Street, Heping District, Shenyang, 110001, Liaoning, China,
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159
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Moon J, Lee ST, Choi J, Jung KH, Yang H, Khalid A, Kim JM, Park KI, Shin JW, Ban JJ, Yi GS, Lee SK, Jeon D, Chu K. Unique behavioral characteristics and microRNA signatures in a drug resistant epilepsy model. PLoS One 2014; 9:e85617. [PMID: 24454901 PMCID: PMC3893246 DOI: 10.1371/journal.pone.0085617] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2013] [Accepted: 12/05/2013] [Indexed: 02/08/2023] Open
Abstract
BACKGROUND Pharmacoresistance is a major issue in the treatment of epilepsy. However, the mechanism underlying pharmacoresistance to antiepileptic drugs (AEDs) is still unclear, and few animal models have been established for studying drug resistant epilepsy (DRE). In our study, spontaneous recurrent seizures (SRSs) were investigated by video-EEG monitoring during the entire procedure. METHODS/PRINCIPAL FINDINGS In the mouse pilocarpine-induced epilepsy model, we administered levetiracetam (LEV) and valproate (VPA) in sequence. AED-responsive and AED-resistant mice were naturally selected after 7-day treatment of LEV and VPA. Behavioral tests (open field, object exploration, elevated plus maze, and light-dark transition test) and a microRNA microarray test were performed. Among the 37 epileptic mice with SRS, 23 showed significantly fewer SRSs during administration of LEV (n = 16, LEV sensitive (LS) group) or VPA (n = 7, LEV resistant/VPA sensitive (LRVS) group), while 7 epileptic mice did not show any amelioration with either of the AEDs (n = 7, multidrug resistant (MDR) group). On the behavioral assessment, MDR mice displayed distinctive behaviors in the object exploration and elevated plus maze tests, which were not observed in the LS group. Expression of miRNA was altered in LS and MDR groups, and we identified 4 miRNAs (miR-206, miR-374, miR-468, and miR-142-5p), which were differently modulated in the MDR group versus both control and LS groups. CONCLUSION This is the first study to identify a pharmacoresistant subgroup, resistant to 2 AEDs, in the pilocarpine-induced epilepsy model. We hypothesize that modulation of the identified miRNAs may play a key role in developing pharmacoresistance and behavioral alterations in the MDR group.
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Affiliation(s)
- Jangsup Moon
- Laboratory for Neurotherapeutics, Department of Neurology, Comprehensive Epilepsy Center, Biomedical Research Institute, Seoul National University Hospital, Seoul National University College of Medicine, Seoul, Republic of Korea
| | - Soon-Tae Lee
- Laboratory for Neurotherapeutics, Department of Neurology, Comprehensive Epilepsy Center, Biomedical Research Institute, Seoul National University Hospital, Seoul National University College of Medicine, Seoul, Republic of Korea
| | - Jiye Choi
- Department of Bio and Brain Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, Republic of Korea
| | - Keun-Hwa Jung
- Laboratory for Neurotherapeutics, Department of Neurology, Comprehensive Epilepsy Center, Biomedical Research Institute, Seoul National University Hospital, Seoul National University College of Medicine, Seoul, Republic of Korea
| | - Hyunwoo Yang
- Department of Bio and Brain Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, Republic of Korea
| | - Arshi Khalid
- Department of Bio and Brain Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, Republic of Korea
| | - Jeong-Min Kim
- Department of Neurology, Chung-Ang University Hospital, Chung-Ang University College of Medicine, Seoul, Republic of Korea
| | - Kyung-Il Park
- Department of Neurology, Seoul Paik Hospital, Inje University College of Medicine, Seoul, Republic of Korea
| | - Jung-Won Shin
- Laboratory for Neurotherapeutics, Department of Neurology, Comprehensive Epilepsy Center, Biomedical Research Institute, Seoul National University Hospital, Seoul National University College of Medicine, Seoul, Republic of Korea
| | - Jae-Jun Ban
- Laboratory for Neurotherapeutics, Department of Neurology, Comprehensive Epilepsy Center, Biomedical Research Institute, Seoul National University Hospital, Seoul National University College of Medicine, Seoul, Republic of Korea
| | - Gwan-Su Yi
- Department of Bio and Brain Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, Republic of Korea
| | - Sang Kun Lee
- Laboratory for Neurotherapeutics, Department of Neurology, Comprehensive Epilepsy Center, Biomedical Research Institute, Seoul National University Hospital, Seoul National University College of Medicine, Seoul, Republic of Korea
| | - Daejong Jeon
- Department of Bio and Brain Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, Republic of Korea
- * E-mail: (DJ); (KC)
| | - Kon Chu
- Laboratory for Neurotherapeutics, Department of Neurology, Comprehensive Epilepsy Center, Biomedical Research Institute, Seoul National University Hospital, Seoul National University College of Medicine, Seoul, Republic of Korea
- * E-mail: (DJ); (KC)
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160
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Menzler K, Hermsen A, Balkenhol K, Duddek C, Bugiel H, Bauer S, Schorge S, Reif PS, Klein KM, Haag A, Oertel WH, Hamer HM, Knake S, Trucks H, Sander T, Rosenow F. A commonSCN1Asplice-site polymorphism modifies the effect of carbamazepine on cortical excitability-A pharmacogenetic transcranial magnetic stimulation study. Epilepsia 2014; 55:362-9. [DOI: 10.1111/epi.12515] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/14/2013] [Indexed: 11/27/2022]
Affiliation(s)
- Katja Menzler
- Epilepsy Center Hessen; Philipps-University Marburg; Marburg Germany
| | - Anke Hermsen
- Epilepsy Center Hessen; Philipps-University Marburg; Marburg Germany
| | | | - Caroline Duddek
- Epilepsy Center Hessen; Philipps-University Marburg; Marburg Germany
| | - Hannes Bugiel
