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Jiao D, Xu L, Gu Z, Yan H, Shen D, Gu X. Pathogenesis, diagnosis, and treatment of epilepsy: electromagnetic stimulation-mediated neuromodulation therapy and new technologies. Neural Regen Res 2025; 20:917-935. [PMID: 38989927 DOI: 10.4103/nrr.nrr-d-23-01444] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2023] [Accepted: 01/18/2024] [Indexed: 07/12/2024] Open
Abstract
Epilepsy is a severe, relapsing, and multifactorial neurological disorder. Studies regarding the accurate diagnosis, prognosis, and in-depth pathogenesis are crucial for the precise and effective treatment of epilepsy. The pathogenesis of epilepsy is complex and involves alterations in variables such as gene expression, protein expression, ion channel activity, energy metabolites, and gut microbiota composition. Satisfactory results are lacking for conventional treatments for epilepsy. Surgical resection of lesions, drug therapy, and non-drug interventions are mainly used in clinical practice to treat pain associated with epilepsy. Non-pharmacological treatments, such as a ketogenic diet, gene therapy for nerve regeneration, and neural regulation, are currently areas of research focus. This review provides a comprehensive overview of the pathogenesis, diagnostic methods, and treatments of epilepsy. It also elaborates on the theoretical basis, treatment modes, and effects of invasive nerve stimulation in neurotherapy, including percutaneous vagus nerve stimulation, deep brain electrical stimulation, repetitive nerve electrical stimulation, in addition to non-invasive transcranial magnetic stimulation and transcranial direct current stimulation. Numerous studies have shown that electromagnetic stimulation-mediated neuromodulation therapy can markedly improve neurological function and reduce the frequency of epileptic seizures. Additionally, many new technologies for the diagnosis and treatment of epilepsy are being explored. However, current research is mainly focused on analyzing patients' clinical manifestations and exploring relevant diagnostic and treatment methods to study the pathogenesis at a molecular level, which has led to a lack of consensus regarding the mechanisms related to the disease.
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Affiliation(s)
- Dian Jiao
- Academy of Medical Engineering and Translational Medicine, Tianjin University, Tianjin, China
| | - Lai Xu
- Academy of Medical Engineering and Translational Medicine, Tianjin University, Tianjin, China
| | - Zhen Gu
- Key Laboratory of Advanced Drug Delivery Systems of Zhejiang Province, College of Pharmaceutical Sciences, Zhejiang University, Hangzhou, Zhejiang Province, China
| | - Hua Yan
- Academy of Medical Engineering and Translational Medicine, Tianjin University, Tianjin, China
| | - Dingding Shen
- Affiliated Hospital of Nantong University, Nantong, Jiangsu Province, China
| | - Xiaosong Gu
- Academy of Medical Engineering and Translational Medicine, Tianjin University, Tianjin, China
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2
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Kaufmann E, Peltola J, Colon AJ, Lehtimäki K, Majtanik M, Mai JK, Bóné B, Bentes C, Coenen V, Gil-Nagel A, Goncalves-Ferreira AJ, Ryvlin P, Taylor R, Brionne TC, Gielen F, Song S, Boon P. Long-term evaluation of anterior thalamic deep brain stimulation for epilepsy in the European MORE registry. Epilepsia 2024; 65:2438-2458. [PMID: 38837755 DOI: 10.1111/epi.18003] [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: 08/10/2023] [Revised: 04/24/2024] [Accepted: 04/25/2024] [Indexed: 06/07/2024]
Abstract
OBJECTIVE Short-term outcomes of deep brain stimulation of the anterior nucleus of the thalamus (ANT-DBS) were reported for people with drug-resistant focal epilepsy (PwE). Because long-term data are still scarce, the Medtronic Registry for Epilepsy (MORE) evaluated clinical routine application of ANT-DBS. METHODS In this multicenter registry, PwE with ANT-DBS were followed up for safety, efficacy, and battery longevity. Follow-up ended after 5 years or upon study closure. Clinical characteristics and stimulation settings were compared between PwE with no benefit, improvers, and responders, that is, PwE with average monthly seizure frequency reduction rates of ≥50%. RESULTS Of 170 eligible PwE, 104, 62, and 49 completed the 3-, 4-, and 5-year follow-up, respectively. Most discontinuations (68%) were due to planned study closure as follow-up beyond 2 years was optional. The 5-year follow-up cohort had a median seizure frequency reduction from 16 per month at baseline to 7.9 per month at 5-year follow-up (p < .001), with most-pronounced effects on focal-to-bilateral tonic-clonic seizures (n = 15, 77% reduction, p = .008). At last follow-up (median 3.5 years), 41% (69/170) of PwE were responders. Unifocal epilepsy (p = .035) and a negative history of epilepsy