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Gulcebi MI, Bartolini E, Lee O, Lisgaras CP, Onat F, Mifsud J, Striano P, Vezzani A, Hildebrand MS, Jimenez-Jimenez D, Junck L, Lewis-Smith D, Scheffer IE, Thijs RD, Zuberi SM, Blenkinsop S, Fowler HJ, Foley A, Sisodiya SM, Berkovic S, Cavalleri G, Correa DJ, Martins Custodio H, Galovic M, Guerrini R, Henshall D, Howard O, Hughes K, Katsarou A, Koeleman BP, Krause R, Lowenstein D, Mandelenaki D, Marini C, O'Brien TJ, Pace A, De Palma L, Perucca P, Pitkänen A, Quinn F, Selmer KK, Steward CA, Swanborough N, Thijs R, Tittensor P, Trivisano M, Weckhuysen S, Zara F. Climate change and epilepsy: Insights from clinical and basic science studies. Epilepsy Behav 2021; 116:107791. [PMID: 33578223 PMCID: PMC9386889 DOI: 10.1016/j.yebeh.2021.107791] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/06/2020] [Revised: 12/24/2020] [Accepted: 01/03/2021] [Indexed: 12/23/2022]
Abstract
Climate change is with us. As professionals who place value on evidence-based practice, climate change is something we cannot ignore. The current pandemic of the novel coronavirus, SARS-CoV-2, has demonstrated how global crises can arise suddenly and have a significant impact on public health. Global warming, a chronic process punctuated by acute episodes of extreme weather events, is an insidious global health crisis needing at least as much attention. Many neurological diseases are complex chronic conditions influenced at many levels by changes in the environment. This review aimed to collate and evaluate reports from clinical and basic science about the relationship between climate change and epilepsy. The keywords climate change, seasonal variation, temperature, humidity, thermoregulation, biorhythm, gene, circadian rhythm, heat, and weather were used to search the published evidence. A number of climatic variables are associated with increased seizure frequency in people with epilepsy. Climate change-induced increase in seizure precipitants such as fevers, stress, and sleep deprivation (e.g. as a result of more frequent extreme weather events) or vector-borne infections may trigger or exacerbate seizures, lead to deterioration of seizure control, and affect neurological, cerebrovascular, or cardiovascular comorbidities and risk of sudden unexpected death in epilepsy. Risks are likely to be modified by many factors, ranging from individual genetic variation and temperature-dependent channel function, to housing quality and global supply chains. According to the results of the limited number of experimental studies with animal models of seizures or epilepsy, different seizure types appear to have distinct susceptibility to seasonal influences. Increased body temperature, whether in the context of fever or not, has a critical role in seizure threshold and seizure-related brain damage. Links between climate change and epilepsy are likely to be multifactorial, complex, and often indirect, which makes predictions difficult. We need more data on possible climate-driven altered risks for seizures, epilepsy, and epileptogenesis, to identify underlying mechanisms at systems, cellular, and molecular levels for better understanding of the impact of climate change on epilepsy. Further focussed data would help us to develop evidence for mitigation methods to do more to protect people with epilepsy from the effects of climate change.
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Affiliation(s)
- Medine I. Gulcebi
- Department of Medical Pharmacology, Marmara University, School of Medicine, Istanbul, Turkey
| | - Emanuele Bartolini
- USL Centro Toscana, Neurology Unit, Nuovo Ospedale Santo Stefano, Via Suor Niccolina Infermiera 20, 59100 Prato, Italy.
| | - Omay Lee
- Department of Neurology and Clinical Neurophysiology, St. George's University Hospitals NHS Foundation Trust, London, UK.
| | - Christos Panagiotis Lisgaras
- New York University Langone Health, 100 First Ave., New York, NY 10016, USA; The Nathan S. Kline Institute for Psychiatric Research, Center for Dementia Research, 140 Old Orangeburg Rd., Orangeburg, NY 10962, USA.
| | - Filiz Onat
- Department of Medical Pharmacology, Marmara University School of Medicine, Istanbul, Turkey,Department of Medical Pharmacology, Acibadem University School of Medicine, Istanbul, Turkey
| | - Janet Mifsud
- Department of Clinical Pharmacology and Therapeutics, University of Malta, Msida MSD2040, Malta.
| | - Pasquale Striano
- Paediatric Neurology and Muscular Diseases Unit, DINOGMI-Department of Neurosciences, Rehabilitation, Ophthalmology, Genetics, Maternal and Child Health, University of Genoa, IRCCS “Giannina Gaslini” Institute, Genova, Italy
| | - Annamaria Vezzani
- Laboratory of Experimental Neurology, Department of Neuroscience, IRCCS 'Mario Negri' Institute for Pharmacological Research, Milan, Italy.
| | - Michael S. Hildebrand
- Department of Medicine (Austin Health), University of Melbourne, and Murdoch Children’s Research Institute, Melbourne, Victoria, Australia
| | - Diego Jimenez-Jimenez
- Department of Clinical and Experimental Epilepsy, UCL Queen Square Institute of Neurology, London, WC1N 3BG, UK and Chalfont Centre for Epilepsy, Bucks, UK.
| | - Larry Junck
- Department of Neurology, University of Michigan, Ann Arbor, MI, USA.
| | - David Lewis-Smith
- Translational and Clinical Research Institute, Newcastle University, Newcastle upon Tyne, UK.