- Epilepsy Center Hessen; Philipps-University Marburg; Marburg Germany
| | - Sebastian Bauer
- Epilepsy Center Hessen; Philipps-University Marburg; Marburg Germany
| | - Stephanie Schorge
- Department of Clinical and Experimental Epilepsy; Institute of Neurology; London United Kingdom
| | - Philipp S. Reif
- Epilepsy Center Hessen; Philipps-University Marburg; Marburg Germany
| | - Karl Martin Klein
- Epilepsy Center Hessen; Philipps-University Marburg; Marburg Germany
| | - Anja Haag
- Epilepsy Center Hessen; Philipps-University Marburg; Marburg Germany
| | | | - Hajo M. Hamer
- Epilepsy Center Erlangen; Department of Neurology; University Hospitals Erlangen; Erlangen Germany
| | - Susanne Knake
- Epilepsy Center Hessen; Philipps-University Marburg; Marburg Germany
| | - Holger Trucks
- Cologne Center for Genomics (CCG); Cologne University; Cologne Germany
| | - Thomas Sander
- Cologne Center for Genomics (CCG); Cologne University; Cologne Germany
| | - Felix Rosenow
- Epilepsy Center Hessen; Philipps-University Marburg; Marburg Germany
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161
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Chen P, Yan Q, Xu H, Lu A, Zhao P. The effects of ABCC2 G1249A polymorphism on the risk of resistance to antiepileptic drugs: a meta-analysis of the literature. Genet Test Mol Biomarkers 2013; 18:106-11. [PMID: 24325761 DOI: 10.1089/gtmb.2013.0362] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
AIMS The G1249A variant of the multidrug resistance-associated protein 2 (ABCC2) gene may be associated with the development of antiepileptic drug (AED) resistance. Although numerous studies have investigated the association between the G1249A variant and the risk of drug resistance in epilepsy, the results of these studies have been inconclusive. To assess the role of G1249A polymorphism in drug resistance in epilepsy, a meta-analysis was performed. MATERIALS AND METHODS We systematically reviewed relevant studies retrieved by the PubMed and Embase. Odds ratios (ORs) and 95% confidence intervals (CIs) were calculated based on the date extracted from the studies to evaluate the strength of association. We also analyzed the heterogeneity and sensitivity of each report and the publication bias of the studies. RESULTS A total of 6 published studies, involving 2213 patients (1100 patients with drug-resistant epilepsy and 1113 controls with drug-responsive epilepsy) were reviewed in the present meta-analysis. The overall results indicated that the variant genotypes were associated with a significantly decreased risk of AED resistance (AA vs. GG: OR=0.372, 95% CI=0.182-0.762; recessive model: OR=0.399, 95% CI=0.200-0.795) (fixed-effects model). A stratified analysis by ethnicity showed similar findings for Caucasians in an additive model (A vs. G: OR=0.700, 95% CI=0.494-0.992). CONCLUSIONS The meta-analysis suggests that the ABCC2 G1249A polymorphism is significantly associated with a decreased risk of AED resistance. However, further functional investigations are warranted to validate the association.
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Affiliation(s)
- Pin Chen
- Department of Neurosurgery, The First Affiliated Hospital of Nanjing Medical University , Nanjing, China
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162
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Guo Y, Jiang L. Drug transporters are altered in brain, liver and kidney of rats with chronic epilepsy induced by lithium–pilocarpine. Neurol Res 2013; 32:106-12. [DOI: 10.1179/174313209x408954] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022]
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163
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Snehunsu A, Mukunda N, Satish Kumar MC, Sadhana N, Naduvil Narayanan S, Vijay Kapgal K, Avinash H, Chandrashekar BR, Raghavendra Rao K, Nayak BS. Evaluation of anti-epileptic property ofMarsilea quadrifoliaLinn. in maximal electroshock and pentylenetetrazole-induced rat models of epilepsy. Brain Inj 2013; 27:1707-14. [DOI: 10.3109/02699052.2013.831121] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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164
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Seven M, Batar B, Unal S, Yesil G, Yuksel A, Guven M. The drug-transporter gene MDR1 C3435T and G2677T/A polymorphisms and the risk of multidrug-resistant epilepsy in Turkish children. Mol Biol Rep 2013; 41:331-6. [PMID: 24213830 PMCID: PMC3877425 DOI: 10.1007/s11033-013-2866-y] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2013] [Accepted: 11/05/2013] [Indexed: 12/21/2022]
Abstract
One-third of all individuals with epilepsy are resistant to antiepileptic drug (AED) treatment. Antiepileptic treatment response has been suggested to be modulated by genetic polymorphisms of drug efflux transporters. Several polymorphic variants within the multidrug resistance 1 (MDR1) gene, which encodes the major transmembrane efflux transporter P-glycoprotein, have been proposed to be associated with AED resistance in epilepsy patients. The aim of this study was to evaluate the effect of C3435T and G2677T/A polymorphisms of MDR1 on AED resistance in Turkish children with epilepsy. MDR1 C3435T and G2677T/A were genotyped in 152 patients with epilepsy, classified as drug-resistant in 69 and drug-responsive in 83. Genotypes of the C3435T and G2677T/A polymorphisms were determined by polymerase chain reaction followed by restriction fragment length polymorphism. Genotype and allele frequencies of C3435T and G2677T/A polymorphisms of the MDR1 gene did not differ between drug-resistant and drug-responsive epilepsy patients. Our results suggest that MDR1 C3435T and G2677T/A polymorphisms are not associated with AED resistance in Turkish epileptic patients. To clarify the exact clinical implication of the MDR1 polymorphisms on the multidrug resistance in epilepsy, further investigations in various ethnic populations would be necessary.