surgery (p = .002) were associated with larger average monthly seizure frequency reductions. Stimulation settings did not differ between response groups. In 179 implanted PwE, DBS-related adverse events (AEs, n = 225) and serious AEs (n = 75) included deterioration in epilepsy or seizure frequency/severity/type (33; 14 serious), memory/cognitive impairment (29; 3 serious), and depression (13; 4 serious). Five deaths occurred (none were ANT-DBS related). Most AEs (76.3%) manifested within the first 2 years after implantation. Activa PC depletion (n = 37) occurred on average after 45 months. SIGNIFICANCE MORE provides further evidence for the long-term application of ANT-DBS in clinical routine practice. Although clinical benefits increased over time, side effects occurred mainly during the first 2 years. Identified outcome modifiers can help inform PwE selection and management.
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Affiliation(s)
- Elisabeth Kaufmann
- Department of Neurology, Epilepsy Center, LMU University Hospital, LMU Munich, Munich, Germany
| | - Jukka Peltola
- Department of Neurology, Tampere University and Tampere University Hospital, Tampere, Finland
| | - Albert J Colon
- Academic Center for Epileptology Kempenhaeghe/Maastricht UMC+, Maastricht, The Netherlands
| | - Kai Lehtimäki
- Department of Neurosurgery, Tampere University Hospital and Tampere University, Tampere, Finland
| | - Milan Majtanik
- MRX-Brain GmbH, Düsseldorf, Germany
- Department of Informatics, Heinrich Heine University of Düsseldorf, Düsseldorf, Germany
| | - Jürgen K Mai
- MRX-Brain GmbH, Düsseldorf, Germany
- Department of Neuroanatomy, Heinrich Heine University of Düsseldorf, Düsseldorf, Germany
| | - Beata Bóné
- Medical School, University of Pécs, Pécs, Hungary
| | - Carla Bentes
- Department of Neurosciences and Mental Health, Centro de Referência para a área de Epilepsia Refratária (Epicare Member), Hospital de Santa Maria- Centro Hospitalar Universitário Lisboa Norte, Lisbon, Portugal
- Faculdade de Medicina, Centro de Estudos Egas Moniz, Universidade de Lisboa, Lisbon, Portugal
| | - Volker Coenen
- Department of Stereotactic and Functional Neurosurgery, Universitätsklinikum Freiburg, Freiburg, Germany
| | - Antonio Gil-Nagel
- Epilepsy Program, Neurology Department, Hospital Ruber Internacional, Madrid, Spain
| | | | - Philippe Ryvlin
- Département des Neurosciences Cliniques, Centre Hospitalier Universitaire Vaudois (CHUV), Lausanne, Switzerland
| | - Rod Taylor
- MRC/CSO Social and Public Health Sciences Unit & Robertson Centre for Biostatistics, Institute of Health and Well Being, University of Glasgow, Glasgow, UK
- College of Medicine and Health, University of Exeter, Exeter, UK
| | - Thomas C Brionne
- Clinical Department, Medtronic Internal Trading Sàrl, Tolochenaz, Switzerland
| | - Frans Gielen
- Medtronic Bakken Research Center, Maastricht, The Netherlands
| | - Shannon Song
- Department of Neurology, Medtronic Operational Headquarters, Minneapolis, Minnesota, USA
| | - Paul Boon
- Department of Neurology, Ghent University Hospital-Ghent University, Ghent, Belgium
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3
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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] [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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4
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Corsi MC, Troisi Lopez E, Sorrentino P, Cuozzo S, Danieli A, Bonanni P, Duma GM. Neuronal avalanches in temporal lobe epilepsy as a noninvasive diagnostic tool investigating large scale brain dynamics. Sci Rep 2024; 14:14039. [PMID: 38890363 PMCID: PMC11189588 DOI: 10.1038/s41598-024-64870-3] [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: 02/19/2024] [Accepted: 06/13/2024] [Indexed: 06/20/2024] Open
Abstract
The epilepsy diagnosis still represents a complex process, with misdiagnosis reaching 40%. We aimed at building an automatable workflow, helping the clinicians in the diagnosis of temporal lobe epilepsy (TLE). We hypothesized that neuronal avalanches (NA) represent a feature better encapsulating the rich brain dynamics compared to classically used functional connectivity measures (Imaginary Coherence; ImCoh). We analyzed large-scale activation bursts (NA) from source estimation of resting-state electroencephalography. Using a support vector machine, we reached a classification accuracy of TLE versus controls of 0.86 ± 0.08 (SD) and an area under the curve of 0.93 ± 0.07. The use of NA features increase by around 16% the accuracy of diagnosis prediction compared to ImCoh. Classification accuracy increased with larger signal duration, reaching a plateau at 5 min of recording. To summarize, NA represents an interpretable feature for an automated epilepsy identification, being related with intrinsic neuronal timescales of pathology-relevant regions.