| | - Ingrid E. Scheffer
- University of Melbourne, Austin Health and Royal Children’s Hospital, Florey Institute and Murdoch Children’s Research Institute, Melbourne, Australia
| | - Roland D. Thijs
- Department of Neurology, Leiden University Medical Centre (LUMC), PO Box 9600, 2300 RC Leiden, the Netherlands
| | - Sameer M. Zuberi
- Paediatric Neurosciences Research Group, Royal Hospital for Children & Institute of Health & Wellbeing, University of Glasgow, Fraser of Allander Neurosciences Unit, Royal Hospital for Children, UK
| | | | - Hayley J. Fowler
- Centre for Earth Systems Engineering Research, School of Engineering, Newcastle University, UK
| | - Aideen Foley
- Department of Geography, Birkbeck College University of London, London, UK.
| | - Epilepsy Climate Change ConsortiumBalestriniSimonaaaBerkovicSamuelabCavalleriGianpieroacCorreaDaniel JoséadMartins CustodioHelenaaeGalovicMarianafGuerriniRenzoagHenshallDavidahHowardOlgaaiHughesKelvinajKatsarouAnnaakKoelemanBobby P.C.alKrauseRolandamLowensteinDanielanMandelenakiDespoinaaoMariniCarlaapO’BrienTerence J.aqPaceAdrianarDe PalmaLucaasPeruccaPieroatPitkänenAslaauQuinnFinolaavSelmerKaja KristineawStewardCharles A.axSwanboroughNicolaayThijsRolandazTittensorPhilbaTrivisanoMarinabbWeckhuysenSarahbcZaraFedericobdDepartment of Clinical and Experimental Epilepsy, UCL Queen Square Institute of Neurology, London, UK and Chalfont Centre for Epilepsy, Bucks, UKEpilepsy Research Centre, Department of Medicine, Austin Health, University of Melbourne, Melbourne, Victoria, AustraliaDepartment of Molecular and Cellular Therapeutics, The Royal College of Surgeons in Ireland, Dublin 2, Ireland; The FutureNeuro Research Centre, Dublin 2, IrelandSaul R. Korey Department of Neurology, Albert Einstein College of Medicine and Montefiore Medical Center, 1410 Pelham Parkway South, K-312, Bronx, NY 10461, USADepartment of Clinical and Experimental Epilepsy, UCL Queen Square Institute of Neurology, London, UK; Chalfont Centre for Epilepsy, Bucks, UKUniversity Hospital Zurich, SwitzerlandDepartment of Child Neurology and Psychiatry, University of Pisa and IRCCS Fondazione Stella Maris, 56018 Calambrone, Pisa, ItalyFutureNeuro SFI Research Centre, Royal College of Surgeons in Ireland, 123 St Stephen’s Green, Dublin D02 YN77, IrelandUCB Pharma Ltd, Slough, UKDravet Syndrome UK, UKLaboratory of Developmental Epilepsy, Saul R. Korey Department of Neurology, Albert Einstein College of Medicine, Bronx, New York, USAUniversity Medical Center, Utrecht, The NetherlandsLuxembourg Centre for Systems Biomedicine, University of Luxembourg, Esch-sur-Alzette, LuxembourgDepartment of Neurology, University of California, San Francisco, CA, USADepartment of Pediatric Neurology, Queen Fabiola Children’s University Hospital, Brussels, Brussels Capital Region, BelgiumNeuroscience Department, Children’s Hospital A. Meyer-University of Florence, Florence, ItalyMelbourne Brain Centre, Departments of Medicine and Neurology, Royal Melbourne Hospital, University of Melbourne, VIC, Australia; Departments of Neuroscience and Neurology, Central Clinical School, Monash University, The Alfred Hospital, Melbourne, VIC, AustraliaGozo General Hospital, MaltaNeurology Unit, Department of Neuroscience, Bambino Gesù Children's Hospital, IRCCS, Rome, ItalyDepartment of Neuroscience, Central Clinical School, Monash University, Melbourne, VIC, Australia; Departments of Medicine and Neurology, The Royal Melbourne Hospital, The University of Melbourne, Melbourne, VIC, Australia; Department of Neurology, Alfred Health, Melbourne, VIC, AustraliaA.I. Virtanen Institute for Molecular Sciences, University of Eastern Finland, PO Box 1627, FIN-70211 Kuopio, FinlandILAE-IBE Congress Secretariat, Dublin, IrelandNational Centre for Rare Epilepsy-related Disorders, Oslo University Hospital, Oslo, Norway; Department of Medical Genetics, Oslo University Hospital, University of Oslo, Oslo, NorwayCongenica Ltd, Wellcome Genome Campus, Hinxton, Cambridge, CB10 1DR, UK; Wellcome Sanger InstituteWellcome Genome Campus, Hinxton, Cambridge CB10 1SA, UKEpilepsy Society, Bucks, UKStichting Epilepsie Instellingen Nederland (SEIN), Heemstede, Netherlands; Department of Neurology, Leiden University Medical Centre, Leiden, Netherlands; NIHR University College London Hospitals Biomedical Research Centre, UCL Queen Square Institute of Neurology, London, UKRoyal Wolverhampton NHS Trust, Wolverhampton, UKRare and Complex Epilepsy Unit, Department of Neuroscience and Neurorehabilitation, Bambino Gesù Children’s Hospital, IRCCS, Rome, ItalyNeurogenetics Group, Center for Molecular Neurology, VIB, University of Antwerp, Antwerp 2610, BelgiumUnit of Medical Genetics, IRCCS Istituto Giannina Gaslini, Genoa, Italy; Department of Neurosciences, Rehabilitation, Ophthalmology, Genetics, Maternal and Child Health (DINOGMI), University of Genoa, Italy
| | - Sanjay M. Sisodiya
- Department of Clinical and Experimental Epilepsy, UCL Queen Square Institute of Neurology, London, WC1N 3BG, UK and Chalfont Centre for Epilepsy, Bucks, UK,Corresponding author at: Department of Clinical and Experimental Epilepsy, UCL Queen Square Institute of Neurology, London, UK
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Abstract