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Affiliation(s)
- Mehmet Seven
- Department of Medical Genetics, Cerrahpasa Medical Faculty, Istanbul University, Istanbul, Turkey
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165
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Guerrini R, Scerrati M, Rubboli G, Esposito V, Colicchio G, Cossu M, Marras CE, Tassi L, Tinuper P, Paola Canevini M, Quarato P, Giordano F, Granata T, Villani F, Giulioni M, Scarpa P, Barbieri V, Bottini G, Del Sole A, Vatti G, Spreafico R, Lo Russo G. Overview of presurgical assessment and surgical treatment of epilepsy from the Italian League Against Epilepsy. Epilepsia 2013; 54 Suppl 7:35-48. [DOI: 10.1111/epi.12308] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Affiliation(s)
- Renzo Guerrini
- Pediatric Neurology Unit and Laboratories; Children's Hospital A. Meyer-University of Florence; Florence Italy
| | - Massimo Scerrati
- Neurosurgery; University Hospital - Polytechnic University of Marche; Ancona Italy
| | - Guido Rubboli
- IRCCS Institute of Neurological Sciences; Bellaria Hospital; Bologna Italy
- Danish Epilepsy Center; Epilepsy Hospital, Dianalund Denmark
| | - Vincenzo Esposito
- Neurosurgery; I.R.C.C.S. Neuromed; Pozzilli (IS) Italy
- Department of Neurology and Psychiatry; Sapienza University of Rome; Rome Italy
| | | | - Massimo Cossu
- C. Munari Epilepsy Surgery Center; Niguarda Hospital; Milan Italy
| | - Carlo Efisio Marras
- Neurosurgery Unit; Department of Neuroscience e Neurorehabilitation; Bambino Gesù Children Hospital; Rome Italy
| | - Laura Tassi
- C. Munari Epilepsy Surgery Center; Niguarda Hospital; Milan Italy
| | - Paolo Tinuper
- Neurological Clinic; Bellaria Hospital IRCCS Institute of Neurological Sciences of Bologna and Department of Biomedical and Neuromotor Sciences; University of Bologna; Bologna Italy
| | - Maria Paola Canevini
- Epilepsy Center; San Paolo Hospital and Department of Health Sciences; University of Milan; Milan Italy
| | - Pierpaolo Quarato
- Epilepsy Surgery Unit; Department of Neurological Sciences; IRCCS “NEUROMED”; Pozzilli (IS) Italy
| | - Flavio Giordano
- Pediatric Neurosurgery Unit; Children's Hospital Meyer-University of Florence; Florence Italy
| | - Tiziana Granata
- Department of Pediatric Neuroscience; Carlo Besta Neurological Institute; Milan Italy
| | - Flavio Villani
- Clinical Epileptology and Experimental Neurophysiology Unit; Carlo Besta Neurological Institute; Milan Italy
| | - Marco Giulioni
- Division of Neurosurgery; IRCCS Institute of Neurological Sciences of Bologna; Bellaria Hospital; Bologna Italy
| | - Pina Scarpa
- Cognitive Neuropsychology Centre; Niguarda Hospital; Milan Italy
| | - Valentina Barbieri
- Psychiatric Branch; Department of Medicine, Surgery and Dentistry; University of Milan and San Paolo Hospital; Milan Italy
| | - Gabriella Bottini
- Cognitive Neuropsychology Centre; Niguarda Hospital; Milan Italy
- Department of Psychology; University of Pavia; Pavia Italy
| | - Angelo Del Sole
- Department of Diagnostic Services; Unit of Nuclear Medicine; San Paolo Hospital and Department of Health Sciences; University of Milan; Milan Italy
| | - Giampaolo Vatti
- Department of Neurological and Sensorial Sciences; University of Siena; Siena Italy
| | - Roberto Spreafico
- Clinical Epileptology and Experimental Neurophysiology Unit; Carlo Besta Neurological Institute; Milan Italy
| | - Giorgio Lo Russo
- C. Munari Epilepsy Surgery Center; Niguarda Hospital; Milan Italy
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166
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Asadi-Pooya AA, Razavizadegan SMA, Abdi-Ardekani A, Sperling MR. Adjunctive use of verapamil in patients with refractory temporal lobe epilepsy: a pilot study. Epilepsy Behav 2013; 29:150-4. [PMID: 23973639 DOI: 10.1016/j.yebeh.2013.07.006] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/08/2013] [Revised: 06/17/2013] [Accepted: 07/08/2013] [Indexed: 11/17/2022]
Abstract
OBJECTIVE The present study aimed to determine if adjunctive use of verapamil, as a P-glycoprotein (P-gp) inhibitor, is efficacious in decreasing seizure frequency in patients with refractory temporal lobe epilepsy. MATERIALS AND METHODS This was an open-label pilot study. Adult patients with refractory temporal lobe epilepsy were studied. Baseline seizure type and seizure count were determined. Patients were divided randomly into two groups. Group A received verapamil 120 mg/day (n=13), and group B received 240 mg/day (n=6). All patients were followed for eight weeks. The proportion of responders, which consist of patients with more than 50% reduction in seizure frequency from baseline, was tabulated. RESULTS Nineteen patients were studied. Seven patients (36.84%) reached the responder rate. Three patients (50%) in group B were among the responders; two of these patients achieved seizure freedom. Four patients (30.7%) in group A responded favorably to verapamil. CONCLUSION Developing new means of improving the effectiveness of existing antiepileptic drugs is a desirable way of tackling the dilemma of medically refractory epilepsy. Hypothetically, P-gp inhibitors (e.g., verapamil) might be used to counteract the removal of AEDs from the epileptogenic tissue. Such a strategy was adopted in this non-placebo-controlled, open-label, pilot study. We observed a significant achievement in seizure control associated with adjunctive use of verapamil in patients with refractory temporal lobe epilepsy.
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Affiliation(s)
- Ali A Asadi-Pooya
- Department of Neurology, School of Medicine, Shiraz University of Medical Sciences, Shiraz, Iran; Jefferson Comprehensive Epilepsy Center, Department of Neurology, Thomas Jefferson University, Philadelphia, USA.
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Löscher W, Klitgaard H, Twyman RE, Schmidt D. New avenues for anti-epileptic drug discovery and development. Nat Rev Drug Discov 2013; 12:757-76. [DOI: 10.1038/nrd4126] [Citation(s) in RCA: 424] [Impact Index Per Article: 38.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
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168
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Zhang Y, Yu N, Su L, Di Q. A prospective cohort study of prognosis for newly diagnosed epilepsy in east China. BMC Neurol 2013; 13:116. [PMID: 24134605 PMCID: PMC3774222 DOI: 10.1186/1471-2377-13-116] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2013] [Accepted: 09/03/2013] [Indexed: 11/24/2022] Open
Abstract
Background Limited data are available on the outcome of antiepileptic drug treatment response in patients of Chinese Han ethnicity with newly diagnosed epilepsy. We sought to explore the prognosis with antiepileptic drug treatment and to identify the predictors of poor drug control of seizures in these patients. Methods For at least 2 years, we prospectively followed up a cohort of patients with newly diagnosed epilepsy and analyzed the response to each antiepileptic drug. Cumulative risk for seizure relapse after initial remission achieved was estimated. The patients were divided into two groups (poor and good control) and compared for clinical characteristics. Results A total of 180 patients were included. Early remission was reached in 125 (69.44%) patients, 19 (10.56%) patients entered late remission, while 36 (20%) patients failed to achieve remission. The relapse rates were 19.5% at 2 years and 31.9% at 3 years of the follow-up. The response rates of the first throughout the fourth treatment regimens were 60.0%, 16.1%, 2.8%, and 0.6%, respectively. Multiple seizure types and changes in seizure type during treatment were significantly (p = 0.013 and 0.047, respectively) associated with a poor control. Conclusions The prognosis of the majority of patients with newly diagnosed epilepsy is good and the clinical pattern of epilepsy during treatment is complex. The chances of seizure control declines with each subsequent treatment regimen. The prognosis for patients with multiple seizure types and seizure type changes during treatment is unfavorable.
