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You J, Huang H, Chan CTY, Li L. Pathological Targets for Treating Temporal Lobe Epilepsy: Discoveries From Microscale to Macroscale. Front Neurol 2022; 12:779558. [PMID: 35069411 PMCID: PMC8777077 DOI: 10.3389/fneur.2021.779558] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2021] [Accepted: 11/30/2021] [Indexed: 12/15/2022] Open
Abstract
Temporal lobe epilepsy (TLE) is one of the most common and severe types of epilepsy, characterized by intractable, recurrent, and pharmacoresistant seizures. Histopathology of TLE is mostly investigated through observing hippocampal sclerosis (HS) in adults, which provides a robust means to analyze the related histopathological lesions. However, most pathological processes underlying the formation of these lesions remain elusive, as they are difficult to detect and observe. In recent years, significant efforts have been put in elucidating the pathophysiological pathways contributing to TLE epileptogenesis. In this review, we aimed to address the new and unrecognized neuropathological discoveries within the last 5 years, focusing on gene expression (miRNA and DNA methylation), neuronal peptides (neuropeptide Y), cellular metabolism (mitochondria and ion transport), cellular structure (microtubule and extracellular matrix), and tissue-level abnormalities (enlarged amygdala). Herein, we describe a range of biochemical mechanisms and their implication for epileptogenesis. Furthermore, we discuss their potential role as a target for TLE prevention and treatment. This review article summarizes the latest neuropathological discoveries at the molecular, cellular, and tissue levels involving both animal and patient studies, aiming to explore epileptogenesis and highlight new potential targets in the diagnosis and treatment of TLE.
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Affiliation(s)
- Jing You
- Department of Biomedical Engineering, University of North Texas, Denton, TX, United States
| | - Haiyan Huang
- Department of Nutrition and Food Science, Texas Women University, Denton, TX, United States
| | - Clement T Y Chan
- Department of Biomedical Engineering, University of North Texas, Denton, TX, United States
| | - Lin Li
- Department of Biomedical Engineering, University of North Texas, Denton, TX, United States.,Department of Neurology, University of California, Los Angeles, Los Angeles, CA, United States
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Altintaş A, Özkara Ç, Sohtaoğlu Sevindik M, Uzan M, Kekik Çinar Ç, Uysal Ö, Savran Oğuz F. Cytokine Polymorphism and HLA Genotyping in Patients with Temporal Lobe Epilepsy Related to Hippocampal Sclerosis. Noro Psikiyatr Ars 2018; 54:350-353. [PMID: 29321710 DOI: 10.5152/npa.2016.12678] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2015] [Accepted: 04/10/2016] [Indexed: 01/01/2023] Open
Abstract
Objective Hippocampal sclerosis (HS) is the most common pathological substrate associated with mesial temporal lobe epilepsy (MTLE), where inflammatory processes are known to play an increasingly important role in the pathogenesis. To further investigate the role of the immune system, both cytokine gene polymorphisms and human leukocyte antigen (HLA) genotyping in patients with MTLE-HS were investigated. Methods The DNA samples of 100 patients with MTLE-HS and 201 healthy individuals were genotyped for cytokines (IL-6,IL-10, TNF-α, TGF-β1 and IFN-γ) and HLA using polymerase chain reaction (PCR)-SSP and SSO methods. The results were statistically analyzed in patient and healthy control groups and then according to the presence of febrile seizures (FS) in the patient group. Results Analysis of cytokine genotyping did not reveal any significant difference between patients with MTLE-HS and controls and patients with or without FS. However, the HLA DRB1*13 allele was found to be more frequent in the patient population after Bonferroni correction. Conclusion This study suggests the possible role of HLA in the pathogenesis of MTLE-HS, although it failed to show any relationship with the cytokine system. However, data regarding the role of HLA are still lacking, and further studies are necessary to verify our results.