BACKGROUND This is an updated version of the original Cochrane review, published in 2015.Focal epilepsies are caused by a malfunction of nerve cells localised in one part of one cerebral hemisphere. In studies, estimates of the number of individuals with focal epilepsy who do not become seizure-free despite optimal drug therapy vary between at least 20% and up to 70%. If the epileptogenic zone can be located, surgical resection offers the chance of a cure with a corresponding increase in quality of life. OBJECTIVES The primary objective is to assess the overall outcome of epilepsy surgery according to evidence from randomised controlled trials.Secondary objectives are to assess the overall outcome of epilepsy surgery according to non-randomised evidence, and to identify the factors that correlate with remission of seizures postoperatively. SEARCH METHODS For the latest update, we searched the following databases on 11 March 2019: Cochrane Register of Studies (CRS Web), which includes the Cochrane Epilepsy Group Specialized Register and the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE (Ovid, 1946 to March 08, 2019), ClinicalTrials.gov, and the World Health Organization (WHO) International Clinical Trials Registry Platform (ICTRP). SELECTION CRITERIA Eligible studies were randomised controlled trials (RCTs) that included at least 30 participants in a well-defined population (age, sex, seizure type/frequency, duration of epilepsy, aetiology, magnetic resonance imaging (MRI) diagnosis, surgical findings), with an MRI performed in at least 90% of cases and an expected duration of follow-up of at least one year, and reporting an outcome related to postoperative seizure control. Cohort studies or case series were included in the previous version of this review. DATA COLLECTION AND ANALYSIS Three groups of two review authors independently screened all references for eligibility, assessed study quality and risk of bias, and extracted data. Outcomes were proportions of participants achieving a good outcome according to the presence or absence of each prognostic factor of interest. We intended to combine data with risk ratios (RRs) and 95% confidence intervals (95% CIs). MAIN RESULTS We identified 182 studies with a total of 16,855 included participants investigating outcomes of surgery for epilepsy. Nine studies were RCTs (including two that randomised participants to surgery or medical treatment (99 participants included in the two trials received medical treatment)). Risk of bias in these RCTs was unclear or high. Most of the remaining 173 non-randomised studies followed a retrospective design. We assessed study quality using the Effective Public Health Practice Project (EPHPP) tool and determined that most studies provided moderate or weak evidence. For 29 studies reporting multivariate analyses, we used the Quality in Prognostic Studies (QUIPS) tool and determined that very few studies were at low risk of bias across domains.In terms of freedom from seizures, two RCTs found surgery (n = 97) to be superior to medical treatment (n = 99); four found no statistically significant differences between anterior temporal lobectomy (ATL) with or without corpus callosotomy (n = 60), between subtemporal or transsylvian approach to selective amygdalohippocampectomy (SAH) (n = 47); between ATL, SAH and parahippocampectomy (n = 43) or between 2.5 cm and 3.5 cm ATL resection (n = 207). One RCT found total hippocampectomy to be superior to partial hippocampectomy (n = 70) and one found ATL to be superior to stereotactic radiosurgery (n = 58); and another provided data to show that for Lennox-Gastaut syndrome, no significant differences in seizure outcomes were evident between those treated with resection of the epileptogenic zone and those treated with resection of the epileptogenic zone plus corpus callosotomy (n = 43). We judged evidence from the nine RCTs to be of moderate to very low quality due to lack of information reported about the randomised trial design and the restricted study populations.Of the 16,756 participants included in this review who underwent a surgical procedure, 10,696 (64%) achieved a good outcome from surgery; this ranged across studies from 13.5% to 92.5%. Overall, we found the quality of data in relation to recording of adverse events to be very poor.In total, 120 studies examined between one and eight prognostic factors in univariate analysis. We found the following prognostic factors to be associated with a better post-surgical seizure outcome: abnormal pre-operative MRI, no use of intracranial monitoring, complete surgical resection, presence of mesial temporal sclerosis, concordance of pre-operative MRI and electroencephalography, history of febrile seizures, absence of focal cortical dysplasia/malformation of cortical development, presence of tumour, right-sided resection, and presence of unilateral interictal spikes. We found no evidence that history of head injury, presence of encephalomalacia, presence of vascular malformation, and presence of postoperative discharges were prognostic factors of outcome.Twenty-nine studies reported multi-variable models of prognostic factors, and showed that the direction of association of factors with outcomes was generally the same as that found in univariate analyses.We observed variability in many of our analyses, likely due to small study sizes with unbalanced group sizes and variation in the definition of seizure outcome, the definition of prognostic factors, and the influence of the site of surgery AUTHORS' CONCLUSIONS: Study design issues and limited information presented in the included studies mean that our results provide limited evidence to aid patient selection for surgery and prediction of likely surgical outcomes. Future research should be of high quality, follow a prospective design, be appropriately powered, and focus on specific issues related to diagnostic tools, the site-specific surgical approach, and other issues such as extent of resection. Researchers should investigate prognostic factors related to the outcome of surgery via multi-variable statistical regression modelling, where variables are selected for modelling according to clinical relevance, and all numerical results of the prognostic models are fully reported. Journal editors should not accept papers for which study authors did not record adverse events from a medical intervention. Researchers have achieved improvements in cancer care over the past three to four decades by answering well-defined questions through the conduct of focused RCTs in a step-wise fashion. The same approach to surgery for epilepsy is required.