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169
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Wassenaar M, Leijten FSS, Egberts TCG, Moons KGM, Uijl SG. Prognostic factors for medically intractable epilepsy: a systematic review. Epilepsy Res 2013; 106:301-10. [PMID: 23880113 DOI: 10.1016/j.eplepsyres.2013.06.013] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2013] [Revised: 06/13/2013] [Accepted: 06/28/2013] [Indexed: 11/15/2022]
Abstract
OBJECTIVE One third of all epilepsy patients have medically intractable epilepsy. Knowledge of prognostic factors that, in an early therapeutic stage of epilepsy, herald intractability could facilitate patient management. In this systematic review, we examined the evidence for independent prognostic factors of intractability in patients with epilepsy. METHODS MEDLINE and EMBASE were searched for cohort studies reporting on prognostic factors for medically intractable epilepsy. After selection of abstracts, full-text articles were obtained and their quality was assessed by two reviewers, using the QUIPS checklist. All independent prognostic factors in the individual studies were summarized. RESULTS Eleven cohort studies were included, of which ten hospital-based. Younger age at seizure onset, symptomatic etiology, high initial seizure frequency, medical history, epileptic EEG abnormalities, and failure of previous antiepileptic-drugs (AEDs) were documented as independent prognostic factors of intractability in at least 2 of the 11 studies; none of these factors was reported in all 11 studies. None of the studies considered genetic, neurobiological, or immunological factors. The studies were of moderate quality, mostly because they did not provide a conceptual model for the choice of predictors. Heterogeneity in study design, population, candidate prognostic factors, and outcome definitions precluded statistical pooling. CONCLUSIONS While potentially relevant prognosticators of medically intractable epilepsy have been identified, the evidence for these factors is not consistent. There is a need for well-designed prognostic population-based cohort studies that also include pharmacological, genetic, neurobiological, and immunological factors. A valid model for the early prediction of medically intractable epilepsy could improve patient management.
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Affiliation(s)
- Merel Wassenaar
- Department of Neurology and Neurosurgery, Rudolf Magnus Institute of Neuroscience, University Medical Center Utrecht, The Netherlands; SEIN-Epilepsy Institute in the Netherlands Foundation, Heemstede, The Netherlands.
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170
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Cifelli P, Palma E, Roseti C, Verlengia G, Simonato M. Changes in the sensitivity of GABAA current rundown to drug treatments in a model of temporal lobe epilepsy. Front Cell Neurosci 2013; 7:108. [PMID: 23874269 PMCID: PMC3708152 DOI: 10.3389/fncel.2013.00108] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2013] [Accepted: 06/21/2013] [Indexed: 01/26/2023] Open
Abstract
The pharmacological treatment of mesial temporal lobe epilepsy (mTLE), the most common epileptic syndrome in adults, is still unsatisfactory, as one-third of the patients are or become refractory to antiepileptic agents. Refractoriness may depend upon drug-induced alterations, but the disease per se may also undergo a progressive evolution that affects the sensitivity to drugs. mTLE has been shown to be associated with a dysfunction of the inhibitory signaling mediated by GABAA receptors. In particular, the repetitive activation of GABAA receptors produces a use-dependent decrease (rundown) of the evoked currents (IGABA), which is markedly enhanced in the hippocampus and cortex of drug-resistant mTLE patients. This phenomenon has been also observed in the pilocarpine model, where the increased IGABA rundown is observed in the hippocampus at the time of the first spontaneous seizure, then extends to the cortex and remains constant in the chronic phase of the disease. Here, we examined the sensitivity of IGABA to pharmacological modulation. We focused on the antiepileptic agent levetiracetam (LEV) and on the neurotrophin brain-derived neurotrophic factor (BDNF), which were previously reported to attenuate mTLE-induced increased rundown in the chronic human tissue. In the pilocarpine model, BDNF displayed a paramount effect, decreasing rundown in the hippocampus at the time of the first seizure, as well as in the hippocampus and cortex in the chronic period. In contrast, LEV did not affect rundown in the hippocampus, but attenuated it in the cortex. Interestingly, this effect of LEV was also observed on the still unaltered rundown observed in the cortex at the time of the first spontaneous seizure. These data suggest that the sensitivity of GABAA receptors to pharmacological interventions undergoes changes during the natural history of mTLE, implicating that the site of seizure initiation and the timing of treatment may highly affect the therapeutic outcome.
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Affiliation(s)
- Pierangelo Cifelli
- Section of Pharmacology, Department of Medical Sciences, University of Ferrara Ferrara, Italy ; National Institute of Neuroscience Ferrara, Italy ; Ri.MED Foundation Palermo, Italy
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Major vault protein (MVP) gene polymorphisms and drug resistance in mesial temporal lobe epilepsy with hippocampal sclerosis. Gene 2013; 526:449-53. [PMID: 23751308 DOI: 10.1016/j.gene.2013.05.067] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2013] [Accepted: 05/27/2013] [Indexed: 11/21/2022]
Abstract
The human major vault protein (MVP) has been implicated in the development of drug resistance in cancer cells. Over expression of MVP has also been reported in brain tissue samples from antiepileptic drug (AED)-resistant human focal epilepsies. To investigate the relationship between single nucleotide polymorphisms (SNPs) involving the MVP gene and AED-resistance, we compared the distribution of three SNPs in the MVP gene, rs4788187, rs3815824 and rs3815823, among 220 patients with mesial temporal lobe epilepsy with hippocampal sclerosis (MTLE-HS) (prototype of AED-resistant epilepsy syndrome), 201 patients with juvenile myoclonic epilepsy (JME) (prototype of AED-responsive epilepsy syndrome) and 213 ethnically matched non-epilepsy controls. All the patients and controls were residents of the South Indian state of Kerala for more than three generations. We did not find any significant difference in allele and genotypic frequencies of the studied SNPs between AED-resistant and AED-responsive cohorts, and between AED-resistant and AED-responsive cohorts independently and pooled together when compared with the controls. We conclude that rs4788187, rs3815824, rs3815823 variants of the MVP gene are associated neither with predisposition for epilepsy nor with AED-resistance in the population that we have studied. Our results suggest the need for further research into the link between MVP and AED-resistance.
