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Samanta D, Aungaroon G, Albert GW, Karakas C, Joshi CN, Singh RK, Oluigbo C, Perry MS, Naik S, Reeders PC, Jain P, Abel TJ, Pati S, Shaikhouni A, Haneef Z. Advancing thalamic neuromodulation in epilepsy: Bridging adult data to pediatric care. Epilepsy Res 2024; 205:107407. [PMID: 38996686 DOI: 10.1016/j.eplepsyres.2024.107407] [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: 04/02/2024] [Revised: 06/27/2024] [Accepted: 07/01/2024] [Indexed: 07/14/2024]
Abstract
Thalamic neuromodulation has emerged as a treatment option for drug-resistant epilepsy (DRE) with widespread and/or undefined epileptogenic networks. While deep brain stimulation (DBS) and responsive neurostimulation (RNS) depth electrodes offer means for electrical stimulation of the thalamus in adult patients with DRE, the application of thalamic neuromodulation in pediatric epilepsy remains limited. To address this gap, the Neuromodulation Expert Collaborative was established within the Pediatric Epilepsy Research Consortium (PERC) Epilepsy Surgery Special Interest Group. In this expert review, existing evidence and recommendations for thalamic neuromodulation modalities using DBS and RNS are summarized, with a focus on the anterior (ANT), centromedian(CMN), and pulvinar nuclei of the thalamus. To-date, only DBS of the ANT is FDA approved for treatment of DRE in adult patients based on the results of the pivotal SANTE (Stimulation of the Anterior Nucleus of Thalamus for Epilepsy) study. Evidence for other thalamic neurmodulation indications and targets is less abundant. Despite the lack of evidence, positive responses to thalamic stimulation in adults with DRE have led to its off-label use in pediatric patients. Although caution is warranted due to differences between pediatric and adult epilepsy, the efficacy and safety of pediatric neuromodulation appear comparable to that in adults. Indeed, CMN stimulation is increasingly accepted for generalized and diffuse onset epilepsies, with recent completion of one randomized trial. There is also growing interest in using pulvinar stimulation for temporal plus and posterior quadrant epilepsies with one ongoing clinical trial in Europe. The future of thalamic neuromodulation holds promise for revolutionizing the treatment landscape of childhood epilepsy. Ongoing research, technological advancements, and collaborative efforts are poised to refine and improve thalamic neuromodulation strategies, ultimately enhancing the quality of life for children with DRE.
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Affiliation(s)
- Debopam Samanta
- Division of Child Neurology, Department of Pediatrics, University of Arkansas for Medical Sciences, Little Rock, AR, USA.
| | - Gewalin Aungaroon
- Comprehensive Epilepsy Center, Division of Neurology, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, USA; Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati, OH, USA
| | - Gregory W Albert
- Department of Neurosurgery, University of Arkansas for Medical Sciences, USA
| | - Cemal Karakas
- Division of Pediatric Neurology, Department of Neurology, Norton Children's Hospital, University of Louisville, Louisville, KY 40202, USA
| | - Charuta N Joshi
- Division of Pediatric Neurology, Childrens Medical Center Dallas, UTSW, USA
| | - Rani K Singh
- Department of Pediatrics, Atrium Health-Levine Children's; Wake Forest University School of Medicine, USA
| | - Chima Oluigbo
- Department of Neurosurgery, Children's National Hospital, Washington, DC, USA
| | - M Scott Perry
- Jane and John Justin Institute for Mind Health, Cook Children's Medical Center, Ft Worth, TX, USA
| | - Sunil Naik
- Department of Pediatrics and Neurology, Penn State Health Milton S. Hershey Medical Center, Hershey, PA 17033, USA
| | - Puck C Reeders
- Brain Institute, Nicklaus Children's Hospital, Miami, FL, USA
| | - Puneet Jain
- Epilepsy Program, Division of Neurology, Department of Pediatrics, Hospital for Sick Children, University of Toronto, Toronto, Ontario, Canada
| | - Taylor J Abel
- Department of Neurological Surgery, University of Pittsburgh School of Medicine and Department of Bioengineering, University of Pittsburgh
| | - Sandipan Pati
- The University of Texas Health Science Center at Houston, USA
| | - Ammar Shaikhouni
- Department of Pediatric Neurosurgery, Nationwide Children's Hospital, The Ohio State University, Columbus, OH, USA
| | - Zulfi Haneef
- Neurology Care Line, VA Medical Center, Houston, TX 77030, USA; Department of Neurology, Baylor College of Medicine, Houston, TX 77030, USA
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2
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Nathan CL, Gavvala JR, Chaitanya G, Cunningham E, Lee JJ, Adney S, Rosenow J, Schuele S, Gerard E. High-Frequency Stimulation of the Centromedian Thalamic Nucleus Aborts Seizures and Ictal Apnea. J Clin Neurophysiol 2024; 41:570-574. [PMID: 38916942 DOI: 10.1097/wnp.0000000000001098] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/26/2024] Open
Abstract
SUMMARY A 32-year-old right-handed woman presented with medically and surgically refractory left temporal neocortical epilepsy secondary to focal cortical dysplasia who underwent stereoelectroencephalography involving the centromedian nucleus of the thalamus. With the use of real-time stereoelectroencephalography monitoring, four electroclinical seizures were aborted by administering high-frequency stimulation at the centromedian nucleus at seizure onset. Seizures before stimulation were all associated with ictal apnea, while those with stimulation had no ictal apnea. This case demonstrates how providing high-frequency stimulation to the centromedian nucleus of the thalamus can abort electroclinical seizures and ictal apnea.
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Affiliation(s)
- Cody L Nathan
- Department of Neurology, Northwestern University Feinberg School of Medicine, Chicago, Illinois, U.S.A
| | - Jay R Gavvala
- Department of Neurology, UT Health Houston McGovern School of Medicine, Houston, Texas, U.S.A
| | - Ganne Chaitanya
- Department of Neurology, UT Health Houston McGovern School of Medicine, Houston, Texas, U.S.A
| | - Elizabeth Cunningham
- Department of Neurology, Northwestern University Feinberg School of Medicine, Chicago, Illinois, U.S.A
| | - Jungwha Julia Lee
- Department of Preventive Medicine, Northwestern University Feinberg School of Medicine, Chicago, Illinois, U.S.A.; and
| | - Scott Adney
- Department of Neurology, Northwestern University Feinberg School of Medicine, Chicago, Illinois, U.S.A
| | - Joshua Rosenow
- Department of Neurosurgery, Northwestern University Feinberg School of Medicine, Chicago, Illinois, U.S.A
| | - Stephan Schuele
- Department of Neurology, Northwestern University Feinberg School of Medicine, Chicago, Illinois, U.S.A
| | - Elizabeth Gerard
- Department of Neurology, Northwestern University Feinberg School of Medicine, Chicago, Illinois, U.S.A
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Nanda P, Sisterson N, Walton A, Chu CJ, Cash SS, Moura LMVR, Oster JM, Urban A, Richardson RM. Centromedian region thalamic responsive neurostimulation mitigates idiopathic generalized and multifocal epilepsy with focal to bilateral tonic-clonic seizures. Epilepsia 2024. [PMID: 39052021 DOI: 10.1111/epi.18070] [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: 04/23/2024] [Revised: 07/03/2024] [Accepted: 07/10/2024] [Indexed: 07/27/2024]
Abstract
OBJECTIVE Although >30% of epilepsy patients have drug-resistant epilepsy (DRE), typically those with generalized or multifocal disease have not traditionally been considered surgical candidates. Responsive neurostimulation (RNS) of the centromedian (CM) region of the thalamus now appears to be a promising therapeutic option for this patient population. We present outcomes following CM RNS for 13 patients with idiopathic generalized epilepsy (IGE) and eight with multifocal onsets that rapidly generalize to bilateral tonic-clonic (focal to bilateral tonic-clonic [FBTC]) seizures. METHODS A retrospective review of all patients undergoing bilateral CM RNS by the senior author through July 2022 were reviewed. Electrodes were localized and volumes of tissue activation were modeled in Lead-DBS. Changes in patient seizure frequency were extracted from electronic medical records. RESULTS Twenty-one patients with DRE underwent bilateral CM RNS implantation. For 17 patients with at least 1 year of postimplantation follow-up, average seizure reduction from preoperative baseline was 82.6% (SD = 19.0%, median = 91.7%), with 18% of patients Engel class 1, 29% Engel class 2, 53% Engel class 3, and 0% Engel class 4. There was a trend for average seizure reduction to be greater for patients with nonlesional FBTC seizures than for other patients. For patients achieving at least Engel class 3 outcome, median time to worthwhile seizure reduction was 203.5 days (interquartile range = 110.5-343.75 days). Patients with IGE with myoclonic seizures had a significantly shorter time to worthwhile seizure reduction than other patients. The surgical targeting strategy evolved after the first four subjects to achieve greater anatomic accuracy. SIGNIFICANCE Patients with both primary and rapidly generalized epilepsy who underwent CM RNS experienced substantial seizure relief. Subsets of these patient populations may particularly benefit from CM RNS. The refinement of lead targeting, tuning of RNS system parameters, and patient selection are ongoing areas of investigation.
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Affiliation(s)
- Pranav Nanda
- Department of Neurosurgery, Massachusetts General Hospital, Boston, Massachusetts, USA
- Department of Neurosurgery, Harvard Medical School, Boston, Massachusetts, USA
| | - Nathaniel Sisterson
- Department of Neurosurgery, Massachusetts General Hospital, Boston, Massachusetts, USA
- Department of Neurosurgery, Harvard Medical School, Boston, Massachusetts, USA
| | - Ashley Walton
- Department of Neurosurgery, Massachusetts General Hospital, Boston, Massachusetts, USA
- Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA
| | - Catherine J Chu
- Department of Neurology, Massachusetts General Hospital, Boston, Massachusetts, USA
| | - Sydney S Cash
- Department of Neurology, Massachusetts General Hospital, Boston, Massachusetts, USA
| | - Lidia M V R Moura
- Department of Neurology, Massachusetts General Hospital, Boston, Massachusetts, USA
| | - Joel M Oster
- Department of Neurology, Tufts Medical Center, Boston, Massachusetts, USA
| | - Alexandra Urban
- Department of Neurology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
| | - Robert Mark Richardson
- Department of Neurosurgery, Massachusetts General Hospital, Boston, Massachusetts, USA
- Department of Neurosurgery, Harvard Medical School, Boston, Massachusetts, USA
- Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, Massachusetts, USA
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Pati S, Agashe S, Kheder A, Riley K, Gavvala J, McGovern R, Suresh S, Chaitanya G, Thompson S. Stereoelectroencephalography of the Deep Brain: Basal Ganglia and Thalami. J Clin Neurophysiol 2024; 41:423-429. [PMID: 38935656 DOI: 10.1097/wnp.0000000000001097] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/29/2024] Open
Abstract
SUMMARY Stereoelectroencephalography (SEEG) has emerged as a transformative tool in epilepsy surgery, shedding light on the complex network dynamics involved in focal epilepsy. This review explores the role of SEEG in elucidating the role of deep brain structures, namely the basal ganglia and thalamus, in epilepsy. SEEG advances understanding of their contribution to seizure generation, propagation, and control by permitting precise and minimally invasive sampling of these brain regions. The basal ganglia, comprising the subthalamic nucleus, globus pallidus, substantia nigra, and striatum, have gained recognition for their involvement in both focal and generalized epilepsy. Electrophysiological recordings reveal hyperexcitability and increased synchrony within these structures, reinforcing their role as critical nodes within the epileptic network. Furthermore, low-frequency and high-frequency stimulation of the basal ganglia have demonstrated potential in modulating epileptogenic networks. Concurrently, the thalamus, a key relay center, has garnered prominence in epilepsy research. Disrupted thalamocortical connectivity in focal epilepsy underscores its significance in seizure maintenance. The thalamic subnuclei, including the anterior nucleus, centromedian, and medial pulvinar, present promising neuromodulatory targets, suggesting pathways for personalized epilepsy therapies. The prospect of multithalamic SEEG and thalamic SEEG stimulation trials has the potential to revolutionize epilepsy management, offering tailored solutions for challenging cases. SEEG's ability to unveil the dynamics of deep brain structures in epilepsy promises enhanced and personalized epilepsy care in our new era of precision medicine. Until deep brain SEEG is accepted as a standard of care, a rigorous informed consent process remains paramount for patients for whom such an exploration is proposed.
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Affiliation(s)
- Sandipan Pati
- Texas Comprehensive Epilepsy Program, Department of Neurology, The University of Texas Health Science Center at Houston, Texas, U.S.A
| | - Shruti Agashe
- Department of Neurology, Duke Comprehensive Epilepsy Center, Duke University, Durham, North Carolina, U.S.A
| | - Ammar Kheder
- Department of Neurology, Children's Healthcare of Atlanta, Emory University, Atlanta, Georgia, U.S.A
| | - Kristen Riley
- Department of Neurosurgery, Heersink School of Medicine, University of Alabama at Birmingham, Alabama, U.S.A
| | - Jay Gavvala
- Texas Comprehensive Epilepsy Program, Department of Neurology, The University of Texas Health Science Center at Houston, Texas, U.S.A
| | - Robert McGovern
- Department of Neurosurgery, University of Minnesota, Minnesota, U.S.A.; and
| | - Surya Suresh
- Texas Comprehensive Epilepsy Program, Department of Neurology, The University of Texas Health Science Center at Houston, Texas, U.S.A
| | - Ganne Chaitanya
- Texas Comprehensive Epilepsy Program, Department of Neurology, The University of Texas Health Science Center at Houston, Texas, U.S.A
| | - Stephen Thompson
- Neurology Division of the Department of Medicine, Hamilton Health Sciences and McMaster University, Canada
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5
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Jacobs J, Klotz KA, Pizzo F, Federico P. Beyond Stereo-EEG: Is It Worth Combining Stereo-EEG With Other Diagnostic Methods? J Clin Neurophysiol 2024; 41:444-449. [PMID: 38935658 DOI: 10.1097/wnp.0000000000001086] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/29/2024] Open
Abstract
SUMMARY Stereo-EEG is a widely used method to improve the diagnostic precision of presurgical workup in patients with refractory epilepsy. Its ability to detect epileptic activity and identify epileptic networks largely depends on the chosen implantation strategy. Even in an ideal situation, electrodes record activity generated in <10% of the brain and contacts only record from brain tissue in their immediate proximity. In this article, the authors discuss how recording stereo-EEG simultaneously with other diagnostic methods can improve its diagnostic value in clinical and research settings. It can help overcome the limited spatial coverage of intracranial recording and better understand the sources of epileptic activity. Simultaneous scalp EEG is the most widely available method, often used to understand large epileptic networks, seizure propagation, and EEG activity occurring on the contralateral hemisphere. Simultaneous magnetoencephalography allows for more precise source localization and identification of deep sources outside the stereo-EEG coverage. Finally, simultaneous functional MRI can highlight metabolic changes following epileptic activity and help understand the widespread network changes associated with interictal activity. This overview highlights advantages and methodological challenges for all these methods. Clinical use and research applications are presented for each approach.
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Affiliation(s)
- Julia Jacobs
- University of Calgary, Calgary, Alberta, Canada
- University Medical Center Freiburg, University of Freiburg, Freiburg, Germany; and
| | | | - Francesca Pizzo
- Epileptology Department, INSERM, Aix Marseille Universite; Marseille, France
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6
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Lyu D, Stiger J, Lusk Z, Buch V, Parvizi J. Causal Cortical and Thalamic Connections in the Human Brain. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.06.22.600166. [PMID: 38979261 PMCID: PMC11230252 DOI: 10.1101/2024.06.22.600166] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/10/2024]
Abstract
The brain's functional architecture is intricately shaped by causal connections between its cortical and subcortical structures. Here, we studied 27 participants with 4864 electrodes implanted across the anterior, mediodorsal, and pulvinar thalamic regions, and the cortex. Using data from electrical stimulation procedures and a data-driven approach informed by neurophysiological standards, we dissociated three unique spectral patterns generated by the perturbation of a given brain area. Among these, a novel waveform emerged, marked by delayed-onset slow oscillations in both ipsilateral and contralateral cortices following thalamic stimulations, suggesting a mechanism by which a thalamic site can influence bilateral cortical activity. Moreover, cortical stimulations evoked earlier signals in the thalamus than in other connected cortical areas suggesting that the thalamus receives a copy of signals before they are exchanged across the cortex. Our causal connectivity data can be used to inform biologically-inspired computational models of the functional architecture of the brain.