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Affiliation(s)
- Siobhan West
- Royal Manchester Children's HospitalDepartment of Paediatric NeurologyHathersage RoadManchesterUKM13 0JH
| | - Sarah J Nevitt
- University of LiverpoolDepartment of BiostatisticsBlock F, Waterhouse Building1‐5 Brownlow HillLiverpoolUKL69 3GL
| | - Jennifer Cotton
- The Clatterbridge Cancer Centre NHS Foundation TrustWirralUK
| | - Sacha Gandhi
- NHS Ayrshire and ArranDepartment of General SurgeryAyrUKKA6 6DX
| | - Jennifer Weston
- Institute of Translational Medicine, University of LiverpoolDepartment of Molecular and Clinical PharmacologyClinical Sciences Centre for Research and Education, Lower LaneFazakerleyLiverpoolMerseysideUKL9 7LJ
| | - Ajay Sudan
- Royal Manchester Children's HospitalDepartment of Paediatric NeurologyHathersage RoadManchesterUKM13 0JH
| | - Roberto Ramirez
- Royal Manchester Children's HospitalHospital RoadPendleburyManchesterUKM27 4HA
| | - Richard Newton
- Royal Manchester Children's HospitalDepartment of Paediatric NeurologyHathersage RoadManchesterUKM13 0JH
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Yu YH, Lee K, Sin DS, Park KH, Park DK, Kim DS. Altered functional efficacy of hippocampal interneuron during epileptogenesis following febrile seizures. Brain Res Bull 2017; 131:25-38. [DOI: 10.1016/j.brainresbull.2017.02.009] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2016] [Revised: 02/17/2017] [Accepted: 02/23/2017] [Indexed: 12/22/2022]
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The Effects of Amiloride on Seizure Activity, Cognitive Deficits and Seizure-Induced Neurogenesis in a Novel Rat Model of Febrile Seizures. Neurochem Res 2015; 41:933-42. [DOI: 10.1007/s11064-015-1777-9] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2015] [Revised: 11/02/2015] [Accepted: 11/14/2015] [Indexed: 12/14/2022]
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Suchomelova L, Lopez-Meraz ML, Niquet J, Kubova H, Wasterlain CG. Hyperthermia aggravates status epilepticus-induced epileptogenesis and neuronal loss in immature rats. Neuroscience 2015; 305:209-24. [PMID: 26259902 DOI: 10.1016/j.neuroscience.2015.08.006] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2015] [Revised: 07/20/2015] [Accepted: 08/03/2015] [Indexed: 01/16/2023]
Abstract
This study tightly controlled seizure duration and severity during status epilepticus (SE) in postnatal day 10 (P10) rats, in order to isolate hyperthermia as the main variable and to study its consequences. Body temperature was maintained at 39 ± 1 °C in hyperthermic SE rats (HT+SE) or at 35 ± 1 °C in normothermic SE animals (NT+SE) during 30 min of SE, which was induced by lithium-pilocarpine (3 mEq/kg, 60 mg/kg) and terminated by diazepam and cooling to NT. All video/EEG measures of SE severity were similar between HT+SE and NT+SE pups. At 24h, neuronal injury was present in the amygdala in the HT+SE group only, and was far more severe in the hippocampus in HT+SE than NT+SE pups. Separate groups of animals were monitored four months later for spontaneous recurrent seizures (SRS). Only HT+SE animals developed convulsive SRS. Both HT+SE and NT+SE animals developed electrographic SRS (83% vs. 55%), but SRS frequency and severity were higher in hyperthermic animals (12.5 ± 3.5 vs. 4.2 ± 2.0 SRS/day). The density of hilar neurons was lower, thickness of the amygdala and perirhinal cortex was reduced, and lateral ventricles were enlarged in HT+SE over NT+SE littermates and HT/NT controls. In this model, hyperthermia greatly increased the epileptogenicity of SE and its neuropathological sequelae.
