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Wan X, Zeng Y, Wang J, Tian M, Yin X, Zhang J. Structural and functional abnormalities and cognitive profiles in older adults with early-onset and late-onset focal epilepsy. Cereb Cortex 2024; 34:bhae300. [PMID: 39052362 DOI: 10.1093/cercor/bhae300] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2024] [Revised: 06/26/2024] [Accepted: 07/09/2024] [Indexed: 07/27/2024] Open
Abstract
This study aimed to determine the patterns of changes in structure, function, and cognitive ability in early-onset and late-onset older adults with focal epilepsy (OFE). This study first utilized the deformation-based morphometry analysis to identify structural abnormalities, which were used as the seed region to investigate the functional connectivity with the whole brain. Next, a correlation analysis was performed between the altered imaging findings and neuropsychiatry assessments. Finally, the potential role of structural-functional abnormalities in the diagnosis of epilepsy was further explored by using mediation analysis. Compared with healthy controls (n = 28), the area of reduced structural volume was concentrated in the bilateral cerebellum, right thalamus, and right middle cingulate cortex, with frontal, temporal, and occipital lobes also affected in early-onset focal epilepsy (n = 26), while late-onset patients (n = 31) displayed cerebellar, thalamic, and cingulate atrophy. Furthermore, correlation analyses suggest an association between structural abnormalities and cognitive assessments. Dysfunctional connectivity in the cerebellum, cingulate cortex, and frontal gyrus partially mediates the relationship between structural abnormalities and the diagnosis of early-onset focal epilepsy. This study identified structural and functional abnormalities in early-onset and late-onset focal epilepsy and explored characters in cognitive performance. Structural-functional coupling may play a potential role in the diagnosis of epilepsy.
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Affiliation(s)
- Xinyue Wan
- Department of Radiology, Huashan Hospital, State Key Laboratory of Medical Neurobiology, Fudan University, Shanghai 200040, China
- Human Phenome Institute, Fudan University, Shanghai 201203, China
| | - Yanwei Zeng
- Department of Radiology, Huashan Hospital, State Key Laboratory of Medical Neurobiology, Fudan University, Shanghai 200040, China
| | - Jianhong Wang
- Department of Neurology, Huashan Hospital, Fudan University, Shanghai 200040, China
| | - Mei Tian
- Human Phenome Institute, Fudan University, Shanghai 201203, China
| | - Xuyang Yin
- Department of Radiology, Huashan Hospital, State Key Laboratory of Medical Neurobiology, Fudan University, Shanghai 200040, China
| | - Jun Zhang
- Department of Radiology, Huashan Hospital, State Key Laboratory of Medical Neurobiology, Fudan University, Shanghai 200040, China
- National Center for Neurological Disorders, Fudan University, Shanghai 200040, China
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Huang Y, Wang N, Li W, Feng T, Zhang H, Fan X, Chen S, Wang Y, Shan Y, Wei P, Zhao G. Aberrant individual structure covariance network in patients with mesial temporal lobe epilepsy. Front Neurosci 2024; 18:1381385. [PMID: 38784092 PMCID: PMC11112066 DOI: 10.3389/fnins.2024.1381385] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2024] [Accepted: 04/08/2024] [Indexed: 05/25/2024] Open
Abstract
Objective Mesial temporal lobe epilepsy (mTLE) is a complex neurological disorder that has been recognized as a widespread global network disorder. The group-level structural covariance network (SCN) could reveal the structural connectivity disruption of the mTLE but could not reflect the heterogeneity at the individual level. Methods This study adopted a recently proposed individual structural covariance network (IDSCN) method to clarify the alternated structural covariance connection mode in mTLE and to associate IDSCN features with the clinical manifestations and regional brain atrophy. Results We found significant IDSCN abnormalities in the ipsilesional hippocampus, ipsilesional precentral gyrus, bilateral caudate, and putamen in mTLE patients than in healthy controls. Moreover, the IDSCNs of these areas were positively correlated with the gray matter atrophy rate. Finally, we identified several connectivities with weak associations with disease duration, frequency, and surgery outcome. Significance Our research highlights the role of hippo-thalamic-basal-cortical circuits in the pathophysiologic process of disrupted whole-brain morphological covariance networks in mTLE, and builds a bridge between brain-wide covariance network changes and regional brain atrophy.
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Affiliation(s)
- Yuda Huang
- Department of Neurosurgery, Xuanwu Hospital Capital Medical University, Beijing, China
| | - Ningrui Wang
- Department of Neurosurgery, Xuanwu Hospital Capital Medical University, Beijing, China
- Beijing Municipal Geriatric Medical Research Center, Beijing, China
| | - Wei Li
- Department of Neurosurgery, Xuanwu Hospital Capital Medical University, Beijing, China
| | - Tao Feng
- Department of Neurosurgery, Xuanwu Hospital Capital Medical University, Beijing, China
| | - Huaqiang Zhang
- Department of Neurosurgery, Xuanwu Hospital Capital Medical University, Beijing, China
| | - Xiaotong Fan
- Department of Neurosurgery, Xuanwu Hospital Capital Medical University, Beijing, China
| | - Sichang Chen
- Department of Neurosurgery, Xuanwu Hospital Capital Medical University, Beijing, China
| | - Yihe Wang
- Department of Neurosurgery, Xuanwu Hospital Capital Medical University, Beijing, China
| | - Yongzhi Shan
- Department of Neurosurgery, Xuanwu Hospital Capital Medical University, Beijing, China
| | - Penghu Wei
- Department of Neurosurgery, Xuanwu Hospital Capital Medical University, Beijing, China
- School of Public Health and Management, Ningxia Medical University, Yinchuan, China
- Clinical Research Center for Epilepsy Capital Medical University, Beijing, China
| | - Guoguang Zhao
- Department of Neurosurgery, Xuanwu Hospital Capital Medical University, Beijing, China
- School of Public Health and Management, Ningxia Medical University, Yinchuan, China
- Clinical Research Center for Epilepsy Capital Medical University, Beijing, China
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Englot DJ. Chronicles of Change: The Shrinking Brain in Epilepsy. Epilepsy Curr 2024; 24:159-161. [PMID: 38898902 PMCID: PMC11185202 DOI: 10.1177/15357597241228475] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/21/2024] Open
Abstract
Identification of Different MRI Atrophy Progression Trajectories in Epilepsy by Subtype and Stage Inference Xiao F, Caciagli L, Wandschneider B, Sone D, Young AL, Vos SB, Winston GP, Zhang Y, Liu W, An D, Kanber B, Zhou D, Sander JW, Thom M, Duncan JS, Alexander DC, Galovic M, Koepp MJ. Brain . 2023;146(11):4702-4716. doi:10.1093/brain/awad284 Artificial intelligence (AI)-based tools are widely employed, but their use for diagnosis and prognosis of neurological disorders is still evolving. Here we analyse a cross-sectional multicentre structural MRI dataset of 696 people with epilepsy and 118 control subjects. We use an innovative machine-learning algorithm, Subtype and Stage Inference, to develop a novel data-driven disease taxonomy, whereby epilepsy subtypes correspond to distinct patterns of spatiotemporal progression of brain atrophy. In a discovery cohort of 814 individuals, we identify two subtypes common to focal and idiopathic generalized epilepsies, characterized by progression of grey matter atrophy driven by the cortex or the basal ganglia. A third subtype, only detected in focal epilepsies, was characterized by hippocampal atrophy. We corroborate external validity via an independent cohort of 254 people and confirm that the basal ganglia subtype is associated with the most severe epilepsy. Our findings suggest fundamental processes underlying the progression of epilepsy-related brain atrophy. We deliver a novel MRI- and AI-guided epilepsy taxonomy, which could be used for individualized prognostics and targeted therapeutics.
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Affiliation(s)
- Dario J Englot
- Department of Neurological Surgery, Vanderbilt University Medical Center
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Alashjaie R, Kerr EN, AlShoumer A, Hawkins C, Yau I, Weiss S, Ochi A, Otsubo H, Krishnan P, Widjaja E, Ibrahim GM, Donner EJ, Jain P. Surgical outcomes in children with drug-resistant epilepsy and hippocampal sclerosis. Epilepsy Res 2024; 203:107367. [PMID: 38703703 DOI: 10.1016/j.eplepsyres.2024.107367] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2024] [Revised: 04/09/2024] [Accepted: 04/22/2024] [Indexed: 05/06/2024]
Abstract
BACKGROUND Hippocampal sclerosis (HS) is a common surgical substrate in adult epilepsy surgery cohorts but variably reported in various pediatric cohorts. OBJECTIVE We aimed to study the epilepsy phenotype, radiological and pathological variability, seizure and neurocognitive outcomes in children with drug-resistant epilepsy and hippocampal sclerosis (HS) with or without additional subtle signal changes in anterior temporal lobe who underwent surgery. METHODS This retrospective study enrolled children with drug-resistant focal epilepsy and hippocampal sclerosis with or without additional subtle T2-Fluid Attenuated Inversion Recovery (FLAR)/Proton Density (PD) signal changes in anterior temporal lobe who underwent anterior temporal lobectomy with amygdalohippocampectomy. Their clinical, EEG, neuropsychological, radiological and pathological data were reviewed and summarized. RESULTS Thirty-six eligible patients were identified. The mean age at seizure onset was 3.7 years; 25% had daily seizures at time of surgery. Isolated HS was noted in 22 (61.1%) cases and additional subtle signal changes in ipsilateral temporal lobe in 14 (38.9%) cases. Compared to the normative population, the group mean performance in intellectual functioning and most auditory and visual memory tasks were significantly lower than the normative sample. The mean age at surgery was 12.3 years; 22 patients (61.1%) had left hemispheric surgeries. ILAE class 1 outcomes was seen in 28 (77.8%) patients after a mean follow up duration of 2.3 years. Hippocampal sclerosis was noted pathologically in 32 (88.9%) cases; type 2 (54.5%) was predominant subtype where further classification was possible. Additional pathological abnormalities were seen in 11 cases (30.6%); these had had similar rates of seizure freedom as compared to children with isolated hippocampal sclerosis/gliosis (63.6% vs 84%, p=0.21). Significant reliable changes were observed across auditory and visual memory tasks at an individual level post surgery. CONCLUSIONS Favourable seizure outcomes were seen in most children with isolated radiological hippocampal sclerosis. Patients with additional pathological abnormalities had similar rates of seizure freedom as compared to children with isolated hippocampal sclerosis/gliosis.