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Efficient synthesis, anticonvulsant and muscle relaxant activities of new 2-((5-amino-1,3,4-thiadiazol-2-yl)methyl)-6-phenyl-4,5-dihydropyridazin-3(2H)-one derivatives. Med Chem Res 2013. [DOI: 10.1007/s00044-013-0618-0] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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173
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Pohlmann-Eden B, Weaver DF. The puzzle(s) of pharmacoresistant epilepsy. Epilepsia 2013; 54 Suppl 2:1-4. [DOI: 10.1111/epi.12174] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Bernd Pohlmann-Eden
- Department of Medicine (Neurology); Dalhousie University; Halifax; Nova Scotia; Canada
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174
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Pohlmann-Eden B, Crocker CE, Schmidt MH. A conceptual framework for the use of neuroimaging to study and predict pharmacoresistance in epilepsy. Epilepsia 2013; 54 Suppl 2:75-9. [DOI: 10.1111/epi.12190] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Affiliation(s)
| | - Candice E. Crocker
- Division of Neurology; Dalhousie University; Halifax; Nova Scotia; Canada
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175
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Weaver DF, Pohlmann-Eden B. Pharmacoresistant epilepsy: Unmet needs in solving the puzzle(s). Epilepsia 2013; 54 Suppl 2:80-5. [DOI: 10.1111/epi.12191] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
| | - Bernd Pohlmann-Eden
- Department of Medicine (Neurology); Dalhousie University; Halifax; Nova Scotia; Canada
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176
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Zhang X, Chen G, Lu Y, Liu J, Fang M, Luo J, Cao Q, Wang X. Association of Mitochondrial Letm1 with Epileptic Seizures. Cereb Cortex 2013; 24:2533-40. [DOI: 10.1093/cercor/bht118] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
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177
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Chen J, Wang Y, Wang Y, Yi X, Ge R. Studies on the effect of adenosine on calcium oscillation in hippocampal neurons. Exp Ther Med 2013; 5:1165-1168. [PMID: 23596485 PMCID: PMC3627451 DOI: 10.3892/etm.2013.973] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2012] [Accepted: 02/13/2013] [Indexed: 11/05/2022] Open
Abstract
Adenosine (Ade) is an antiepileptic agent. In order to investigate the possible mechanism of action of Ade, its effect on calcium (Ca2+) oscillations in hippocampal neurons of Sprague Dawley (SD) rats was explored. Primary hippocampal neurons were cultured from suckling neonatal SD rats. Cells were cultured for 7–9 days and the Ca2+ oscillations in response to perfusion with Ade were detected using confocal laser scanning microscopy in combination with Fluo-3/AM labeling. This study found that Ade inhibits the spontaneous synchronized Ca2+ oscillation frequency and amplitude in mature hippocampal neurons and such inhibition depends on the Ade dosage level to a certain extent. Ade also had a significant inhibitory effect on high potassium-induced Ca2+ oscillation frequency and amplitude. Ade had a significant inhibitory effect on high-voltage-activated Ca2+ channel-mediated Ca2+ influx and Ca2+ oscillations in neurons. This may be one of the mechanisms for Ade to exert antiepileptic effects as an endogenous substance.
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Affiliation(s)
- Jinbo Chen
- Department of Neurology, The Affiliated Hospital of Binzhou Medical University, Binzhou 256603, P.R. China
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178
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Imaging P-glycoprotein function in rats using [11C]-N-desmethyl-loperamide. Ann Nucl Med 2013; 27:618-24. [DOI: 10.1007/s12149-013-0725-5] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2012] [Accepted: 04/01/2013] [Indexed: 01/16/2023]
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179
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The protective effect of myo-inositol on hippocamal cell loss and structural alterations in neurons and synapses triggered by kainic acid-induced status epilepticus. Cell Mol Neurobiol 2013; 33:659-71. [PMID: 23568659 DOI: 10.1007/s10571-013-9930-y] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2013] [Accepted: 03/18/2013] [Indexed: 02/02/2023]
Abstract
It is known that myo-inositol pretreatment attenuates the seizure severity and several biochemical changes provoked by experimentally induced status epilepticus. However, it remains unidentified whether such properties of myo-inositol influence the structure of epileptic brain. In the present light and electron microscopic research we elucidate if pretreatment with myo-inositol has positive effect on hippocampal cell loss, and cell and synapses damage provoked by kainic acid-induced status epilepticus. Adult male Wistar rats were treated with (i) saline, (ii) saline + kainic acid, (iii) myo-inositol + kainic acid. Assessment of cell loss at 2, 14, and 30 days after treatment demonstrate cytoprotective effect of myo-inositol in CA1 and CA3 areas. It was strongly expressed in pyramidal layer of CA1, radial and oriental layers of CA3 and in less degree-in other layers of both fields. Ultrastructural alterations were described in CA1, 14 days after treatment. The structure of neurons, synapses, and porosomes are well preserved in the rats pretreated with myo-inositol in comparing with rats treated with only kainic acid.
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180
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Jędrzejczak J, Marusic P, Haldre S, Majkowska-Zwolińska B, Bojinova-Tchamova V, Mameniskiene R, Mindruta I, Ravnik IM, Szupera Z, Sykora P, Verzbickis A, Daniluk J. Current status of epilepsy health care for adult patients from central and eastern European Union countries--a survey of members of the Central Europe Epilepsy Experts Working Group. Seizure 2013; 22:452-6. [PMID: 23528980 DOI: 10.1016/j.seizure.2013.03.001] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2012] [Revised: 03/03/2013] [Accepted: 03/04/2013] [Indexed: 11/30/2022] Open
Abstract
PURPOSE The aim of this survey was to review and compare the current approaches to epilepsy management in central and eastern EU (CEEU) countries. METHOD The questionnaire was sent to ten invited experts from Bulgaria, Czech Republic, Estonia, Hungary, Latvia, Lithuania, Poland, Romania, Slovakia, and Slovenia. It focused on the treatment of adults. RESULTS The number of neurologists and epilepsy reference centers is highly variable in CEEU countries. None of the analyzed states has a formal specialization in epileptology. No universal state-approved criteria for reference centers exist in Czech Republic, Estonia, Hungary, Latvia, and Slovenia. Generally, the protocols for epilepsy treatment in CEEU countries, including drug-resistant epilepsy, are in accordance with international guidelines; however, most countries have their own national standards of care and some have local clinical guidelines. Also, the reimbursement systems for antiepileptic drugs in CEEU countries are highly variable. Seven countries have epilepsy surgery centers. The costs of epilepsy surgeries are fully reimbursed, procedures performed abroad may also be covered. The length of time spent on waiting lists for surgery following the completion of preoperative investigations varies from two weeks to three years. The fraction of patients who qualified and were operated on within 12 months ranges from 20% to 100%. CONCLUSION The lack of unified procedures pertaining to the evaluation and therapy of epilepsy is reflected by marked differences in access to treatment modalities for patients from CEEU countries.
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Affiliation(s)
- Joanna Jędrzejczak
- Department of Neurology and Epileptology, Medical Center for Postgraduate Education, Warsaw, Poland.
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181
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Syvänen S, Eriksson J. Advances in PET imaging of P-glycoprotein function at the blood-brain barrier. ACS Chem Neurosci 2013; 4:225-37. [PMID: 23421673 DOI: 10.1021/cn3001729] [Citation(s) in RCA: 55] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Abstract
Efflux transporter P-glycoprotein (P-gp) at the blood-brain barrier (BBB) restricts substrate compounds from entering the brain and may thus contribute to pharmacoresistance observed in patient groups with refractory epilepsy and HIV. Altered P-gp function has also been implicated in neurodegenerative diseases such as Alzheimer's and Parkinson's disease. Positron emission tomography (PET), a molecular imaging modality, has become a promising method to study the role of P-gp at the BBB. The first PET study of P-gp function was conducted in 1998, and during the past 15 years two main categories of P-gp PET tracers have been investigated: tracers that are substrates of P-gp efflux and tracers that are inhibitors of P-gp function. PET, as a noninvasive imaging technique, allows translational research. Examples of this are preclinical investigations of P-gp function before and after administering P-gp modulating drugs, investigations in various animal and disease models, and clinical investigations regarding disease and aging. The objective of the present review is to give an overview of available PET radiotracers for studies of P-gp and to discuss how such studies can be designed. Further, the review summarizes results from PET studies of P-gp function in different central nervous system disorders.