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Affiliation(s)
- L Suchomelova
- Veterans Administration Greater Los Angeles Healthcare System, Epilepsy Research (151), 11 301 Wilshire Boulevard, Building 114, Room 139, Los Angeles, CA 90073, USA.
| | - M L Lopez-Meraz
- Centro de Investigaciones Cerebrales, Universidad Veracruzana, Veracruz 91190, Mexico
| | - J Niquet
- Veterans Administration Greater Los Angeles Healthcare System, Epilepsy Research (151), 11 301 Wilshire Boulevard, Building 114, Room 139, Los Angeles, CA 90073, USA
| | - H Kubova
- Department of Developmental Epileptology, Institute of Physiology, Academy of Sciences of the Czech Republic, Videnska 1083, Prague 14220, Czech Republic
| | - C G Wasterlain
- Department of Neurology, David Geffen School of Medicine at UCLA, VA Medical Center (127), 11 301 Wilshire Boulevard, Los Angeles, CA 90073, USA
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Abstract
BACKGROUND Focal epilepsies are caused by a malfunction of nerve cells localised in one part of one cerebral hemisphere. In studies, estimates of the number of individuals with focal epilepsy who do not become seizure-free despite optimal drug therapy vary according to the age of the participants and which focal epilepsies are included, but have been reported as at least 20% and in some studies up to 70%. If the epileptogenic zone can be located surgical resection offers the chance of a cure with a corresponding increase in quality of life. OBJECTIVES The primary objective is to assess the overall outcome of epilepsy surgery according to evidence from randomised controlled trials.The secondary objectives are to assess the overall outcome of epilepsy surgery according to non-randomised evidence and to identify the factors that correlate to remission of seizures postoperatively. SEARCH METHODS We searched the Cochrane Epilepsy Group Specialised Register (June 2013), the Cochrane Central Register of Controlled Trials (CENTRAL 2013, Issue 6), MEDLINE (Ovid) (2001 to 4 July 2013), ClinicalTrials.gov and the World Health Organization (WHO) International Clinical Trials Registry Platform (ICTRP) for relevant trials up to 4 July 2013. SELECTION CRITERIA Eligible studies were randomised controlled trials (RCTs), cohort studies or case series, with either a prospective and/or retrospective design, including at least 30 participants, a well-defined population (age, sex, seizure type/frequency, duration of epilepsy, aetiology, magnetic resonance imaging (MRI) diagnosis, surgical findings), an MRI performed in at least 90% of cases and an expected duration of follow-up of at least one year, and reporting an outcome relating to postoperative seizure control. DATA COLLECTION AND ANALYSIS Three groups of two review authors independently screened all references for eligibility, assessed study quality and risk of bias, and extracted data. Outcomes were proportion of participants achieving a good outcome according to the presence or absence of each prognostic factor of interest. We intended to combine data with risk ratios (RR) and 95% confidence intervals. MAIN RESULTS We identified 177 studies (16,253 participants) investigating the outcome of surgery for epilepsy. Four studies were RCTs (including one that randomised participants to surgery or medical treatment). The risk of bias in the RCTs was unclear or high, limiting our confidence in the evidence that addressed the primary review objective. Most of the remaining 173 non-randomised studies had a retrospective design; they were of variable size, were conducted in a range of countries, recruited a wide demographic range of participants, used a wide range of surgical techniques and used different scales used to measure outcomes. We performed quality assessment using the Effective Public Health Practice Project (EPHPP) tool and determined that most studies provided moderate or weak evidence. For 29 studies reporting multivariate analyses we used the Quality in Prognostic Studies (QUIPS) tool and determined that very few studies were at low risk of bias across the domains.In terms of freedom from seizures, one RCT found surgery to be superior to medical treatment, two RCTs found no statistically significant difference between anterior temporal lobectomy (ATL) with or without corpus callosotomy or between 2.5 cm or 3.5 cm ATL resection, and one RCT found total hippocampectomy to be superior to partial hippocampectomy. We judged the evidence from the four RCTs to be of moderate to very low quality due to the lack of information reported about the randomised trial design and the restricted study populations.Of the 16,253 participants included in this review, 10,518 (65%) achieved a good outcome from surgery; this ranged across studies from 13.5% to 92.5%. Overall, we found the quality of data in relation to the recording of adverse events to be very poor.In total, 118 studies examined between one and eight prognostic factors in univariate analysis. We found the following prognostic factors to be associated with a better post-surgical seizure outcome: an abnormal pre-operative MRI, no use of intracranial monitoring, complete surgical resection, presence of mesial temporal sclerosis, concordance of pre-operative MRI and electroencephalography (EEG), history of febrile seizures, absence of focal cortical dysplasia/malformation of cortical development, presence of tumour, right-sided resection and presence of unilateral interictal spikes. We found no evidence that history of head injury, presence of encephalomalacia, presence of vascular malformation or presence of postoperative discharges were prognostic factors of outcome. We observed variability between studies for many of our analyses, likely due to the small study sizes with unbalanced group sizes, variation in the definition of seizure outcome, definition of the prognostic factor and the influence of the site of surgery, all of which we observed to be related to postoperative seizure outcome. Twenty-nine studies reported multivariable models of prognostic factors and the direction of association of factors with outcome was generally the same as found in the univariate analyses. However, due to the different multivariable analysis approaches and selective reporting of results, meaningful comparison of multivariate analysis with univariate meta-analysis is difficult. AUTHORS' CONCLUSIONS The study design issues and limited information presented in the included studies mean that our results provide limited evidence to aid patient selection for surgery and prediction of likely surgical outcome. Future research should be of high quality, have a prospective design, be appropriately powered and focus on specific issues related to diagnostic tools, the site-specific surgical approach and other issues such as the extent of resection. Prognostic factors related to the outcome of surgery should be investigated via multivariable statistical regression modelling, where variables are selected for modelling according to clinical relevance and all numerical results of the prognostic models are fully reported. Protocols should include pre- and postoperative measures of speech and language function, cognition and social functioning along with a mental state assessment. Journal editors should not accept papers where adverse events from a medical intervention are not recorded. Improvements in the development of cancer care over the past three to four decades have been achieved by answering well-defined questions through the conduct of focused RCTs in a step-wise fashion. The same approach to surgery for epilepsy is required.