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Affiliation(s)
- Ream Alashjaie
- Epilepsy Program, Division of Neurology, Department of Pediatrics, Hospital for Sick Children, University of Toronto, Toronto, Ontario, Canada
| | - Elizabeth N Kerr
- Department of Psychology, Hospital for Sick Children, Toronto, University of Toronto, Ontario, Canada
| | - Azhar AlShoumer
- Division of Neuropathology, Department of Laboratory Medicine and Pathology, Hospital for Sick Children, Toronto, Ontario, Canada
| | - Cynthia Hawkins
- Division of Neuropathology, Department of Laboratory Medicine and Pathology, Hospital for Sick Children, Toronto, Ontario, Canada
| | - Ivanna Yau
- Epilepsy Program, Division of Neurology, Department of Pediatrics, Hospital for Sick Children, University of Toronto, Toronto, Ontario, Canada
| | - Shelly Weiss
- Epilepsy Program, Division of Neurology, Department of Pediatrics, Hospital for Sick Children, University of Toronto, Toronto, Ontario, Canada
| | - Ayako Ochi
- Epilepsy Program, Division of Neurology, Department of Pediatrics, Hospital for Sick Children, University of Toronto, Toronto, Ontario, Canada
| | - Hiroshi Otsubo
- Epilepsy Program, Division of Neurology, Department of Pediatrics, Hospital for Sick Children, University of Toronto, Toronto, Ontario, Canada
| | - Pradeep Krishnan
- Department of Diagnostic Imaging, Hospital for Sick Children, University of Toronto, Toronto, Ontario, Canada
| | - Elysa Widjaja
- Department of Medical Imaging, Lurie Children's Hospital of Chicago, Chicago, United States of America
| | - George M Ibrahim
- Division of Neurosurgery, Hospital for Sick Children, University of Toronto, Toronto, Ontario, Canada
| | - Elizabeth J Donner
- Epilepsy Program, Division of Neurology, Department of Pediatrics, Hospital for Sick Children, University of Toronto, Toronto, Ontario, Canada
| | - Puneet Jain
- Epilepsy Program, Division of Neurology, Department of Pediatrics, Hospital for Sick Children, University of Toronto, Toronto, Ontario, Canada.
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Jiang S, Liu B, Lin K, Li L, Li R, Tan S, Zhang X, Jiang L, Ni H, Wang Y, Ding H, Hu J, Qian H, Ge R. Impacted spike frequency adaptation associated with reduction of KCNQ2/3 exacerbates seizure activity in temporal lobe epilepsy. Hippocampus 2024; 34:58-72. [PMID: 38049972 DOI: 10.1002/hipo.23587] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2022] [Revised: 09/21/2023] [Accepted: 10/28/2023] [Indexed: 12/06/2023]
Abstract
Numerous epilepsy-related genes have been identified in recent decades by unbiased genome-wide screens. However, the available druggable targets for temporal lobe epilepsy (TLE) remain limited. Furthermore, a substantial pool of candidate genes potentially applicable to TLE therapy awaits further validation. In this study, we reveal the significant role of KCNQ2 and KCNQ3, two M-type potassium channel genes, in the onset of seizures in TLE. Our investigation began with a quantitative analysis of two publicly available TLE patient databases to establish a correlation between seizure onset and the downregulated expression of KCNQ2/3. We then replicated these pathological changes in a pilocarpine seizure mouse model and observed a decrease in spike frequency adaptation due to the affected M-currents in dentate gyrus granule neurons. In addition, we performed a small-scale simulation of the dentate gyrus network and confirmed that the impaired spike frequency adaptation of granule cells facilitated epileptiform activity throughout the network. This, in turn, resulted in prolonged seizure duration and reduced interictal intervals. Our findings shed light on an underlying mechanism contributing to ictogenesis in the TLE hippocampus and suggest a promising target for the development of antiepileptic drugs.
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Affiliation(s)
- Shicheng Jiang
- Department of Pathophysiology, Bengbu Medical College, Bengbu, Anhui, China
- Laboratory of Brain and Psychiatric Disease, Bengbu Medical College, Bengbu, Anhui, China
| | - Bei Liu
- Sichuan Provincial Key Laboratory for Human Disease Gene Study, Sichuan Provincial People's Hospital, University of Electronic Science and Technology of China, Chengdu, China
| | - Kaiwen Lin
- Department of Pathophysiology, Bengbu Medical College, Bengbu, Anhui, China
- Laboratory of Brain and Psychiatric Disease, Bengbu Medical College, Bengbu, Anhui, China
| | - Lianjun Li
- Department of Pathophysiology, Bengbu Medical College, Bengbu, Anhui, China
- Laboratory of Brain and Psychiatric Disease, Bengbu Medical College, Bengbu, Anhui, China
| | - Rongrong Li
- Department of Pathophysiology, Bengbu Medical College, Bengbu, Anhui, China
- Laboratory of Brain and Psychiatric Disease, Bengbu Medical College, Bengbu, Anhui, China
| | - Shuo Tan
- Department of Pathophysiology, Bengbu Medical College, Bengbu, Anhui, China
- Laboratory of Brain and Psychiatric Disease, Bengbu Medical College, Bengbu, Anhui, China
| | - Xinyu Zhang
- Department of Pathophysiology, Bengbu Medical College, Bengbu, Anhui, China
- Laboratory of Brain and Psychiatric Disease, Bengbu Medical College, Bengbu, Anhui, China
| | - Lei Jiang
- Department of General Surgery, The Second Affiliated Hospital of Bengbu Medical College, Bengbu, Anhui, China
| | - Hong Ni
- Department of Pathophysiology, Bengbu Medical College, Bengbu, Anhui, China
- Laboratory of Brain and Psychiatric Disease, Bengbu Medical College, Bengbu, Anhui, China
| | - Yuanyuan Wang
- Department of Pathophysiology, Bengbu Medical College, Bengbu, Anhui, China
- Laboratory of Brain and Psychiatric Disease, Bengbu Medical College, Bengbu, Anhui, China
| | - Haihu Ding
- Department of Pathophysiology, Bengbu Medical College, Bengbu, Anhui, China
- Key Laboratory of Cardiovascular and Cerebrovascular Diseases, Bengbu Medical College, Bengbu, Anhui, China
| | - Jing Hu
- Sichuan Provincial Key Laboratory for Human Disease Gene Study, Sichuan Provincial People's Hospital, University of Electronic Science and Technology of China, Chengdu, China
| | - Hao Qian
- Sichuan Provincial Key Laboratory for Human Disease Gene Study, Sichuan Provincial People's Hospital, University of Electronic Science and Technology of China, Chengdu, China
| | - Rongjing Ge
- Department of Pathophysiology, Bengbu Medical College, Bengbu, Anhui, China
- Laboratory of Brain and Psychiatric Disease, Bengbu Medical College, Bengbu, Anhui, China
- Key Laboratory of Cardiovascular and Cerebrovascular Diseases, Bengbu Medical College, Bengbu, Anhui, China
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Casillas-Espinosa PM, Anderson A, Harutyunyan A, Li C, Lee J, Braine EL, Brady RD, Sun M, Huang C, Barlow CK, Shah AD, Schittenhelm RB, Mychasiuk R, Jones NC, Shultz SR, O'Brien TJ. Disease-modifying effects of sodium selenate in a model of drug-resistant, temporal lobe epilepsy. eLife 2023; 12:e78877. [PMID: 36892461 PMCID: PMC10208637 DOI: 10.7554/elife.78877] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2022] [Accepted: 03/08/2023] [Indexed: 03/10/2023] Open
Abstract
There are no pharmacological disease-modifying treatments with an enduring effect to mitigate the seizures and comorbidities of established chronic temporal lobe epilepsy (TLE). This study aimed to evaluate for disease modifying effects of sodium selenate treatment in the chronically epileptic rat post-status epilepticus (SE) model of drug-resistant TLE. Wistar rats underwent kainic acid-induced SE or sham. Ten-weeks post-SE, animals received sodium selenate, levetiracetam, or vehicle subcutaneousinfusion continuously for 4 weeks. To evaluate the effects of the treatments, one week of continuous video-EEG was acquired before, during, and 4, 8 weeks post-treatment, followed by behavioral tests. Targeted and untargeted proteomics and metabolomics were performed on post-mortem brain tissue to identify potential pathways associated with modified disease outcomes. Telomere length was investigated as a novel surrogate marker of epilepsy disease severity in our current study. The results showed that sodium selenate treatment was associated with mitigation of measures of disease severity at 8 weeks post-treatment cessation; reducing the number of spontaneous seizures (p< 0.05), cognitive dysfunction (p< 0.05), and sensorimotor deficits (p< 0.01). Moreover, selenate treatment was associated with increased protein phosphatase 2A (PP2A) expression, reduced hyperphosphorylated tau, and reversed telomere length shortening (p< 0.05). Network medicine integration of multi-omics/pre-clinical outcomes identified protein-metabolite modules positively correlated with TLE. Our results provide evidence that treatment with sodium selenate results in a sustained disease-modifying effect in chronically epileptic rats in the post-KA SE model of TLE, including improved comorbid learning and memory deficits.