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Affiliation(s)
- Stina Syvänen
- Department of Public Health and Caring Sciences, Uppsala University, Rudbecklaboratoriet, 751 85 Uppsala, Sweden
| | - Jonas Eriksson
- PET Centre, Uppsala University Hospital, 751 85 Uppsala, Sweden
- Preclinical PET Platform, Department
of Medicinal Chemistry, Uppsala University, Dag Hammarskjöldsv 14C, 751 83 Uppsala, Sweden
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182
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Pavlov I, Kaila K, Kullmann DM, Miles R. Cortical inhibition, pH and cell excitability in epilepsy: what are optimal targets for antiepileptic interventions? J Physiol 2013; 591:765-74. [PMID: 22890709 PMCID: PMC3591695 DOI: 10.1113/jphysiol.2012.237958] [Citation(s) in RCA: 51] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2012] [Accepted: 08/10/2012] [Indexed: 12/14/2022] Open
Abstract
Epilepsy is characterised by the propensity of the brain to generate spontaneous recurrent bursts of excessive neuronal activity, seizures. GABA-mediated inhibition is critical for restraining neuronal excitation in the brain, and therefore potentiation of GABAergic neurotransmission is commonly used to prevent seizures. However, data obtained in animal models of epilepsy and from human epileptic tissue suggest that GABA-mediated signalling contributes to interictal and ictal activity. Prolonged activation of GABA(A) receptors during epileptiform bursts may even initiate a shift in GABAergic neurotransmission from inhibitory to excitatory and so have a proconvulsant action. Direct targeting of the membrane mechanisms that reduce spiking in glutamatergic neurons may better control neuronal excitability in epileptic tissue. Manipulation of brain pH may be a promising approach and recent advances in gene therapy and optogenetics seem likely to provide further routes to effective therapeutic intervention.
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Affiliation(s)
- Ivan Pavlov
- Department of Clinical and Experimental Epilepsy, UCL Institute of Neurology, London WC1N 3BG, UK.
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183
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Di Ianni ME, Enrique AV, Palestro PH, Gavernet L, Talevi A, Bruno-Blanch LE. Several new diverse anticonvulsant agents discovered in a virtual screening campaign aimed at novel antiepileptic drugs to treat refractory epilepsy. J Chem Inf Model 2012. [PMID: 23181365 DOI: 10.1021/ci300423q] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
A virtual screening campaign was conducted in order to discover new anticonvulsant drug candidates for the treatment of refractory epilepsy. To this purpose, a topological discriminant function to identify antiMES drugs and a sequential filtering methodology to discriminate P-glycoprotein substrates and nonsubstrates were jointly applied to ZINC 5 and DrugBank databases. The virtual filters combine an ensemble of 2D classifiers and docking simulations. In the light of the results, 10 structurally diverse compounds were acquired and tested in animal models of seizure and the rotorod test. All 10 candidates showed some level of protection against MES test.
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Affiliation(s)
- Mauricio E Di Ianni
- Medicinal Chemistry, Department of Biological Sciences, Faculty of Exact Sciences, National University of La Plata, 47 & 115, La Plata B1900AJI, Buenos Aires, Argentina
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Salih MR, Bahari MB, Hassali MAA, Shafie AA, Al-Lela OQB, Abd AY, Ganesan VM. Characteristics of seizure frequency among Malaysian children diagnosed with structural-metabolic epilepsy. J Neurosci Rural Pract 2012. [PMID: 23188969 PMCID: PMC3505308 DOI: 10.4103/0976-3147.102596] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
Introduction: Seizure-free patients or substantial reduction in seizure frequency are the most important outcome measures in the management of epilepsy. The study aimed to evaluate the patterns of seizure frequency and its relationship with demographics, clinical characteristics, and outcomes. Materials and Methods: A retrospective cohort study was conducted at the Pediatric Neurology Clinic, Hospital Pulau Pinang. Over a period of 6 months, the required data were extracted from the medical records using a pre-designed data collection form. Results: Seizure frequency showed no significant association with patient's demographics and clinical characteristic. However, significant reduction in seizure frequency from the baseline to the last follow-up visit was only seen in certain subgroups of patients including Malays, females, patients <4 years of age, patients with global developmental delay/intellectual disability, and patients with focal seizure. There was no significant association between seizure frequency and rate of adverse events. Polytherapy visits were associated with higher seizure frequency than monotherapy visits (27.97 ± 56.66, 10.94 ± 30.96 attack per month, respectively) (P < 0.001). There was a clear tendency to get antiepileptic drugs used at doses above the recommended range in polytherapy (8.4%) rather than in monotherapy (1.4%) visits (P < 0.001). A significant correlation was found between seizure frequency and number of visits per patient per year (r = 0.450, P < 0.001). Conclusion: Among children with structural–metabolic epilepsy, Malays, females, patients <4 years of age, patients with global developmental delay/intellectual disability and patients manifested with focal seizure are more responsive antiepileptic drug therapy than the other subgroups of patients.
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Plech T, Luszczki JJ, Wujec M, Flieger J, Pizoń M. Synthesis, characterization and preliminary anticonvulsant evaluation of some 4-alkyl-1,2,4-triazoles. Eur J Med Chem 2012; 60:208-15. [PMID: 23291122 DOI: 10.1016/j.ejmech.2012.11.026] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2012] [Revised: 10/18/2012] [Accepted: 11/18/2012] [Indexed: 10/27/2022]
Abstract
Designed and synthesized 4-alkyl-1,2,4-triazole-3-thione derivatives showed significant anticonvulsant activity, determined in the maximal electroshock-induced seizure (MES) test. The chemical structure of all new compounds was confirmed by spectral methods ((1)H NMR, (13)C NMR, IR, MS). A sensitive and selective method was elaborated for the determination of the anticonvulsant compounds levels in mice brain tissue, based on HPLC with diode array detector (DAD). Chromatographic tests showed that lack of anticonvulsant effect of two derivatives (15, 16) with long alkyl chains at N-4 position of the 1,2,4-triazole ring was due to the inability to cross the blood-brain barrier (BBB).
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Affiliation(s)
- Tomasz Plech
- Department of Organic Chemistry, Faculty of Pharmacy, Medical University of Lublin, Chodźki 4a, 20-093 Lublin, Poland.