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Affiliation(s)
- Dian Lyu
- Laboratory of Behavioral and Cognitive Neuroscience, Department of Neurology and Neurological Sciences, Stanford University School of Medicine, Stanford, California USA
| | - James Stiger
- Laboratory of Behavioral and Cognitive Neuroscience, Department of Neurology and Neurological Sciences, Stanford University School of Medicine, Stanford, California USA
| | - Zoe Lusk
- Laboratory of Behavioral and Cognitive Neuroscience, Department of Neurology and Neurological Sciences, Stanford University School of Medicine, Stanford, California USA
| | - Vivek Buch
- Department of Neurosurgery, Stanford University School of Medicine, Stanford, California USA
| | - Josef Parvizi
- Laboratory of Behavioral and Cognitive Neuroscience, Department of Neurology and Neurological Sciences, Stanford University School of Medicine, Stanford, California USA
- Department of Neurosurgery, Stanford University School of Medicine, Stanford, California USA
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7
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Ikegaya N, Aung T, Mallela A, Hect JL, Damiani A, Gonzalez-Martinez JA. Thalamic stereoelectroencephalography for neuromodulation target selection: Proof of concept and review of literature of pulvinar direct electrical stimulation. Epilepsia 2024; 65:e79-e86. [PMID: 38625609 DOI: 10.1111/epi.17986] [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: 11/08/2023] [Revised: 04/01/2024] [Accepted: 04/02/2024] [Indexed: 04/17/2024]
Abstract
In patients with drug-resistant epilepsy (DRE) who are not candidates for resective surgery, various thalamic nuclei, including the anterior, centromedian, and pulvinar nuclei, have been extensively investigated as targets for neuromodulation. However, the therapeutic effects of different targets for thalamic neuromodulation on various types of epilepsy are not well understood. Here, we present a 32-year-old patient with multifocal bilateral temporoparieto-occipital epilepsy and bilateral malformations of cortical development (MCDs) who underwent bilateral stereoelectroencephalographic (SEEG) recordings of the aforementioned three thalamic nuclei bilaterally. The change in the rate of interictal epileptiform discharges (IEDs) from baseline were compared in temporal, central, parietal, and occipital regions after direct electrical stimulation (DES) of each thalamic nucleus. A significant decrease in the rate of IEDs (33% from baseline) in the posterior quadrant regions was noted in the ipsilateral as well as contralateral hemisphere following DES of the pulvinar. A scoping review was also performed to better understand the current standpoint of pulvinar thalamic stimulation in the treatment of DRE. The therapeutic effect of neuromodulation can differ among thalamic nuclei targets and epileptogenic zones (EZs). In patients with multifocal EZs with extensive MCDs, personalized thalamic targeting could be achieved through DES with thalamic SEEG electrodes.
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Affiliation(s)
- Naoki Ikegaya
- Department of Neurological Surgery, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
- Department of Neurosurgery, Yokohama City University Graduate School of Medicine, Yokohama, Japan
| | - Thandar Aung
- Department of Neurological Surgery, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
- Department of Neurology, Epilepsy Center, University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania, USA
| | - Arka Mallela
- Department of Neurological Surgery, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Jasmine L Hect
- Department of Neurological Surgery, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Arianna Damiani
- Department of Neurological Surgery, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
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Luppi AI, Uhrig L, Tasserie J, Signorelli CM, Stamatakis EA, Destexhe A, Jarraya B, Cofre R. Local orchestration of distributed functional patterns supporting loss and restoration of consciousness in the primate brain. Nat Commun 2024; 15:2171. [PMID: 38462641 PMCID: PMC10925605 DOI: 10.1038/s41467-024-46382-w] [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: 07/16/2023] [Accepted: 02/26/2024] [Indexed: 03/12/2024] Open
Abstract
A central challenge of neuroscience is to elucidate how brain function supports consciousness. Here, we combine the specificity of focal deep brain stimulation with fMRI coverage of the entire cortex, in awake and anaesthetised non-human primates. During propofol, sevoflurane, or ketamine anaesthesia, and subsequent restoration of responsiveness by electrical stimulation of the central thalamus, we investigate how loss of consciousness impacts distributed patterns of structure-function organisation across scales. We report that distributed brain activity under anaesthesia is increasingly constrained by brain structure across scales, coinciding with anaesthetic-induced collapse of multiple dimensions of hierarchical cortical organisation. These distributed signatures are observed across different anaesthetics, and they are reversed by electrical stimulation of the central thalamus, coinciding with recovery of behavioural markers of arousal. No such effects were observed upon stimulating the ventral lateral thalamus, demonstrating specificity. Overall, we identify consistent distributed signatures of consciousness that are orchestrated by specific thalamic nuclei.
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Affiliation(s)
- Andrea I Luppi
- Division of Anaesthesia and Department of Clinical Neurosciences, University of Cambridge, Cambridge, UK.
- Montreal Neurological Institute, McGill University, Montreal, QC, Canada.
| | - Lynn Uhrig
- Cognitive Neuroimaging Unit, CEA, INSERM, Université Paris-Saclay, NeuroSpin Center, 91191, Gif-sur-Yvette, France
- Department of Anesthesiology and Critical Care, Necker Hospital, AP-HP, Université de Paris Cité, Paris, France
| | - Jordy Tasserie
- Cognitive Neuroimaging Unit, CEA, INSERM, Université Paris-Saclay, NeuroSpin Center, 91191, Gif-sur-Yvette, France
- Center for Brain Circuit Therapeutics, Department of Neurology, Brigham & Women's Hospital, Harvard Medical School, Boston, MA, USA
| | - Camilo M Signorelli
- Cognitive Neuroimaging Unit, CEA, INSERM, Université Paris-Saclay, NeuroSpin Center, 91191, Gif-sur-Yvette, France
- Laboratory of Neurophysiology and Movement Biomechanics, Université Libre de Bruxelles, 1070, Brussels, Belgium
- Department of Computer Science, University of Oxford, Oxford, 7 Parks Rd, Oxford, OX1 3QG, UK
| | - Emmanuel A Stamatakis
- Division of Anaesthesia and Department of Clinical Neurosciences, University of Cambridge, Cambridge, UK
| | - Alain Destexhe
- Institute of Neuroscience (NeuroPSI), Paris-Saclay University, Centre National de la Recherche Scientifique (CNRS), Gif-sur-Yvette, France
| | - Bechir Jarraya
- Cognitive Neuroimaging Unit, CEA, INSERM, Université Paris-Saclay, NeuroSpin Center, 91191, Gif-sur-Yvette, France
- Department of Neurology, Hopital Foch, 92150, Suresnes, France
| | - Rodrigo Cofre
- Institute of Neuroscience (NeuroPSI), Paris-Saclay University, Centre National de la Recherche Scientifique (CNRS), Gif-sur-Yvette, France.
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Burdette D, Patra S, Johnson L. Corticothalamic Responsive Neurostimulation for Focal Epilepsy: A Single-Center Experience. J Clin Neurophysiol 2024:00004691-990000000-00122. [PMID: 38194631 DOI: 10.1097/wnp.0000000000001060] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2024] Open
Abstract
PURPOSE Owing to its extensive, reciprocal connectivity with the cortex and other subcortical structures, the thalamus is considered an important target for neuromodulation in drug-resistant focal epilepsy. Using corticothalamic stimulation, it is possible to modulate both the thalamus and the cortical seizure onset zone. Limited published clinical experience describes corticothalamic stimulation with depth leads targeting one of the anterior (ANT), centromedian (centromedian nucleus), or pulvinar (PUL) thalamic nuclei. However, it is not clear which of these nuclei is the "best" therapeutic target. METHODS This study comprised a single-center experience with corticothalamic responsive neurostimulation using the RNS System to target these three thalamic nuclei. Presented here are the methods for target selection and device programming as well as clinical outcomes and a comparison of ictal and nonictal electrophysiological features. RESULTS In this small retrospective study (N = 19), responsive corticothalamic neurostimulation was an effective therapy for 79% of patients (≥50% reduction in disabling seizure frequency), regardless of whether the thalamic lead was implanted in the ANT (N = 2), PUL (N = 6), or centromedian nucleus (N = 11). Twenty-six percent of patients reported a reduction in disabling seizure frequency ≥90%. Both high frequency (≥100 Hz) and low (≤20 Hz) frequency were used to stimulate the thalamus depending on the patient's response and ability to tolerate higher charge densities. In all patients, a longer burst duration (2000-5000 ms) was ultimately implemented on the thalamic leads. Across patients, peaks in the intracranial EEG were observed at theta, beta, gamma, and sleep spindle frequencies. Changes in frequency content and distribution were observed over time in all three nuclei. CONCLUSIONS These results indicate that both high frequency and low frequency corticothalamic responsive neurostimulation can potentially be an effective adjunctive therapy in drug-resistant focal epilepsy. These data can also contribute to a broader understanding of thalamic electrophysiology in the context of focal epilepsy.
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Affiliation(s)
- David Burdette
- Corewell Health and Michigan State University College of Human Medicine, Grand Rapids, Michigan, U.S.A.; and
| | - Sanjay Patra
- Corewell Health and Michigan State University College of Human Medicine, Grand Rapids, Michigan, U.S.A.; and
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10
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Wong GM, Hofmann K, Shlobin NA, Tsuchida TN, Gaillard WD, Oluigbo CO. Stimulation of the pulvinar nucleus of the thalamus in epilepsy: A systematic review and individual patient data (IPD) analysis. Clin Neurol Neurosurg 2023; 235:108041. [PMID: 37979562 DOI: 10.1016/j.clineuro.2023.108041] [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: 08/21/2023] [Revised: 10/05/2023] [Accepted: 10/31/2023] [Indexed: 11/20/2023]
Abstract
Emerging neuromodulatory treatments, such as deep brain stimulation (DBS) and responsive neurostimulation (RNS), have shown promise in reducing drug-resistant seizures. While centromedian thalamic nucleus and anterior thalamic nucleus stimulation have been effective in certain types of seizures, limited research has explored pulvinar nucleus stimulation for epilepsy. To address this gap, we conducted a systematic review and individual patient data analysis. Of 78 resultant articles, 5 studies with transient stimulation and chronic stimulation of the pulvinar nucleus were included. Of the 20 patients reviewed, 65% of patients had temporal lobe seizures, while 20% had temporooccipital/occipital lobe seizures. Transient stimulation studies via stereoelectroencephalography (SEEG) showed pulvinar evoked potential response rates of 80% in the mesial temporal region, 76% in the temporal neocortex, and 67% in the TP junction. Another study reported clinically less severe seizures in 62.5% of patients with pulvinar stimulation. In chronic stimulation studies, 80% of patients responded to RNS or DBS, and 2 of 4 patients experienced > 90% seizure reduction. The pulvinar nucleus of the thalamus emerges as a potential target for chronic stimulation in drug-resistant epilepsy. However, knowledge regarding pulvinar connectivity and chronic stimulation remains limited. Further research should investigate specific subregions of the pulvinar for epilepsy treatment. Understanding the role of pulvinar stimulation and its cortical connectivity will advance therapeutic interventions for epilepsy patients.
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Affiliation(s)
- Georgia M Wong
- Department of Neurological Surgery, Georgetown University School of Medicine, Washington, DC, USA.
| | - Katherine Hofmann
- Department of Neurosurgery, Children's National Hospital, Washington, DC, USA
| | - Nathan A Shlobin
- Department of Neurological Surgery, Northwestern University Feinberg School of Medicine, Chicago, IL, USA
| | - Tammy N Tsuchida
- Department of Neurology, Children's National Hospital, Washington, DC, USA
| | - William D Gaillard
- Department of Neurology, Children's National Hospital, Washington, DC, USA
| | - Chima O Oluigbo
- Department of Neurosurgery, Children's National Hospital, Washington, DC, USA
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11
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Frauscher B, Bartolomei F, Baud MO, Smith RJ, Worrell G, Lundstrom BN. Stimulation to probe, excite, and inhibit the epileptic brain. Epilepsia 2023; 64 Suppl 3:S49-S61. [PMID: 37194746 PMCID: PMC10654261 DOI: 10.1111/epi.17640] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2023] [Revised: 05/01/2023] [Accepted: 05/02/2023] [Indexed: 05/18/2023]
Abstract
Direct cortical stimulation has been applied in epilepsy for nearly a century and has experienced a renaissance, given unprecedented opportunities to probe, excite, and inhibit the human brain. Evidence suggests stimulation can increase diagnostic and therapeutic utility in patients with drug-resistant epilepsies. However, choosing appropriate stimulation parameters is not a trivial issue, and is further complicated by epilepsy being characterized by complex brain state dynamics. In this article derived from discussions at the ICTALS 2022 Conference (International Conference on Technology and Analysis for Seizures), we succinctly review the literature on cortical stimulation applied acutely and chronically to the epileptic brain for localization, monitoring, and therapeutic purposes. In particular, we discuss how stimulation is used to probe brain excitability, discuss evidence on the usefulness of stimulation to trigger and stop seizures, review therapeutic applications of stimulation, and finally discuss how stimulation parameters are impacted by brain dynamics. Although research has advanced considerably over the past decade, there are still significant hurdles to optimizing use of this technique. For example, it remains unclear to what extent short timescale diagnostic biomarkers can predict long-term outcomes and to what extent these biomarkers add information to already existing biomarkers from passive electroencephalographic recordings. Further questions include the extent to which closed loop stimulation offers advantages over open loop stimulation, what the optimal closed loop timescales may be, and whether biomarker-informed stimulation can lead to seizure freedom. The ultimate goal of bioelectronic medicine remains not just to stop seizures but rather to cure epilepsy and its comorbidities.
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Affiliation(s)
- Birgit Frauscher
- Analytical Neurophysiology Lab, Montreal Neurological Institute and Hospital, Montreal, Quebec, Canada
| | - Fabrice Bartolomei
- Institut de Neurosciences des Systèmes, Aix Marseille University, Marseille, France. AP-HM, Service de Neurophysiologie Clinique, Hôpital de la Timone, Marseille, France
| | - Maxime O. Baud
- Sleep-Wake-Epilepsy Center, NeuroTec and Center for Experimental Neurology, Department of Neurology, Inselspital Bern, University Hospital, University of Bern, Bern
| | - Rachel J. Smith
- University of Alabama at Birmingham, Electrical and Computer Engineering Department, Birmingham, Alabama, US. University of Alabama at Birmingham, Neuroengineering Program, Birmingham, Alabama, US
| | - Greg Worrell
- Department of Neurology, Mayo Clinic, Rochester, US
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12
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Zelmann R, Paulk AC, Tian F, Balanza Villegas GA, Dezha Peralta J, Crocker B, Cosgrove GR, Richardson RM, Williams ZM, Dougherty DD, Purdon PL, Cash SS. Differential cortical network engagement during states of un/consciousness in humans. Neuron 2023; 111:3479-3495.e6. [PMID: 37659409 PMCID: PMC10843836 DOI: 10.1016/j.neuron.2023.08.007] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2022] [Revised: 06/13/2023] [Accepted: 08/08/2023] [Indexed: 09/04/2023]
Abstract
What happens in the human brain when we are unconscious? Despite substantial work, we are still unsure which brain regions are involved and how they are impacted when consciousness is disrupted. Using intracranial recordings and direct electrical stimulation, we mapped global, network, and regional involvement during wake vs. arousable unconsciousness (sleep) vs. non-arousable unconsciousness (propofol-induced general anesthesia). Information integration and complex processing we`re reduced, while variability increased in any type of unconscious state. These changes were more pronounced during anesthesia than sleep and involved different cortical engagement. During sleep, changes were mostly uniformly distributed across the brain, whereas during anesthesia, the prefrontal cortex was the most disrupted, suggesting that the lack of arousability during anesthesia results not from just altered overall physiology but from a disconnection between the prefrontal and other brain areas. These findings provide direct evidence for different neural dynamics during loss of consciousness compared with loss of arousability.