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Affiliation(s)
- Pablo M Casillas-Espinosa
- Department of Medicine, The Royal Melbourne Hospital, The University of MelbourneMelbourneAustralia
- Department of Neuroscience, Central Clinical School, Monash UniversityMelbourneAustralia
- Monash Proteomics & Metabolomics Facility and Monash Biomedicine Discovery Institute, Monash UniversityClayton, VictoriaAustralia
| | - Alison Anderson
- Department of Medicine, The Royal Melbourne Hospital, The University of MelbourneMelbourneAustralia
- Department of Neuroscience, Central Clinical School, Monash UniversityMelbourneAustralia
| | - Anna Harutyunyan
- Department of Medicine, The Royal Melbourne Hospital, The University of MelbourneMelbourneAustralia
- Department of Neuroscience, Central Clinical School, Monash UniversityMelbourneAustralia
| | - Crystal Li
- Department of Neuroscience, Central Clinical School, Monash UniversityMelbourneAustralia
| | - Jiyoon Lee
- Department of Medicine, The Royal Melbourne Hospital, The University of MelbourneMelbourneAustralia
| | - Emma L Braine
- Department of Medicine, The Royal Melbourne Hospital, The University of MelbourneMelbourneAustralia
- Department of Neuroscience, Central Clinical School, Monash UniversityMelbourneAustralia
| | - Rhys D Brady
- Department of Medicine, The Royal Melbourne Hospital, The University of MelbourneMelbourneAustralia
- Department of Neuroscience, Central Clinical School, Monash UniversityMelbourneAustralia
| | - Mujun Sun
- Department of Neuroscience, Central Clinical School, Monash UniversityMelbourneAustralia
| | - Cheng Huang
- Department of Neurology, The Alfred Hospital, Commercial Road,Melbourne, VictoriaAustralia
| | - Christopher K Barlow
- Department of Neurology, The Alfred Hospital, Commercial Road,Melbourne, VictoriaAustralia
| | - Anup D Shah
- Department of Neurology, The Alfred Hospital, Commercial Road,Melbourne, VictoriaAustralia
| | - Ralf B Schittenhelm
- Department of Neurology, The Alfred Hospital, Commercial Road,Melbourne, VictoriaAustralia
| | - Richelle Mychasiuk
- Department of Neuroscience, Central Clinical School, Monash UniversityMelbourneAustralia
| | - Nigel C Jones
- Department of Medicine, The Royal Melbourne Hospital, The University of MelbourneMelbourneAustralia
- Department of Neuroscience, Central Clinical School, Monash UniversityMelbourneAustralia
| | - Sandy R Shultz
- Department of Medicine, The Royal Melbourne Hospital, The University of MelbourneMelbourneAustralia
- Department of Neuroscience, Central Clinical School, Monash UniversityMelbourneAustralia
| | - Terence J O'Brien
- Department of Medicine, The Royal Melbourne Hospital, The University of MelbourneMelbourneAustralia
- Department of Neuroscience, Central Clinical School, Monash UniversityMelbourneAustralia
- Monash Proteomics & Metabolomics Facility and Monash Biomedicine Discovery Institute, Monash UniversityClayton, VictoriaAustralia
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Le JT, Ballester-Rosado CJ, Frost JD, Swann JW. Neurobehavioral deficits and a progressive ictogenesis in the tetrodotoxin model of epileptic spasms. Epilepsia 2022; 63:3078-3089. [PMID: 36179064 PMCID: PMC9742150 DOI: 10.1111/epi.17428] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2022] [Revised: 09/28/2022] [Accepted: 09/28/2022] [Indexed: 01/11/2023]
Abstract
OBJECTIVE Our goal was to determine whether animals with a history of epileptic spasms have learning and memory deficits. We also used continuous (24/7) long-term electroencephalographic (EEG) recordings to evaluate the evolution of epileptiform activity in the same animals over time. METHODS Object recognition memory and object location memory tests were undertaken, as well as a matching to place water maze test that evaluated working memory. A retrospective analysis was undertaken of long-term video/EEG recordings from rats with epileptic spasms. The frequency and duration of the ictal events of spasms were quantified. RESULTS Rats with a history of epileptic spasms showed impairment on the three behavioral tests, and their scores on the object recognition memory and matching to place water maze tests indicated neocortical involvement in the observed impaired cognition. Analysis of EEG recordings unexpectedly showed that the ictal events of spasms and their accompanying behaviors progressively increased in duration over a 2-week period soon after onset, after which spasm duration plateaued. At the same time, spasm frequency remained unchanged. Soon after spasm onset, ictal events were variable in wave form but became more stereotyped as the syndrome evolved. SIGNIFICANCE Our EEG findings are the first to demonstrate progressive ictogenesis for epileptic spasms. Furthermore, in demonstrating cognitive deficits in the tetrodotoxin model, we have met a criterion for an animal model of West syndrome. Animal models will allow in-depth studies of spasm progression's potential role in cognitive regression and may elucidate why early treatment is considered essential for improved neurodevelopmental outcomes in children.
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Affiliation(s)
- John T. Le
- The Cain Foundation Laboratories, the Jan and Dan Neurological Research Institute, Texas Children’s Hospital, Houston Texas
- Department of Pediatrics, Baylor College of Medicine, Houston Texas
| | - Carlos J. Ballester-Rosado
- The Cain Foundation Laboratories, the Jan and Dan Neurological Research Institute, Texas Children’s Hospital, Houston Texas
- Department of Pediatrics, Baylor College of Medicine, Houston Texas
| | - James D. Frost
- Department of Neurology, Baylor College of Medicine, Houston Texas
| | - John W. Swann
- The Cain Foundation Laboratories, the Jan and Dan Neurological Research Institute, Texas Children’s Hospital, Houston Texas
- Department of Pediatrics, Baylor College of Medicine, Houston Texas
- Department of Neuroscience, Baylor College of Medicine, Houston Texas
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8
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Investigating the Role of GABA in Neural Development and Disease Using Mice Lacking GAD67 or VGAT Genes. Int J Mol Sci 2022; 23:ijms23147965. [PMID: 35887307 PMCID: PMC9318753 DOI: 10.3390/ijms23147965] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2022] [Revised: 07/12/2022] [Accepted: 07/16/2022] [Indexed: 11/18/2022] Open
Abstract
Normal development and function of the central nervous system involves a balance between excitatory and inhibitory neurotransmission. Activity of both excitatory and inhibitory neurons is modulated by inhibitory signalling of the GABAergic and glycinergic systems. Mechanisms that regulate formation, maturation, refinement, and maintenance of inhibitory synapses are established in early life. Deviations from ideal excitatory and inhibitory balance, such as down-regulated inhibition, are linked with many neurological diseases, including epilepsy, schizophrenia, anxiety, and autism spectrum disorders. In the mammalian forebrain, GABA is the primary inhibitory neurotransmitter, binding to GABA receptors, opening chloride channels and hyperpolarizing the cell. We review the involvement of down-regulated inhibitory signalling in neurological disorders, possible mechanisms for disease progression, and targets for therapeutic intervention. We conclude that transgenic models of disrupted inhibitory signalling—in GAD67+/− and VGAT−/− mice—are useful for investigating the effects of down-regulated inhibitory signalling in a range of neurological diseases.
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Bakhtiari A, Bjørke AB, Larsson PG, Olsen KB, Nævra MCJ, Taubøll E, Heuser K, Østby Y. Episodic Memory Dysfunction and Effective Connectivity in Adult Patients With Newly Diagnosed Nonlesional Temporal Lobe Epilepsy. Front Neurol 2022; 13:774532. [PMID: 35222242 PMCID: PMC8866246 DOI: 10.3389/fneur.2022.774532] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2021] [Accepted: 01/06/2022] [Indexed: 11/13/2022] Open
Abstract
Objective Epilepsy is associated with both changes in brain connectivity and memory function, usually studied in the chronic patients. The aim of this study was to explore the presence of connectivity alterations measured by EEG in the parietofrontal network in patients with temporal lobe epilepsy (TLE), and to examine episodic memory, at the time point of diagnosis. Methods The parietofrontal network of newly diagnosed patients with TLE (N = 21) was assessed through electroencephalography (EEG) effective connectivity and compared with that of matched controls (N = 21). Furthermore, we assessed phenomenological aspects of episodic memory in both groups. Association between effective connectivity and episodic memory were assessed through correlation. Results Patients with TLE displayed decreased episodic (p ≤ 0.001, t = −5.18) memory scores compared with controls at the time point of diagnosis. The patients showed a decreased right parietofrontal connectivity (p = 0.03, F = 4.94) compared with controls, and significantly weaker connectivity in their right compared with their left hemisphere (p = 0.008, t = −2.93). There were no significant associations between effective connectivity and episodic memory scores. Conclusions We found changes in both memory function and connectivity at the time point of diagnosis, supporting the notion that TLE involves complex memory functions and brain networks beyond the seizure focus to strongly interconnected brain regions, already early in the disease course. Whether the observed connectivity changes can be interpreted as functionally important to the alterations in memory function, it remains speculative.