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Affiliation(s)
- Marie-Constance Corsi
- Sorbonne Université, Institut du Cerveau - Paris Brain Institute -ICM, CNRS, Inria, Inserm, AP-HP, Hopital de la Pitié Salpêtrière, 75013, Paris, France.
| | - Emahnuel Troisi Lopez
- Institute of Applied Sciences and Intelligent Systems of National Research Council, Pozzuoli, Italy
| | - Pierpaolo Sorrentino
- Institut de Neurosciences des Systèmes, Aix-Marseille Université, 13005, Marseille, France.
- Department of Biomedical Sciences, University of Sassari, Viale San Pietro, 07100, Sassari, Italy.
| | - Simone Cuozzo
- Epilepsy Unit, IRCCS E. Medea Scientific Institute, Via Costa Alta 37, 31015, Conegliano, Treviso, Italy
| | - Alberto Danieli
- Epilepsy Unit, IRCCS E. Medea Scientific Institute, Via Costa Alta 37, 31015, Conegliano, Treviso, Italy
| | - Paolo Bonanni
- Epilepsy Unit, IRCCS E. Medea Scientific Institute, Via Costa Alta 37, 31015, Conegliano, Treviso, Italy
| | - Gian Marco Duma
- Epilepsy Unit, IRCCS E. Medea Scientific Institute, Via Costa Alta 37, 31015, Conegliano, Treviso, Italy
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Nobili L, Cordani R, Arnaldi D, Mattioli P, Veneruso M, Ng M. Rapid eye movement sleep and epilepsy: exploring interactions and therapeutic prospects. J Sleep Res 2024:e14251. [PMID: 38842061 DOI: 10.1111/jsr.14251] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2024] [Revised: 03/21/2024] [Accepted: 05/07/2024] [Indexed: 06/07/2024]
Abstract
While research interest in the relationship between sleep and epilepsy is growing, it primarily centres on the effects of non-rapid eye movement (NREM) sleep in favouring seizures. Nonetheless, a noteworthy aspect is the observation that, in the lives of patients with epilepsy, REM sleep represents the moment with the least epileptic activity and the lowest probability of having a seizure. Studies demonstrate a suppressive effect of phasic REM sleep on interictal epileptiform discharges, potentially offering insights into epilepsy localisation and management. Furthermore, epilepsy impacts REM sleep, with successful treatment correlating with improved REM sleep quality. Novel therapeutic strategies aim to harness REM's anti-epileptic effects, including pharmacological approaches targeting orexinergic systems and neuromodulation techniques promoting cortical desynchronisation. These findings underscore the intricate relationship between REM sleep and epilepsy, highlighting avenues for further research and therapeutic innovation in epilepsy management.