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186
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Jung S, Yang H, Kim BS, Chu K, Lee SK, Jeon D. The immunosuppressant cyclosporin A inhibits recurrent seizures in an experimental model of temporal lobe epilepsy. Neurosci Lett 2012; 529:133-8. [DOI: 10.1016/j.neulet.2012.08.087] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2012] [Revised: 08/17/2012] [Accepted: 08/30/2012] [Indexed: 12/11/2022]
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Pharmacogenetic association study of 30 genes with phenobarbital drug response in epileptic dogs. Pharmacogenet Genomics 2012; 19:911-22. [PMID: 19841609 DOI: 10.1097/fpc.0b013e3283307cba] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
BACKGROUND Epilepsy, with a prevalence as high as 6%, is the most common neurological disorder in dogs. Although several antiepileptic drugs are in common use, in one-third of all epileptic dogs, adequate seizure control is not achieved with a single medication, and hence a combinatorial drug treatment must be adopted. Exploration of the genetic mechanisms involved in drug response may provide better treatment options for epileptic patients. METHODS AND RESULTS A custom Illumina BeadChip was designed for high throughput genotyping of 384 single nucleotide polymorphisms in 30 genes involved in drug metabolism, drug targeting, and drug transport. A case-control association study of 125 epileptic dogs identified five genes with suggestive association to phenobarbital drug response: KCNQ3, P=0.0003; SNC2A2, P=0.0008; EPOX HYD, P=0.0005; ABCC4, P=0.0091; and GABRA2, P=0.0130. These associations are not significant after adjustment for multiple comparisons, but on functional grounds may tag strong candidate genes. The study was powered to detect alleles with at least 3.5-fold additive increases in responsiveness. A combined area under the curve value of 0.74 from receiver operating curve analysis also provides suggestive support for their consideration as canine pharmacogenetic markers. CONCLUSION Further replication and assessment of breed specificity is required before these markers can be considered as predictive of responsiveness to phenobarbital in dogs.
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Zhang C, Kwan P, Zuo Z, Baum L. The transport of antiepileptic drugs by P-glycoprotein. Adv Drug Deliv Rev 2012; 64:930-42. [PMID: 22197850 DOI: 10.1016/j.addr.2011.12.003] [Citation(s) in RCA: 120] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2011] [Revised: 12/05/2011] [Accepted: 12/07/2011] [Indexed: 01/16/2023]
Abstract
Epilepsy is the most common serious chronic neurological disorder. Current data show that one-third of patients do not respond to anti-epileptic drugs (AEDs). Most non-responsive epilepsy patients are resistant to several, often all, AEDs, even though the drugs differ from each other in pharmacokinetics, mechanisms of action, and interaction potential. The mechanisms underlying drug resistance of epilepsy patients are still not clear. In recent years, one of the potential mechanisms interesting researchers is over-expression of P-glycoprotein (P-gp, also known as ABCB1 or MDR1) in endothelial cells of the blood-brain barrier (BBB) in epilepsy patients. P-gp plays a central role in drug absorption and distribution in many organisms. The expression of P-gp is greater in drug-resistant than in drug-responsive patients. Some studies also indicate that several AEDs are substrates or inhibitors of P-gp, implying that P-gp may play an important role in drug resistance in refractory epilepsy. In this article, we review the clinical and laboratory evidence that P-gp expression is increased in epileptic brain tissues and that AEDs are substrates of P-gp in vitro and in vivo. We discuss criteria for identifying the substrate status of AEDs and use structure-activity relationship (SAR) models to predict which AEDs act as P-gp substrates.
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189
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Halliday AJ, Moulton SE, Wallace GG, Cook MJ. Novel methods of antiepileptic drug delivery -- polymer-based implants. Adv Drug Deliv Rev 2012; 64:953-64. [PMID: 22564384 DOI: 10.1016/j.addr.2012.04.004] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2011] [Revised: 03/15/2012] [Accepted: 04/04/2012] [Indexed: 12/15/2022]
Abstract
Epilepsy is a neurological disorder characterised by spontaneous seizures. Over one third of patients receive insufficient benefit from oral anti-epileptic drug (AED) therapy, and continue to experience seizures whilst on medication. Epilepsy researchers are consequently seeking new ways to deliver AEDs directly to the seizure focus in the brain in order to deliver higher, more effective doses to the seizure focus whilst bypassing the remainder of the brain and body to prevent side effects. The focus of this review will be polymer-based implants, which are polymeric devices loaded with AED that are designed for implantation at the seizure focus in order to achieve gradual, continuous release of AED direct into the region of the brain responsible for seizures. Polymer-based implants produced for epilepsy to date are based on a range of polymers, both biodegradable and non-biodegradable, and range from simple materials development studies through to investigations of implants in animal models of seizures and epilepsy, with varying degrees of success. This review describes the range of methods employed to manufacture polymer-based implants and compares their advantages and potential appeal to industry, and describes and compares the results and successes of polymer-based materials and devices produced to date for the treatment of epilepsy. We also discuss disadvantages and hurdles to be overcome in the field, and describe our predictions for advances to be made in the field in the coming decade.
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Neuron to astrocyte communication via cannabinoid receptors is necessary for sustained epileptiform activity in rat hippocampus. PLoS One 2012; 7:e37320. [PMID: 22615976 PMCID: PMC3352897 DOI: 10.1371/journal.pone.0037320] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2012] [Accepted: 04/18/2012] [Indexed: 11/19/2022] Open
Abstract
Astrocytes are integral functional components of synapses, regulating transmission and plasticity. They have also been implicated in the pathogenesis of epilepsy, although their precise roles have not been comprehensively characterized. Astrocytes integrate activity from neighboring synapses by responding to neuronally released neurotransmitters such as glutamate and ATP. Strong activation of astrocytes mediated by these neurotransmitters can promote seizure-like activity by initiating a positive feedback loop that induces excessive neuronal discharge. Recent work has demonstrated that astrocytes express cannabinoid 1 (CB1) receptors, which are sensitive to endocannabinoids released by nearby pyramidal cells. In this study, we tested whether this mechanism also contributes to epileptiform activity. In a model of 4-aminopyridine induced epileptic-like activity in hippocampal slice cultures, we show that pharmacological blockade of astrocyte CB1 receptors did not modify the initiation, but significantly reduced the maintenance of epileptiform discharge. When communication in astrocytic networks was disrupted by chelating astrocytic calcium, this CB1 receptor-mediated modulation of epileptiform activity was no longer observed. Thus, endocannabinoid signaling from neurons to astrocytes represents an additional significant factor in the maintenance of epileptiform activity in the hippocampus.