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Affiliation(s)
- Ayşe Altintaş
- Department of Neurology, İstanbul University Cerrahpaşa School of Medicine, İstanbul, Turkey
| | - Çiğdem Özkara
- Department of Neurology, İstanbul University Cerrahpaşa School of Medicine, İstanbul, Turkey
| | | | - Mustafa Uzan
- Department of Neurosurgery, İstanbul University Cerrahpaşa School of Medicine, İstanbul, Turkey
| | - Çiğdem Kekik Çinar
- Department of Medical Biology, İstanbul University İstanbul School of Medicine, İstanbul, Turkey
| | - Ömer Uysal
- Department of Biostatistics and Medicine Informatics, Bezmialem Vakıf University School of Medicine, İstanbul, Turkey
| | - Fatma Savran Oğuz
- Department of Medical Biology, İstanbul University İstanbul School of Medicine, İstanbul, Turkey
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Bianchin MM, Velasco TR, Wichert-Ana L, Dos Santos AC, Sakamoto AC. Understanding the association of neurocysticercosis and mesial temporal lobe epilepsy and its impact on the surgical treatment of patients with drug-resistant epilepsy. Epilepsy Behav 2017; 76:168-177. [PMID: 28462844 DOI: 10.1016/j.yebeh.2017.02.030] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/14/2016] [Revised: 02/18/2017] [Accepted: 02/20/2017] [Indexed: 11/29/2022]
Abstract
Mesial temporal lobe epilepsy associated with hippocampal sclerosis (MTLE-HS) is one of the most common types of focal epilepsies. This is an epileptic syndrome commonly associated with treatment-resistant seizures, being also the most prevalent form of drug-resistant epilepsy which is treated surgically in most epilepsy surgery centers. Neurocysticercosis (NCC) is one of the most common parasitic infections of the central nervous system, and one of the most common etiological agents of focal epilepsy, affecting millions of patients worldwide. Recently, researchers reported a curious association between MTLE-HS with NCC, but this association remains poorly understood. Some argue that calcified NCC lesions in MTLE-HS patients is only a coincidental finding, since both disorders are prevalent worldwide. However, others suppose there might exist a pathogenic relationship between both disorders and some even suspect that NCC, by acting as an initial precipitating injury (IPI), might cause hippocampal damage and, eventually, MTLE-HS. In this review, we discuss the various reports that examine this association, and suggest possible explanations for why calcified NCC lesions are also observed in patients with MTLE-HS. We also propose mechanisms by which NCC could lead to MTLE-HS. Finally, we discuss the implications of NCC for the treatment of pharmacologically-resistant focal epilepsies in patients with calcified NCC or in patients with MTLE-HS and calcified NCC lesions. We believe that investigations in the relationship between NCC and MTLE-HS might offer further insights into how NCC may trigger epilepsy, and into how MTLE-HS originates. Moreover, observations in patients with drug-resistant epilepsy with both NCC and hippocampal sclerosis may not only aid in the understanding and treatment of patients with MTLE-HS, but also of patients with other forms of dual pathologies aside from NCC. This article is part of a Special Issue titled Neurocysticercosis and Epilepsy.
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Affiliation(s)
- Marino Muxfeldt Bianchin
- CIREP, Centro de Cirurgia de Epilepsia, Faculdade de Medicina, Universidade de São Paulo, Ribeirão Preto, Brazil; CETER, Centro de Tratamento de Epilepsia Refratária, BRAIN, Basic Research and Advanced Investigations in Neurology, Hospital de Clínicas de Porto Alegre, Universidade Federal do Rio Grande do Sul, Brazil.