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Affiliation(s)
- Lino Nobili
- Child Neuropsychiatry Unit, IRCCS Istituto Giannina Gaslini, Member of the European Reference Network EpiCARE, Genoa, Italy
- Department of Neuroscience, Rehabilitation, Ophthalmology, Genetics, Child and Maternal Health (DINOGMI), University of Genoa, Genoa, Italy
| | - Ramona Cordani
- Child Neuropsychiatry Unit, IRCCS Istituto Giannina Gaslini, Member of the European Reference Network EpiCARE, Genoa, Italy
- Department of Neuroscience, Rehabilitation, Ophthalmology, Genetics, Child and Maternal Health (DINOGMI), University of Genoa, Genoa, Italy
| | - Dario Arnaldi
- Department of Neuroscience, Rehabilitation, Ophthalmology, Genetics, Child and Maternal Health (DINOGMI), University of Genoa, Genoa, Italy
- Neurophysiopathology Unit, IRCCS Ospedale Policlinico San Martino, Genoa, Italy
| | - Pietro Mattioli
- Department of Neuroscience, Rehabilitation, Ophthalmology, Genetics, Child and Maternal Health (DINOGMI), University of Genoa, Genoa, Italy
- Neurophysiopathology Unit, IRCCS Ospedale Policlinico San Martino, Genoa, Italy
| | - Marco Veneruso
- Child Neuropsychiatry Unit, IRCCS Istituto Giannina Gaslini, Member of the European Reference Network EpiCARE, Genoa, Italy
- Department of Neuroscience, Rehabilitation, Ophthalmology, Genetics, Child and Maternal Health (DINOGMI), University of Genoa, Genoa, Italy
| | - Marcus Ng
- Biomedical Engineering, University of Manitoba, Winnipeg, Manitoba, Canada
- Section of Neurology, University of Manitoba, Winnipeg, Manitoba, Canada
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6
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Wang Q, Zhang Y, Xue H, Zeng Y, Lu G, Fan H, Jiang L, Wu J. Lead-free dual-frequency ultrasound implants for wireless, biphasic deep brain stimulation. Nat Commun 2024; 15:4017. [PMID: 38740759 DOI: 10.1038/s41467-024-48250-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2023] [Accepted: 04/25/2024] [Indexed: 05/16/2024] Open
Abstract
Ultrasound-driven bioelectronics could offer a wireless scheme with sustainable power supply; however, current ultrasound implantable systems present critical challenges in biocompatibility and harvesting performance related to lead/lead-free piezoelectric materials and devices. Here, we report a lead-free dual-frequency ultrasound implants for wireless, biphasic deep brain stimulation, which integrates two developed lead-free sandwich porous 1-3-type piezoelectric composite elements with enhanced harvesting performance in a flexible printed circuit board. The implant is ultrasonically powered through a portable external dual-frequency transducer and generates programmable biphasic stimulus pulses in clinically relevant frequencies. Furthermore, we demonstrate ultrasound-driven implants for long-term biosafety therapy in deep brain stimulation through an epileptic rodent model. With biocompatibility and improved electrical performance, the lead-free materials and devices presented here could provide a promising platform for developing implantable ultrasonic electronics in the future.
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Affiliation(s)
- Qian Wang
- College of Materials Science and Engineering, Sichuan University, Chengdu, China
| | - Yusheng Zhang
- National Engineering Research Center for Biomaterials, Sichuan University, Chengdu, China
| | - Haoyue Xue
- College of Materials Science and Engineering, Sichuan University, Chengdu, China
| | - Yushun Zeng
- Alfred E. Mann Department of Biomedical Engineering, Viterbi School of Engineering, University of Southern California, Los Angeles, California, USA
| | - Gengxi Lu
- Alfred E. Mann Department of Biomedical Engineering, Viterbi School of Engineering, University of Southern California, Los Angeles, California, USA
| | - Hongsong Fan
- National Engineering Research Center for Biomaterials, Sichuan University, Chengdu, China.
| | - Laiming Jiang
- College of Materials Science and Engineering, Sichuan University, Chengdu, China.
| | - Jiagang Wu
- College of Materials Science and Engineering, Sichuan University, Chengdu, China.
