1
|
Song H, Mah B, Sun Y, Aloysius N, Bai Y, Zhang L. Development of spontaneous recurrent seizures accompanied with increased rates of interictal spikes and decreased hippocampal delta and theta activities following extended kindling in mice. Exp Neurol 2024; 379:114860. [PMID: 38876195 DOI: 10.1016/j.expneurol.2024.114860] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2023] [Revised: 05/30/2024] [Accepted: 06/09/2024] [Indexed: 06/16/2024]
Abstract
Interictal epileptiform discharges refer to aberrant brain electrographic signals between seizures and feature intermittent interictal spikes (ISs), sharp waves, and/or abnormal rhythms. Recognition of these epileptiform activities by electroencephalographic (EEG) examinations greatly aids epilepsy diagnosis and localization of the seizure onset zone. ISs are a major form of interictal epileptiform discharges recognized in animal models of epilepsy. Progressive changes in IS waveforms, IS rates, and/or associated fast ripple oscillations have been shown to precede the development of spontaneous recurrent seizures (SRS) in various animal models. IS expressions in the kindling model of epilepsy have been demonstrated but IS changes during the course of SRS development in extended kindled animals remain to be detailed. We hence addressed this issue using a mouse model of kindling-induced SRS. Adult C57 black mice received twice daily hippocampal stimulations until SRS occurrence, with 24-h EEG monitoring performed following 50, 80, and ≥ 100 stimulations and after observation of SRS. In the stimulated hippocampus, increases in spontaneous ISs rates, but not in IS waveforms nor IS-associated fast ripples, along with decreased frequencies of hippocampal delta and theta rhythms, were observed before SRS onset. Comparable increases in IS rates were further observed in the unstimulated hippocampus, piriform cortex, and entorhinal cortex, but not in the unstimulated parietal cortex and dorsomedial thalamus. These data provide original evidence suggesting that increases in hippocampal IS rates, together with reductions in hippocampal delta and theta rhythms are closely associated with development of SRS in a rodent kindling model.
Collapse
Affiliation(s)
- Hongmei Song
- Department of Neurosurgery, the First Hospital of Jilin University, China; Krembil Research Institute, University Health Network, Canada.
| | - Bryan Mah
- Krembil Research Institute, University Health Network, Canada
| | - Yuqing Sun
- Krembil Research Institute, University Health Network, Canada
| | - Nancy Aloysius
- Krembil Research Institute, University Health Network, Canada
| | - Yang Bai
- Department of Neuro-Oncology, the First Hospital of Jilin University, China.
| | - Liang Zhang
- Krembil Research Institute, University Health Network, Canada; Division of Neurology, Department of Medicine, University of Toronto, Toronto, Ontario, Canada.
| |
Collapse
|
2
|
Banjac S, Roger E, Cousin E, Mosca C, Minotti L, Krainik A, Kahane P, Baciu M. Mapping of Language-and-Memory Networks in Patients With Temporal Lobe Epilepsy by Using the GE2REC Protocol. Front Hum Neurosci 2022; 15:752138. [PMID: 35069148 PMCID: PMC8772037 DOI: 10.3389/fnhum.2021.752138] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2021] [Accepted: 12/13/2021] [Indexed: 11/17/2022] Open
Abstract
Preoperative mapping of language and declarative memory functions in temporal lobe epilepsy (TLE) patients is essential since they frequently encounter deterioration of these functions and show variable degrees of cerebral reorganization. Due to growing evidence on language and declarative memory interdependence at a neural and neuropsychological level, we propose the GE2REC protocol for interactive language-and-memory network (LMN) mapping. GE2REC consists of three inter-related tasks, sentence generation with implicit encoding (GE) and two recollection (2REC) memory tasks: recognition and recall. This protocol has previously been validated in healthy participants, and in this study, we showed that it also maps the LMN in the left TLE (N = 18). Compared to healthy controls (N = 19), left TLE (LTLE) showed widespread inter- and intra-hemispheric reorganization of the LMN through reduced activity of regions engaged in the integration and the coordination of this meta-network. We also illustrated how this protocol could be implemented in clinical practice individually by presenting two case studies of LTLE patients who underwent efficient surgery and became seizure-free but showed different cognitive outcomes. This protocol can be advantageous for clinical practice because it (a) is short and easy to perform; (b) allows brain mapping of essential cognitive functions, even at an individual level; (c) engages language-and-memory interaction allowing to evaluate the integrative processes within the LMN; (d) provides a more comprehensive assessment by including both verbal and visual modalities, as well as various language and memory processes. Based on the available postsurgical data, we presented preliminary results obtained with this protocol in LTLE patients that could potentially inform the clinical practice. This implies the necessity to further validate the potential of GE2REC for neurosurgical planning, along with two directions, guiding resection and describing LMN neuroplasticity at an individual level.