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Affiliation(s)
- Siobhan West
- Department of Paediatric Neurology, Royal Manchester Children's Hospital, Hathersage Road, Manchester, UK, M13 0JH
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Atypical febrile seizures, mesial temporal lobe epilepsy, and dual pathology. EPILEPSY RESEARCH AND TREATMENT 2012; 2012:342928. [PMID: 22957226 PMCID: PMC3420631 DOI: 10.1155/2012/342928] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/25/2011] [Revised: 02/02/2012] [Accepted: 02/07/2012] [Indexed: 12/02/2022]
Abstract
Febrile seizures occurring in the neonatal period, especially when prolonged, are thought to be involved in the later development of mesial temporal lobe epilepsy (mTLE) in children. The presence of an often undetected, underlying cortical malformation has also been reported to be implicated in the epileptogenesis process following febrile seizures. This paper highlights some of the various animal models of febrile seizures and of cortical malformation and portrays a two-hit model that efficiently mimics these two insults and leads to spontaneous recurrent seizures in adult rats. Potential mechanisms are further proposed to explain how these two insults may each, or together, contribute to network hyperexcitability and epileptogenesis. Finally the clinical relevance of the two-hit model is briefly discussed in light of a therapeutic and preventive approach to mTLE.
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Scantlebury MH, Heida JG. Febrile seizures and temporal lobe epileptogenesis. Epilepsy Res 2009; 89:27-33. [PMID: 20005077 DOI: 10.1016/j.eplepsyres.2009.11.002] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2009] [Revised: 10/26/2009] [Accepted: 11/07/2009] [Indexed: 11/19/2022]
Abstract
Febrile seizures (FS) are a common neurological disorder that affects children. Simple FS are thought to be benign but experimental and clinical evidence support that the risk of developing epilepsy after FS increases if the FS are prolonged and the brain is abnormal. In addition, prolonged FS (PFS) have many deleterious long-term effects characterized mainly in the hippocampus but may involve the whole brain and that prompt abortive treatment of PFS may prevent some of the adverse effects. This review focuses on some of the key factors involved in the generation of FS, factors leading to PFS and potential mechanisms and functional correlates leading to temporal lobe epilepsy (TLE).
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Affiliation(s)
- Morris H Scantlebury
- Saul R. Korey Department of Neurology, Albert Einstein College of Medicine and Montefiore Medical Center, Bronx, New York, USA.
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Tonini C, Beghi E, Berg AT, Bogliun G, Giordano L, Newton RW, Tetto A, Vitelli E, Vitezic D, Wiebe S. Predictors of epilepsy surgery outcome: a meta-analysis. Epilepsy Res 2004; 62:75-87. [PMID: 15519134 DOI: 10.1016/j.eplepsyres.2004.08.006] [Citation(s) in RCA: 224] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2004] [Revised: 08/29/2004] [Accepted: 08/31/2004] [Indexed: 11/27/2022]
Abstract
The potential efficacy of temporal and extratemporal resection in patients with partial epilepsy uncontrolled by anti-epileptic drugs is undisputed. However, there are still uncertainties about which patients will benefit most. A systematic review of the available literature has been undertaken by four pairs of reviewers to assess the overall outcome of epilepsy surgery and to identify factors better correlated to seizure outcome. A Medline search for studies on epilepsy surgery published since 1984 was performed. Studies were included if they had a well-defined population and design, a sample size of at least 30 patients, an MRI performed in least 90% of cases, an expected duration of follow-up of at least one year, and a post-operative outcome measured as seizure remission. A good outcome was considered as seizure control or seizure-free status for at least one year or Engel class I. Based on the review of 47 articles meeting all the eligibility criteria, febrile seizures (odds ratio, OR, 0.48; 95% confidence interval, CI, 0.27-0.83), mesial temporal sclerosis (OR 0.47; 95% CI 0.35-0.64), tumors (OR 0.58; 95% CI 0.42-0.80), abnormal MRI (OR 0.44; 95% CI 0.29-0.65), EEG/MRI concordance (OR 0.52; 95% CI 0.32-0.83), and extensive surgical resection (OR 0.24; 95% CI 0.16-0.36) were the strongest prognostic indicators of seizure remission (positive predictors); by contrast, post-operative discharges (OR 2.41; 95% CI 1.37-4.27) and intracranial monitoring (OR 2.72; 95% CI 1.60-4.60) predicted an unfavorable prognosis (negative predictors). Firm conclusions cannot be drawn for extent of resection, EEG/MRI concordance and post-operative discharges for the heterogeneity of study results. Neuromigrational defects, CNS infections, vascular lesions, interictal spikes, and side of resection did not affect the chance of seizure remission after surgery. Despite a number of limitations, the results of the review provide some insight into the selection of the best surgical candidates in clinical practice but raise concerns on the quality of published reports, and may serve as the basis for the identification of better standards to assess surgical outcome in observational studies.