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7
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Toutant DB, El-Alawi H, Choi EH, Wright N, Khanam M, Paunovic B, Ko JH, Ng MC. High-definition transcranial direct current stimulation desynchronizes refractory status epilepticus. Neurotherapeutics 2024; 21:e00343. [PMID: 38580510 PMCID: PMC11067454 DOI: 10.1016/j.neurot.2024.e00343] [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: 11/23/2023] [Revised: 02/28/2024] [Accepted: 03/01/2024] [Indexed: 04/07/2024] Open
Abstract
Recently, we showed that high-definition transcranial direct current stimulation (hd-tDCS) can acutely reduce epileptic spike rates during and after stimulation in refractory status epilepticus (RSE), with a greater likelihood of patient discharge from the intensive care unit compared to historical controls. We investigate whether electroencephalographic (EEG) desynchronization during hd-tDCS can help account for observed anti-epileptic effects. Defining desynchronization as greater power in higher frequencies such as above 30 Hz ("gamma") and lesser power in frequency bands lower than 30 Hz, we analyzed 27 EEG sessions from 10 RSE patients who had received 20-minute session(s) of 2-milliamperes of transcranial direct current custom-targeted at the epileptic focus as previously determined by a clinical EEGer monitoring the EEG in real-time. During hd-tDCS, median relative power change over the EEG electrode chains in which power changes were maximal was +4.84%, -5.25%, -1.88%, -1.94%, and +4.99% for respective delta, theta, alpha, beta, and gamma frequency bands in the bipolar longitudinal montage (p = 0.0001); and +4.13%, -5.44%, -1.81%, -3.23%, and +5.41% in the referential Laplacian montage (p = 0.0012). After hd-tDCS, median relative power changes reversed over the EEG electrode chains in which power changes were maximal: -2.74%, +4.20%, +1.74%, +1.75%, and -4.68% for the respective delta, theta, alpha, beta, and gamma frequency bands in the bipolar longitudinal montage (p = 0.0001); and +1.59%, +5.07%, +1.74%, +2.40%, and -5.12% in the referential Laplacian montage (p = 0.0004). These findings are consistent with EEG desynchronization through theta-alpha-beta-gamma bands during hd-tDCS, helping account for the efficacy of hd-tDCS as an emerging novel anti-epileptic therapy against RSE.
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Affiliation(s)
- Darion B Toutant
- Graduate Program in Biomedical Engineering, University of Manitoba, Winnipeg, Canada.
| | - Hussam El-Alawi
- Undergraduate Medical Education, Max Rady College of Medicine, University of Manitoba, Winnipeg, Canada
| | - Eun Hyung Choi
- Department of Human Anatomy and Cell Science, University of Manitoba, Winnipeg, Canada
| | - Natalie Wright
- Department of Human Anatomy and Cell Science, University of Manitoba, Winnipeg, Canada
| | - Manzuma Khanam
- Department of Human Anatomy and Cell Science, University of Manitoba, Winnipeg, Canada
| | - Bojan Paunovic
- Undergraduate Medical Education, Max Rady College of Medicine, University of Manitoba, Winnipeg, Canada; Section of Critical Care Medicine, Department of Internal Medicine, University of Manitoba, Winnipeg, Canada
| | - Ji Hyun Ko
- Graduate Program in Biomedical Engineering, University of Manitoba, Winnipeg, Canada; Department of Human Anatomy and Cell Science, University of Manitoba, Winnipeg, Canada
| | - Marcus C Ng
- Graduate Program in Biomedical Engineering, University of Manitoba, Winnipeg, Canada; Undergraduate Medical Education, Max Rady College of Medicine, University of Manitoba, Winnipeg, Canada; Section of Neurology, Department of Internal Medicine, University of Manitoba, Winnipeg, Canada
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8
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Hines K, Wu C. Epilepsy Networks and Their Surgical Relevance. Brain Sci 2023; 14:31. [PMID: 38248246 PMCID: PMC10813558 DOI: 10.3390/brainsci14010031] [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: 11/09/2023] [Revised: 12/22/2023] [Accepted: 12/24/2023] [Indexed: 01/23/2024] Open
Abstract
Surgical epilepsy is a rapidly evolved field. As the understanding and concepts of epilepsy shift towards a network disorder, surgical outcomes may shed light on numerous components of these systems. This review documents the evolution of the understanding of epilepsy networks and examines the data generated by resective, ablative, neuromodulation, and invasive monitoring surgeries in epilepsy patients. As these network tools are better integrated into epilepsy practice, they may eventually inform surgical decisions and improve clinical outcomes.