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Affiliation(s)
- Rina Zelmann
- Department of Neurology, Massachusetts General Hospital, Boston, MA, USA; Center for Neurotechnology and Neurorecovery, Massachusetts General Hospital, Boston, MA, USA.
| | - Angelique C Paulk
- Department of Neurology, Massachusetts General Hospital, Boston, MA, USA; Center for Neurotechnology and Neurorecovery, Massachusetts General Hospital, Boston, MA, USA
| | - Fangyun Tian
- Department of Anesthesia, Massachusetts General Hospital, Boston, MA, USA
| | | | | | - Britni Crocker
- Department of Neurology, Massachusetts General Hospital, Boston, MA, USA; Harvard-MIT Health Sciences and Technology, Institute for Medical Engineering and Science, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - G Rees Cosgrove
- Department of Neurosurgery, Brigham and Women's Hospital, Boston, MA, USA
| | - R Mark Richardson
- Department of Neurosurgery, Massachusetts General Hospital, Boston, MA, USA
| | - Ziv M Williams
- Department of Neurosurgery, Massachusetts General Hospital, Boston, MA, USA
| | - Darin D Dougherty
- Department of Psychiatry, Massachusetts General Hospital, Boston, MA, USA
| | - Patrick L Purdon
- Department of Anesthesia, Massachusetts General Hospital, Boston, MA, USA
| | - Sydney S Cash
- Department of Neurology, Massachusetts General Hospital, Boston, MA, USA; Center for Neurotechnology and Neurorecovery, Massachusetts General Hospital, Boston, MA, USA
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13
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Manjunatha RT, Vakilna YS, Chaitanya G, Alamoudi O, Ilyas A, Pati S. Advancing the frontiers of thalamic neuromodulation: A review of emerging targets and paradigms. Epilepsy Res 2023; 196:107219. [PMID: 37660585 DOI: 10.1016/j.eplepsyres.2023.107219] [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: 05/14/2023] [Revised: 08/23/2023] [Accepted: 08/27/2023] [Indexed: 09/05/2023]
Abstract
The thalamus is a key structure that plays a crucial role in initiating and propagating seizures. Recent advancements in neuroimaging and neurophysiology have identified the thalamus as a promising target for neuromodulation in drug-resistant epilepsies. This review article presents the latest innovations in thalamic targets and neuromodulation paradigms being explored in pilot or pivotal clinical trials. Multifocal temporal plus or posterior quadrant epilepsies are evaluated with pulvinar thalamus neuromodulation, while centromedian thalamus is explored in generalized epilepsies and Lennox Gastaut syndrome. Multinodal thalamocortical neuromodulation with novel stimulation paradigms such as long bursting or low-frequency stimulation is being investigated to quench the epileptic network excitability. Beyond seizure control, thalamic neuromodulation to restore consciousness is being studied. This review highlights the promising potential of thalamic neuromodulation in epilepsy treatment, offering hope to patients who have not responded to conventional medical therapies. However, it also emphasizes the need for larger randomized controlled trials and personalized stimulation paradigms to improve patient outcomes further.
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Affiliation(s)
- Ramya Talanki Manjunatha
- Texas Institute of Restorative Neurotechnologies [TIRN], University of Texas Health Science Center, Houston, TX, USA; Texas Comprehensive Epilepsy Program, Texas Institute of Restorative Neurotechnologies, McGovern Medical School, University of Texas Health Science Center, Houston, TX, USA
| | - Yash Shashank Vakilna
- Texas Institute of Restorative Neurotechnologies [TIRN], University of Texas Health Science Center, Houston, TX, USA; Texas Comprehensive Epilepsy Program, Texas Institute of Restorative Neurotechnologies, McGovern Medical School, University of Texas Health Science Center, Houston, TX, USA
| | - Ganne Chaitanya
- Texas Institute of Restorative Neurotechnologies [TIRN], University of Texas Health Science Center, Houston, TX, USA; Texas Comprehensive Epilepsy Program, Texas Institute of Restorative Neurotechnologies, McGovern Medical School, University of Texas Health Science Center, Houston, TX, USA
| | - Omar Alamoudi
- Texas Institute of Restorative Neurotechnologies [TIRN], University of Texas Health Science Center, Houston, TX, USA; Texas Comprehensive Epilepsy Program, Texas Institute of Restorative Neurotechnologies, McGovern Medical School, University of Texas Health Science Center, Houston, TX, USA
| | - Adeel Ilyas
- Department of Neurosurgery, UAB Heersink School of Medicine, Birmingham, AL, USA
| | - Sandipan Pati
- Texas Institute of Restorative Neurotechnologies [TIRN], University of Texas Health Science Center, Houston, TX, USA; Texas Comprehensive Epilepsy Program, Texas Institute of Restorative Neurotechnologies, McGovern Medical School, University of Texas Health Science Center, Houston, TX, USA.
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14
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Philipp LR, Kennedy BC. The Wild West of Pediatric Epilepsy-Thalamic Stimulation. World Neurosurg 2023; 178:262-263. [PMID: 37580189 DOI: 10.1016/j.wneu.2023.07.070] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/16/2023]
Affiliation(s)
- Lucas R Philipp
- Department of Neurosurgery, Thomas Jefferson University Hospitals, Philadelphia, Pennsylvania, USA
| | - Benjamin C Kennedy
- Division of Neurosurgery, Children's Hospital of Philadelphia, Philadelphia, Pennsylvania, USA; Department of Neurosurgery, University of Pennsylvania, Philadelphia, Pennsylvania, USA
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15
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Venkatesh P, Wolfe C, Lega B. Neuromodulation of the anterior thalamus: Current approaches and opportunities for the future. CURRENT RESEARCH IN NEUROBIOLOGY 2023; 5:100109. [PMID: 38020810 PMCID: PMC10663132 DOI: 10.1016/j.crneur.2023.100109] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2023] [Revised: 08/28/2023] [Accepted: 08/31/2023] [Indexed: 12/01/2023] Open
Abstract
The role of thalamocortical circuits in memory has driven a recent burst of scholarship, especially in animal models. Investigating this circuitry in humans is more challenging. And yet, the development of new recording and stimulation technologies deployed for clinical indications has created novel opportunities for data collection to elucidate the cognitive roles of thalamic structures. These technologies include stereoelectroencephalography (SEEG), deep brain stimulation (DBS), and responsive neurostimulation (RNS), all of which have been applied to memory-related thalamic regions, specifically for seizure localization and treatment. This review seeks to summarize the existing applications of neuromodulation of the anterior thalamic nuclei (ANT) and highlight several devices and their capabilities that can allow cognitive researchers to design experiments to assay its functionality. Our goal is to introduce to investigators, who may not be familiar with these clinical devices, the capabilities, and limitations of these tools for understanding the neurophysiology of the ANT as it pertains to memory and other behaviors. We also briefly cover the targeting of other thalamic regions including the centromedian (CM) nucleus, dorsomedial (DM) nucleus, and pulvinar, with associated potential avenues of experimentation.
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Affiliation(s)
- Pooja Venkatesh
- Department of Neurosurgery, University of Texas Southwestern, Dallas, TX, 75390, USA
| | - Cody Wolfe
- Department of Neurosurgery, University of Texas Southwestern, Dallas, TX, 75390, USA
| | - Bradley Lega
- Department of Neurosurgery, University of Texas Southwestern, Dallas, TX, 75390, USA
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16
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Yan H, Wang X, Zhang X, Qiao L, Gao R, Ni D, Shu W, Xu C, Ren L, Yu T. Deep brain stimulation for patients with refractory epilepsy: nuclei selection and surgical outcome. Front Neurol 2023; 14:1169105. [PMID: 37251216 PMCID: PMC10213517 DOI: 10.3389/fneur.2023.1169105] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2023] [Accepted: 04/17/2023] [Indexed: 05/31/2023] Open
Abstract
Objective By studying the surgical outcome of deep brain stimulation (DBS) of different target nuclei for patients with refractory epilepsy, we aimed to explore a clinically feasible target nucleus selection strategy. Methods We selected patients with refractory epilepsy who were not eligible for resective surgery. For each patient, we performed DBS on a thalamic nucleus [anterior nucleus of the thalamus (ANT), subthalamic nucleus (STN), centromedian nucleus (CMN), or pulvinar nucleus (PN)] selected based on the location of the patient's epileptogenic zone (EZ) and the possible epileptic network involved. We monitored the clinical outcomes for at least 12 months and analyzed the clinical characteristics and seizure frequency changes to assess the postoperative efficacy of DBS on the different target nuclei. Results Out of the 65 included patients, 46 (70.8%) responded to DBS. Among the 65 patients, 45 underwent ANT-DBS, 29 (64.4%) responded to the treatment, and four (8.9%) of them reported being seizure-free for at least 1 year. Among the patients with temporal lobe epilepsy (TLE, n = 36) and extratemporal lobe epilepsy (ETLE, n = 9), 22 (61.1%) and 7 (77.8%) responded to the treatment, respectively. Among the 45 patients who underwent ANT-DBS, 28 (62%) had focal to bilateral tonic-clonic seizures (FBTCS). Of these 28 patients, 18 (64%) responded to the treatment. Out of the 65 included patients, 16 had EZ related to the sensorimotor cortex and underwent STN-DBS. Among them, 13 (81.3%) responded to the treatment, and two (12.5%) were seizure-free for at least 6 months. Three patients had Lennox-Gastaut syndrome (LGS)-like epilepsy and underwent CMN-DBS; all of them responded to the treatment (seizure frequency reductions: 51.6%, 79.6%, and 79.5%). Finally, one patient with bilateral occipital lobe epilepsy underwent PN-DBS, reducing the seizure frequency by 69.7%. Significance ANT-DBS is effective for patients with TLE or ETLE. In addition, ANT-DBS is effective for patients with FBTCS. STN-DBS might be an optimal treatment for patients with motor seizures, especially when the EZ overlaps the sensorimotor cortex. CMN and PN may be considered modulating targets for patients with LGS-like epilepsy or occipital lobe epilepsy, respectively.
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Affiliation(s)
- Hao Yan
- Department of Functional Neurosurgery, Beijing Institute of Functional Neurosurgery, Xuanwu Hospital, Capital Medical University, Beijing, China
| | - Xueyuan Wang
- Department of Functional Neurosurgery, Beijing Institute of Functional Neurosurgery, Xuanwu Hospital, Capital Medical University, Beijing, China
| | - Xiaohua Zhang
- Department of Functional Neurosurgery, Beijing Institute of Functional Neurosurgery, Xuanwu Hospital, Capital Medical University, Beijing, China
| | - Liang Qiao
- Department of Functional Neurosurgery, Beijing Institute of Functional Neurosurgery, Xuanwu Hospital, Capital Medical University, Beijing, China
| | - Runshi Gao
- Department of Functional Neurosurgery, Beijing Institute of Functional Neurosurgery, Xuanwu Hospital, Capital Medical University, Beijing, China
| | - Duanyu Ni
- Department of Functional Neurosurgery, Beijing Institute of Functional Neurosurgery, Xuanwu Hospital, Capital Medical University, Beijing, China
| | - Wei Shu
- Department of Functional Neurosurgery, Beijing Institute of Functional Neurosurgery, Xuanwu Hospital, Capital Medical University, Beijing, China
| | - Cuiping Xu
- Department of Functional Neurosurgery, Beijing Institute of Functional Neurosurgery, Xuanwu Hospital, Capital Medical University, Beijing, China
| | - Liankun Ren
- Department of Neurology, Comprehensive Epilepsy Center of Beijing, Beijing Key Laboratory of Neuromodulation, Xuanwu Hospital, Capital Medical University, Beijing, China
| | - Tao Yu
- Department of Functional Neurosurgery, Beijing Institute of Functional Neurosurgery, Xuanwu Hospital, Capital Medical University, Beijing, China
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17
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Soulier H, Pizzo F, Jegou A, Lagarde S, Garnier E, Makhalova J, Medina Villalon S, Carron R, Bénar C, Bartolomei F. The anterior and pulvinar thalamic nuclei interactions in mesial temporal lobe seizure networks. Clin Neurophysiol 2023; 150:176-183. [PMID: 37075682 DOI: 10.1016/j.clinph.2023.03.016] [Citation(s) in RCA: 11] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2023] [Revised: 02/16/2023] [Accepted: 03/17/2023] [Indexed: 04/21/2023]
Abstract
OBJECTIVE To evaluate the respective roles of the anterior thalamic nucleus (ANT) and the medial pulvinar (PuM) during mesial temporal lobe seizures recorded by stereoelectroencephalography (SEEG). METHODS We assessed functional connectivity (FC) in 15 SEEG recorded seizures from 6 patients using a non-linear correlation method. Functional interactions were explored between the mesial temporal region, the temporal neocortex, ANT and PuM. The node total-strength (the summed connectivity of the node with all other nodes) as well as the directionality of the links (IN and OUT strengths) were calculated to estimate drivers and receivers during the cortico-thalamic interactions. RESULTS Significant increased thalamo-cortical FC during seizures was observed, with the node total-strength reaching a maximum at seizure end. There was no significant difference in global connectivity values between ANT and PuM. Regarding directionality, significantly higher thalamic IN strength values were observed. However, compared to ANT, PuM appeared to be the driver at the end of seizures with synchronous termination. CONCLUSIONS This work demonstrates that during temporal seizures, both thalamic nuclei are highly connected with the mesial temporal region and that PuM could play a role in seizure termination. SIGNIFICANCE Understanding functional connectivity between the mesial temporal and thalamic nuclei could contribute to the development of target-specific deep brain stimulation strategies for drug-resistant epilepsy.
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Affiliation(s)
- Hugo Soulier
- Aix Marseille Univ, INSERM, INS, Inst Neurosci Syst, Marseille 13005, France
| | - Francesca Pizzo
- Aix Marseille Univ, INSERM, INS, Inst Neurosci Syst, Marseille 13005, France; APHM, Timone Hospital, Epileptology and Cerebral Rhythmology, Marseille 13005, France
| | - Aude Jegou
- Aix Marseille Univ, INSERM, INS, Inst Neurosci Syst, Marseille 13005, France
| | - Stanislas Lagarde
- Aix Marseille Univ, INSERM, INS, Inst Neurosci Syst, Marseille 13005, France; APHM, Timone Hospital, Epileptology and Cerebral Rhythmology, Marseille 13005, France
| | - Elodie Garnier
- Aix Marseille Univ, INSERM, INS, Inst Neurosci Syst, Marseille 13005, France
| | - Julia Makhalova
- Aix Marseille Univ, INSERM, INS, Inst Neurosci Syst, Marseille 13005, France; APHM, Timone Hospital, Epileptology and Cerebral Rhythmology, Marseille 13005, France
| | - Samuel Medina Villalon
- Aix Marseille Univ, INSERM, INS, Inst Neurosci Syst, Marseille 13005, France; APHM, Timone Hospital, Epileptology and Cerebral Rhythmology, Marseille 13005, France
| | - Romain Carron
- Aix Marseille Univ, INSERM, INS, Inst Neurosci Syst, Marseille 13005, France; APHM, Timone Hospital, Stereotactic and Functional Neurosurgery, Marseille, France
| | - Christian Bénar
- Aix Marseille Univ, INSERM, INS, Inst Neurosci Syst, Marseille 13005, France
| | - Fabrice Bartolomei
- Aix Marseille Univ, INSERM, INS, Inst Neurosci Syst, Marseille 13005, France; APHM, Timone Hospital, Epileptology and Cerebral Rhythmology, Marseille 13005, France.
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Carron R, Pizzo F, Trébuchon A, Bartolomei F. Letter to the Editor. Thalamic sEEG and epilepsy. J Neurosurg 2023; 138:1172-1173. [PMID: 36461824 DOI: 10.3171/2022.9.jns222169] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
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19
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Fisher RS. Deep brain stimulation of thalamus for epilepsy. Neurobiol Dis 2023; 179:106045. [PMID: 36809846 DOI: 10.1016/j.nbd.2023.106045] [Citation(s) in RCA: 19] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2022] [Revised: 02/10/2023] [Accepted: 02/13/2023] [Indexed: 02/22/2023] Open
Abstract
Neuromodulation (neurostimulation) is a relatively new and rapidly growing treatment for refractory epilepsy. Three varieties are approved in the US: vagus nerve stimulation (VNS), deep brain stimulation (DBS) and responsive neurostimulation (RNS). This article reviews thalamic DBS for epilepsy. Among many thalamic sub-nuclei, DBS for epilepsy has been targeted to the anterior nucleus (ANT), centromedian nucleus (CM), dorsomedial nucleus (DM) and pulvinar (PULV). Only ANT is FDA-approved, based upon a controlled clinical trial. Bilateral stimulation of ANT reduced seizures by 40.5% at three months in the controlled phase (p = .038) and 75% by 5 years in the uncontrolled phase. Side effects related to paresthesias, acute hemorrhage, infection, occasional increased seizures, and usually transient effects on mood and memory. Efficacy was best documented for focal onset seizures in temporal or frontal lobe. CM stimulation may be useful for generalized or multifocal seizures and PULV for posterior limbic seizures. Mechanisms of DBS for epilepsy are largely unknown, but animal work points to changes in receptors, channels, neurotransmitters, synapses, network connectivity and neurogenesis. Personalization of therapies, in terms of connectivity of the seizure onset zone to the thalamic sub- nucleus and individual characteristics of the seizures, might lead to improved efficacy. Many questions remain about DBS, including the best candidates for different types of neuromodulation, the best targets, the best stimulation parameters, how to minimize side effects and how to deliver current noninvasively. Despite the questions, neuromodulation provides useful new opportunities to treat people with refractory seizures not responding to medicines and not amenable to resective surgery.
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Affiliation(s)
- Robert S Fisher
- Department of Neurology and Neurological Sciences and Neurosurgery by Courtesy, Department of Neurology and Neurological Sciences, Stanford University School of Medicine, 213 Quarry Road, Room 4865, Palo Alto, CA 94304, USA.