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Affiliation(s)
- Aftab Bakhtiari
- Department of Psychology, Faculty of Social Sciences, University of Oslo, Oslo, Norway
| | - Agnes Balint Bjørke
- Division of Clinical Neuroscience, Department of Neurology, Oslo University Hospital, Rikshospitalet, Oslo, Norway
- Division of Neurology, Rheumatology and Habilitation, Department of Neurology, Drammen Hospital, Vestre Viken Hospital Trust, Drammen, Norway
- Faculty of Medicine, Institute of Clinical Medicine, University of Oslo, Oslo, Norway
| | - Pål Gunnar Larsson
- Section of Clinical Neurophysiology, Division of Clinical Neuroscience, Department of Neurosurgery, Oslo University Hospital–Rikshospitalet, Oslo, Norway
| | - Ketil Berg Olsen
- Section of Clinical Neurophysiology, Division of Clinical Neuroscience, Department of Neurosurgery, Oslo University Hospital–Rikshospitalet, Oslo, Norway
| | - Marianne C. Johansen Nævra
- Section of Clinical Neurophysiology, Division of Clinical Neuroscience, Department of Neurosurgery, Oslo University Hospital–Rikshospitalet, Oslo, Norway
| | - Erik Taubøll
- Division of Clinical Neuroscience, Department of Neurology, Oslo University Hospital, Rikshospitalet, Oslo, Norway
- Division of Neurology, Rheumatology and Habilitation, Department of Neurology, Drammen Hospital, Vestre Viken Hospital Trust, Drammen, Norway
| | - Kjell Heuser
- Division of Clinical Neuroscience, Department of Neurology, Oslo University Hospital, Rikshospitalet, Oslo, Norway
- *Correspondence: Kjell Heuser
| | - Ylva Østby
- Department of Psychology, Faculty of Social Sciences, University of Oslo, Oslo, Norway
- Ylva Østby
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Gage M, Putra M, Wachter L, Dishman K, Gard M, Gomez-Estrada C, Thippeswamy T. Saracatinib, a Src Tyrosine Kinase Inhibitor, as a Disease Modifier in the Rat DFP Model: Sex Differences, Neurobehavior, Gliosis, Neurodegeneration, and Nitro-Oxidative Stress. Antioxidants (Basel) 2021; 11:61. [PMID: 35052568 PMCID: PMC8773289 DOI: 10.3390/antiox11010061] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2021] [Revised: 12/17/2021] [Accepted: 12/23/2021] [Indexed: 12/13/2022] Open
Abstract
Diisopropylfluorophosphate (DFP), an organophosphate nerve agent (OPNA), exposure causes status epilepticus (SE) and epileptogenesis. In this study, we tested the protective effects of saracatinib (AZD0530), a Src kinase inhibitor, in mixed-sex or male-only Sprague Dawley rats exposed to 4-5 mg/kg DFP followed by 2 mg/kg atropine and 25 mg/kg 2-pralidoxime. Midazolam (3 mg/kg) was given to the mixed-sex cohort (1 h post-DFP) and male-only cohort (~30 min post-DFP). Saracatinib (20 mg/kg, oral, daily for 7 days) or vehicle was given two hours later and euthanized eight days or ten weeks post-DFP. Brain immunohistochemistry (IHC) showed increased microgliosis, astrogliosis, and neurodegeneration in DFP-treated animals. In the 10-week post-DFP male-only group, there were no significant differences between groups in the novel object recognition, Morris water maze, rotarod, or forced swim test. Brain IHC revealed significant mitigation by saracatinib in contrast to vehicle-treated DFP animals in microgliosis, astrogliosis, neurodegeneration, and nitro-oxidative stressors, such as inducible nitric oxide synthase, GP91phox, and 3-Nitrotyrosine. These findings suggest the protective effects of saracatinib on brain pathology seem to depend on the initial SE severity. Further studies on dose optimization, including extended treatment regimen depending on the SE severity, are required to determine its disease-modifying potential in OPNA models.
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Affiliation(s)
| | | | | | | | | | | | - Thimmasettappa Thippeswamy
- Department of Biomedical Sciences and Interdepartmental Neuroscience Program, Iowa State University, Ames, IA 50011, USA; (M.G.); (M.P.); (L.W.); (K.D.); (M.G.); (C.G.-E.)
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11
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Yeh WC, Lin HC, Chuang YC, Hsu CY. Exploring factors associated with interictal heart rate variability in patients with medically controlled focal epilepsy. Seizure 2021; 92:24-28. [PMID: 34416420 DOI: 10.1016/j.seizure.2021.08.003] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2021] [Revised: 07/28/2021] [Accepted: 08/06/2021] [Indexed: 01/08/2023] Open
Abstract
PURPOSE Heart rate variability (HRV) reflects the balance between the functional outputs of the sympathetic and parasympathetic nervous systems. It is lower in patients with epilepsy than in the healthy controls. However, HRV has been inadequately studied in different patient subgroups with medically controlled epilepsy. Hence, this study aimed to investigate factors associated with interictal HRV in patients with medically controlled epilepsy. METHODS This retrospective cohort study included 54 patients (24 males and 30 females) with medically controlled focal epilepsy who only received monotherapy to eliminate the confounding effect of different antiseizure medications (ASMs). Patients with major systemic or psychiatric disorder comorbidities were excluded. For HRV analysis, electroencephalography and 5-minute well-qualified electrocardiogram segment recording were conducted during stage N1 or N2 sleep. In addition, the association between age, gender, seizure onset type, ASMs, and the time domain and frequency-domain HRV measures was analyzed. RESULTS HRV negatively correlated with advanced age. Patients with focal to bilateral tonic-clonic seizure (FBTCS) had a significantly lower HRV than focal impaired awareness seizures (FIAS). HRV was not associated with any gender and ASMs. CONCLUSIONS HRV negatively correlated with age, and patients with FBTCS had a decreased HRV. Thus, these patients may have a declining autonomic function. Therefore, different seizure types may carry different risks of autonomic dysfunction in patients with medically controlled focal epilepsy.
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Affiliation(s)
- Wei-Chih Yeh
- Department of Neurology, Kaohsiung Medical University Hospital, No. 100, Tzyou 1st. Road, Kaohsiung City 80754, Taiwan; Graduate Institute of Medicine, College of Medicine, Kaohsiung Medical University, No. 100, Shih-Chuan 1st Road, Kaohsiung City 80708, Taiwan
| | - Hsun-Chang Lin
- Department of Neurology, Health and Welfare Ministry Pingtung Hospital, No.270, Ziyou Rd., Pingtung City, Pingtung County 900, Taiwan
| | - Yao-Chung Chuang
- Department of Neurology, Kaohsiung Chang Gung Memorial Hospital and Chang Gung, University College of Medicine, Kaohsiung, Taiwan
| | - Chung-Yao Hsu
- Department of Neurology, Kaohsiung Medical University Hospital, No.100, Tzyou 1st Rd., Kaohsiung City 80754, Taiwan; Department of Neurology, Faculty of Medicine, College of Medicine, Kaohsiung Medical, University, Kaohsiung City 80708, Taiwan..
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12
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Longitudinal analysis of interictal electroencephalograms in patients with temporal lobe epilepsy with hippocampal sclerosis. Seizure 2021; 90:141-144. [DOI: 10.1016/j.seizure.2021.02.008] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2020] [Revised: 02/05/2021] [Accepted: 02/06/2021] [Indexed: 12/14/2022] Open
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Gangar K, Bhatt LK. Therapeutic Targets for the Treatment of Comorbidities Associated with Epilepsy. Curr Mol Pharmacol 2021; 13:85-93. [PMID: 31793425 DOI: 10.2174/1874467212666191203101606] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2019] [Revised: 11/03/2019] [Accepted: 11/18/2019] [Indexed: 12/17/2022]
Abstract
One of the most common neurological disorders, which occurs among 1% of the population worldwide, is epilepsy. Therapeutic failure is common with epilepsy and nearly about 30% of patients fall in this category. Seizure suppression should not be the only goal while treating epilepsy but associated comorbidities, which can further worsen the condition, should also be considered. Treatment of such comorbidities such as depression, anxiety, cognition, attention deficit hyperactivity disorder and, various other disorders which co-exist with epilepsy or are caused due to epilepsy should also be treated. Novel targets or the existing targets are needed to be explored for the dual mechanism which can suppress both the disease and the comorbidity. New therapeutic targets such as IDO, nNOS, PAR1, NF-κb are being explored for their role in epilepsy and various comorbidities. This review explores recent therapeutic targets for the treatment of comorbidities associated with epilepsy.
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Affiliation(s)
- Kinjal Gangar
- Department of Pharmacology, SVKM's Dr. Bhanuben Nanavati College of Pharmacy, Vile Parle (West), Mumbai, India
| | - Lokesh Kumar Bhatt
- Department of Pharmacology, SVKM's Dr. Bhanuben Nanavati College of Pharmacy, Vile Parle (West), Mumbai, India
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14
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Global enhancement of cortical excitability following coactivation of large neuronal populations. Proc Natl Acad Sci U S A 2020; 117:20254-20264. [PMID: 32747543 DOI: 10.1073/pnas.1914869117] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Correlated activation of cortical neurons often occurs in the brain and repetitive correlated neuronal firing could cause long-term modifications of synaptic efficacy and intrinsic excitability. We found that repetitive optogenetic activation of neuronal populations in the mouse cortex caused enhancement of optogenetically evoked firing of local coactivated neurons as well as distant cortical neurons in both ipsilateral and contralateral hemispheres. This global enhancement of evoked responses required coactivation of a sufficiently large population of neurons either within one cortical area or distributed in several areas. Enhancement of neuronal firing was saturable after repeated episodes of coactivation, diminished by inhibition of N-methyl-d-aspartic acid receptors, and accompanied by elevated excitatory postsynaptic potentials, all consistent with activity-induced synaptic potentiation. Chemogenetic inhibition of neuronal activity of the thalamus decreased the enhancement effect, suggesting thalamic involvement. Thus, correlated excitation of large neuronal populations leads to global enhancement of neuronal excitability.