Collapse
Affiliation(s)
- Sonja Banjac
- Université Grenoble Alpes, CNRS LPNC UMR 5105, Grenoble, France
| | - Elise Roger
- Université Grenoble Alpes, CNRS LPNC UMR 5105, Grenoble, France
| | - Emilie Cousin
- Université Grenoble Alpes, CNRS LPNC UMR 5105, Grenoble, France
- Université Grenoble Alpes, UMS IRMaGe CHU Grenoble, Grenoble, France
| | - Chrystèle Mosca
- Université Grenoble Alpes, Grenoble Institute of Neuroscience ‘Synchronisation et modulation des réseaux neuronaux dans l’épilepsie’ & Neurology Department, Grenoble, France
| | - Lorella Minotti
- Université Grenoble Alpes, Grenoble Institute of Neuroscience ‘Synchronisation et modulation des réseaux neuronaux dans l’épilepsie’ & Neurology Department, Grenoble, France
| | - Alexandre Krainik
- Université Grenoble Alpes, UMS IRMaGe CHU Grenoble, Grenoble, France
| | - Philippe Kahane
- Université Grenoble Alpes, Grenoble Institute of Neuroscience ‘Synchronisation et modulation des réseaux neuronaux dans l’épilepsie’ & Neurology Department, Grenoble, France
| | - Monica Baciu
- Université Grenoble Alpes, CNRS LPNC UMR 5105, Grenoble, France
| |
Collapse
|
3
|
Gamblin A, Fredrickson VL, Hollon TC, Salzman KL, Couldwell WT. Idiopathic chronic temporal lobe herniation with associated epilepsy. Acta Neurochir (Wien) 2021; 163:2805-2808. [PMID: 34292392 DOI: 10.1007/s00701-021-04926-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2021] [Accepted: 06/18/2021] [Indexed: 11/30/2022]
Abstract
Herniation of parahippocampal gyrus is usually caused by pressure differentials intracranially, and herniation without known risk factors is extremely rare. We describe a patient with a long history of seizures and a remote status epilepticus event. On magnetic resonance imaging, a presumed left temporal lobe tumor was observed. On neurosurgical consultation, the lesion was identified as a chronic mesial temporal lobe herniation. The patient lacked history that would suggest risk of cerebral herniation. Accurately identifying the patient's chronic temporal lobe herniation radiographically likely saved this patient from unnecessary surgery or biopsy and allowed the patient to receive appropriate conservative care.
Collapse
Affiliation(s)
- Austin Gamblin
- School of Medicine, University of Utah, Salt Lake City, UT, USA
| | - Vance L Fredrickson
- Department of Neurosurgery, Clinical Neurosciences Center, University of Utah, Salt Lake City, UT, USA
| | - Todd C Hollon
- Department of Neurosurgery, Clinical Neurosciences Center, University of Utah, Salt Lake City, UT, USA
| | - Karen L Salzman
- Department of Radiology, University of Utah, Salt Lake City, UT, USA
| | - William T Couldwell
- Department of Neurosurgery, Clinical Neurosciences Center, University of Utah, Salt Lake City, UT, USA.