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20
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Lundstrom BN, Osman GM, Starnes K, Gregg NM, Simpson HD. Emerging approaches in neurostimulation for epilepsy. Curr Opin Neurol 2023; 36:69-76. [PMID: 36762660 PMCID: PMC9992108 DOI: 10.1097/wco.0000000000001138] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/11/2023]
Abstract
PURPOSE OF REVIEW Neurostimulation is a quickly growing treatment approach for epilepsy patients. We summarize recent approaches to provide a perspective on the future of neurostimulation. RECENT FINDINGS Invasive stimulation for treatment of focal epilepsy includes vagus nerve stimulation, responsive neurostimulation of the cortex and deep brain stimulation of the anterior nucleus of the thalamus. A wide range of other targets have been considered, including centromedian, central lateral and pulvinar thalamic nuclei; medial septum, nucleus accumbens, subthalamic nucleus, cerebellum, fornicodorsocommissure and piriform cortex. Stimulation for generalized onset seizures and mixed epilepsies as well as increased efforts focusing on paediatric populations have emerged. Hardware with more permanently implanted lead options and sensing capabilities is emerging. A wider variety of programming approaches than typically used may improve patient outcomes. Finally, noninvasive brain stimulation with its favourable risk profile offers the potential to treat increasingly diverse epilepsy patients. SUMMARY Neurostimulation for the treatment of epilepsy is surprisingly varied. Flexibility and reversibility of neurostimulation allows for rapid innovation. There remains a continued need for excitability biomarkers to guide treatment and innovation. Neurostimulation, a part of bioelectronic medicine, offers distinctive benefits as well as unique challenges.
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Affiliation(s)
| | | | - Keith Starnes
- Department of Neurology, Mayo Clinic, Rochester, Minnesota, USA
| | | | - Hugh D Simpson
- Department of Neurology, Alfred Health
- Department of Neuroscience, Central Clinical School, Monash University, Melbourne, Victoria, Australia
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21
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Kalamatianos T, Mavrovounis G, Skouras P, Pandis D, Fountas K, Stranjalis G. Medial Pulvinar Stimulation in Temporal Lobe Epilepsy: A Literature Review and a Hypothesis Based on Neuroanatomical Findings. Cureus 2023; 15:e35772. [PMID: 37025746 PMCID: PMC10071339 DOI: 10.7759/cureus.35772] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/05/2023] [Indexed: 03/07/2023] Open
Abstract
While bilateral stimulation of the anterior thalamic nuclei remains the only approved deep brain stimulation (DBS) option for focal epilepsy, two additional thalamic targets have been proposed. Earlier work indicated the potential of centromedian thalamic nucleus stimulation with recent findings highlighting the medial pulvinar nucleus. The latter has been shown to exhibit electrophysiological and imaging alterations in patients with partial status epilepticus and temporal lobe epilepsy. On this basis, recent studies have begun assessing the feasibility and efficacy of pulvinar stimulation, with encouraging results on the reduction of seizure frequency and severity. Building on existing neuroanatomical knowledge, indicating that the medial pulvinar is connected to the temporal lobe via the temporopulvinar bundle of Arnold, we hypothesize that this is one of the routes through which medial pulvinar stimulation affects temporal lobe structures. We suggest that further anatomic, imaging, and electrophysiologic studies are warranted to deepen our understanding of the subject and guide future clinical applications.
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22
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Zheng B, Liu DD, Theyel BB, Abdulrazeq H, Kimata AR, Lauro PM, Asaad WF. Thalamic neuromodulation in epilepsy: A primer for emerging circuit-based therapies. Expert Rev Neurother 2023; 23:123-140. [PMID: 36731858 DOI: 10.1080/14737175.2023.2176752] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
INTRODUCTION Epilepsy is a common, often debilitating disease of hyperexcitable neural networks. While medically intractable cases may benefit from surgery, there may be no single, well-localized focus for resection or ablation. In such cases, approaching the disease from a network-based perspective may be beneficial. AREAS COVERED Herein, the authors provide a narrative review of normal thalamic anatomy and physiology and propose general strategies for preventing and/or aborting seizures by modulating this structure. Additionally, they make specific recommendations for targeting the thalamus within different contexts, motivated by a more detailed discussion of its distinct nuclei and their respective connectivity. By describing important principles governing thalamic function and its involvement in seizure networks, the authors aim to provide a primer for those now entering this fast-growing field of thalamic neuromodulation for epilepsy. EXPERT OPINION The thalamus is critically involved with the function of many cortical and subcortical areas, suggesting it may serve as a compelling node for preventing or aborting seizures, and so it has increasingly been targeted for the surgical treatment of epilepsy. As various thalamic neuromodulation strategies for seizure control are developed, there is a need to ground such interventions in a mechanistic, circuit-based framework.
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Affiliation(s)
- Bryan Zheng
- The Warren Alpert Medical School of Brown University, Providence, RI, USA.,Department of Neurosurgery, Rhode Island Hospital, Providence, RI, USA
| | - David D Liu
- The Warren Alpert Medical School of Brown University, Providence, RI, USA
| | - Brian B Theyel
- Department of Psychiatry, Rhode Island Hospital, Providence, RI, USA.,Department of Neuroscience, Brown University, Providence, RI, USA
| | - Hael Abdulrazeq
- Department of Neurosurgery, Rhode Island Hospital, Providence, RI, USA
| | - Anna R Kimata
- The Warren Alpert Medical School of Brown University, Providence, RI, USA.,Department of Neurosurgery, Rhode Island Hospital, Providence, RI, USA
| | - Peter M Lauro
- The Warren Alpert Medical School of Brown University, Providence, RI, USA.,Department of Neuroscience, Brown University, Providence, RI, USA
| | - Wael F Asaad
- Department of Neurosurgery, Rhode Island Hospital, Providence, RI, USA.,Department of Neuroscience, Brown University, Providence, RI, USA.,The Carney Institute for Brain Science, Brown University, Providence, RI, USA.,The Norman Prince Neurosciences Institute, Rhode Island Hospital, Providence, RI, USA
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23
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Juan E, Górska U, Kozma C, Papantonatos C, Bugnon T, Denis C, Kremen V, Worrell G, Struck AF, Bateman LM, Merricks EM, Blumenfeld H, Tononi G, Schevon C, Boly M. Distinct signatures of loss of consciousness in focal impaired awareness versus tonic-clonic seizures. Brain 2023; 146:109-123. [PMID: 36383415 PMCID: PMC10582624 DOI: 10.1093/brain/awac291] [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: 10/06/2021] [Revised: 05/17/2022] [Accepted: 06/11/2022] [Indexed: 11/17/2022] Open
Abstract
Loss of consciousness is a hallmark of many epileptic seizures and carries risks of serious injury and sudden death. While cortical sleep-like activities accompany loss of consciousness during focal impaired awareness seizures, the mechanisms of loss of consciousness during focal to bilateral tonic-clonic seizures remain unclear. Quantifying differences in markers of cortical activation and ictal recruitment between focal impaired awareness and focal to bilateral tonic-clonic seizures may also help us to understand their different consequences for clinical outcomes and to optimize neuromodulation therapies. We quantified clinical signs of loss of consciousness and intracranial EEG activity during 129 focal impaired awareness and 50 focal to bilateral tonic-clonic from 41 patients. We characterized intracranial EEG changes both in the seizure onset zone and in areas remote from the seizure onset zone with a total of 3386 electrodes distributed across brain areas. First, we compared the dynamics of intracranial EEG sleep-like activities: slow-wave activity (1-4 Hz) and beta/delta ratio (a validated marker of cortical activation) during focal impaired awareness versus focal to bilateral tonic-clonic. Second, we quantified differences between focal to bilateral tonic-clonic and focal impaired awareness for a marker validated to detect ictal cross-frequency coupling: phase-locked high gamma (high-gamma phased-locked to low frequencies) and a marker of ictal recruitment: the epileptogenicity index. Third, we assessed changes in intracranial EEG activity preceding and accompanying behavioural generalization onset and their correlation with electromyogram channels. In addition, we analysed human cortical multi-unit activity recorded with Utah arrays during three focal to bilateral tonic-clonic seizures. Compared to focal impaired awareness, focal to bilateral tonic-clonic seizures were characterized by deeper loss of consciousness, even before generalization occurred. Unlike during focal impaired awareness, early loss of consciousness before generalization was accompanied by paradoxical decreases in slow-wave activity and by increases in high-gamma activity in parieto-occipital and temporal cortex. After generalization, when all patients displayed loss of consciousness, stronger increases in slow-wave activity were observed in parieto-occipital cortex, while more widespread increases in cortical activation (beta/delta ratio), ictal cross-frequency coupling (phase-locked high gamma) and ictal recruitment (epileptogenicity index). Behavioural generalization coincided with a whole-brain increase in high-gamma activity, which was especially synchronous in deep sources and could not be explained by EMG. Similarly, multi-unit activity analysis of focal to bilateral tonic-clonic revealed sustained increases in cortical firing rates during and after generalization onset in areas remote from the seizure onset zone. Overall, these results indicate that unlike during focal impaired awareness, the neural signatures of loss of consciousness during focal to bilateral tonic-clonic consist of paradoxical increases in cortical activation and neuronal firing found most consistently in posterior brain regions. These findings suggest differences in the mechanisms of ictal loss of consciousness between focal impaired awareness and focal to bilateral tonic-clonic and may account for the more negative prognostic consequences of focal to bilateral tonic-clonic.
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Affiliation(s)
- Elsa Juan
- Department of Psychiatry, University of Wisconsin-Madison, Madison, WI 53719, USA
- Department of Psychology, University of Amsterdam, Amsterdam, 1018 WS, The Netherlands
| | - Urszula Górska
- Department of Psychiatry, University of Wisconsin-Madison, Madison, WI 53719, USA
- Smoluchowski Institute of Physics, Jagiellonian University, 30-348 Krakow, Poland
| | - Csaba Kozma
- Department of Psychiatry, University of Wisconsin-Madison, Madison, WI 53719, USA
- Department of Neurology, University of Wisconsin-Madison, Madison, WI 53705, USA
| | - Cynthia Papantonatos
- Department of Neurology, University of Wisconsin-Madison, Madison, WI 53705, USA
| | - Tom Bugnon
- Department of Psychiatry, University of Wisconsin-Madison, Madison, WI 53719, USA
| | - Colin Denis
- Department of Neurology, University of Wisconsin-Madison, Madison, WI 53705, USA
| | - Vaclav Kremen
- Department of Neurology, Mayo Clinic, Rochester, MN 55905, USA
- Czech Institute of Informatics, Robotics, and Cybernetics, Czech Technical University in Prague, Prague, 16000, Czech Republic
| | - Greg Worrell
- Department of Neurology, Mayo Clinic, Rochester, MN 55905, USA
| | - Aaron F Struck
- Department of Neurology, University of Wisconsin-Madison, Madison, WI 53705, USA
- Department of Neurology, William S. Middleton Veterans Administration Hospital, Madison, WI 53705, USA
| | - Lisa M Bateman
- Department of Neurology, Cedars-Sinai Medical Center, Los Angeles, CA 90048, USA
| | - Edward M Merricks
- Department of Neurology, Columbia University, New York City, NY 10032, USA
| | - Hal Blumenfeld
- Department of Neurology, Yale School of Medicine, New Haven, CT 06519, USA
| | - Giulio Tononi
- Department of Psychiatry, University of Wisconsin-Madison, Madison, WI 53719, USA
| | - Catherine Schevon
- Department of Neurology, Columbia University, New York City, NY 10032, USA
| | - Melanie Boly
- Department of Psychiatry, University of Wisconsin-Madison, Madison, WI 53719, USA
- Department of Neurology, University of Wisconsin-Madison, Madison, WI 53705, USA
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Kundu B, Arain A, Davis T, Charlebois CM, Rolston JD. Using chronic recordings from a closed-loop neurostimulation system to capture seizures across multiple thalamic nuclei. Ann Clin Transl Neurol 2022; 10:136-143. [PMID: 36480536 PMCID: PMC9852392 DOI: 10.1002/acn3.51701] [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: 05/25/2022] [Revised: 10/21/2022] [Accepted: 10/26/2022] [Indexed: 12/13/2022] Open
Abstract
We report the case of a patient with unilateral diffuse frontotemporal epilepsy in whom we implanted a responsive neurostimulation system with leads spanning the anterior and centromedian nucleus of the thalamus. During chronic recording, ictal activity in the centromedian nucleus consistently preceded the anterior nucleus, implying a temporally organized seizure network involving the thalamus. With stimulation, the patient had resolution of focal impaired awareness seizures and secondarily generalized seizures. This report describes chronic recordings of seizure activity from multiple thalamic nuclei within a hemisphere and demonstrates the potential efficacy of closed-loop neurostimulation of multiple thalamic nuclei to control seizures.
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Affiliation(s)
- Bornali Kundu
- Department of Neurosurgery, Clinical Neurosciences CenterUniversity of UtahSalt Lake CityUtahUSA
| | - Amir Arain
- Department of NeurologyUniversity of UtahSalt Lake CityUtahUSA
| | - Tyler Davis
- Department of Neurosurgery, Clinical Neurosciences CenterUniversity of UtahSalt Lake CityUtahUSA
| | | | - John D. Rolston
- Department of NeurosurgeryBrigham and Women's Hospital, Harvard Medical SchoolBostonMassachusettsUSA
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25
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Lagarde S, Bénar CG, Wendling F, Bartolomei F. Interictal Functional Connectivity in Focal Refractory Epilepsies Investigated by Intracranial EEG. Brain Connect 2022; 12:850-869. [PMID: 35972755 PMCID: PMC9807250 DOI: 10.1089/brain.2021.0190] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
Introduction: Focal epilepsies are diseases of neuronal excitability affecting macroscopic networks of cortical and subcortical neural structures. These networks ("epileptogenic networks") can generate pathological electrophysiological activities during seizures, and also between seizures (interictal period). Many works attempt to describe these networks by using quantification methods, particularly based on the estimation of statistical relationships between signals produced by brain regions, namely functional connectivity (FC). Results: FC has been shown to be greatly altered during seizures and in the immediate peri-ictal period. An increasing number of studies have shown that FC is also altered during the interictal period depending on the degree of epileptogenicity of the structures. Furthermore, connectivity values could be correlated with other clinical variables including surgical outcome. Significance: This leads to a conceptual change and to consider epileptic areas as both hyperexcitable and abnormally connected. These data open the door to the use of interictal FC as a marker of epileptogenicity and as a complementary tool for predicting the effect of surgery. Aim: In this article, we review the available data concerning interictal FC estimated from intracranial electroencephalograhy (EEG) in focal epilepsies and discuss it in the light of data obtained from other modalities (EEG imaging) and modeling studies.
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Affiliation(s)
- Stanislas Lagarde
- Aix Marseille Univ, INSERM, INS, Inst Neurosci Syst, Marseille, France.,Department of Epileptology and Cerebral Rythmology, APHM, Timone Hospital, Marseille, France.,Address correspondence to: Stanislas Lagarde, Department of Epileptology and Cerebral Rythmology, APHM, Timone Hospital, 264 Rue Saint-Pierre, 13005 Marseille, France
| | | | | | - Fabrice Bartolomei
- Aix Marseille Univ, INSERM, INS, Inst Neurosci Syst, Marseille, France.,Department of Epileptology and Cerebral Rythmology, APHM, Timone Hospital, Marseille, France
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26
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Tran TPY, Dionne A, Toffa D, Bergeron D, Obaid S, Robert M, Bouthillier A, Assi EB, Nguyen DK. Acute Effects of High-Frequency Insular Stimulation on Interictal Epileptiform Discharge Rates in Patients with Refractory Epilepsy. Brain Sci 2022; 12:brainsci12121616. [PMID: 36552076 PMCID: PMC9775111 DOI: 10.3390/brainsci12121616] [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: 10/18/2022] [Revised: 11/09/2022] [Accepted: 11/16/2022] [Indexed: 11/27/2022] Open
Abstract
Rationale: Deep brain stimulation (DBS) of several sites, such as the thalamus, has been shown to reduce seizure frequency and interictal epileptiform activity in patients with refractory epilepsy. Recent findings have demonstrated that the insula is part of the ‘rich club’ of highly connected brain regions. This pilot study investigated short-term effects of high-frequency (HF) insular DBS on interictal epileptiform discharge (IED) rate in patients with refractory epilepsy. Methods: Six patients with drug-resistant epilepsy undergoing an intracranial electroencephalographic study received two sets of 10 min continuous 150 Hz HF-DBS of the insula. For each patient, epileptiform activity was analyzed for a total of 80 min, starting 20 min prior to stimulation set 1 (S1), and ending 20 min after stimulation set 2 (S2). All IEDs were identified and classified according to their anatomic localization by a board-certified epileptologist. The IED rate during the 20 min preceding S1 served as a baseline for comparison with IED rate during S1, S2 and post-stimulation periods. Results: HF-DBS of the anterior insula (aINS) was performed in a patient with an aINS epileptic focus (patient 1). HF-DBS of the posterior insula (pINS) was performed in two patients with a pINS epileptic focus (patients 2 and 4), in one patient with an aINS focus (patient 3), and in two non-insular patients (patients 5 and 6). The total IED (irrespective of their location) rate significantly decreased (p < 0.01) in two patients (patients 1 and 2) during the stimulation period, whereas it significantly increased (p < 0.01) in one patient (patient 6); there was no change in the other three patients. Looking at subsets of spike localization, HF-DBS of the aINS significantly reduced aINS and orbitofrontal IEDs in patient 1 (p < 0.01), while HF-DBS of the pINS had an effect on pINS IEDs (p < 0.01) in both patients with a pINS focus; there was no significant effect of HF-DBS of the insula on IEDs in temporal or other frontal regions. Conclusion: Short-term HF-DBS of the insula had heterogeneous effects on the IED rate. Further work is required to examine factors underlying these heterogeneous effects, such as stimulation frequency, location of IEDs and subregions of the insula stimulated.