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Affiliation(s)
- Kevin Hines
- Department of Neurosurgery, Thomas Jefferson University Hospital, Philadelphia, PA 19107, USA;
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9
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Aiello G, Ledergerber D, Dubcek T, Stieglitz L, Baumann C, Polanìa R, Imbach L. Functional network dynamics between the anterior thalamus and the cortex in deep brain stimulation for epilepsy. Brain 2023; 146:4717-4735. [PMID: 37343140 DOI: 10.1093/brain/awad211] [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: 01/13/2023] [Revised: 05/10/2023] [Accepted: 06/08/2023] [Indexed: 06/23/2023] Open
Abstract
Owing to its unique connectivity profile with cortical brain regions, and its suggested role in the subcortical propagation of seizures, the anterior nucleus of the thalamus (ANT) has been proposed as a key deep brain stimulation (DBS) target in drug-resistant epilepsy. However, the spatio-temporal interaction dynamics of this brain structure, and the functional mechanisms underlying ANT DBS in epilepsy remain unknown. Here, we study how the ANT interacts with the neocortex in vivo in humans and provide a detailed neurofunctional characterization of mechanisms underlying the effectiveness of ANT DBS, aiming at defining intraoperative neural biomarkers of responsiveness to therapy, assessed at 6 months post-implantation as the reduction in seizure frequency. A cohort of 15 patients with drug-resistant epilepsy (n = 6 males, age = 41.6 ± 13.79 years) underwent bilateral ANT DBS implantation. Using intraoperative cortical and ANT simultaneous electrophysiological recordings, we found that the ANT is characterized by high amplitude θ (4-8 Hz) oscillations, mostly in its superior part. The strongest functional connectivity between the ANT and the scalp EEG was also found in the θ band in ipsilateral centro-frontal regions. Upon intraoperative stimulation in the ANT, we found a decrease in higher EEG frequencies (20-70 Hz) and a generalized increase in scalp-to-scalp connectivity. Crucially, we observed that responders to ANT DBS treatment were characterized by higher EEG θ oscillations, higher θ power in the ANT, and stronger ANT-to-scalp θ connectivity, highlighting the crucial role of θ oscillations in the dynamical network characterization of these structures. Our study provides a comprehensive characterization of the interaction dynamic between the ANT and the cortex, delivering crucial information to optimize and predict clinical DBS response in patients with drug-resistant epilepsy.
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Affiliation(s)
- Giovanna Aiello
- Decision Neuroscience Lab, Department of Health Sciences and Technology, ETH Zurich, 8092 Zurich, Switzerland
- Swiss Epilepsy Center (Klinik Lengg), 8008 Zurich, Switzerland
- Neuroscience Center Zurich, University of Zurich and ETH Zurich, 8057 Zurich, Switzerland
| | - Debora Ledergerber
- Swiss Epilepsy Center (Klinik Lengg), 8008 Zurich, Switzerland
- Neuroscience Center Zurich, University of Zurich and ETH Zurich, 8057 Zurich, Switzerland
| | - Tena Dubcek
- Decision Neuroscience Lab, Department of Health Sciences and Technology, ETH Zurich, 8092 Zurich, Switzerland
- Swiss Epilepsy Center (Klinik Lengg), 8008 Zurich, Switzerland
- Neuroscience Center Zurich, University of Zurich and ETH Zurich, 8057 Zurich, Switzerland
| | - Lennart Stieglitz
- Department of Neurosurgery, University Hospital Zurich, 8091 Zurich, Switzerland
| | - Christian Baumann
- Department of Neurology, University Hospital Zurich, 8091 Zurich, Switzerland
| | - Rafael Polanìa
- Decision Neuroscience Lab, Department of Health Sciences and Technology, ETH Zurich, 8092 Zurich, Switzerland
- Neuroscience Center Zurich, University of Zurich and ETH Zurich, 8057 Zurich, Switzerland
| | - Lukas Imbach
- Swiss Epilepsy Center (Klinik Lengg), 8008 Zurich, Switzerland
- Neuroscience Center Zurich, University of Zurich and ETH Zurich, 8057 Zurich, Switzerland
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Skelton HM, Brandman DM, Bullinger K, Isbaine F, Gross RE. Distinct Biomarkers of ANT Stimulation and Seizure Freedom in an Epilepsy Patient with Ambulatory Hippocampal Electrocorticography. Stereotact Funct Neurosurg 2023; 101:349-358. [PMID: 37742626 DOI: 10.1159/000533680] [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: 05/01/2023] [Accepted: 08/15/2023] [Indexed: 09/26/2023]