| |
Collapse
|
4
|
Banjac S, Roger E, Pichat C, Cousin E, Mosca C, Lamalle L, Krainik A, Kahane P, Baciu M. Reconfiguration dynamics of a language-and-memory network in healthy participants and patients with temporal lobe epilepsy. Neuroimage Clin 2021; 31:102702. [PMID: 34090125 PMCID: PMC8186554 DOI: 10.1016/j.nicl.2021.102702] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2021] [Revised: 04/21/2021] [Accepted: 05/14/2021] [Indexed: 12/03/2022]
Abstract
Current theoretical frameworks suggest that human behaviors are based on strong and complex interactions between cognitive processes such as those underlying language and memory functions in normal and neurological populations. We were interested in assessing the dynamic cerebral substrate of such interaction between language and declarative memory, as the composite function, in healthy controls (HC, N = 19) and patients with temporal lobe epilepsy (TLE, N = 16). Our assumption was that the language and declarative memory integration is based on a language-and-memory network (LMN) that is dynamic and reconfigures according to task demands and brain status. Therefore, we explored two types of LMN dynamics, a state reconfiguration (intrinsic resting-state compared to extrinsic state assessed with a sentence recall task) and a reorganization of state reconfiguration (TLE compared to HC). The dynamics was evaluated in terms of segregation (community or module detection) and integration (connector hubs). In HC, the level of segregation was the same in both states and the mechanism of LMN state reconfiguration was shown through module change of key language and declarative memory regions with integrative roles. In TLE patients, the reorganization of LMN state reconfiguration was reflected in segregation increase and extrinsic modules that were based on shorter-distance connections. While lateral and mesial temporal regions enabled state reconfiguration in HC, these regions showed reduced flexibility in TLE. We discuss our results in a connectomic perspective and propose a dynamic model of language and declarative memory functioning. We claim that complex and interactive cognitive functions, such as language and declarative memory, should be investigated dynamically, considering the interaction between cognitive networks.
Collapse
Affiliation(s)
- Sonja Banjac
- Univ. Grenoble Alpes, CNRS LPNC UMR 5105, 38000 Grenoble, France
| | - Elise Roger
- Univ. Grenoble Alpes, CNRS LPNC UMR 5105, 38000 Grenoble, France
| | - Cédric Pichat
- Univ. Grenoble Alpes, CNRS LPNC UMR 5105, 38000 Grenoble, France
| | - Emilie Cousin
- Univ. Grenoble Alpes, CNRS LPNC UMR 5105, 38000 Grenoble, France; Univ. Grenoble Alpes, UMS IRMaGe CHU Grenoble, 38000 Grenoble, France
| | - Chrystèle Mosca
- Neurology Department, Grenoble Hospital, Univ. Grenoble Alpes, 38000 Grenoble, France
| | - Laurent Lamalle
- Univ. Grenoble Alpes, UMS IRMaGe CHU Grenoble, 38000 Grenoble, France
| | - Alexandre Krainik
- Univ. Grenoble Alpes, UMS IRMaGe CHU Grenoble, 38000 Grenoble, France
| | - Philippe Kahane
- Neurology Department, Grenoble Hospital, Univ. Grenoble Alpes, 38000 Grenoble, France
| | - Monica Baciu
- Univ. Grenoble Alpes, CNRS LPNC UMR 5105, 38000 Grenoble, France.
| |
Collapse
|
5
|
Ugur Yilmaz C, Emik S, Orhan N, Temizyurek A, Atis M, Akcan U, Khodadust R, Arican N, Kucuk M, Gurses C, Ahishali B, Kaya M. Targeted delivery of lacosamide-conjugated gold nanoparticles into the brain in temporal lobe epilepsy in rats. Life Sci 2020; 257:118081. [DOI: 10.1016/j.lfs.2020.118081] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2020] [Revised: 07/05/2020] [Accepted: 07/07/2020] [Indexed: 11/16/2022]
|
6
|
Kundap UP, Paudel YN, Shaikh MF. Animal Models of Metabolic Epilepsy and Epilepsy Associated Metabolic Dysfunction: A Systematic Review. Pharmaceuticals (Basel) 2020; 13:ph13060106. [PMID: 32466498 PMCID: PMC7345684 DOI: 10.3390/ph13060106] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2020] [Revised: 05/22/2020] [Accepted: 05/23/2020] [Indexed: 12/13/2022] Open
Abstract
Epilepsy is a serious neurological disorder affecting around 70 million people globally and is characterized by spontaneous recurrent seizures. Recent evidence indicates that dysfunction in metabolic processes can lead to the alteration of neuronal and network excitability, thereby contributing to epileptogenesis. Developing a suitable animal model that can recapitulate all the clinical phenotypes of human metabolic epilepsy (ME) is crucial yet challenging. The specific environment of many symptoms as well as the primary state of the applicable neurobiology, genetics, and lack of valid biomarkers/diagnostic tests are the key factors that hinder the process of developing a suitable animal model. The present systematic review summarizes the current state of available animal models of metabolic dysfunction associated with epileptic disorders. A systematic search was performed by using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) model. A range of electronic databases, including google scholar, Springer, PubMed, ScienceDirect, and Scopus, were scanned between January 2000 and April 2020. Based on the selection criteria, 23 eligible articles were chosen and are discussed in the current review. Critical analysis of the selected literature delineated several available approaches that have been modeled into metabolic epilepsy and pointed out several drawbacks associated with the currently available models. The result describes available models of metabolic dysfunction associated with epileptic disorder, such as mitochondrial respiration deficits, Lafora disease (LD) model-altered glycogen metabolism, causing epilepsy, glucose transporter 1 (GLUT1) deficiency, adiponectin responsive seizures, phospholipid dysfunction, glutaric aciduria, mitochondrial disorders, pyruvate dehydrogenase (PDH) α-subunit gene (PDHA1), pyridoxine dependent epilepsy (PDE), BCL2-associated agonist of cell death (BAD), Kcna1 knock out (KO), and long noncoding RNAs (lncRNA) cancer susceptibility candidate 2 (lncRNA CASC2). Finally, the review highlights certain focus areas that may increase the possibilities of developing more suitable animal models and underscores the importance of the rationalization of animal models and evaluation methods for studying ME. The review also suggests the pressing need of developing precise robust animal models and evaluation methods for investigating ME.