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Affiliation(s)
- Thi Phuoc Yen Tran
- CHUM Research Center, University of Montreal, Montreal, QC H3T 1J4, Canada
- Department of Neurosurgery, Vinmec Central Park International Hospital, Ho Chi Minh City 700000, Vietnam
| | - Antoine Dionne
- CHUM Research Center, University of Montreal, Montreal, QC H3T 1J4, Canada
| | - Denahin Toffa
- CHUM Research Center, University of Montreal, Montreal, QC H3T 1J4, Canada
| | - David Bergeron
- Division of Neurosurgery, CHUM, University of Montreal, Montreal, QC H3T 1J4, Canada
| | - Sami Obaid
- Division of Neurosurgery, CHUM, University of Montreal, Montreal, QC H3T 1J4, Canada
| | - Manon Robert
- CHUM Research Center, University of Montreal, Montreal, QC H3T 1J4, Canada
| | - Alain Bouthillier
- Division of Neurosurgery, CHUM, University of Montreal, Montreal, QC H3T 1J4, Canada
| | - Elie Bou Assi
- CHUM Research Center, University of Montreal, Montreal, QC H3T 1J4, Canada
| | - Dang Khoa Nguyen
- Division of Neurology, CHUM Research Center, University of Montreal, Montreal, QC H3T 1J4, Canada
- Correspondence:
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27
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Gadot R, Korst G, Shofty B, Gavvala JR, Sheth SA. Thalamic stereoelectroencephalography in epilepsy surgery: a scoping literature review. J Neurosurg 2022; 137:1210-1225. [PMID: 35276641 DOI: 10.3171/2022.1.jns212613] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2021] [Accepted: 01/10/2022] [Indexed: 11/06/2022]
Abstract
OBJECTIVE Stereoelectroencephalography (sEEG) is a well-established surgical method for defining the epileptogenic network. Traditionally reserved for identifying discrete cortical regions for resection or ablation, sEEG in current practice is also used for identifying more broadly involved subcortical epileptic network components, driven by the availability of brain-based neuromodulation strategies. In particular, sEEG investigations including thalamic nuclei are becoming more frequent in parallel with the increase in therapeutic strategies involving thalamic targets such as deep brain stimulation (DBS) and responsive neurostimulation (RNS). The objective to this study was to evaluate existing evidence and trends regarding the purpose, techniques, and relevant electrographic findings of thalamic sEEG. METHODS MEDLINE and Embase databases were systematically queried for eligible peer-reviewed studies involving sEEG electrode implantation into thalamic nuclei of patients with epilepsy. Available data were abstracted concerning preoperative workup and purpose for implanting the thalamus, thalamic targets and trajectories, and electrophysiological methodology and findings. RESULTS sEEG investigations have included thalamic targets for both basic and clinical research purposes. Medial pulvinar, dorsomedial, anterior, and centromedian nuclei have been the most frequently studied. Few studies have reported any complications with thalamic sEEG implantation, and no studies have reported long-term complications. Various methods have been utilized to characterize thalamic activity in epileptic disorders including evoked potentials, power spectrograms, synchronization indices, and the epileptogenicity index. Thalamic intracranial recordings are beginning to be used to guide neuromodulation strategies including RNS and DBS, as well as to understand complex, network-dependent seizure disorders. CONCLUSIONS Inclusion of thalamic coverage during sEEG evaluation in drug-resistant epilepsy is a growing practice and is amenable to various methods of electrographic data analysis. Further study is required to establish well-defined criteria for thalamic implantation during invasive investigations as well as safety and ethical considerations.
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Affiliation(s)
| | | | | | - Jay R Gavvala
- 2Neurology, Baylor College of Medicine, Houston, Texas
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28
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Piper RJ, Richardson RM, Worrell G, Carmichael DW, Baldeweg T, Litt B, Denison T, Tisdall MM. Towards network-guided neuromodulation for epilepsy. Brain 2022; 145:3347-3362. [PMID: 35771657 PMCID: PMC9586548 DOI: 10.1093/brain/awac234] [Citation(s) in RCA: 64] [Impact Index Per Article: 32.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2022] [Revised: 05/30/2022] [Accepted: 06/16/2022] [Indexed: 11/30/2022] Open
Abstract
Epilepsy is well-recognized as a disorder of brain networks. There is a growing body of research to identify critical nodes within dynamic epileptic networks with the aim to target therapies that halt the onset and propagation of seizures. In parallel, intracranial neuromodulation, including deep brain stimulation and responsive neurostimulation, are well-established and expanding as therapies to reduce seizures in adults with focal-onset epilepsy; and there is emerging evidence for their efficacy in children and generalized-onset seizure disorders. The convergence of these advancing fields is driving an era of 'network-guided neuromodulation' for epilepsy. In this review, we distil the current literature on network mechanisms underlying neurostimulation for epilepsy. We discuss the modulation of key 'propagation points' in the epileptogenic network, focusing primarily on thalamic nuclei targeted in current clinical practice. These include (i) the anterior nucleus of thalamus, now a clinically approved and targeted site for open loop stimulation, and increasingly targeted for responsive neurostimulation; and (ii) the centromedian nucleus of the thalamus, a target for both deep brain stimulation and responsive neurostimulation in generalized-onset epilepsies. We discuss briefly the networks associated with other emerging neuromodulation targets, such as the pulvinar of the thalamus, piriform cortex, septal area, subthalamic nucleus, cerebellum and others. We report synergistic findings garnered from multiple modalities of investigation that have revealed structural and functional networks associated with these propagation points - including scalp and invasive EEG, and diffusion and functional MRI. We also report on intracranial recordings from implanted devices which provide us data on the dynamic networks we are aiming to modulate. Finally, we review the continuing evolution of network-guided neuromodulation for epilepsy to accelerate progress towards two translational goals: (i) to use pre-surgical network analyses to determine patient candidacy for neurostimulation for epilepsy by providing network biomarkers that predict efficacy; and (ii) to deliver precise, personalized and effective antiepileptic stimulation to prevent and arrest seizure propagation through mapping and modulation of each patients' individual epileptogenic networks.
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Affiliation(s)
- Rory J Piper
- Department of Neurosurgery, Great Ormond Street Hospital, London, UK
- Developmental Neurosciences, UCL Great Ormond Street Institute of Child Health, University College London, London, UK
| | - R Mark Richardson
- Department of Neurosurgery, Massachusetts General Hospital and Harvard Medical School, Boston, USA
| | | | | | - Torsten Baldeweg
- Developmental Neurosciences, UCL Great Ormond Street Institute of Child Health, University College London, London, UK
| | - Brian Litt
- Department of Neurology and Bioengineering, University of Pennsylvania, Philadelphia, USA
| | | | - Martin M Tisdall
- Department of Neurosurgery, Great Ormond Street Hospital, London, UK
- Developmental Neurosciences, UCL Great Ormond Street Institute of Child Health, University College London, London, UK
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29
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Simpson HD, Schulze-Bonhage A, Cascino GD, Fisher RS, Jobst BC, Sperling MR, Lundstrom BN. Practical considerations in epilepsy neurostimulation. Epilepsia 2022; 63:2445-2460. [PMID: 35700144 PMCID: PMC9888395 DOI: 10.1111/epi.17329] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2022] [Revised: 06/10/2022] [Accepted: 06/13/2022] [Indexed: 02/02/2023]
Abstract
Neuromodulation is a key therapeutic tool for clinicians managing patients with drug-resistant epilepsy. Multiple devices are available with long-term follow-up and real-world experience. The aim of this review is to give a practical summary of available neuromodulation techniques to guide the selection of modalities, focusing on patient selection for devices, common approaches and techniques for initiation of programming, and outpatient management issues. Vagus nerve stimulation (VNS), deep brain stimulation of the anterior nucleus of the thalamus (DBS-ANT), and responsive neurostimulation (RNS) are all supported by randomized controlled trials that show safety and a significant impact on seizure reduction, as well as a suggestion of reduction in the risk of sudden unexplained death in epilepsy (SUDEP). Significant seizure reductions are observed after 3 months for DBS, RNS, and VNS in randomized controlled trials, and efficacy appears to improve with time out to 7 to 10 years of follow-up for all modalities, albeit in uncontrolled follow-up or retrospective studies. A significant number of patients experience seizure-free intervals of 6 months or more with all three modalities. Number and location of epileptogenic foci are important factors affecting efficacy, and together with comorbidities such as severe mood or sleep disorders, may influence the choice of modality. Programming has evolved-DBS is typically initiated at lower current/voltage than used in the pivotal trial, whereas target charge density is lower with RNS, however generalizable optimal parameters are yet to be defined. Noninvasive brain stimulation is an emerging stimulation modality, although it is currently not used widely. In summary, clinical practice has evolved from those established in pivotal trials. Guidance is now available for clinicians who wish to expand their approach, and choice of neuromodulation technique may be tailored to individual patients based on their epilepsy characteristics, risk tolerance, and preferences.
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Affiliation(s)
- Hugh D. Simpson
- Division of Epilepsy, Department of Neurology, Mayo Clinic, Rochester, MN, USA
| | | | - Gregory D. Cascino
- Division of Epilepsy, Department of Neurology, Mayo Clinic, Rochester, MN, USA
| | - Robert S. Fisher
- Department of Neurology, Stanford Neuroscience Health Center, Palo Alto, CA, USA
| | - Barbara C. Jobst
- Geisel School of Medicine at Dartmouth, Department of Neurology, Dartmouth-Hitchcock Medical Center, NH, USA
| | - Michael R. Sperling
- Division of Epilepsy, Department of Neurology, Thomas Jefferson University, Philadelphia, PA, USA
| | - Brian N. Lundstrom
- Division of Epilepsy, Department of Neurology, Mayo Clinic, Rochester, MN, USA
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30
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Cortico-cortical and thalamo-cortical connectivity during non-REM and REM sleep: Insights from intracranial recordings in humans. Clin Neurophysiol 2022; 143:84-94. [PMID: 36166901 DOI: 10.1016/j.clinph.2022.08.026] [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: 10/03/2021] [Revised: 08/23/2022] [Accepted: 08/31/2022] [Indexed: 11/23/2022]
Abstract
OBJECTIVE To study changes of thalamo-cortical and cortico-cortical connectivity during wakefulness, non-Rapid Eye Movement (non-REM) sleep, including N2 and N3 stages, and REM sleep, using stereoelectroencephalography (SEEG) recording in humans. METHODS We studied SEEG recordings of ten patients during wakefulness, non-REM sleep and REM sleep, in seven brain regions of interest including the thalamus. We calculated directed and undirected functional connectivity using a measure of non-linear correlation coefficient h2. RESULTS The thalamus was more connected to other brain regions during N2 stage and REM sleep than during N3 stage during which cortex was more connected than the thalamus. We found two significant directed links: the first from the prefrontal region to the lateral parietal region in the delta band during N3 sleep and the second from the thalamus to the insula during REM sleep. CONCLUSIONS These results showed that cortico-cortical connectivity is more prominent in N3 stage than in N2 and REM sleep. During REM sleep we found significant thalamo-insular connectivity, with a driving role of the thalamus. SIGNIFICANCE We found a pattern of cortical connectivity during N3 sleep concordant with antero-posterior traveling slow waves. The thalamus seemed particularly involved as a hub of connectivity during REM sleep.
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31
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Scholly J, Gras A, Guye M, Bilger M, Valenti Hirsch MP, Hirsch E, Timofeev A, Vidailhet P, Bénar CG, Bartolomei F. Connectivity Alterations in Emotional and Cognitive Networks During a Manic State Induced by Direct Electrical Stimulation. Brain Topogr 2022; 35:627-635. [PMID: 36071370 DOI: 10.1007/s10548-022-00913-0] [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: 11/19/2021] [Accepted: 08/27/2022] [Indexed: 11/28/2022]
Abstract
Mania is characterized by affective and cognitive alterations, with heightened external and self-awareness that are opposite to the alteration of awareness during epileptic seizures. Electrical stimulations carried out routinely during stereotactic intracerebral EEG (SEEG) recordings for presurgical evaluation of epilepsy may represent a unique opportunity to study the pathophysiology of such complex emotional-behavioral phenomenon, particularly difficult to reproduce in experimental setting. We investigated SEEG signals-based functional connectivity between different brain regions involved in emotions and in consciousness processing during a manic state induced by electrical stimulation in a patient with drug-resistant focal epilepsy. The stimulation inducing manic state and an asymptomatic stimulation of the same site, as well as a seizure with alteration of awareness (AOA) were analyzed. Functional connectivity analysis was performed by measuring interdependencies (nonlinear regression analysis based on the h2 coefficient) between broadband SEEG signals and within typical sub-bands, before and after stimulation, or before and during the seizure with AOA, respectively. Stimulation of the right lateral prefrontal cortex induced a manic state lasting several hours. Its onset was associated with significant increase of broadband-signal functional coupling between the right hemispheric limbic nodes, the temporal pole and the claustrum, whereas significant decorrelation between the right lateral prefrontal and the anterior cingulate cortex was observed in theta-band. In contrast, ictal alteration of awareness was associated with increased broadband and sub-bands synchronization within and between the internal and external awareness networks, including the anterior and middle cingulate, the mesial and lateral prefrontal, the inferior parietal and the temporopolar cortex. Our data suggest the existence of network- and frequency-specific functional connectivity patterns during manic state. A transient desynchronization of theta activity between the external and internal awareness network hubs is likely to increase awareness, with potential therapeutic effect.
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Affiliation(s)
- Julia Scholly
- Service d'Epileptologie et de Rythmololgie Cérébrale, Hôpital Timone, AP-HM, Marseille, France. .,Aix Marseille Univ, CNRS, CRMBM, Marseille, France. .,Service d'Epileptologie et Rythmologie Cérébrale, Hôpital Timone, AP-HM, 264 Rue St Pierre, 13005, Marseille, France.
| | - Adrien Gras
- Consultation-Liaison Psychiatry Unit, University Hospital of Strasbourg, Strasbourg, France
| | - Maxime Guye
- Service d'Epileptologie et de Rythmololgie Cérébrale, Hôpital Timone, AP-HM, Marseille, France.,Aix Marseille Univ, CNRS, CRMBM, Marseille, France
| | - Mathias Bilger
- Medical and Surgical Epilepsy Unit, University Hospital of Strasbourg, Strasbourg, France
| | | | - Edouard Hirsch
- Medical and Surgical Epilepsy Unit, University Hospital of Strasbourg, Strasbourg, France
| | - Alexander Timofeev
- Medical and Surgical Epilepsy Unit, University Hospital of Strasbourg, Strasbourg, France
| | - Pierre Vidailhet
- Consultation-Liaison Psychiatry Unit, University Hospital of Strasbourg, Strasbourg, France
| | - Christian G Bénar
- Aix Marseille Univ, INSERM, INS, Inst Neurosci Syst, Marseille, France
| | - Fabrice Bartolomei
- Service d'Epileptologie et de Rythmololgie Cérébrale, Hôpital Timone, AP-HM, Marseille, France.,Aix Marseille Univ, INSERM, INS, Inst Neurosci Syst, Marseille, France
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Carron R, Roncon P, Lagarde S, Dibué M, Zanello M, Bartolomei F. Latest Views on the Mechanisms of Action of Surgically Implanted Cervical Vagal Nerve Stimulation in Epilepsy. Neuromodulation 2022; 26:498-506. [PMID: 36064522 DOI: 10.1016/j.neurom.2022.08.447] [Citation(s) in RCA: 19] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2022] [Revised: 07/05/2022] [Accepted: 08/01/2022] [Indexed: 11/25/2022]
Abstract
BACKGROUND Vagus nerve stimulation (VNS) is approved as an adjunctive treatment for drug-resistant epilepsy. Although there is a substantial amount of literature aiming at unraveling the mechanisms of action of VNS in epilepsy, it is still unclear how the cascade of events triggered by VNS leads to its antiepileptic effect. OBJECTIVE In this review, we integrated available peer-reviewed data on the effects of VNS in clinical and experimental research to identify those that are putatively responsible for its therapeutic effect. The topic of transcutaneous VNS will not be covered owing to the current lack of data supporting the differences and commonalities of its mechanisms of action in relation to invasive VNS. SUMMARY OF THE MAIN FINDINGS There is compelling evidence that the effect is obtained through the stimulation of large-diameter afferent myelinated fibers that project to the solitary tract nucleus, then to the parabrachial nucleus, which in turn alters the activity of the limbic system, thalamus, and cortex. VNS-induced catecholamine release from the locus coeruleus in the brainstem plays a pivotal role. Functional imaging studies tend to point toward a common vagal network that comes into play, made up of the amygdalo-hippocampal regions, left thalamus, and insular cortex. CONCLUSIONS Even though some crucial pieces are missing, neurochemical, molecular, cellular, and electrophysiological changes occur within the vagal afferent network at three main levels (the brainstem, the limbic system [amygdala and hippocampus], and the cortex). At this final level, VNS notably alters functional connectivity, which is known to be abnormally high within the epileptic zone and was shown to be significantly decreased by VNS in responders. The effect of crucial VNS parameters such as frequency or current amplitude on functional connectivity metrics is of utmost importance and requires further investigation.