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Affiliation(s)
- C Tonini
- Laboratory of Neurological Disorders, Institute for Pharmacological Research Mario Negri, Via Eritrea, 62, 20157 Milan, Italy
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10
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Scantlebury MH, Ouellet PL, Psarropoulou C, Carmant L. Freeze Lesion-Induced Focal Cortical Dysplasia Predisposes to Atypical Hyperthermic Seizures in the Immature Rat. Epilepsia 2004; 45:592-600. [PMID: 15144423 DOI: 10.1111/j.0013-9580.2004.51503.x] [Citation(s) in RCA: 58] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
PURPOSE To determine the effects of focal cortical dysplasia on the behavioral and electrographic features of hyperthermia-induced seizures (HSs) in rats. METHODS A right sensorimotor cortex freeze lesion was induced in postnatal day 1 (P1) rat pups, and HSs were provoked at P10 under continuous monitoring of core temperature; EEGs were recorded from the right amygdala during and after hyperthermia. Controls included both sham-operated at P1 and naïve rats. RESULTS HSs began with jaw myoclonus, followed by hindlimb clonus and generalized convulsions (GCs), and terminated by a period of posthyperthermia depression. The threshold temperature and latency of jaw myoclonus were similar across the groups. However, both the threshold temperature and latency of GCs were significantly lower in lesioned pups than in controls (40.5 +/- 0.5 degrees C, n = 24, vs. 42.0 +/- 0.2 degrees C, n = 21; p < 0.001; 6.7 +/- 0.6 min, n = 20, vs. 8.4 +/- 0.6 min, n = 22; p < 0.05). In lesioned pups, the threshold and latencies for jaw myoclonus and hindlimb clonus were similar, whereas in controls, the progression from one to the other was marked by significant differences in both parameters. Posthyperthermia depression was longer in lesioned (13.3 +/- 1.2 min, n = 21) than in control (8.0 +/- 0.8 min, n = 20; p < 0.0001) pups. Ictal EEG activity was recorded during both behavioral seizures and posthyperthermia depression. CONCLUSIONS An HS in rats with a localized freeze lesion results in lower threshold GC and prolonged ictal manifestations, thus supporting a pathophysiologic link between focal cortical dysplasia and atypical febrile seizures, conditions that have a high prevalence in children with mesial temporal lobe epilepsy.
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Affiliation(s)
- Morris H Scantlebury
- Department of Pediatrics and Ste-Justine Hospital Research Center, Faculty of Medicine, Université de Montréal, Montreal, Québec, Canada
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11
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Abstract
The hippocampal formation participates in learning and memory, particularly that of a spatial nature. In adult rats, individual CA1 pyramidal neurons only fire when the animal visits specific locations in an environment, the "place field" of the neuron. Other structures (postsubiculum, thalamus, cingulum) contain neurons that code for the animal's instantaneous head direction. Previous work has shown that the rat hippocampal formation undergoes anatomical and neurophysiological maturation during the first 2 months of life and that rats <40 days of age are impaired in spatial navigation tasks. Here we show that the locational firing of CA1 pyramidal neurons is both less specific and less stable in animals aged <50 days. However, preliminary results indicate that head directional firing recorded around day 30 is essentially identical to that seen in adult animals. Therefore, the development of reliable, spatially specific place cell activity parallels the developmental time course of spatial navigational ability, but head directional firing appears before full maturation of the hippocampus.
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Affiliation(s)
- Patrick D Martin
- Department of Anatomy, School of Medical Sciences, University of Bristol, UK.
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12
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Bender RA, Dubé C, Gonzalez-Vega R, Mina EW, Baram TZ. Mossy fiber plasticity and enhanced hippocampal excitability, without hippocampal cell loss or altered neurogenesis, in an animal model of prolonged febrile seizures. Hippocampus 2003; 13:399-412. [PMID: 12722980 PMCID: PMC2927853 DOI: 10.1002/hipo.10089] [Citation(s) in RCA: 134] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Seizures induced by fever (febrile seizures) are the most frequent seizures affecting infants and children; however, their impact on the developing hippocampal formation is not completely understood. Such understanding is highly important because of the potential relationship of prolonged febrile seizures to temporal lobe epilepsy. Using an immature rat model, we have previously demonstrated that prolonged experimental febrile seizures render the hippocampus hyperexcitable throughout life. Here we examined whether (1) neuronal loss, (2) altered neurogenesis, or (3) mossy fiber sprouting, all implicated in epileptogenesis in both animal models and humans, were involved in the generation of a pro-epileptic, hyperexcitable hippocampus by these seizures. The results demonstrated that prolonged experimental febrile seizures did not result in appreciable loss of any vulnerable hippocampal cell population, though causing strikingly enhanced sensitivity to hippocampal excitants later in life. In addition, experimental febrile seizures on postnatal day 10 did not enhance proliferation of granule cells, whereas seizures generated by kainic acid during the same developmental age increased neurogenesis in the immature hippocampus. However, prolonged febrile seizures resulted in long-term axonal reorganization in the immature hippocampal formation: Mossy fiber densities in granule cell- and molecular layers were significantly increased by 3 months (but not 10 days) after the seizures. Thus, the data indicate that prolonged febrile seizures influence connectivity of the immature hippocampus long-term, and this process requires neither significant neuronal loss nor altered neurogenesis. In addition, the temporal course of the augmented mossy fiber invasion of the granule cell and molecular layers suggests that it is a consequence, rather than the cause, of the hyperexcitable hippocampal network resulting from these seizures.