Collapse
Affiliation(s)
- Uday Praful Kundap
- Research Center of the University of Montreal Hospital Center (CRCHUM), Department of Neurosciences, Université de Montréal, Montréal, QC H2X 0A9, Canada; (U.P.K.); (Y.N.P.)
- Neuropharmacology Research Strength, Jeffrey Cheah School of Medicine and Health Sciences, Monash University Malaysia, Selangor 47500, Malaysia
| | - Yam Nath Paudel
- Research Center of the University of Montreal Hospital Center (CRCHUM), Department of Neurosciences, Université de Montréal, Montréal, QC H2X 0A9, Canada; (U.P.K.); (Y.N.P.)
| | - Mohd. Farooq Shaikh
- Neuropharmacology Research Strength, Jeffrey Cheah School of Medicine and Health Sciences, Monash University Malaysia, Selangor 47500, Malaysia
- Correspondence: ; Tel.: +60-3-551-44-483
| |
Collapse
|
7
|
Rosal Lustosa Í, Soares JI, Biagini G, Lukoyanov NV. Neuroplasticity in Cholinergic Projections from the Basal Forebrain to the Basolateral Nucleus of the Amygdala in the Kainic Acid Model of Temporal Lobe Epilepsy. Int J Mol Sci 2019; 20:ijms20225688. [PMID: 31766245 PMCID: PMC6887742 DOI: 10.3390/ijms20225688] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2019] [Revised: 11/08/2019] [Accepted: 11/10/2019] [Indexed: 02/06/2023] Open
Abstract
The amygdala is a cerebral region whose function is compromised in temporal lobe epilepsy (TLE). Patients with TLE present cognitive and emotional dysfunctions, of which impairments in recognizing facial expressions have been clearly attributed to amygdala damage. However, damage to the amygdala has been scarcely addressed, with the majority of studies focusing on the hippocampus. The aim of this study was to evaluate epilepsy-related plasticity of cholinergic projections to the basolateral nucleus (BL) of the amygdala. Adult rats received kainic acid (KA) injections and developed status epilepticus. Weeks later, they showed spontaneous recurrent seizures documented by behavioral observations. Changes in cholinergic innervation of the BL were investigated by using an antibody against the vesicular acetylcholine transporter (VAChT). In KA-treated rats, it was found that (i) the BL shrunk to 25% of its original size (p < 0.01 vs. controls, Student’s t-test), (ii) the density of vesicular acetylcholine transporter-immunoreactive (VAChT-IR) varicosities was unchanged, (iii) the volumes of VAChT-IR cell bodies projecting to the BL from the horizontal limb of the diagonal band of Broca, ventral pallidum, and subcommissural part of the substantia innominata were significantly increased (p < 0.05, Bonferroni correction). These results illustrate significant changes in the basal forebrain cholinergic cells projecting to the BL in the presence of spontaneous recurrent seizures.