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Pizzo F, Carron R, Bartolomei F. Letter to Brain-responsive corticothalamic stimulation in the pulvinar nucleus for the treatment of regional neocortical epilepsy: A case series. Epilepsia Open 2022; 7:541-542. [PMID: 35917183 PMCID: PMC9436297 DOI: 10.1002/epi4.12611] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2021] [Accepted: 01/09/2022] [Indexed: 11/24/2022] Open
Affiliation(s)
- Francesca Pizzo
- Aix Marseille Univ, INSERM, INS, Inst Neurosci Syst, Marseille, France.,APHM, Timone Hospital, Epileptology and Cerebral Rhythmology, Marseille, France
| | - Romain Carron
- Aix Marseille Univ, INSERM, INS, Inst Neurosci Syst, Marseille, France.,APHM, Timone Hospital, Stereotactic and Functional Neurosurgery, Marseille, France
| | - Fabrice Bartolomei
- Aix Marseille Univ, INSERM, INS, Inst Neurosci Syst, Marseille, France.,APHM, Timone Hospital, Epileptology and Cerebral Rhythmology, Marseille, France
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Ilyas A, Tandon N, Lhatoo SD. Thalamic neuromodulation for epilepsy: A clinical perspective. Epilepsy Res 2022; 183:106942. [PMID: 35580382 DOI: 10.1016/j.eplepsyres.2022.106942] [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: 03/15/2022] [Revised: 04/12/2022] [Accepted: 05/06/2022] [Indexed: 11/29/2022]
Abstract
Thalamic neuromodulation can be an effective therapeutic option for select patients with medically refractory epilepsy. However, successful outcome depends on several factors, beginning with appropriate patient and thalamic target selection. Among thalamic targets, the anterior (ANT) and centromedian (CeM) nuclei have the greatest clinical evidence for efficacy. However, the place of thalamic neuromodulation in the treatment armamentarium for intractable seizures is at the tail end of a long list of options. It's relative efficacy, if any, in relation to other treatment modalities however, can be inferred. As we will discuss, considerable work remains to be done in optimal targeting of thalamic nuclei, appropriate to the epilepsy syndrome and seizure type of the individual patient, which may change our current understanding of the place of thalamic neuromodulation on a range of treatment modality efficacies. Currently, it appears that ANT DBS is most efficacious for limbic epilepsies whereas CM, for generalized, multifocal (especially frontotemporal) epilepsies. Based on controlled studies, the efficacy of ANT and CeM DBS is roughly in line with other neuromodulatory therapies (i.e. RNS, VNS) when assessed within the cohort of patients for which the therapy is indicated. Much improvement is needed to render thalamic DBS more efficacious, and use of optimal targeting strategies, especially direct targeting, can positively affect outcomes. Thalamic neuromodulation is still in its infancy; however, clinical advances in this therapy are being realized.
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Affiliation(s)
- Adeel Ilyas
- Department of Neurological Surgery, University of Alabama at Birmingham, Birmingham, AL, USA; Vivian L. Smith Department of Neurosurgery, McGovern Medical School at UT Health Houston, Houston, TX, USA; Texas Institute for Restorative Neurotechnologies, The University of Texas Health Science Center at Houston, Houston, TX, USA.
| | - Nitin Tandon
- Vivian L. Smith Department of Neurosurgery, McGovern Medical School at UT Health Houston, Houston, TX, USA; Texas Institute for Restorative Neurotechnologies, The University of Texas Health Science Center at Houston, Houston, TX, USA; Department of Neurology, McGovern Medical School at UT Health Houston, Houston, TX, USA; Memorial Hermann Hospital, Texas Medical Center, Houston, TX, USA
| | - Samden D Lhatoo
- Texas Institute for Restorative Neurotechnologies, The University of Texas Health Science Center at Houston, Houston, TX, USA; Department of Neurology, McGovern Medical School at UT Health Houston, Houston, TX, USA; Memorial Hermann Hospital, Texas Medical Center, Houston, TX, USA
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Middlebrooks EH, He X, Grewal SS, Keller SS. Neuroimaging and thalamic connectomics in epilepsy neuromodulation. Epilepsy Res 2022; 182:106916. [PMID: 35367691 DOI: 10.1016/j.eplepsyres.2022.106916] [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: 01/11/2022] [Revised: 03/05/2022] [Accepted: 03/27/2022] [Indexed: 11/03/2022]
Abstract
Neuromodulation is an increasingly utilized therapy for the treatment of people with drug-resistant epilepsy. To date, the most common and effective target has been the thalamus, which is known to play a key role in multiple forms of epilepsy. Neuroimaging has facilitated rapid developments in the understanding of functional targets, surgical and programming techniques, and the effects of thalamic stimulation. In this review, the role of neuroimaging in neuromodulation is explored. First, the structural and functional changes of the thalamus in common epilepsy syndromes are discussed as the rationale for neuromodulation of the thalamus. Next, methods for imaging different thalamic nuclei are presented, as well as rationale for the need of direct surgical targeting rather than reliance on traditional stereotactic coordinates. Lastly, we discuss the potential role of neuroimaging in assessing the effects of thalamic stimulation and as a potential biomarker for neuromodulation outcomes.
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Affiliation(s)
- Erik H Middlebrooks
- Department of Radiology, Mayo Clinic, Jacksonville, FL, USA; Department of Neurosurgery, Mayo Clinic, Jacksonville, FL, USA.
| | - Xiaosong He
- Department of Psychology, University of Science and Technology of China, Hefei, Anhui, China
| | | | - Simon S Keller
- Department of Pharmacology and Therapeutics, Institute of Systems, Molecular and Integrative Biology, University of Liverpool, UK
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Ilyas A, Snyder KM, Pati S, Tandon N. Optimally Targeting the Centromedian Nucleus of the Thalamus for Generalized Epilepsy: A Meta-Analysis. Epilepsy Res 2022; 184:106954. [DOI: 10.1016/j.eplepsyres.2022.106954] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2022] [Revised: 05/13/2022] [Accepted: 05/25/2022] [Indexed: 12/18/2022]
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Vetkas A, Germann J, Elias G, Loh A, Boutet A, Yamamoto K, Sarica C, Samuel N, Milano V, Fomenko A, Santyr B, Tasserie J, Gwun D, Jung HH, Valiante T, Ibrahim GM, Wennberg R, Kalia SK, Lozano AM. Identifying the neural network for neuromodulation in epilepsy through connectomics and graphs. Brain Commun 2022; 4:fcac092. [PMID: 35611305 PMCID: PMC9123846 DOI: 10.1093/braincomms/fcac092] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2021] [Revised: 12/13/2021] [Accepted: 03/31/2022] [Indexed: 02/01/2023] Open
Abstract
Deep brain stimulation is a treatment option for patients with drug-resistant epilepsy. The precise mechanism of neuromodulation in epilepsy is unknown, and biomarkers are needed for optimizing treatment. The aim of this study was to describe the neural network associated with deep brain stimulation targets for epilepsy and to explore its potential application as a novel biomarker for neuromodulation. Using seed-to-voxel functional connectivity maps, weighted by seizure outcomes, brain areas associated with stimulation were identified in normative resting state functional scans of 1000 individuals. To pinpoint specific regions in the normative epilepsy deep brain stimulation network, we examined overlapping areas of functional connectivity between the anterior thalamic nucleus, centromedian thalamic nucleus, hippocampus and less studied epilepsy deep brain stimulation targets. Graph network analysis was used to describe the relationship between regions in the identified network. Furthermore, we examined the associations of the epilepsy deep brain stimulation network with disease pathophysiology, canonical resting state networks and findings from a systematic review of resting state functional MRI studies in epilepsy deep brain stimulation patients. Cortical nodes identified in the normative epilepsy deep brain stimulation network were in the anterior and posterior cingulate, medial frontal and sensorimotor cortices, frontal operculum and bilateral insulae. Subcortical nodes of the network were in the basal ganglia, mesencephalon, basal forebrain and cerebellum. Anterior thalamic nucleus was identified as a central hub in the network with the highest betweenness and closeness values, while centromedian thalamic nucleus and hippocampus showed average centrality values. The caudate nucleus and mammillothalamic tract also displayed high centrality values. The anterior cingulate cortex was identified as an important cortical hub associated with the effect of deep brain stimulation in epilepsy. The neural network of deep brain stimulation targets shared hubs with known epileptic networks and brain regions involved in seizure propagation and generalization. Two cortical clusters identified in the epilepsy deep brain stimulation network included regions corresponding to resting state networks, mainly the default mode and salience networks. Our results were concordant with findings from a systematic review of resting state functional MRI studies in patients with deep brain stimulation for epilepsy. Our findings suggest that the various epilepsy deep brain stimulation targets share a common cortico-subcortical network, which might in part underpin the antiseizure effects of stimulation. Interindividual differences in this network functional connectivity could potentially be used as biomarkers in selection of patients, stimulation parameters and neuromodulation targets.
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Affiliation(s)
- Artur Vetkas
- Division of Neurosurgery, Toronto Western Hospital, University Health Network, University of Toronto, Toronto, Ontario, Canada
- Neurology clinic, Department of Neurosurgery, Tartu University Hospital, University of Tartu, Tartu, Estonia
| | - Jürgen Germann
- Division of Neurosurgery, Toronto Western Hospital, University Health Network, University of Toronto, Toronto, Ontario, Canada
| | - Gavin Elias
- Division of Neurosurgery, Toronto Western Hospital, University Health Network, University of Toronto, Toronto, Ontario, Canada
| | - Aaron Loh
- Division of Neurosurgery, Toronto Western Hospital, University Health Network, University of Toronto, Toronto, Ontario, Canada
| | - Alexandre Boutet
- Division of Neurosurgery, Toronto Western Hospital, University Health Network, University of Toronto, Toronto, Ontario, Canada
- Joint Department of Medical Imaging, University of Toronto, Toronto, Ontario, Canada
| | - Kazuaki Yamamoto
- Division of Neurosurgery, Toronto Western Hospital, University Health Network, University of Toronto, Toronto, Ontario, Canada
| | - Can Sarica
- Division of Neurosurgery, Toronto Western Hospital, University Health Network, University of Toronto, Toronto, Ontario, Canada
| | - Nardin Samuel
- Division of Neurosurgery, Toronto Western Hospital, University Health Network, University of Toronto, Toronto, Ontario, Canada
| | - Vanessa Milano
- Division of Neurosurgery, Toronto Western Hospital, University Health Network, University of Toronto, Toronto, Ontario, Canada
| | - Anton Fomenko
- Division of Neurosurgery, Toronto Western Hospital, University Health Network, University of Toronto, Toronto, Ontario, Canada
- Section of Neurosurgery, Health Sciences Centre, University of Manitoba, Winnipeg, Manitoba, Canada
| | - Brendan Santyr
- Division of Neurosurgery, Toronto Western Hospital, University Health Network, University of Toronto, Toronto, Ontario, Canada
- Schulich School of Medicine and Dentistry, Western University, London, ON, Canada
| | - Jordy Tasserie
- Division of Neurosurgery, Toronto Western Hospital, University Health Network, University of Toronto, Toronto, Ontario, Canada
| | - Dave Gwun
- Division of Neurosurgery, Toronto Western Hospital, University Health Network, University of Toronto, Toronto, Ontario, Canada
| | - Hyun Ho Jung
- Division of Neurosurgery, Toronto Western Hospital, University Health Network, University of Toronto, Toronto, Ontario, Canada
- Department of Neurosurgery, Yonsei University College of Medicine, Seoul, Republic of Korea
| | - Taufik Valiante
- Division of Neurosurgery, Toronto Western Hospital, University Health Network, University of Toronto, Toronto, Ontario, Canada
- Krembil Research Institute, Toronto, Ontario, Canada
- CRANIA, University Health Network and University of Toronto, Toronto, ON, M5G 2A2, Canada
- The KITE Research Institute, University Health Network, Toronto, ON, M5G 2A2, Canada
| | - George M Ibrahim
- Division of Pediatric Neurosurgery, Sick Kids Toronto, University of Toronto, Toronto, ON, Canada
| | - Richard Wennberg
- Division of Neurosurgery, Toronto Western Hospital, University Health Network, University of Toronto, Toronto, Ontario, Canada
- Krembil Research Institute, Toronto, Ontario, Canada
| | - Suneil K Kalia
- Division of Neurosurgery, Toronto Western Hospital, University Health Network, University of Toronto, Toronto, Ontario, Canada
- Krembil Research Institute, Toronto, Ontario, Canada
- CRANIA, University Health Network and University of Toronto, Toronto, ON, M5G 2A2, Canada
- The KITE Research Institute, University Health Network, Toronto, ON, M5G 2A2, Canada
| | - Andres M Lozano
- Division of Neurosurgery, Toronto Western Hospital, University Health Network, University of Toronto, Toronto, Ontario, Canada
- Krembil Research Institute, Toronto, Ontario, Canada
- CRANIA, University Health Network and University of Toronto, Toronto, ON, M5G 2A2, Canada
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Abouelleil M, Deshpande N, Ali R. Emerging Trends in Neuromodulation for Treatment of Drug-Resistant Epilepsy. FRONTIERS IN PAIN RESEARCH 2022; 3:839463. [PMID: 35386582 PMCID: PMC8977768 DOI: 10.3389/fpain.2022.839463] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2021] [Accepted: 02/21/2022] [Indexed: 01/12/2023] Open
Abstract
Epilepsy is a neurological disorder that affects more than 70 million people globally. A considerable proportion of epilepsy is resistant to anti-epileptic drugs (AED). For patients with drug-resistant epilepsy (DRE), who are not eligible for resective or ablative surgery, neuromodulation has been a palliative option. Since the approval of vagus nerve stimulation (VNS) in 1997, expansion to include other modalities, such as deep brain stimulation (DBS) and responsive neurostimulation (RNS), has led to improved seizure control in this population. In this article, we discuss the current updates and emerging trends on neuromodulation for epilepsy.
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Affiliation(s)
- Mohamed Abouelleil
- Division of Neurological Surgery, Spectrum Health, Grand Rapids, MI, United States
| | - Nachiket Deshpande
- College of Human Medicine, Michigan State University, East Lansing, MI, United States
| | - Rushna Ali
- Division of Neurological Surgery, Spectrum Health, Grand Rapids, MI, United States
- *Correspondence: Rushna Ali
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Mercadal B, Salvador R, Biagi MC, Bartolomei F, Wendling F, Ruffini G. Modeling implanted metals in electrical stimulation applications. J Neural Eng 2022; 19. [PMID: 35172293 DOI: 10.1088/1741-2552/ac55ae] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2021] [Accepted: 02/16/2022] [Indexed: 11/11/2022]
Abstract
OBJECTIVE Metal implants impact the dosimetry assessment in electrical stimulation techniques. Therefore, they need to be included in numerical models. While currents in the body are ionic, metals only allow electron transport. In fact, charge transfer between tissues and metals requires electric fields to drive electrochemical reactions at the interface. Thus, metal implants may act as insulators or as conductors depending on the scenario. The aim of this paper is to provide a theoretical argument that guides the choice of the correct representation of metal implants in electrical models while considering the electrochemical nature of the problem Approach: We built a simple model of a metal implant exposed to a homogeneous electric field of various magnitudes. The same geometry was solved using two different models: a purely electric one (with different conductivities for the implant), and an electrochemical one. As an example of application, we also modeled a transcranial electrical stimulation (tES) treatment in a realistic head model with a skull plate using a high and low conductivity value for the plate. MAIN RESULTS Metal implants generally act as electric insulators when exposed to electric fields up to around 100 V/m and they only resemble a perfect conductor for fields in the order of 1000 V/m and above. The results are independent of the implant's metal, but they depend on its geometry. tES modeling with implants incorrectly treated as conductors can lead to errors of 50% or more in the estimation of the induced fields Significance: Metal implants can be accurately represented by a simple electrical model of constant conductivity, but an incorrect model choice can lead to large errors in the dosimetry assessment. Our results can be used to guide the selection of the most appropriate model in each scenario.