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MESH Headings
- Animals
- Animals, Newborn
- Cell Death/drug effects
- Cell Death/physiology
- Cell Division/drug effects
- Cell Division/physiology
- Dentate Gyrus/drug effects
- Dentate Gyrus/pathology
- Dentate Gyrus/physiopathology
- Disease Models, Animal
- Epilepsy, Temporal Lobe/etiology
- Epilepsy, Temporal Lobe/pathology
- Epilepsy, Temporal Lobe/physiopathology
- Hippocampus/drug effects
- Hippocampus/pathology
- Hippocampus/physiopathology
- Kainic Acid/pharmacology
- Membrane Potentials/drug effects
- Membrane Potentials/physiology
- Mossy Fibers, Hippocampal/drug effects
- Mossy Fibers, Hippocampal/pathology
- Mossy Fibers, Hippocampal/physiopathology
- Neural Pathways/drug effects
- Neural Pathways/pathology
- Neural Pathways/physiopathology
- Neuronal Plasticity/drug effects
- Neuronal Plasticity/physiology
- Rats
- Rats, Sprague-Dawley
- Seizures, Febrile/complications
- Seizures, Febrile/pathology
- Seizures, Febrile/physiopathology
- Synaptic Transmission/drug effects
- Synaptic Transmission/physiology
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Affiliation(s)
- Roland A. Bender
- Department of Anatomy and Neurobiology, University of California at Irvine, Irvine California
- Department of Pediatrics, University of California at Irvine, Irvine California
| | - Celine Dubé
- Department of Anatomy and Neurobiology, University of California at Irvine, Irvine California
| | - Rebeca Gonzalez-Vega
- Department of Anatomy and Neurobiology, University of California at Irvine, Irvine California
| | - Erene W. Mina
- Department of Anatomy and Neurobiology, University of California at Irvine, Irvine California
| | - Tallie Z. Baram
- Department of Anatomy and Neurobiology, University of California at Irvine, Irvine California
- Department of Pediatrics, University of California at Irvine, Irvine California
- Department of Neurology, University of California at Irvine, Irvine California
- Correspondence to: Tallie Z. Baram, Departments of Anatomy and Neurobiology and Pediatrics, Medical Science I, 4475, University of California at Irvine, Irvine, CA 92697-4475.
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13
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Lewis DV, Barboriak DP, MacFall JR, Provenzale JM, Mitchell TV, VanLandingham KE. Do prolonged febrile seizures produce medial temporal sclerosis? Hypotheses, MRI evidence and unanswered questions. PROGRESS IN BRAIN RESEARCH 2002; 135:263-78. [PMID: 12143347 DOI: 10.1016/s0079-6123(02)35025-8] [Citation(s) in RCA: 56] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/10/2023]
Abstract
Whether or not severe febrile seizures in infancy cause hippocampal injury and subsequent medial temporal sclerosis is an often debated question in epilepsy. Recent magnetic resonance imaging (MRI) of infants suffering from febrile seizures has provided preliminary evidence that abnormally increased T2 signal intensity can be seen in the hippocampi of infants following prolonged and focal febrile seizures. Follow-up MRIs in a few of these infants have confirmed that medial temporal sclerosis can develop following these acute MRI signal changes. In this article, we review the hypotheses and MRI evidence relating to hippocampal injury during prolonged febrile seizures and the later development of medial temporal sclerosis.
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Affiliation(s)
- Darrell V Lewis
- Department of Pediatrics (Neurology), Duke University Medical Center, Durham, NC 27710, USA.
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14
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Lado FA, Sankar R, Lowenstein D, Moshé SL. Age-dependent consequences of seizures: relationship to seizure frequency, brain damage, and circuitry reorganization. MENTAL RETARDATION AND DEVELOPMENTAL DISABILITIES RESEARCH REVIEWS 2001; 6:242-52. [PMID: 11107189 DOI: 10.1002/1098-2779(2000)6:4<242::aid-mrdd3>3.0.co;2-w] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
Seizures in the developing brain pose a challenge to the clinician. In addition to the acute effects of the seizure, there are questions regarding the impact of severe or recurrent seizures on the developing brain. Whether provoked seizures cause brain damage, synaptic reorganization, or epilepsy is of paramount importance to patients and physicians. Such questions are especially relevant in the decision to treat or not treat febrile seizures, a common occurrence in childhood. These clinical questions have been addressed using clinical and animal research. The largest prospective studies do not find a causal connection between febrile seizures and later temporal lobe epilepsy. The immature brain seems relatively resistant to the seizure-induced neuronal loss and new synapse formation seen in the mature brain. Laboratory investigations using a developmental rat model corresponding to human febrile seizures find that even though structural changes do not result from hyperthermic seizures, synaptic function may be chronically altered. The increased understanding of the cellular and synaptic mechanisms of seizure-induced damage may benefit patients and clinicians in the form of improved therapies to attenuate damage and changes induced by seizures and to prevent the development of epilepsy.
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Affiliation(s)
- F A Lado
- Department of Neurology, Albert Einstein College of Medicine, Bronx, New York 10461, USA.
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