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15
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Teh KX, Henien NPB, Wong LS, Wong ZKH, Raja Ismail RZ, Achok HN, Mariapun J, Yunos NM. A cross-sectional study on the rate of non-adherence to anti-seizure medications and factors associated with non-adherence among patients with epilepsy. PLoS One 2020; 15:e0235674. [PMID: 32649723 PMCID: PMC7351198 DOI: 10.1371/journal.pone.0235674] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2019] [Accepted: 06/19/2020] [Indexed: 12/13/2022] Open
Abstract
Background Non-adherence to anti-seizure medication (ASM) therapy is an important contributing factor to the higher mortality rate and treatment failure of epilepsy. This study aimed to determine the rate and factors associated with non-adherence to ASM therapy through the WHO five dimensions of medication adherence framework. Methods We conducted a cross-sectional study at an outpatient Neurology Clinic of a tertiary government hospital in Malaysia. Between March and July 2019, we identified 217 patients with a confirmed diagnosis of epilepsy, receiving oral ASM therapy and able to administer their medications. We performed a semi-structured interview to gather information on sociodemographic background, clinical and medication history, and perceptions on healthcare services. Adherence to ASM therapy was evaluated using the Medication Compliance Questionnaire (MCQ). Patient’s illness perception was assessed by the Brief Illness Perception Questionnaire (B-IPQ). Results 208 patients participated in this study. The median age of the study participants was 35 years (IQR 26–44). 58.2% were females and majority, 55.8%, were from the Malay ethnic group. Based on the MCQ scoring, 89 patients (42.8%) were non-adherent. Multiple logistic regression demonstrated that being employed or students (adjusted odds ratio [aOR] 2.26, 95%CI: 1.19–4.29 p = 0.012) and having an average or below average perceived access to pharmacy services (aOR 2.94, 95%CI: 1.38–6.24, p = 0.005) were significant contributors to non-adherence. Conclusion Being employed or students and having an average or below average perceived access to pharmacy services were associated with ASM non-adherence Efforts to improve ASM adherence should adopt a comprehensive approach considering the success of adherence is contingent on the interrelationship of multiple dimensions.
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Affiliation(s)
- Kai Xuan Teh
- Clinical School Johor Bahru, Jeffrey Cheah School of Medicine and Health Sciences, Monash University Malaysia, Johor Bahru, Johor, Malaysia
| | - Nevein Philip Botross Henien
- Clinical School Johor Bahru, Jeffrey Cheah School of Medicine and Health Sciences, Monash University Malaysia, Johor Bahru, Johor, Malaysia
- * E-mail:
| | - Lyang Shenz Wong
- Clinical School Johor Bahru, Jeffrey Cheah School of Medicine and Health Sciences, Monash University Malaysia, Johor Bahru, Johor, Malaysia
| | - Zoe Kee Hui Wong
- Clinical School Johor Bahru, Jeffrey Cheah School of Medicine and Health Sciences, Monash University Malaysia, Johor Bahru, Johor, Malaysia
| | - Raja Zarina Raja Ismail
- Clinical School Johor Bahru, Jeffrey Cheah School of Medicine and Health Sciences, Monash University Malaysia, Johor Bahru, Johor, Malaysia
| | - Hamdi Najman Achok
- Department of Medicine, Hospital Sultanah Aminah, Johor Bahru, Johor, Malaysia
| | - Jeevitha Mariapun
- Clinical School Johor Bahru, Jeffrey Cheah School of Medicine and Health Sciences, Monash University Malaysia, Johor Bahru, Johor, Malaysia
| | - Nor’azim Mohd Yunos
- Clinical School Johor Bahru, Jeffrey Cheah School of Medicine and Health Sciences, Monash University Malaysia, Johor Bahru, Johor, Malaysia
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16
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Huesmann GR, Schwarb H, Smith DR, Pohlig RT, Anderson AT, McGarry MDJ, Paulsen KD, Wszalek TM, Sutton BP, Johnson CL. Hippocampal stiffness in mesial temporal lobe epilepsy measured with MR elastography: Preliminary comparison with healthy participants. NEUROIMAGE-CLINICAL 2020; 27:102313. [PMID: 32585569 PMCID: PMC7322100 DOI: 10.1016/j.nicl.2020.102313] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/06/2019] [Revised: 06/09/2020] [Accepted: 06/10/2020] [Indexed: 01/26/2023]
Abstract
Hippocampal stiffness in MTLE is measured with magnetic resonance elastography. The epileptogenic hippocampus is stiffer than non-epileptogenic hippocampus in MTLE. Hippocampal stiffness ratio is higher in MTLE patients than in healthy participants. Stiffness ratio provides additional diagnostic information to hippocampal volume.
Mesial temporal lobe epilepsy (MTLE) is the most common form of refractory epilepsy. Common imaging biomarkers are often not sensitive enough to identify MTLE sufficiently early to facilitate the greatest benefit from surgical or pharmacological intervention. The objective of this work is to establish hippocampal stiffness measured with magnetic resonance elastography (MRE) as a biomarker for MTLE; we hypothesized that the epileptogenic hippocampus in MTLE is stiffer than the non-epileptogenic hippocampus. MRE was used to measure hippocampal stiffness in a group of patients with unilateral MTLE (n = 12) and a group of healthy comparison participants (n = 13). We calculated the ratio of hippocampal stiffness ipsilateral to epileptogenesis to the contralateral side for both groups. We found a higher hippocampal stiffness ratio in patients with MTLE compared with healthy participants (1.14 v. 0.99; p = 0.004), and that stiffness ratio differentiated MTLE from control groups effectively (AUC = 0.85). Hippocampal stiffness ratio, when added to volume ratio, an established MTLE biomarker, significantly improved the ability to differentiate the two groups (p = 0.038). Stiffness measured with MRE is sensitive to hippocampal pathology in MTLE and the addition of MRE to neuroimaging assessments may improve detection and characterization of the disease.
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Affiliation(s)
- Graham R Huesmann
- Carle Neuroscience Institute, Carle Foundation Hospital, Urbana, IL, United States; Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, IL, United States; Department of Molecular and Integrative Physiology, University of Illinois at Urbana-Champaign, Urbana, IL, United States; Neuroscience Program, University of Illinois at Urbana-Champaign, Urbana, IL, United States.
| | - Hillary Schwarb
- Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, IL, United States; Interdisciplinary Health Sciences Institute, University of Illinois at Urbana-Champaign, Urbana, IL, United States.
| | - Daniel R Smith
- Department of Biomedical Engineering, University of Delaware, Newark, DE, United States
| | - Ryan T Pohlig
- College of Health Sciences, University of Delaware, Newark, DE, United States
| | - Aaron T Anderson
- Carle Neuroscience Institute, Carle Foundation Hospital, Urbana, IL, United States; Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, IL, United States
| | | | - Keith D Paulsen
- Thayer School of Engineering, Dartmouth College, Hanover, NH, United States
| | - Tracey Mencio Wszalek
- Carle Neuroscience Institute, Carle Foundation Hospital, Urbana, IL, United States; Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, IL, United States
| | - Bradley P Sutton
- Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, IL, United States; Department of Bioengineering, University of Illinois at Urbana-Champaign, Urbana, IL, United States
| | - Curtis L Johnson
- Department of Biomedical Engineering, University of Delaware, Newark, DE, United States.
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17
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Casillas‐Espinosa PM, Ali I, O'Brien TJ. Neurodegenerative pathways as targets for acquired epilepsy therapy development. Epilepsia Open 2020; 5:138-154. [PMID: 32524040 PMCID: PMC7278567 DOI: 10.1002/epi4.12386] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2018] [Revised: 02/13/2020] [Accepted: 02/24/2020] [Indexed: 12/16/2022] Open
Abstract
There is a growing body of clinical and experimental evidence that neurodegenerative diseases and epileptogenesis after an acquired brain insult may share common etiological mechanisms. Acquired epilepsy commonly develops as a comorbid condition in patients with neurodegenerative diseases such as Alzheimer's disease, although it is likely much under diagnosed in practice. Progressive neurodegeneration has also been described after traumatic brain injury, stroke, and other forms of brain insults. Moreover, recent evidence has shown that acquired epilepsy is often a progressive disorder that is associated with the development of drug resistance, cognitive decline, and worsening of other neuropsychiatric comorbidities. Therefore, new pharmacological therapies that target neurobiological pathways that underpin neurodegenerative diseases have potential to have both an anti-epileptogenic and disease-modifying effect on the seizures in patients with acquired epilepsy, and also mitigate the progressive neurocognitive and neuropsychiatric comorbidities. Here, we review the neurodegenerative pathways that are plausible targets for the development of novel therapies that could prevent the development or modify the progression of acquired epilepsy, and the supporting published experimental and clinical evidence.
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Affiliation(s)
- Pablo M. Casillas‐Espinosa
- Departments of Neuroscience and MedicineCentral Clinical SchoolMonash UniversityMelbourneVic.Australia
- Department of MedicineThe Royal Melbourne HospitalThe University of MelbourneMelbourneVic.Australia
| | - Idrish Ali
- Departments of Neuroscience and MedicineCentral Clinical SchoolMonash UniversityMelbourneVic.Australia
- Department of MedicineThe Royal Melbourne HospitalThe University of MelbourneMelbourneVic.Australia
| | - Terence J. O'Brien
- Departments of Neuroscience and MedicineCentral Clinical SchoolMonash UniversityMelbourneVic.Australia
- Department of MedicineThe Royal Melbourne HospitalThe University of MelbourneMelbourneVic.Australia
- Department of NeurologyThe Alfred HospitalMelbourneVic.Australia
- Department of NeurologyThe Royal Melbourne HospitalParkvilleVic.Australia
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18
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Chauvière L. Potential causes of cognitive alterations in temporal lobe epilepsy. Behav Brain Res 2020; 378:112310. [DOI: 10.1016/j.bbr.2019.112310] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2019] [Revised: 10/15/2019] [Accepted: 10/15/2019] [Indexed: 12/11/2022]
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19
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Arnold EC, McMurray C, Gray R, Johnston D. Epilepsy-Induced Reduction in HCN Channel Expression Contributes to an Increased Excitability in Dorsal, But Not Ventral, Hippocampal CA1 Neurons. eNeuro 2019; 6:ENEURO.0036-19.2019. [PMID: 30957013 PMCID: PMC6449163 DOI: 10.1523/eneuro.0036-19.2019] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2019] [Accepted: 03/05/2019] [Indexed: 12/31/2022] Open
Abstract
CA1 neurons in epileptic animals are vulnerable to selective changes in ion channel expression, called acquired channelopathies, which can increase the excitability of a neuron. Under normal conditions there is a gradient of ion channel expression and intrinsic excitability along the longitudinal, dorsoventral axis of hippocampal area CA1 of the rodent. Many of these channels, including M-channels, GIRK channels and HCN channels, all have dorsoventral expression gradients that might be altered in rodent models of epilepsy. Here, we show that the excitability of dorsal, but not ventral CA1 neurons, had an increased firing rate, reduced interspike interval (ISI) and increased input resistance in a status epilepticus (SE) model of temporal lobe epilepsy (TLE). As a result, the excitability of CA1 neurons became uniform across the dorsoventral axis of the rat hippocampus post-SE. Using current clamp recordings with pharmacology and immunohistochemistry, we demonstrate that the expression of HCN channels was downregulated in the dorsal CA1 region post-SE, while the expression of M and GIRK channels were unchanged. We did not find this acquired channelopathy in ventral CA1 neurons post-SE. Our results suggest that the excitability of dorsal CA1 neurons post-SE increase to resemble the intrinsic properties of ventral CA1 neurons, which likely makes the hippocampal circuit more permissible to seizures, and contributes to the cognitive impairments associated with chronic epilepsy.