| | - Tonicarlo Rodrigues Velasco
- CIREP, Centro de Cirurgia de Epilepsia, Faculdade de Medicina, Universidade de São Paulo, Ribeirão Preto, Brazil
| | - Lauro Wichert-Ana
- CIREP, Centro de Cirurgia de Epilepsia, Faculdade de Medicina, Universidade de São Paulo, Ribeirão Preto, Brazil
| | - Antonio Carlos Dos Santos
- CIREP, Centro de Cirurgia de Epilepsia, Faculdade de Medicina, Universidade de São Paulo, Ribeirão Preto, Brazil
| | - Américo Ceiki Sakamoto
- CIREP, Centro de Cirurgia de Epilepsia, Faculdade de Medicina, Universidade de São Paulo, Ribeirão Preto, Brazil
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Xiao Z, Peng J, Wu L, Arafat A, Yin F. The effect of IL-1β on synaptophysin expression and electrophysiology of hippocampal neurons through the PI3K/Akt/mTOR signaling pathway in a rat model of mesial temporal lobe epilepsy. Neurol Res 2017; 39:640-648. [PMID: 28372486 DOI: 10.1080/01616412.2017.1312070] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Affiliation(s)
- Zhaohua Xiao
- Department of Pediatrics, Xiangya Hospital of Central South University, Changsha, China
| | - Jing Peng
- Department of Pediatrics, Xiangya Hospital of Central South University, Changsha, China
- Hunan Intellectual and Developmental Disabilities Research Center of Children, Changsha, China
| | - Liwen Wu
- Department of Pediatrics, Xiangya Hospital of Central South University, Changsha, China
| | - Ahmed Arafat
- Department of Pediatrics, Xiangya Hospital of Central South University, Changsha, China
| | - Fei Yin
- Department of Pediatrics, Xiangya Hospital of Central South University, Changsha, China
- Hunan Intellectual and Developmental Disabilities Research Center of Children, Changsha, China
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Kopachev DN, Shishkina LV, Bychenko VG, Shkatova AM, Golovteev AL, Troitskiy AA, Grinenko OA. [Hippocampal sclerosis: pathogenesis, clinical features, diagnosis, and treatment]. ZHURNAL VOPROSY NEĬROKHIRURGII IMENI N. N. BURDENKO 2016. [PMID: 28635866 DOI: 10.17116/neiro2016804109-116] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Hippocampal sclerosis, also known as Ammon horn sclerosis or mesial temporal sclerosis, is usually associated with intractable epilepsy and characterized by specific patterns of neuronal loss and gliosis in the medial temporal lobe structures. Hippocampal sclerosis manifests clinically as epilepsy, often intractable epilepsy; in most cases, this condition is surgically treatable. As the most common histological diagnosis in adult patients subjected to epilepsy surgery, hippocampal sclerosis is characterized by complex pathogenesis and requires a multidisciplinary approach to its diagnosis and treatment. This article reviews the pathologic features, natural history, pathogenesis, and electroclinical and MRI signs of hippocampal sclerosis.
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Affiliation(s)
- D N Kopachev
- Burdenko Neurosurgical Institute, Moscow, Russia
| | | | - V G Bychenko
- Kulakov Scientific Center for Obstetrics, Gynecology, and Perinatology, Moscow, Russia
| | - A M Shkatova
- Burdenko Neurosurgical Institute, Moscow, Russia
| | - A L Golovteev
- Burdenko Neurosurgical Institute, Moscow, Russia, Kulakov Scientific Center for Obstetrics, Gynecology, and Perinatology, Moscow, Russia
| | - A A Troitskiy
- Burdenko Neurosurgical Institute, Moscow, Russia, Kulakov Scientific Center for Obstetrics, Gynecology, and Perinatology, Moscow, Russia
| | - O A Grinenko
- Burdenko Neurosurgical Institute, Moscow, Russia
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Lee SK. Treatment strategy for the patient with hippocampal sclerosis who failed to the first antiepileptic drug. J Epilepsy Res 2014; 4:1-6. [PMID: 24977123 PMCID: PMC4066627 DOI: 10.14581/jer.14001] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2014] [Accepted: 05/15/2014] [Indexed: 11/03/2022] Open
Abstract
Despite many epilepsy patients respond to antiepileptic drugs (AED) successfully, more than 30% of patients continue to have seizures on multiple AEDs. The refractory epilepsy increases the risk of cognitive deterioration, psychosocial dysfunction, and sudden unexpected death of epilepsy patients (SUDEP). It is important to identify refractory epilepsy early and make the goal of epilepsy treatment as the prevention of decline in social, vocational, and cognitive performances and minimizing the risk of accident or SUDEP. The syndrome of medial temporal lobe epilepsy with hippocampal sclerosis (MTLE with HS) is often resistant to AEDs, and surgically remediable. Initially well-controlled seizures often become intractable to AEDs. There are progressive behavioral changes including increasing memory deficit. Surgical outcome is also worse with longer duration of epilepsy or increasing age at surgery, which suggests that MTLE is a progressive disorder. Some emphasized the ultimate intractability of MTLE in which intractability of MTLE could be evident only after some years following initial diagnosis. However, when patients considered to have intractable epilepsy were followed up for a long period of time, many of them experienced seizure-free state. Some studies clearly demonstrated the wax and wane courses of treatment response in epilepsy. Late remission could be achieved up to in a half of patients. Thus intractable state is not a static condition but a fluctuating one and initial refractoriness does not necessarily mean the final intractability. Even though the chance of seizure remission with AEDs is not high for MTLE, some of them do well respond to drugs. It is even possible to withdraw AEDs for a few patients. Though epilepsy surgery is very effective method to treat MTLE, considering the fluctuation courses of intractability and the possibility of delayed remission, at least two adequate AEDs could be applied to the patients before surgery. However, medical intractability becomes evident by definition, it is not reasonable to delay epilepsy surgery.