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Affiliation(s)
- Borja Mercadal
- Neuroelectrics Barcelona SL, Av. del Tibidabo, 47B, Barcelona, Catalunya, 08035, SPAIN
| | - Ricardo Salvador
- Neuroelectrics Barcelona SL, Av. del Tibidabo, 47B, Barcelona, Catalunya, 08035, SPAIN
| | - Maria Chiara Biagi
- Neuroelectrics Barcelona SL, Av. del Tibidabo, 47B, Barcelona, Catalunya, 08035, SPAIN
| | - Fabrice Bartolomei
- INS, Institut de Neurosciences des Systèmes, Aix-Marseille Universite, 27, Boulevard Jean Moulin, Marseille, Provence-Alpes-Côte d'Azu, 13284, FRANCE
| | - Fabrice Wendling
- INSERM, LTSI (Laboratoire de Traitement du Signal et de l'Image) U1099, Universite de Rennes 1, Campus Beaulieu, Rennes, Bretagne, 35065, FRANCE
| | - Giulio Ruffini
- Neuroelectrics Barcelona SL, Av. del Tibidabo, 47B, Barcelona, Catalunya, 08035, SPAIN
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Abstract
Impaired consciousness during seizures severely affects quality of life for people with
epilepsy but the mechanisms are just beginning to be understood. Consciousness is thought
to involve large-scale brain networks, so it is puzzling that focal seizures often impair
consciousness. Recent work investigating focal temporal lobe or limbic seizures in human
patients and experimental animal models suggests that impaired consciousness is caused by
active inhibition of subcortical arousal mechanisms. Focal limbic seizures exhibit
decreased neuronal firing in brainstem, basal forebrain, and thalamic arousal networks,
and cortical arousal can be restored when subcortical arousal circuits are stimulated
during seizures. These findings open the possibility of restoring arousal and
consciousness therapeutically during and following seizures by thalamic neurostimulation.
When seizures cannot be stopped by existing treatments, targeted subcortical stimulation
may improve arousal and consciousness, leading to improved safety and better psychosocial
function for people with epilepsy.
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Affiliation(s)
- Hal Blumenfeld
- Departments of Neurology, Neuroscience, Neurosurgery, Yale University School of Medicine, New Haven, CT, USA
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Impaired awareness in mesial temporal lobe epilepsy: Network analysis of foramen ovale and scalp EEG. Clin Neurophysiol 2021; 132:3084-3094. [PMID: 34717226 DOI: 10.1016/j.clinph.2021.09.011] [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: 08/11/2021] [Accepted: 09/01/2021] [Indexed: 11/22/2022]
Abstract
OBJECTIVE We use co-registration of foramen-ovale and scalp-EEG to investigate network alterations in temporal-lobe epilepsy during focal seizures without (aura) or with impairment of awareness (SIA). METHODS One aura and one SIA were selected from six patients. Temporal dynamic among 4 epochs, as well as the differences between aura and SIA, were analyzed through partial directed coherence and graph theory-based indices of centrality. RESULTS Regarding the auras temporal evolution, fronto-parietal (FP) regions showed decreased connectivity with respect to the interictal period, in both epileptogenic (EH) and non-epileptogenic hemisphere (nEH). During SIAs, temporal dynamic showed more changes than auras: centrality of mesial temporal (mT) regions changes during all conditions, and nEH FP centrality showed the same dynamic trend of the aura (decreased centrality), until the last epoch, close to the impaired awareness, when showed increased centrality. Comparing SIA with aura, in proximity of impaired awareness, increased centrality was found in all the regions, except in nEH mT. CONCLUSIONS Our findings suggested that the impairment of awareness is related to network alterations occurring first in neocortical regions and when awareness is still retained. SIGNIFICANCE The analysis of 'hub' alteration can represent a suitable biomarker for scalp EEG-based prediction of awareness impairment.
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Tan G, Li X, Niu R, Wang H, Chen D, Gong Q, Liu L. Functional connectivity of the thalamocortical circuit in patients with seizure relapse after antiseizure medication withdrawal. Epilepsia 2021; 62:2463-2473. [PMID: 34342885 DOI: 10.1111/epi.17014] [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: 12/10/2020] [Revised: 07/12/2021] [Accepted: 07/12/2021] [Indexed: 02/05/2023]
Abstract
OBJECTIVE To characterize the features of thalamocortical functional connectivity during seizure recurrence at the time of antiseizure medication (ASM) withdrawal. METHODS Patients with chronic epilepsy who attempted to discontinue medications were prospectively registered and followed up; 19 patients remained seizure-free (SF-group), 18 patients had seizure relapses (SR-group) after ASM withdrawal, and 28 healthy controls were recruited. Resting-state functional magnetic resonance imaging was performed before ASM withdrawal. Thalamus subdivisions were set as seeds to calculate voxelwise functional connectivity. Partial correlation analysis between functional connectivity and clinical variables was performed. A support vector machine was used to assess the predictive ability of the specific functional connectivity for seizure relapse. RESULTS The within-group comparison indicated that the SR-group had more extensive functional connectivity than the SF-group; the left inferior pulvinar, left medial pulvinar, and right anterior pulvinar showed a significantly stronger functional connection with the precuneus in the SR-group than in the SF-group (Gaussian random field correction, voxel-level p < .001 and cluster-level p < .05). In the SR-group, a positive correlation was found between the left inferior pulvinar-precuneus connectivity and the active period (r = .46, p = .05), seizure-free period (r = .67, p = .002), and disease duration (r = .53, p = .02), and between the left medial pulvinar-precuneus connectivity and the seizure-free period (r = .58, p = .01). The combination of these thalamocortical connections showed a high predictive ability, with an area under the curve of .92 and accuracy of .90 (p = .01). SIGNIFICANCE This study determined distinct features of thalamocortical functional connectivity at the time of ASM withdrawal in patients with and without seizure relapse, showing a potential for predicting seizure outcomes following ASM withdrawal.
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Affiliation(s)
- Ge Tan
- Epilepsy Center, Department of Neurology, West China Hospital, Sichuan University, Chengdu, China
| | - Xiuli Li
- Huaxi MR Research Center (HMRRC), Department of Radiology, West China Hospital, Sichuan University, Chengdu, China.,Research Unit of Psychoradiology, Chinese Academy of Medical Sciences, Chengdu, China
| | - Running Niu
- Huaxi MR Research Center (HMRRC), Department of Radiology, West China Hospital, Sichuan University, Chengdu, China.,Research Unit of Psychoradiology, Chinese Academy of Medical Sciences, Chengdu, China
| | - Haijiao Wang
- Epilepsy Center, Department of Neurology, West China Hospital, Sichuan University, Chengdu, China
| | - Deng Chen
- Epilepsy Center, Department of Neurology, West China Hospital, Sichuan University, Chengdu, China
| | - Qiyong Gong
- Huaxi MR Research Center (HMRRC), Department of Radiology, West China Hospital, Sichuan University, Chengdu, China.,Research Unit of Psychoradiology, Chinese Academy of Medical Sciences, Chengdu, China
| | - Ling Liu
- Epilepsy Center, Department of Neurology, West China Hospital, Sichuan University, Chengdu, China
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Garcia-Cairasco N, Podolsky-Gondim G, Tejada J. Searching for a paradigm shift in the research on the epilepsies and associated neuropsychiatric comorbidities. From ancient historical knowledge to the challenge of contemporary systems complexity and emergent functions. Epilepsy Behav 2021; 121:107930. [PMID: 33836959 DOI: 10.1016/j.yebeh.2021.107930] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/05/2021] [Accepted: 03/06/2021] [Indexed: 10/21/2022]
Abstract
In this review, we will discuss in four scenarios our challenges to offer possible solutions for the puzzle associated with the epilepsies and neuropsychiatric comorbidities. We need to recognize that (1) since quite old times, human wisdom was linked to the plural (distinct global places/cultures) perception of the Universe we are in, with deep respect for earth and nature. Plural ancestral knowledge was added with the scientific methods; however, their joint efforts are the ideal scenario; (2) human behavior is not different than animal behavior, in essence the product of Darwinian natural selection; knowledge of animal and human behavior are complementary; (3) the expression of human behavior follows the same rules that complex systems with emergent properties, therefore, we can measure events in human, clinical, neurobiological situations with complexity systems' tools; (4) we can use the semiology of epilepsies and comorbidities, their neural substrates, and potential treatments (including experimental/computational modeling, neurosurgical interventions), as a source and collection of integrated big data to predict with them (e.g.: machine/deep learning) diagnosis/prognosis, individualized solutions (precision medicine), basic underlying mechanisms and molecular targets. Once the group of symptoms/signals (with a myriad of changing definitions and interpretations over time) and their specific sequences are determined, in epileptology research and clinical settings, the use of modern and contemporary techniques such as neuroanatomical maps, surface electroencephalogram and stereoelectroencephalography (SEEG) and imaging (MRI, BOLD, DTI, SPECT/PET), neuropsychological testing, among others, are auxiliary in the determination of the best electroclinical hypothesis, and help design a specific treatment, usually as the first attempt, with available pharmacological resources. On top of ancient knowledge, currently known and potentially new antiepileptic drugs, alternative treatments and mechanisms are usually produced as a consequence of the hard, multidisciplinary, and integrated studies of clinicians, surgeons, and basic scientists, all over the world. The existence of pharmacoresistant patients, calls for search of other solutions, being along the decades the surgeries the most common interventions, such as resective procedures (i.e., selective or standard lobectomy, lesionectomy), callosotomy, hemispherectomy and hemispherotomy, added by vagus nerve stimulation (VNS), deep brain stimulation (DBS), neuromodulation, and more recently focal minimal or noninvasive ablation. What is critical when we consider the pharmacoresistance aspect with the potential solution through surgery, is still the pursuit of localization-dependent regions (e.g.: epileptogenic zone (EZ)), in order to decide, no matter how sophisticated are the brain mapping tools (EEG and MRI), the size and location of the tissue to be removed. Mimicking the semiology and studying potential neural mechanisms and molecular targets - by means of experimental and computational modeling - are fundamental steps of the whole process. Concluding, with the conjunction of ancient knowledge, coupled to critical and creative contemporary, scientific (not dogmatic) clinical/surgical, and experimental/computational contributions, a better world and of improved quality of life can be offered to the people with epilepsy and neuropsychiatric comorbidities, who are still waiting (as well as the scientists) for a paradigm shift in epileptology, both in the Basic Science, Computational, Clinical, and Neurosurgical Arenas. This article is part of the Special Issue "NEWroscience 2018".
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Affiliation(s)
- Norberto Garcia-Cairasco
- Laboratório de Neurofisiologia e Neuroetologia Experimental, Departmento de Fisiologia, Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto. Brazil; Departamento de Neurociências e Ciências do Comportamento, Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, Brazil.
| | - Guilherme Podolsky-Gondim
- Departamento de Neurociências e Ciências do Comportamento, Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, Brazil.
| | - Julian Tejada
- Departamento de Psicologia, Universidade Federal de Sergipe, Brazil.
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Middlebrooks EH, Okromelidze L, Lin C, Jain A, Westerhold E, Ritaccio A, Quiñones-Hinojosa A, Gupta V, Grewal SS. Edge-enhancing gradient echo with multi-image co-registration and averaging (EDGE-MICRA) for targeting thalamic centromedian and parafascicular nuclei. Neuroradiol J 2021; 34:667-675. [PMID: 34121497 DOI: 10.1177/19714009211021781] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
BACKGROUND AND PURPOSE Deep brain stimulation of the thalamus is an effective treatment for multiple neurological disorders. The centromedian and parafascicular nuclei are recently emerging targets for multiple conditions, such as epilepsy and Tourette syndrome; however, their limited visibility on conventional magnetic resonance imaging sequences has been a major obstacle. The goal of this study was to demonstrate the feasibility of a high-resolution and high-contrast targeting sequence for centromedian-parafascicular deep brain stimulation using a recently described magnetic resonance imaging sequence, three-dimensional edge-enhancing gradient echo. METHODS The three-dimensional edge-enhancing gradient echo sequence was performed on a normal volunteer for a total of six acquisitions. Multi-image co-registration and averaging was performed by first co-registering each of the six scans and then averaging to produce an edge-enhancing gradient echo-multi-image co-registration and averaging scan. The averaging was also performed for two, three, four and five scans to assess the change in the signal-to-noise ratio and identify the ideal balance of image quality and scan time. RESULTS The edge-enhancing gradient echo-multi-image co-registration and averaging scan allowed clear boundary delineation of the centromedian and parafascicular nuclei. The signal-to-noise ratio increased as a function of increasing scan number, but the added gain was small beyond four scans for the imaging parameters used in this study. CONCLUSIONS The recently described three-dimensional edge-enhancing gradient echo sequence provides an easily implementable approach, using widely available magnetic resonance imaging technology without complex post-processing techniques, to delineate centromedian and parafascicular nuclei for deep brain stimulation targeting.
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Affiliation(s)
- Erik H Middlebrooks
- Department of Radiology, Mayo Clinic, Florida, USA.,Department of Neurosurgery, Mayo Clinic, Florida, USA
| | | | - Chen Lin
- Department of Radiology, Mayo Clinic, Florida, USA
| | - Ayushi Jain
- Department of Radiology, Mayo Clinic, Florida, USA
| | | | | | | | - Vivek Gupta
- Department of Radiology, Mayo Clinic, Florida, USA
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Kreilkamp BAK, McKavanagh A, Alonazi B, Bryant L, Das K, Wieshmann UC, Marson AG, Taylor PN, Keller SS. Altered structural connectome in non-lesional newly diagnosed focal epilepsy: Relation to pharmacoresistance. Neuroimage Clin 2021; 29:102564. [PMID: 33508622 PMCID: PMC7841400 DOI: 10.1016/j.nicl.2021.102564] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2020] [Revised: 01/10/2021] [Accepted: 01/11/2021] [Indexed: 12/19/2022]
Abstract
Despite an expanding literature on brain alterations in patients with longstanding epilepsy, few neuroimaging studies investigate patients with newly diagnosed focal epilepsy (NDfE). Understanding brain network impairments at diagnosis is necessary to elucidate whether or not brain abnormalities are principally due to the chronicity of the disorder and to develop prognostic markers of treatment outcome. Most adults with NDfE do not have MRI-identifiable lesions and the reasons for seizure onset and refractoriness are unknown. We applied structural connectomics to T1-weighted and multi-shell diffusion MRI data with generalized q-sampling image reconstruction using Network Based Statistics (NBS). We scanned 27 patients within an average of 3.7 (SD = 2.9) months of diagnosis and anti-epileptic drug treatment outcomes were collected 24 months after diagnosis. Seven patients were excluded due to lesional NDfE and outcome data was available in 17 patients. Compared to 29 healthy controls, patients with non-lesional NDfE had connectomes with significantly decreased quantitative anisotropy in edges connecting right temporal, frontal and thalamic nodes and increased diffusivity in edges between bilateral temporal, frontal, occipital and parietal nodes. Compared to controls, patients with persistent seizures showed the largest effect size (|d|>=1) for decreased anisotropy in right parietal edges and increased diffusivity in edges between left thalamus and left parietal nodes. Compared to controls, patients who were rendered seizure-free showed the largest effect size for decreased anisotropy in the edge connecting the left thalamus and right temporal nodes and increased diffusivity in edges connecting right frontal nodes. As demonstrated by large effect sizes, connectomes with decreased anisotropy (edge between right frontal and left insular nodes) and increased diffusivity (edge between right thalamus and left parietal nodes) were found in patients with persistent seizures compared to patients who became seizure-free. Patients who had persistent seizures showed larger effect sizes in all network metrics than patients who became seizure-free when compared to each other and compared to controls. Furthermore, patients with focal-to-bilateral tonic-clonic seizures (FBTCS, N = 11) had decreased quantitative anisotropy in a bilateral network involving edges between temporal, parietal and frontal nodes with greater effect sizes than those of patients without FBTCS (N = 9). NBS findings between patients and controls indicated that structural network changes are not necessarily a consequence of longstanding refractory epilepsy and instead are present at the time of diagnosis. Computed effect sizes suggest that there may be structural network MRI-markers of future pharmacoresistance and seizure severity in patients with a new diagnosis of focal epilepsy.