Collapse
Affiliation(s)
- Ítalo Rosal Lustosa
- Clinical and Experimental Medicine PhD Program, University of Modena and Reggio Emilia, 41125 Modena, Italy;
| | - Joana I. Soares
- Instituto de Investigação e Inovação em Saúde, Universidade do Porto, 4200-135 Porto, Portugal;
- Instituto de Biologia Molecular e Celular da Universidade do Porto, 4200-135 Porto, Portugal
- Departamento de Biomedicina, Faculdade de Medicina da Universidade do Porto, 4200-319 Porto, Portugal
- Programa Doutoral em Neurociências, Universidade do Porto, 4200-319 Porto, Portugal
| | - Giuseppe Biagini
- Department of Biomedical, Metabolic and Neural Sciences, University of Modena and Reggio Emilia, 41125 Modena, Italy
- Center for Neuroscience and Neurotechnology, University of Modena and Reggio Emilia, 41125 Modena, Italy
- Correspondence: (G.B.); (N.V.L.)
| | - Nikolai V. Lukoyanov
- Instituto de Investigação e Inovação em Saúde, Universidade do Porto, 4200-135 Porto, Portugal;
- Instituto de Biologia Molecular e Celular da Universidade do Porto, 4200-135 Porto, Portugal
- Departamento de Biomedicina, Faculdade de Medicina da Universidade do Porto, 4200-319 Porto, Portugal
- Correspondence: (G.B.); (N.V.L.)
| |
Collapse
|
8
|
Choy M, Duffy BA, Lee JH. Optogenetic study of networks in epilepsy. J Neurosci Res 2016; 95:2325-2335. [PMID: 27413006 PMCID: PMC5548626 DOI: 10.1002/jnr.23767] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2016] [Revised: 04/27/2016] [Accepted: 04/28/2016] [Indexed: 01/23/2023]
Abstract
Currently, approximately 30% of patients with epilepsy do not have adequate seizure control. A greater understanding of the underlying mechanisms by which seizures start or propagate could lead to new therapeutic strategies. The recent development of optogenetics, because of its unprecedented precision for controlling activity within distinct neuronal populations, has revolutionized neuroscience, including epilepsy research. This Review discusses recent breakthroughs made with optogenetics in epilepsy research. These breakthroughs include new insights into the key roles that different cell types play in mediating seizures as well as in the development of epilepsy. Subsequently, we discuss how targeting different brain regions and cell populations has opened up the possibility of highly specific therapies that can stop seizures on demand. Finally, we illustrate how combining newly available neuroscience tools with whole-brain imaging techniques will allow researchers to understand better the spread of seizures on a network level. © 2016 The Authors. Journal of Neuroscience Research Published by Wiley Periodicals, Inc.
Collapse
Affiliation(s)
- ManKin Choy
- Department of Neurology and Neurological Sciences, Stanford University, Stanford, California
| | - Ben A Duffy
- Department of Neurology and Neurological Sciences, Stanford University, Stanford, California
| | - Jin Hyung Lee
- Department of Neurology and Neurological Sciences, Stanford University, Stanford, California.,Department of Bioengineering, Stanford University, Stanford, California.,Department of Neurosurgery, Stanford University, Stanford, California.,Department of Electrical Engineering, Stanford University, Stanford, California
| |
Collapse
|
9
|
Childhood onset temporal lobe epilepsy: Beyond hippocampal sclerosis. Eur J Paediatr Neurol 2016; 20:228-235. [PMID: 26791392 DOI: 10.1016/j.ejpn.2015.12.010] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/17/2015] [Revised: 12/02/2015] [Accepted: 12/21/2015] [Indexed: 11/20/2022]
Abstract
OBJECTIVE Hippocampal Sclerosis (HS) is widely recognized as a significant underlying cause of drug-resistant temporal lobe epilepsy (TLE) in adults. In contrast, HS is a rare finding in pediatric surgical series, and a higher incidence of HS associated with cortical dysplasia (i.e. FCD type IIIa according to the new ILAE classification) than in adult series has been reported. Data about the electro-clinical characteristics of this subgroup are scarce. METHODS We studied 15 children and adolescents with drug-resistant TLE and HS who had anterior temporal lobe resection at our center with regard to electroclinical characteristics, MRI features and histopathology. Children in whom histopathology was consistent with Focal Cortical Dysplasia (FCD) type IIIa (n = 7) were compared with those who had HS only (n = 8). RESULTS Clinical characteristics associated with this highly selective subset of patients with FCD type IIIa were: the presence of febrile seizures during infancy, a shorter duration of active epilepsy and a lower age at epilepsy surgery. In addition, there were non-significant trends towards more extended abnormalities on both EEG and neuroimaging. We were, however, not able to find group differences with respect to neuropathologic subtyping of the HS. CONCLUSION We present the first detailed description and comprehensive data analysis of children with FCD type IIIa. According to our results, this patient group seems to show a distinct clinical phenotype.