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Chen W, Cahoy DO, Tasker JG, Chiu AWL. Kernel duration and modulation gain in a coupled oscillator model and their implications on the progression of seizures. NETWORK (BRISTOL, ENGLAND) 2012; 23:59-75. [PMID: 22571251 DOI: 10.3109/0954898x.2012.678463] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
The coupled oscillator model has previously been used for the simulation of neuronal activities in in vitro rat hippocampal slice seizure data and the evaluation of seizure suppression algorithms. Each model unit can be described as either an oscillator which can generate action potential spike trains without inputs, or a threshold-based unit. With the change of only one parameter, each unit can either be an oscillator or a threshold-based spiking unit. This would eliminate the need of a new set of equations for each type of unit. Previous analysis has suggested that long kernel duration and imbalance of inhibitory feedback can cause the system to intermittently transition into and out of ictal activities. The state transitions of seizure-like events were investigated here; specifically, how the system excitability may change when the system underwent transitions in the preictal and postictal processes. Analysis showed that the area of the excitation kernel is positively correlated with the mean firing rate of ictal activity. The kernel duration is also correlated to the amount of ictal activity. The transition into ictal involved the escape from the saddle point foci in the state space trajectory identified using Newton's method.
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Affiliation(s)
- Wu Chen
- Biomedical Engineering, Louisiana Tech University, Ruston, LA, United States
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Sillanpaa M, Schmidt D. Is incident drug-resistance of childhood-onset epilepsy reversible? A long-term follow-up study. Brain 2012; 135:2256-62. [DOI: 10.1093/brain/aws062] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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Wang L, Luo J, Fang M, Jiang G, Zhang X, Yu W, Wang X. A new trick of INPP4A: Decreased expression of INPP4A in patients with temporal lobe epilepsy and pilocarpine-induced rat model. Synapse 2012; 66:533-41. [DOI: 10.1002/syn.21540] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2011] [Revised: 01/12/2012] [Accepted: 01/13/2012] [Indexed: 11/06/2022]
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Inter-individual variation in the anticonvulsant effect of phenobarbital in the pilocarpine rat model of temporal lobe epilepsy. Exp Neurol 2012; 234:70-84. [DOI: 10.1016/j.expneurol.2011.12.014] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2011] [Revised: 12/02/2011] [Accepted: 12/09/2011] [Indexed: 11/18/2022]
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Fortuna A, Alves G, Falcão A, Soares-da-Silva P. Evaluation of the permeability and P-glycoprotein efflux of carbamazepine and several derivatives across mouse small intestine by the Ussing chamber technique. Epilepsia 2012; 53:529-38. [DOI: 10.1111/j.1528-1167.2012.03409.x] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
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Syvänen S, Schenke M, van den Berg DJ, Voskuyl RA, de Lange EC. Alteration in P-glycoprotein functionality affects intrabrain distribution of quinidine more than brain entry-a study in rats subjected to status epilepticus by kainate. AAPS JOURNAL 2012; 14:87-96. [PMID: 22215264 PMCID: PMC3281999 DOI: 10.1208/s12248-011-9318-1] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/15/2011] [Accepted: 12/15/2011] [Indexed: 01/03/2023]
Abstract
This study aimed to investigate the use of quinidine microdialysis to study potential changes in brain P-glycoprotein functionality after induction of status epilepticus (SE) by kainate. Rats were infused with 10 or 20 mg/kg quinidine over 30 min or 4 h. Plasma, brain extracellular fluid (brain ECF), and end-of-experiment total brain concentrations of quinidine were determined during 7 h after the start of the infusion. Effect of pretreatment with tariquidar (15 mg/kg, administered 30 min before the start of the quinidine infusion) on the brain distribution of quinidine was assessed. This approach was repeated in kainate-treated rats. Quinidine kinetics were analyzed with population modeling (NONMEM). The quinidine microdialysis assay clearly revealed differences in brain distribution upon changes in P-glycoprotein functionality by pre-administration of tariquidar, which resulted in a 7.2-fold increase in brain ECF and a 40-fold increase in total brain quinidine concentration. After kainate treatment alone, however, no difference in quinidine transport across the blood–brain barrier was found, but kainate-treated rats tended to have a lower total brain concentration but a higher brain ECF concentration of quinidine than saline-treated rats. This study did not provide evidence for the hypothesis that P-glycoprotein function at the blood–brain barrier is altered at 1 week after SE induction, but rather suggests that P-glycoprotein function might be altered at the brain parenchymal level.
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Affiliation(s)
- Stina Syvänen
- Division of Pharmacology, LACDR, Leiden University, The Netherlands.
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The anticonvulsant response to valproate in kindled rats is correlated with its effect on neuronal firing in the substantia nigra pars reticulata: a new mechanism of pharmacoresistance. J Neurosci 2012; 31:16423-34. [PMID: 22072692 DOI: 10.1523/jneurosci.2506-11.2011] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
Resistance to antiepileptic drugs (AEDs) is a major problem in epilepsy treatment. However, mechanisms of resistance are only incompletely understood. We have recently shown that repeated administration of the AED phenytoin allows selecting resistant and responsive rats from the amygdala kindling model of epilepsy, providing a tool to study mechanisms of AED resistance. We now tested whether individual amygdala-kindled rats also differ in their anticonvulsant response to the major AED valproate (VPA) and which mechanism may underlie the different response to VPA. VPA has been proposed to act, at least in part, by reducing spontaneous activity in the substantia nigra pars reticulata (SNr), a main basal ganglia output structure involved in seizure propagation, seizure control, and epilepsy-induced neuroplasticity. Thus, we evaluated whether poor anticonvulsant response to VPA is correlated with low efficacy of VPA on SNr firing rate and pattern in kindled rats. We found (1) that good and poor VPA responders can be selected in kindled rats by repeatedly determining the effect of VPA on the electrographic seizure threshold, and (2) a significant correlation between the anticonvulsant response to VPA in kindled rats and its effect on SNr firing rate and pattern. The less VPA was able to raise seizure threshold, the lower was the VPA-induced reduction of SNr firing rate and the VPA-induced regularity of SNr firing. The data demonstrate for the first time an involvement of the SNr in pharmacoresistant experimental epilepsy and emphasize the relevance of the basal ganglia as target structures for new treatment options.
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Babu M, Pitchumani K, Ramesh P. Design and synthesis of 3,5-diarylpiperidin-2,6-diones as anticonvulsant agents. Bioorg Med Chem Lett 2012; 22:1263-6. [DOI: 10.1016/j.bmcl.2011.11.035] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2011] [Revised: 10/28/2011] [Accepted: 11/07/2011] [Indexed: 11/16/2022]
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Affiliation(s)
- Heidrun Potschka
- Institute of Pharmacology, Toxicology, and Therapeutics, Ludwig-Maximilians-University, Munich, Germany.
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