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Affiliation(s)
- Barbara A K Kreilkamp
- Department of Pharmacology & Therapeutics, Institute of Systems, Molecular and Integrative Biology, University of Liverpool, Liverpool, UK; Department of Neuroradiology, The Walton Centre NHS Foundation Trust, Liverpool, UK; Department of Clinical Neurophysiology, University Medicine Göttingen, Göttingen, Germany.
| | - Andrea McKavanagh
- Department of Pharmacology & Therapeutics, Institute of Systems, Molecular and Integrative Biology, University of Liverpool, Liverpool, UK; Department of Neuroradiology, The Walton Centre NHS Foundation Trust, Liverpool, UK
| | - Batil Alonazi
- Department of Radiology and Medical Imaging, Prince Sattam Bin Abdulaziz University, Al Kharj, Saudi Arabia
| | - Lorna Bryant
- Department of Pharmacology & Therapeutics, Institute of Systems, Molecular and Integrative Biology, University of Liverpool, Liverpool, UK; Department of Neuroradiology, The Walton Centre NHS Foundation Trust, Liverpool, UK
| | - Kumar Das
- Department of Neuroradiology, The Walton Centre NHS Foundation Trust, Liverpool, UK
| | - Udo C Wieshmann
- Department of Neuroradiology, The Walton Centre NHS Foundation Trust, Liverpool, UK
| | - Anthony G Marson
- Department of Pharmacology & Therapeutics, Institute of Systems, Molecular and Integrative Biology, University of Liverpool, Liverpool, UK; Department of Neuroradiology, The Walton Centre NHS Foundation Trust, Liverpool, UK
| | - Peter N Taylor
- CNNP Lab, Interdisciplinary Computing and Complex BioSystems Group, School of Computing, Newcastle University, UK; UCL Queen Square Institute of Neurology, Queen Square, London, UK
| | - Simon S Keller
- Department of Pharmacology & Therapeutics, Institute of Systems, Molecular and Integrative Biology, University of Liverpool, Liverpool, UK; Department of Neuroradiology, The Walton Centre NHS Foundation Trust, Liverpool, UK
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Pizzo F, Roehri N, Giusiano B, Lagarde S, Carron R, Scavarda D, McGonigal A, Filipescu C, Lambert I, Bonini F, Trebuchon A, Bénar CG, Bartolomei F. The Ictal Signature of Thalamus and Basal Ganglia in Focal Epilepsy: A SEEG Study. Neurology 2020; 96:e280-e293. [PMID: 33024023 DOI: 10.1212/wnl.0000000000011003] [Citation(s) in RCA: 42] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2020] [Accepted: 08/26/2020] [Indexed: 11/15/2022] Open
Abstract
OBJECTIVE To determine the involvement of subcortical regions in human epilepsy by analyzing direct recordings from these regions during epileptic seizures using stereo-EEG (SEEG). METHODS We studied the SEEG recordings of a large series of patients (74 patients, 157 seizures) with an electrode sampling the thalamus and in some cases also the basal ganglia (caudate nucleus, 22 patients; and putamen, 4 patients). We applied visual analysis and signal quantification methods (Epileptogenicity Index [EI]) to their ictal recordings and compared electrophysiologic with clinical data. RESULTS We found that in 86% of patients, thalamus was involved during seizures (visual analysis) and 20% showed high values of epileptogenicity (EI >0.3). Basal ganglia may also disclose high values of epileptogenicity (9% in caudate nucleus) but to a lesser degree than thalamus (p < 0.01). We observed different seizure onset patterns including low voltage high frequency activities. We found high values of thalamic epileptogenicity in different epilepsy localizations, including opercular and motor epilepsies. We found no difference between epilepsy etiologies (cryptogenic vs malformation of cortical development, p = 0.77). Thalamic epileptogenicity was correlated with the extension of epileptogenic networks (p = 0.02, ρ 0.32). We found a significant effect (p < 0.05) of thalamic epileptogenicity regarding the postsurgical outcome (higher thalamic EI corresponding to higher probability of surgical failure). CONCLUSIONS Thalamic involvement during seizures is common in different seizure types. The degree of thalamic epileptogenicity is a possible marker of the epileptogenic network extension and of postsurgical prognosis.
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Affiliation(s)
- Francesca Pizzo
- From the Epileptology Department (F.P., S.L., A.M., I.L., F. Bonini, A.T., F. Bartolomei), Functional and Stereotactic Neurosurgery (R.C.), and Pediatric Neurosurgery (D.S.), APHM, Timone Hospital, Institut de Neurosciences des Systèmes (F.P., N.R., B.G., S.L., R.C., D.S., A.M., I.L., F. Bonini, A.T., C.-G.B, F. Bartolomei), INSERM, Aix Marseille Universite; and Psychiatrie et Neurosciences (C.F.), GHU Paris, St Anne, Paris.
| | - Nicolas Roehri
- From the Epileptology Department (F.P., S.L., A.M., I.L., F. Bonini, A.T., F. Bartolomei), Functional and Stereotactic Neurosurgery (R.C.), and Pediatric Neurosurgery (D.S.), APHM, Timone Hospital, Institut de Neurosciences des Systèmes (F.P., N.R., B.G., S.L., R.C., D.S., A.M., I.L., F. Bonini, A.T., C.-G.B, F. Bartolomei), INSERM, Aix Marseille Universite; and Psychiatrie et Neurosciences (C.F.), GHU Paris, St Anne, Paris
| | - Bernard Giusiano
- From the Epileptology Department (F.P., S.L., A.M., I.L., F. Bonini, A.T., F. Bartolomei), Functional and Stereotactic Neurosurgery (R.C.), and Pediatric Neurosurgery (D.S.), APHM, Timone Hospital, Institut de Neurosciences des Systèmes (F.P., N.R., B.G., S.L., R.C., D.S., A.M., I.L., F. Bonini, A.T., C.-G.B, F. Bartolomei), INSERM, Aix Marseille Universite; and Psychiatrie et Neurosciences (C.F.), GHU Paris, St Anne, Paris
| | - Stanislas Lagarde
- From the Epileptology Department (F.P., S.L., A.M., I.L., F. Bonini, A.T., F. Bartolomei), Functional and Stereotactic Neurosurgery (R.C.), and Pediatric Neurosurgery (D.S.), APHM, Timone Hospital, Institut de Neurosciences des Systèmes (F.P., N.R., B.G., S.L., R.C., D.S., A.M., I.L., F. Bonini, A.T., C.-G.B, F. Bartolomei), INSERM, Aix Marseille Universite; and Psychiatrie et Neurosciences (C.F.), GHU Paris, St Anne, Paris
| | - Romain Carron
- From the Epileptology Department (F.P., S.L., A.M., I.L., F. Bonini, A.T., F. Bartolomei), Functional and Stereotactic Neurosurgery (R.C.), and Pediatric Neurosurgery (D.S.), APHM, Timone Hospital, Institut de Neurosciences des Systèmes (F.P., N.R., B.G., S.L., R.C., D.S., A.M., I.L., F. Bonini, A.T., C.-G.B, F. Bartolomei), INSERM, Aix Marseille Universite; and Psychiatrie et Neurosciences (C.F.), GHU Paris, St Anne, Paris
| | - Didier Scavarda
- From the Epileptology Department (F.P., S.L., A.M., I.L., F. Bonini, A.T., F. Bartolomei), Functional and Stereotactic Neurosurgery (R.C.), and Pediatric Neurosurgery (D.S.), APHM, Timone Hospital, Institut de Neurosciences des Systèmes (F.P., N.R., B.G., S.L., R.C., D.S., A.M., I.L., F. Bonini, A.T., C.-G.B, F. Bartolomei), INSERM, Aix Marseille Universite; and Psychiatrie et Neurosciences (C.F.), GHU Paris, St Anne, Paris
| | - Aileen McGonigal
- From the Epileptology Department (F.P., S.L., A.M., I.L., F. Bonini, A.T., F. Bartolomei), Functional and Stereotactic Neurosurgery (R.C.), and Pediatric Neurosurgery (D.S.), APHM, Timone Hospital, Institut de Neurosciences des Systèmes (F.P., N.R., B.G., S.L., R.C., D.S., A.M., I.L., F. Bonini, A.T., C.-G.B, F. Bartolomei), INSERM, Aix Marseille Universite; and Psychiatrie et Neurosciences (C.F.), GHU Paris, St Anne, Paris
| | - Cristina Filipescu
- From the Epileptology Department (F.P., S.L., A.M., I.L., F. Bonini, A.T., F. Bartolomei), Functional and Stereotactic Neurosurgery (R.C.), and Pediatric Neurosurgery (D.S.), APHM, Timone Hospital, Institut de Neurosciences des Systèmes (F.P., N.R., B.G., S.L., R.C., D.S., A.M., I.L., F. Bonini, A.T., C.-G.B, F. Bartolomei), INSERM, Aix Marseille Universite; and Psychiatrie et Neurosciences (C.F.), GHU Paris, St Anne, Paris
| | - Isabelle Lambert
- From the Epileptology Department (F.P., S.L., A.M., I.L., F. Bonini, A.T., F. Bartolomei), Functional and Stereotactic Neurosurgery (R.C.), and Pediatric Neurosurgery (D.S.), APHM, Timone Hospital, Institut de Neurosciences des Systèmes (F.P., N.R., B.G., S.L., R.C., D.S., A.M., I.L., F. Bonini, A.T., C.-G.B, F. Bartolomei), INSERM, Aix Marseille Universite; and Psychiatrie et Neurosciences (C.F.), GHU Paris, St Anne, Paris
| | - Francesca Bonini
- From the Epileptology Department (F.P., S.L., A.M., I.L., F. Bonini, A.T., F. Bartolomei), Functional and Stereotactic Neurosurgery (R.C.), and Pediatric Neurosurgery (D.S.), APHM, Timone Hospital, Institut de Neurosciences des Systèmes (F.P., N.R., B.G., S.L., R.C., D.S., A.M., I.L., F. Bonini, A.T., C.-G.B, F. Bartolomei), INSERM, Aix Marseille Universite; and Psychiatrie et Neurosciences (C.F.), GHU Paris, St Anne, Paris
| | - Agnes Trebuchon
- From the Epileptology Department (F.P., S.L., A.M., I.L., F. Bonini, A.T., F. Bartolomei), Functional and Stereotactic Neurosurgery (R.C.), and Pediatric Neurosurgery (D.S.), APHM, Timone Hospital, Institut de Neurosciences des Systèmes (F.P., N.R., B.G., S.L., R.C., D.S., A.M., I.L., F. Bonini, A.T., C.-G.B, F. Bartolomei), INSERM, Aix Marseille Universite; and Psychiatrie et Neurosciences (C.F.), GHU Paris, St Anne, Paris
| | - Christian-George Bénar
- From the Epileptology Department (F.P., S.L., A.M., I.L., F. Bonini, A.T., F. Bartolomei), Functional and Stereotactic Neurosurgery (R.C.), and Pediatric Neurosurgery (D.S.), APHM, Timone Hospital, Institut de Neurosciences des Systèmes (F.P., N.R., B.G., S.L., R.C., D.S., A.M., I.L., F. Bonini, A.T., C.-G.B, F. Bartolomei), INSERM, Aix Marseille Universite; and Psychiatrie et Neurosciences (C.F.), GHU Paris, St Anne, Paris
| | - Fabrice Bartolomei
- From the Epileptology Department (F.P., S.L., A.M., I.L., F. Bonini, A.T., F. Bartolomei), Functional and Stereotactic Neurosurgery (R.C.), and Pediatric Neurosurgery (D.S.), APHM, Timone Hospital, Institut de Neurosciences des Systèmes (F.P., N.R., B.G., S.L., R.C., D.S., A.M., I.L., F. Bonini, A.T., C.-G.B, F. Bartolomei), INSERM, Aix Marseille Universite; and Psychiatrie et Neurosciences (C.F.), GHU Paris, St Anne, Paris.
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Capecchi F, Mothersill I, Imbach LL. The medial pulvinar as a subcortical relay in temporal lobe status epilepticus. Seizure 2020; 81:276-279. [DOI: 10.1016/j.seizure.2020.08.016] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2020] [Revised: 07/03/2020] [Accepted: 08/13/2020] [Indexed: 10/23/2022] Open
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He X, Chaitanya G, Asma B, Caciagli L, Bassett DS, Tracy JI, Sperling MR. Disrupted basal ganglia-thalamocortical loops in focal to bilateral tonic-clonic seizures. Brain 2020; 143:175-190. [PMID: 31860076 DOI: 10.1093/brain/awz361] [Citation(s) in RCA: 74] [Impact Index Per Article: 18.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2019] [Revised: 08/16/2019] [Accepted: 09/24/2019] [Indexed: 02/07/2023] Open
Abstract
Focal to bilateral tonic-clonic seizures are associated with lower quality of life, higher risk of seizure-related injuries, increased chance of sudden unexpected death, and unfavourable treatment outcomes. Achieving greater understanding of their underlying circuitry offers better opportunity to control these seizures. Towards this goal, we provide a network science perspective of the interactive pathways among basal ganglia, thalamus and cortex, to explore the imprinting of secondary seizure generalization on the mesoscale brain network in temporal lobe epilepsy. Specifically, we parameterized the functional organization of both the thalamocortical network and the basal ganglia-thalamus network with resting state functional MRI in three groups of patients with different focal to bilateral tonic-clonic seizure histories. Using the participation coefficient to describe the pattern of thalamocortical connections among different cortical networks, we showed that, compared to patients with no previous history, those with positive histories of focal to bilateral tonic-clonic seizures, including both remote (none for >1 year) and current (within the past year) histories, presented more uniform distribution patterns of thalamocortical connections in the ipsilateral medial-dorsal thalamic nuclei. As a sign of greater thalamus-mediated cortico-cortical communication, this result comports with greater susceptibility to secondary seizure generalization from the epileptogenic temporal lobe to broader brain networks in these patients. Using interregional integration to characterize the functional interaction between basal ganglia and thalamus, we demonstrated that patients with current history presented increased interaction between putamen and globus pallidus internus, and decreased interaction between the latter and the thalamus, compared to the other two patient groups. Importantly, through a series of 'disconnection' simulations, we showed that these changes in interactive profiles of the basal ganglia-thalamus network in the current history group mainly depended upon the direct but not the indirect basal ganglia pathway. It is intuitively plausible that such disruption in the striatum-modulated tonic inhibition of the thalamus from the globus pallidus internus could lead to an under-suppressed thalamus, which in turn may account for their greater vulnerability to secondary seizure generalization. Collectively, these findings suggest that the broken balance between basal ganglia inhibition and thalamus synchronization can inform the presence and effective control of focal to bilateral tonic-clonic seizures. The mechanistic underpinnings we uncover may shed light on the development of new treatment strategies for patients with temporal lobe epilepsy.
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Affiliation(s)
- Xiaosong He
- Department of Bioengineering, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Ganne Chaitanya
- Department of Neurology, Thomas Jefferson University, Philadelphia, Pennsylvania, USA
| | - Burcu Asma
- Department of Neurology, Thomas Jefferson University, Philadelphia, Pennsylvania, USA
| | - Lorenzo Caciagli
- Department of Bioengineering, University of Pennsylvania, Philadelphia, Pennsylvania, USA.,Department of Clinical and Experimental Epilepsy, UCL Queen Square Institute of Neurology, London, UK
| | - Danielle S Bassett
- Department of Bioengineering, University of Pennsylvania, Philadelphia, Pennsylvania, USA.,Department of Physics and Astronomy, University of Pennsylvania, Philadelphia, Pennsylvania, USA.,Department of Electrical and Systems Engineering, University of Pennsylvania, Philadelphia, Pennsylvania, USA.,Department of Neurology, University of Pennsylvania, Philadelphia, Pennsylvania, USA.,Department of Psychiatry, University of Pennsylvania, Philadelphia, Pennsylvania, USA.,Santa Fe Institute, Santa Fe, New Mexico, USA
| | - Joseph I Tracy
- Department of Neurology, Thomas Jefferson University, Philadelphia, Pennsylvania, USA
| | - Michael R Sperling
- Department of Neurology, Thomas Jefferson University, Philadelphia, Pennsylvania, USA
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Abstract
PURPOSE OF REVIEW Despite the increase in the number of novel antiseizure medications over the past 20 years, approximately one-third of patients will not have adequate seizure control on medications. For these patients, additional options need to be considered, including dietary, device, and surgical treatments. In addition, many complementary therapies can be considered as adjunctive treatment, with the intent of improving quality of life for persons with epilepsy and potentially allowing for improvement in seizure control. RECENT FINDINGS This review outlines established and developing treatments for drug-resistant epilepsy. Surgical treatments, including resective surgery and vagus nerve stimulation, have been routine care for several decades. In the last several years, new neurostimulation options have been approved (responsive neurostimulation and deep brain stimulation) or are under development (continuous subthreshold cortical stimulation). For patients with lesion or well-defined seizure-onset zones, less invasive options including laser ablation and ultrasound therapy provide the potential for faster recovery times and less morbidity. Not all therapies are in the pharmacological or surgical arenas. This review also explores the evidence for complementary treatments, including relaxation and meditation techniques, and art and music therapy. Despite the range of antiseizure medications available, they still provide inadequate for a large number of patients with epilepsy, either due to ongoing seizures or intolerable side effects. Complementary therapies, including diet, meditation techniques, and music therapy, provide compelling treatment options to improve quality of life while potentially improving seizure control. In appropriate patients, stimulation devices or surgical resection can offer options for significant seizure reduction or even cure. The full range of therapeutics should be considered for each patient with epilepsy when they are struggling with inadequate seizure control or side effects with traditional pharmacological treatment.
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