Collapse
|
10
|
Bernhardt BC, Bonilha L, Gross DW. Network analysis for a network disorder: The emerging role of graph theory in the study of epilepsy. Epilepsy Behav 2015; 50:162-70. [PMID: 26159729 DOI: 10.1016/j.yebeh.2015.06.005] [Citation(s) in RCA: 177] [Impact Index Per Article: 19.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/09/2015] [Revised: 06/03/2015] [Accepted: 06/04/2015] [Indexed: 01/01/2023]
Abstract
Recent years have witnessed a paradigm shift in the study and conceptualization of epilepsy, which is increasingly understood as a network-level disorder. An emblematic case is temporal lobe epilepsy (TLE), the most common drug-resistant epilepsy that is electroclinically defined as a focal epilepsy and pathologically associated with hippocampal sclerosis. In this review, we will summarize histopathological, electrophysiological, and neuroimaging evidence supporting the concept that the substrate of TLE is not limited to the hippocampus alone, but rather is broadly distributed across multiple brain regions and interconnecting white matter pathways. We will introduce basic concepts of graph theory, a formalism to quantify topological properties of complex systems that has recently been widely applied to study networks derived from brain imaging and electrophysiology. We will discuss converging graph theoretical evidence indicating that networks in TLE show marked shifts in their overall topology, providing insight into the neurobiology of TLE as a network-level disorder. Our review will conclude by discussing methodological challenges and future clinical applications of this powerful analytical approach.
Collapse
Affiliation(s)
- Boris C Bernhardt
- Neuroimaging of Epilepsy Laboratory, Brain Imaging Center, Montreal Neurological Institute and Hospital, McGill University, Montreal, QC, Canada; Department of Social Neuroscience, Max Planck Institute for Human Cognitive and Brain Sciences, Leipzig, Germany.
| | - Leonardo Bonilha
- Department of Neurology, Medical University of South Carolina, SC, USA
| | - Donald W Gross
- Division of Neurology, Department of Medicine, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Alberta, Canada
| |
Collapse
|
11
|
Meningioma Induced Temporal Lobe Epilepsy; a Case Report. ARCHIVES OF NEUROSCIENCE 2014. [DOI: 10.5812/archneurosci.21644] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
|
12
|
Temporally unstructured electrical stimulation to the amygdala suppresses behavioral chronic seizures of the pilocarpine animal model. Epilepsy Behav 2014; 36:159-64. [PMID: 24935084 DOI: 10.1016/j.yebeh.2014.05.005] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/17/2014] [Revised: 04/30/2014] [Accepted: 05/06/2014] [Indexed: 11/21/2022]
Abstract
Electrical stimulation applied to the basolateral amygdala in the pentylenetetrazole animal model of seizures may result in either a proconvulsant or an anticonvulsant effect depending on the interpulse intervals used: periodic or nonperiodic, respectively. We tested the effect of this electrical stimulation temporal coding on the spontaneous and recurrent behavioral seizures produced in the chronic phase of the pilocarpine animal model of temporal lobe epilepsy, an experimental protocol that better mimics the human condition. After 45 days of the pilocarpine-induced status epilepticus, male Wistar rats were submitted to a surgical procedure for the implantation of a bipolar electrical stimulation electrode in the right basolateral amygdala and were allowed to recover for seven days. The animals were then placed in a glass box, and their behaviors were recorded daily on DVD for 6h for 4 consecutive days (control period). Spontaneous recurrent behavioral seizures when showed in animals were further recorded for an extra 4-day period (treatment period), under periodic or nonperiodic electrical stimulation. The number, duration, and severity of seizures (according to the modified Racine's scale) during treatment were compared with those during the control period. The nonperiodically stimulated group displayed a significantly reduced total number and duration of seizures. There was no difference between control and treatment periods for the periodically stimulated group. Results corroborate previous findings from our group showing that nonperiodic electrical stimulation has a robust anticonvulsant property. In addition, results from the pilocarpine animal model further strengthen nonperiodic electrical stimulation as a valid therapeutic approach in current medical practice. Our working hypothesis is that temporally unstructured electrical stimulation may wield its effect by desynchronizing neural networks involved in the ictogenic process.
Collapse
|
13
|
Carney PR. Special issue on epilepsy. Exp Neurol 2013; 244:1-3. [PMID: 23651566 DOI: 10.1016/j.expneurol.2013.04.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Affiliation(s)
- Paul R Carney
- Department of Pediatrics, University of Florida, Gainesville, FL 32610, USA
| |
Collapse
|