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Affiliation(s)
- Elizabeth C. Arnold
- Institute for Neuroscience, University of Texas at Austin, Austin, TX 78712
- Center for Learning and Memory, University of Texas at Austin, Austin, TX 78712
| | - Calli McMurray
- Center for Learning and Memory, University of Texas at Austin, Austin, TX 78712
| | - Richard Gray
- Center for Learning and Memory, University of Texas at Austin, Austin, TX 78712
| | - Daniel Johnston
- Institute for Neuroscience, University of Texas at Austin, Austin, TX 78712
- Center for Learning and Memory, University of Texas at Austin, Austin, TX 78712
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20
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Duarte JTC, Jardim AP, Comper SM, De Marchi LR, Gaça LB, Garcia MTFC, Sandim GB, Assunção-Leme IB, Carrete H, Centeno RS, Lancellotti CLP, Jackowski AP, Cavalheiro EA, Guaranha MSB, Yacubian EMT. The impact of epilepsy duration in a series of patients with mesial temporal lobe epilepsy due to unilateral hippocampal sclerosis. Epilepsy Res 2018; 147:51-57. [DOI: 10.1016/j.eplepsyres.2018.08.009] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2017] [Revised: 08/04/2018] [Accepted: 08/21/2018] [Indexed: 10/28/2022]
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21
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Wallace E, Wright S, Schoenike B, Roopra A, Rho JM, Maganti RK. Altered circadian rhythms and oscillation of clock genes and sirtuin 1 in a model of sudden unexpected death in epilepsy. Epilepsia 2018; 59:1527-1539. [DOI: 10.1111/epi.14513] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/18/2018] [Indexed: 12/25/2022]
Affiliation(s)
- Eli Wallace
- Cellular and Molecular Pathology Graduate Program; University of Wisconsin School of Medicine and Public Health; Madison WI USA
- Department of Neuroscience; University of Wisconsin School of Medicine and Public Health; Madison WI USA
- Department of Neurology; University of Wisconsin School of Medicine and Public Health; Madison WI USA
| | - Samantha Wright
- Department of Neurology; University of Wisconsin School of Medicine and Public Health; Madison WI USA
| | - Barry Schoenike
- Department of Neuroscience; University of Wisconsin School of Medicine and Public Health; Madison WI USA
| | - Avtar Roopra
- Department of Neuroscience; University of Wisconsin School of Medicine and Public Health; Madison WI USA
| | - Jong M. Rho
- Departments of Pediatrics, Clinical Neurosciences, and Physiology & Pharmacology; Alberta Children's Hospital Research Institute; Cumming School of Medicine; University of Calgary; Calgary Alberta Canada
| | - Rama K. Maganti
- Department of Neurology; University of Wisconsin School of Medicine and Public Health; Madison WI USA
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22
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Scharfman HE, Kanner AM, Friedman A, Blümcke I, Crocker CE, Cendes F, Diaz-Arrastia R, Förstl H, Fenton AA, Grace AA, Palop J, Morrison J, Nehlig A, Prasad A, Wilcox KS, Jette N, Pohlmann-Eden B. Epilepsy as a Network Disorder (2): What can we learn from other network disorders such as dementia and schizophrenia, and what are the implications for translational research? Epilepsy Behav 2018; 78:302-312. [PMID: 29097123 PMCID: PMC5756681 DOI: 10.1016/j.yebeh.2017.09.016] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/11/2017] [Revised: 09/18/2017] [Accepted: 09/18/2017] [Indexed: 12/18/2022]
Abstract
There is common agreement that many disorders of the central nervous system are 'complex', that is, there are many potential factors that influence the development of the disease, underlying mechanisms, and successful treatment. Most of these disorders, unfortunately, have no cure at the present time, and therapeutic strategies often have debilitating side effects. Interestingly, some of the 'complexities' of one disorder are found in another, and the similarities are often network defects. It seems likely that more discussions of these commonalities could advance our understanding and, therefore, have clinical implications or translational impact. With this in mind, the Fourth International Halifax Epilepsy Conference and Retreat was held as described in the prior paper, and this companion paper focuses on the second half of the meeting. Leaders in various subspecialties of epilepsy research were asked to address aging and dementia or psychosis in people with epilepsy (PWE). Commonalities between autism, depression, aging and dementia, psychosis, and epilepsy were the focus of the presentations and discussion. In the last session, additional experts commented on new conceptualization of translational epilepsy research efforts. Here, the presentations are reviewed, and salient points are highlighted.
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Affiliation(s)
- Helen E Scharfman
- Departments of Psychiatry, Neurosciences and Physiology, and the Neuroscience Institute, New York University Langone Medical Center, New York, NY 10016, USA.
| | - Andres M Kanner
- University of Miami, Miller School of Medicine, 1120 NW 14th Street, Room #1324, Miami, FL 33136, USA
| | - Alon Friedman
- Department of Medical Neuroscience, Faculty of Medicine, Dalhousie University, Halifax, NS, Canada; Department of Pediatrics, Faculty of Medicine, Dalhousie University, Halifax, NS, Canada; Department of Physiology and Cell Biology, Zlotowski Center for Neuroscience, Ben-Gurion University of the Negev, Beer-Sheva, Israel
| | - Ingmar Blümcke
- Neuropathological Institute, University Hospitals Erlangen, Germany
| | - Candice E Crocker
- Nova Scotia Early Psychosis Program, Department of Psychiatry, Dalhousie University, Halifax, NS, Canada
| | - Fernando Cendes
- Department of Neurology, University of Campinas, 13083-888 Campinas, Sao Paulo, Brazil
| | - Ramon Diaz-Arrastia
- Centre for Neuroscience & Regenerative Medicine, Uniformed Services University of the Health Sciences, 12725 Twinbrook Parkway, Rockville, MD 20852, USA
| | - Hans Förstl
- Department of Psychiatry, University of Munich, Klinikum rechts der Isar, Ismaninger Strabe 22, D-81675 Munich, Germany
| | - André A Fenton
- Centre for Neural Science, New York University, 4 Washington Place, Room 809, New York, NY 10003, USA
| | - Anthony A Grace
- University of Pittsburgh, 456 Langley Hall, 4200 Fifth Avenue, Pittsburgh, PA 15269, USA
| | - Jorge Palop
- Department of Neurology, Gladstone Institute, 1650 Owens Street, San Francisco, CA 94158-2261, USA
| | - Jason Morrison
- Department of Psychiatry, Dalhousie University, Halifax, NS, Canada
| | - Astrid Nehlig
- INSERM U 1129, Hôpital Necker, Paris, Faculty of Medicine, Strasbourg, France
| | - Asuri Prasad
- Department of Pediatrics, Children's Hospital of Western Ontario, London, ON, Canada
| | - Karen S Wilcox
- Department of Pharmacology & Toxicology, Anticonvulsant Drug Development Program, University of Utah, Salt Lake City, UT, USA
| | - Nathalie Jette
- Icahn School of Medicine at Mount Sinai, Department of Neurology, New York, NY, USA; Department of Clinical Neurosciences, University of Calgary, Calgary, Alberta, Canada
| | - Bernd Pohlmann-Eden
- Brain Repair Center, Life Science Research Institute, Dalhousie University, Room 229, PO Box 15000, Halifax, NS B3H4R2, Canada.
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Progressive cortical reorganisation: A framework for investigating structural changes in schizophrenia. Neurosci Biobehav Rev 2017; 79:1-13. [DOI: 10.1016/j.neubiorev.2017.04.028] [Citation(s) in RCA: 53] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2017] [Revised: 04/26/2017] [Accepted: 04/26/2017] [Indexed: 12/27/2022]
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Zhang Z, Liao W, Xu Q, Wei W, Zhou HJ, Sun K, Yang F, Mantini D, Ji X, Lu G. Hippocampus-associated causal network of structural covariance measuring structural damage progression in temporal lobe epilepsy. Hum Brain Mapp 2016; 38:753-766. [PMID: 27677885 DOI: 10.1002/hbm.23415] [Citation(s) in RCA: 52] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2015] [Revised: 08/24/2016] [Accepted: 09/21/2016] [Indexed: 01/06/2023] Open
Abstract
In mesial temporal lobe epilepsy (mTLE), the causal relationship of morphometric alterations between hippocampus and the other regions, that is, how the hippocampal atrophy leads to progressive morphometric alterations in the epileptic network regions remains largely unclear. In this study, a causal network of structural covariance (CaSCN) was proposed to map the causal effects of hippocampal atrophy on the network-based morphometric alterations in mTLE. It was hypothesized that if cross-sectional morphometric MRI data could be attributed temporal information, for example, by sequencing the data according to disease progression information, GCA would be a feasible approach for constructing a CaSCN. Based on a large cohort of mTLE patients (n = 108), the hippocampus-associated CaSCN revealed that the hippocampus and the thalamus were prominent nodes exerting causal effects (i.e., GM reduction) on other regions and that the prefrontal cortex and cerebellum were prominent nodes being subject to causal effects. Intriguingly, compensatory increased gray matter volume in the contralateral temporal region and post cingulate cortex were also detected. The method unraveled richer information for mapping network atrophy in mTLE relative to the traditional methods of stage-specific comparisons and structured covariance network. This study provided new evidence on the network spread mechanism in terms of the causal influence of hippocampal atrophy on progressive brain structural alterations in mTLE. Hum Brain Mapp 38:753-766, 2017. © 2016 Wiley Periodicals, Inc.