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Affiliation(s)
- Sang Kun Lee
- Department of Neurology, Seoul National University College of Medicine, Seoul, Korea
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Widespread activation of microglial cells in the hippocampus of chronic epileptic rats correlates only partially with neurodegeneration. Brain Struct Funct 2014; 220:2423-39. [PMID: 24878824 DOI: 10.1007/s00429-014-0802-0] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2014] [Accepted: 05/14/2014] [Indexed: 12/30/2022]
Abstract
Activation of microglial cells (brain macrophages) soon after status epilepticus has been suggested to be critical for the pathogenesis of mesial temporal lobe epilepsy (MTLE). However, microglial activation in the chronic phase of experimental MTLE has been scarcely addressed. In this study, we questioned whether microglial activation persists in the hippocampus of pilocarpine-treated, epileptic Wistar rats and to which extent it is associated with segmental neurodegeneration. Microglial cells were immunostained for the universal microglial marker, ionized calcium-binding adapter molecule-1 and the activation marker, CD11b (also known as OX42, Mac-1). Using quantitative morphology, i.e., stereology and Neurolucida-based reconstructions, we investigated morphological correlates of microglial activation such as cell number, ramification, somatic size and shape. We find that microglial cells in epileptic rats feature widespread, activation-related morphological changes such as increase in cell number density, massive up-regulation of CD11b and de-ramification. The parameters show heterogeneity in different hippocampal subregions. For instance, de-ramification is most prominent in the outer molecular layer of the dentate gyrus, whereas CD11b expression dominates in hilus. Interestingly, microglial activation only partially correlates with segmental neurodegeneration. Major neuronal death in the hilus, CA3 and CA1 coincides with strong up-regulation of CD11b. However, microglial activation is also observed in subregions that do not feature neurodegeneration, such as the molecular and granular layer of the dentate gyrus. This in vivo study provides solid experimental evidence that microglial cells feature widespread heterogeneous activation that only partially correlates with hippocampal segmental neuronal loss in experimental MTLE.
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Cataldi M, Avoli M, de Villers-Sidani E. Resting state networks in temporal lobe epilepsy. Epilepsia 2013; 54:2048-59. [PMID: 24117098 DOI: 10.1111/epi.12400] [Citation(s) in RCA: 132] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/30/2013] [Indexed: 12/17/2022]
Abstract
Temporal lobe epilepsy (TLE) is typically described as a neurologic disorder affecting a cerebral network comprising the hippocampus proper and several anatomically related extrahippocampal regions. A new level of complexity was recently added to the study of this disorder by the evidence that TLE also appears to chronically alter the activity of several brain-wide neural networks involved in the control of higher order brain functions and not traditionally linked to epilepsy. Recently developed brain imaging techniques such as functional magnetic resonance imaging (fMRI) analysis of resting state connectivity, have greatly contributed to these observations by allowing the precise characterization of several brain networks with distinct functional signatures in the resting brain, and therefore also known as "resting state networks." These significant advances in imaging represent an opportunity to investigate the still elusive origins of the disabling cognitive and psychiatric manifestations of TLE, and could have important implications for its pathophysiology and, perhaps, its therapy. Herein we review recent studies in this field by focusing on resting state networks that have been implicated in the pathophysiology of psychiatric disorders and cognitive impairment in patients with epilepsy: the default mode network, the attention network, and the reward/emotion network.
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Affiliation(s)
- Mauro Cataldi
- Division of Pharmacology, Department of Neuroscience, Reproductive and Odontostomatologic Sciences, Federico II University of Naples, Naples, Italy
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