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Affiliation(s)
- Zhiqiang Zhang
- Department of Medical Imaging, Jinling Hospital, Nanjing University School of Medicine, Nanjing, 210002, China.,State Key Laboratory of Analytical Chemistry for Life Science, Nanjing University, Nanjing, 210093, China
| | - Wei Liao
- Department of Medical Imaging, Jinling Hospital, Nanjing University School of Medicine, Nanjing, 210002, China.,Center for Cognition and Brain Disorders, Affiliated Hospital of Hangzhou Normal University, Hangzhou, 310015, China
| | - Qiang Xu
- Department of Medical Imaging, Jinling Hospital, Nanjing University School of Medicine, Nanjing, 210002, China
| | - Wei Wei
- Department of Medical Imaging, Jinling Hospital, Nanjing University School of Medicine, Nanjing, 210002, China
| | - Helen Juan Zhou
- Center for Cognitive Neuroscience, Neuroscience and Behavioral Disorder Program, Duke-NUS Graduate Medical School, National University of Singapore, Singapore, Singapore
| | - Kangjian Sun
- Department of Neurosurgery, Jinling Hospital, Nanjing University School of Medicine, Nanjing, 210002, China
| | - Fang Yang
- Department of Neurology, Jinling Hospital, Nanjing University School of Medicine, Nanjing, 210002, China
| | - Dante Mantini
- Faculty of Kinesiology and Rehabilitation Sciences, KU Leuven, Belgium
| | - Xueman Ji
- Department of Medical Imaging, Jinling Hospital, Nanjing University School of Medicine, Nanjing, 210002, China
| | - Guangming Lu
- Department of Medical Imaging, Jinling Hospital, Nanjing University School of Medicine, Nanjing, 210002, China.,State Key Laboratory of Analytical Chemistry for Life Science, Nanjing University, Nanjing, 210093, China
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Singh P, Kaur R, Saggar K, Singh G, Aggarwal S. Amygdala Volumetry in Patients with Temporal Lobe Epilepsy and Normal Magnetic Resonance Imaging. Pol J Radiol 2016; 81:212-8. [PMID: 27231493 PMCID: PMC4865273 DOI: 10.12659/pjr.896077] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2015] [Accepted: 10/27/2015] [Indexed: 11/09/2022] Open
Abstract
BACKGROUND It has been suggested that the pathophysiology of temporal lobe epilepsy may relate to abnormalities in various brain structures, including the amygdala. Patients with mesial temporal lobe epilepsy (MTLE) without MRI abnormalities (MTLE-NMRI) represent a challenge for diagnosis of the underlying abnormality and for presurgical evaluation. To date, however, only few studies have used quantitative structural Magnetic Resonance Imaging-based techniques to examine amygdalar pathology in these patients. MATERIAL/METHODS Based on clinical examination, 24-hour video EEG recordings and MRI findings, 50 patients with EEG lateralized TLE and normal structural Magnetic Resonance Imaging results were included in this study. Volumetric magnetic resonance imaging (MRI) studies of the amygdalas and hippocampi were conducted in 50 non-epileptic controls (age 7-79 years) and 50 patients with MTLE with normal MRI on a 1.5-Tesla scanner. Visual assessment and amygdalar volumetry were performed on oblique coronal T2W and T1W MP-RAGE images respectively. The T2 relaxation times were measured using the 16-echo Carr-Purcell-Meiboom-Gill sequence (TE, 22-352). Volumetric data were normalized for variation in head size between individuals. Results were assessed by SSPS statistic program. RESULTS Individual manual volumetric analysis confirmed statistically significant amygdala enlargement (AE) in eight (16%) patients. Overall, among all patients with AE and a defined epileptic focus, 7 had predominant increased volume ipsilateral to the epileptic focus. The T2 relaxometry demonstrated no hyperintense signal of the amygdala in any patient with significant AE. CONCLUSIONS This paper presented AE in a few patients with TLE and normal MRI. These findings support the hypothesis that there might be a subgroup of patients with MTLE-NMRI in which the enlarged amygdala could be related to the epileptogenic process.
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Affiliation(s)
- Paramdeep Singh
- Department of Radiology, Guru Gobind Singh Medical College and Hospital, Baba Farid University of Health Sciences, Faridkot, India
| | - Rupinderjeet Kaur
- Department of Medicine, Guru Gobind Singh Medical College and Hospital, Baba Farid University of Health Sciences, Faridkot, India
| | - Kavita Saggar
- Department of Radiology, Dayanand Medical College and Hospital, Ludhiana, India
| | - Gagandeep Singh
- Department of Neurology, Dayanand Medical College and Hospital, Ludhiana, India
| | - Simmi Aggarwal
- Department of Radiology, Guru Gobind Singh Medical College and Hospital, Baba Farid University of Health Sciences, Faridkot, India
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Wu C, Boorman DW, Gorniak RJ, Farrell CJ, Evans JJ, Sharan AD. The effects of anatomic variations on stereotactic laser amygdalohippocampectomy and a proposed protocol for trajectory planning. Neurosurgery 2015; 11 Suppl 2:345-56; discussion 356-7. [PMID: 25850599 DOI: 10.1227/neu.0000000000000767] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND Stereotactic laser amygdalohippocampectomy (SLAH) is a promising minimally invasive alternative for mesial temporal lobe epilepsy. As seizure outcome has been associated with the extent of amygdalar and hippocampal ablation, it is important to select a safe trajectory optimizing involvement of both structures; however, variations in temporal anatomy significantly affect the overall complexity of planning. OBJECTIVE To quantify anatomic variables of SLAH and facilitate stereotactic planning by developing a protocol for optimally targeting the amygdalohippocampal complex (AHC). METHODS We performed a retrospective analysis of 19 SLAHs. Anatomic measurements from preoperative magnetic resonance imaging and laser trajectory measurements from coregistered postoperative magnetic resonance imaging were taken in 11 patients. Simple linear regression analysis was performed to identify significant predictor variables determining ablation extent. Based on these data, a protocol for optimal trajectory planning was developed and subsequently implemented in 8 patients. RESULTS The medial angle of the laser trajectory correlated with the medial angle of the AHC. The length of amygdalar cannulation was predictive of its ablation volume. All trajectories passed through a posteroinferior corridor formed by the lateral ventricle superiorly and collateral sulcus inferiorly. Our protocol facilitated planning and increased the volume of AHC ablation. CONCLUSION The medial AHC angle dictates the medial trajectory angle and a path from the posteroinferior corridor through the hippocampus and the center of the amygdala dictates the caudal angle. These observations led to a protocol for long-axis AHC cannulation that maintains an extraventricular trajectory to minimize hemorrhage risk and targets the center of the amygdala to optimize ablation volumes.
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Affiliation(s)
- Chengyuan Wu
- Departments of *Neurosurgery and ‡Radiology, Thomas Jefferson University, Philadelphia, Pennsylvania
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27
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Pohlmann-Eden B, Aldenkamp A, Baker GA, Brandt C, Cendes F, Coras R, Crocker CE, Helmstaedter C, Jones-Gotman M, Kanner AM, Mazarati A, Mula M, Smith ML, Omisade A, Tellez-Zenteno J, Hermann BP. The relevance of neuropsychiatric symptoms and cognitive problems in new-onset epilepsy - Current knowledge and understanding. Epilepsy Behav 2015; 51:199-209. [PMID: 26291774 DOI: 10.1016/j.yebeh.2015.07.005] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/24/2015] [Accepted: 07/03/2015] [Indexed: 01/11/2023]
Abstract
Neurobehavioral and cognition problems are highly prevalent in epilepsy, but most research studies to date have not adequately addressed the precise nature of the relationship between these comorbidities and seizures. To address this complex issue and to facilitate collaborative, innovative research in the rising field of neurobehavioral comorbidities and cognition disturbances in new-onset epilepsy, international epilepsy experts met at the 3rd Halifax International Epilepsy Conference & Retreat at White Point, South Shore, Nova Scotia, Canada from September 18 to 20, 2014. This Conference Proceedings provides a summary of the conference proceedings. Specifically, the following topics are discussed: (i) role of comorbidities in epilepsy diagnosis and management, (ii) role of antiepileptic medications in understanding the relationship between epilepsy and neurobehavioral and cognition problems, and (iii) animal data and diagnostic approaches. Evidence to date, though limited, strongly suggests a bidirectional relationship between epilepsy and cognitive and psychiatric comorbidities. In fact, it is likely that seizures and neurobehavioral problems represent different symptoms of a common etiology or network-wide disturbance. As a reflection of this shared network, psychiatric comorbidities and/or cognition problems may actually precede the seizure occurrence and likely get often missed if not screened.
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Affiliation(s)
- B Pohlmann-Eden
- Division of Neurology, Dalhousie University of Halifax, Canada; Brain Repair Center, Dalhousie University of Halifax, Canada.
| | - A Aldenkamp
- Epilepsiecentrum Kempenhaeghe, The Netherlands
| | - G A Baker
- Division of Neurosciences, University of Liverpool, United Kingdom
| | - C Brandt
- Bethel Epilepsy Center, Mara Hospital, Bielefeld, Germany
| | - F Cendes
- Department of Neurology, University of Campinas, São Paulo, Brazil
| | - R Coras
- Department of Neuropathology, University of Erlangen, Germany
| | - C E Crocker
- Division of Neurology, Dalhousie University of Halifax, Canada
| | | | - M Jones-Gotman
- McGill University, Montreal Neurological Institute, Montreal, Canada
| | - A M Kanner
- Epilepsy Center, University of Miami, Miller School of Medicine, USA
| | - A Mazarati
- Children's Discovery and Innovation Institute, D. Geffen School of Medicine at UCLA, Los Angeles, USA
| | - M Mula
- Epilepsy Group, Atkinson Morley Regional Neuroscience Centre, St. George's University Hospitals NHS Foundation Trust and Institute of Medical and Biomedical Sciences St. George's University of London, United Kingdom
| | - M L Smith
- Department of Psychology, University of Toronto, Canada
| | - A Omisade
- Division of Neurology, Dalhousie University of Halifax, Canada
| | | | - B P Hermann
- Department of Neurology, University of Wisconsin School of Medicine and Public Health, Madison, USA
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28
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Laxer KD, Trinka E, Hirsch LJ, Cendes F, Langfitt J, Delanty N, Resnick T, Benbadis SR. The consequences of refractory epilepsy and its treatment. Epilepsy Behav 2014; 37:59-70. [PMID: 24980390 DOI: 10.1016/j.yebeh.2014.05.031] [Citation(s) in RCA: 431] [Impact Index Per Article: 43.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/24/2014] [Revised: 05/27/2014] [Accepted: 05/29/2014] [Indexed: 12/12/2022]
Abstract
Seizures in some 30% to 40% of patients with epilepsy fail to respond to antiepileptic drugs or other treatments. While much has been made of the risks of new drug therapies, not enough attention has been given to the risks of uncontrolled and progressive epilepsy. This critical review summarizes known risks associated with refractory epilepsy, provides practical clinical recommendations, and indicates areas for future research. Eight international epilepsy experts from Europe, the United States, and South America met on May 4, 2013, to present, review, and discuss relevant concepts, data, and literature on the consequences of refractory epilepsy. While patients with refractory epilepsy represent the minority of the population with epilepsy, they require the overwhelming majority of time, effort, and focus from treating physicians. They also represent the greatest economic and psychosocial burdens. Diagnostic procedures and medical/surgical treatments are not without risks. Overlooked, however, is that these risks are usually smaller than the risks of long-term, uncontrolled seizures. Refractory epilepsy may be progressive, carrying risks of structural damage to the brain and nervous system, comorbidities (osteoporosis, fractures), and increased mortality (from suicide, accidents, sudden unexpected death in epilepsy, pneumonia, vascular disease), as well as psychological (depression, anxiety), educational, social (stigma, driving), and vocational consequences. Adding to this burden is neuropsychiatric impairment caused by underlying epileptogenic processes ("essential comorbidities"), which appears to be independent of the effects of ongoing seizures themselves. Tolerating persistent seizures or chronic medicinal adverse effects has risks and consequences that often outweigh risks of seemingly "more aggressive" treatments. Future research should focus not only on controlling seizures but also on preventing these consequences.
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Affiliation(s)
- Kenneth D Laxer
- Sutter Pacific Epilepsy Program, California Pacific Medical Center, San Francisco, CA, USA.
| | - Eugen Trinka
- Department of Neurology, Christian Doppler Medical Centre, Paracelsus Medical University, Salzburg, Austria; Centre for Cognitive Neuroscience, Salzburg, Austria
| | - Lawrence J Hirsch
- Division of Epilepsy and EEG, Department of Neurology, Yale Comprehensive Epilepsy Center, New Haven, CT, USA
| | - Fernando Cendes
- Department of Neurology, University of Campinas (UNICAMP), Campinas, Brazil
| | - John Langfitt
- Department of Neurology, University of Rochester School of Medicine, Rochester, NY, USA; Department Psychiatry, University of Rochester School of Medicine, Rochester, NY, USA; Strong Epilepsy Center, University of Rochester School of Medicine, Rochester, NY, USA
| | - Norman Delanty
- Epilepsy Service and National Epilepsy Surgery Programme, Beaumont Hospital, Dublin, Ireland
| | - Trevor Resnick
- Comprehensive Epilepsy Program, Miami Children's Hospital, Miami, FL, USA
| | - Selim R Benbadis
- Comprehensive Epilepsy Program, University of South Florida, Tampa, FL, USA
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29
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Cendes F, Sakamoto AC, Spreafico R, Bingaman W, Becker AJ. Epilepsies associated with hippocampal sclerosis. Acta Neuropathol 2014; 128:21-37. [PMID: 24823761 DOI: 10.1007/s00401-014-1292-0] [Citation(s) in RCA: 93] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2014] [Revised: 05/05/2014] [Accepted: 05/06/2014] [Indexed: 01/22/2023]
Abstract
Hippocampal sclerosis (HS) is considered the most frequent neuropathological finding in patients with mesial temporal lobe epilepsy (MTLE). Hippocampal specimens of pharmacoresistant MTLE patients that underwent epilepsy surgery for seizure control reveal the characteristic pattern of segmental neuronal cell loss and concomitant astrogliosis. However, classification issues of hippocampal lesion patterns have been a matter of intense debate. International consensus classification has only recently provided significant progress for comparisons of neurosurgical and clinic-pathological series between different centers. The respective four-tiered classification system of the International League Against Epilepsy subdivides HS into three types and includes a term of "gliosis only, no-HS". Future studies will be necessary to investigate whether each of these subtypes of HS may be related to different etiological factors or with postoperative memory and seizure outcome. Molecular studies have provided potential deeper insights into the pathogenesis of HS and MTLE on the basis of epilepsy-surgical hippocampal specimens and corresponding animal models. These include channelopathies, activation of NMDA receptors, and other conditions related to Ca(2+) influx into neurons, the imbalance of Ca(2+)-binding proteins, acquired channelopathies that increase neuronal excitability, paraneoplastic and non-paraneoplastic inflammatory events, and epigenetic regulation promoting or facilitating hippocampal epileptogenesis. Genetic predisposition for HS is clearly suggested by the high incidence of family history in patients with HS, and by familial MTLE with HS. So far, it is clear that HS is multifactorial and there is no individual pathogenic factor either necessary or sufficient to generate this intriguing histopathological condition. The obvious variety of pathogenetic combinations underlying HS may explain the multitude of clinical presentations, different responses to clinical and surgical treatment. We believe that the stratification of neuropathological patterns can help to characterize specific clinic-pathological entities and predict the postsurgical seizure control in an improved fashion.
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30
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Coan AC, Morita ME, Campos BM, Bergo FPG, Kubota BY, Cendes F. Amygdala enlargement occurs in patients with mesial temporal lobe epilepsy and hippocampal sclerosis with early epilepsy onset. Epilepsy Behav 2013; 29:390-4. [PMID: 24074891 DOI: 10.1016/j.yebeh.2013.08.022] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/17/2013] [Revised: 08/21/2013] [Accepted: 08/22/2013] [Indexed: 10/26/2022]
Abstract
Mesial temporal lobe epilepsy (MTLE) associated with hippocampal sclerosis (HS) is considered an electroclinical syndrome, and there is a debate whether it is a unique disease or an entity with distinct subtypes. Together with other mesial temporal structures, the amygdala is important in the epileptogenic network of patients with MTLE with HS. During automatic volumetric analysis of mesial structures in a group of 102 patients with MTLE with MRI signs of HS, we observed significant amygdala enlargement in 14 (14%) individuals compared to a group of 79 healthy subjects. The increased amygdala volume was contralateral to the epileptogenic zone and MRI signs of HS in 93% of these patients. Patients with MTLE with HS and enlarged amygdala had significantly earlier epilepsy onset than those without an increase of amygdala volumes. Mesial temporal lobe epilepsy with HS and enlarged amygdala may be a part of the spectrum of this condition.
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Affiliation(s)
- Ana C Coan
- Neuroimaging Laboratory, Department of Neurology, State University of Campinas, Campinas, SP, Brazil.
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31
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Bernhardt BC, Hong S, Bernasconi A, Bernasconi N. Imaging structural and functional brain networks in temporal lobe epilepsy. Front Hum Neurosci 2013; 7:624. [PMID: 24098281 PMCID: PMC3787804 DOI: 10.3389/fnhum.2013.00624] [Citation(s) in RCA: 158] [Impact Index Per Article: 14.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2013] [Accepted: 09/09/2013] [Indexed: 11/24/2022] Open
Abstract
Early imaging studies in temporal lobe epilepsy (TLE) focused on the search for mesial temporal sclerosis, as its surgical removal results in clinically meaningful improvement in about 70% of patients. Nevertheless, a considerable subgroup of patients continues to suffer from post-operative seizures. Although the reasons for surgical failure are not fully understood, electrophysiological and imaging data suggest that anomalies extending beyond the temporal lobe may have negative impact on outcome. This hypothesis has revived the concept of human epilepsy as a disorder of distributed brain networks. Recent methodological advances in non-invasive neuroimaging have led to quantify structural and functional networks in vivo. While structural networks can be inferred from diffusion MRI tractography and inter-regional covariance patterns of structural measures such as cortical thickness, functional connectivity is generally computed based on statistical dependencies of neurophysiological time-series, measured through functional MRI or electroencephalographic techniques. This review considers the application of advanced analytical methods in structural and functional connectivity analyses in TLE. We will specifically highlight findings from graph-theoretical analysis that allow assessing the topological organization of brain networks. These studies have provided compelling evidence that TLE is a system disorder with profound alterations in local and distributed networks. In addition, there is emerging evidence for the utility of network properties as clinical diagnostic markers. Nowadays, a network perspective is considered to be essential to the understanding of the development, progression, and management of epilepsy.
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Affiliation(s)
- Boris C Bernhardt
- Neuroimaging of Epilepsy Laboratory, 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
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