Abstract
INTRODUCTION Deep brain stimulation (DBS) of the anterior nucleus of the thalamus (ANT) and responsive neurostimulation (RNS) of the hippocampus are the predominant approaches to brain stimulation for treating mesial temporal lobe epilepsy (MTLE). Both are similarly effective at reducing seizures in drug-resistant patients, but the underlying mechanisms are poorly understood. In rare cases where it is clinically indicated to use RNS and DBS simultaneously, ambulatory electrophysiology from RNS may provide the opportunity to measure the effects of ANT DBS in the putative seizure onset zone and identify biomarkers associated with clinical improvement. Here, one such patient became seizure free, allowing us to identify and compare the changes in hippocampal electrophysiology associated with ANT stimulation and seizure freedom. METHODS Ambulatory electrocorticography and clinical history were retrospectively analyzed for a patient treated with RNS and DBS for MTLE. DBS artifacts were used to identify ANT stimulation periods on RNS recordings and measure peri-stimulus electrographic changes. Clinical history was used to determine the chronic electrographic changes associated with seizure freedom. RESULTS ANT stimulation acutely suppressed hippocampal gamma (25-90Hz) power, with minimal theta (4-8Hz) suppression and without clear effects on seizure frequency. Eventually, the patient became seizure free alongside the emergence of chronic gamma increase and theta suppression, which started at the same time as clobazam was introduced. Both seizure freedom and the associated electrophysiology persisted after inadvertent DBS discontinuation, further implicating the clobazam relationship. Unexpectedly, RNS detections and long episodes increased, although they were not considered to be electrographic seizures, and the patient remained clinically seizure free. CONCLUSION ANT stimulation and seizure freedom were associated with distinct, dissimilar spectral changes in RNS-derived electrophysiology. The time course of these changes supported a new medication as the most likely cause of clinical improvement. Broadly, this work showcases the use of RNS recordings to interpret the effects of multimodal therapy. Specifically, it lends additional credence to hippocampal theta suppression as a biomarker previously associated with seizure reduction in RNS patients.
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Affiliation(s)
- Henry M Skelton
- Department of Neurosurgery, Emory University School of Medicine, Atlanta, Georgia, USA,
- Morehouse School of Medicine, Atlanta, Georgia, USA,
| | - David M Brandman
- Department of Neurosurgery, University of California, Davis, California, USA
| | - Katie Bullinger
- Department of Neurology, Emory University School of Medicine, Atlanta, Georgia, USA
| | - Faical Isbaine
- Department of Neurosurgery, Emory University School of Medicine, Atlanta, Georgia, USA
| | - Robert E Gross
- Department of Neurosurgery, Emory University School of Medicine, Atlanta, Georgia, USA
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11
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Zhang Y, Wu X, Ding J, Su B, Chen Z, Xiao Z, Wu C, Wei D, Sun J, Luo F, Yin H, Fan H. Wireless-Powering Deep Brain Stimulation Platform Based on 1D-Structured Magnetoelectric Nanochains Applied in Antiepilepsy Treatment. ACS NANO 2023; 17:15796-15809. [PMID: 37530448 DOI: 10.1021/acsnano.3c03661] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/03/2023]
Abstract
Electrical deep brain stimulation (DBS) is a top priority for pharmacoresistant epilepsy treatment, while less-invasive wireless DBS is an urgent priority but challenging. Herein, we developed a conceptual wireless DBS platform to realize local electric stimulation via 1D-structured magnetoelectric Fe3O4@BaTiO3 nanochains (FBC). The FBC was facilely synthesized via magnetic-assisted interface coassembly, possessing a higher electrical output by inducing larger local strain from the anisotropic structure and strain coherence. Subsequently, wireless magnetoelectric neuromodulation in vitro was synergistically achieved by voltage-gated ion channels and to a lesser extent, the mechanosensitive ion channels. Furthermore, FBC less-invasively injected into the anterior nucleus of the thalamus (ANT) obviously inhibited acute and continuous seizures under magnetic loading, exhibiting excellent therapeutic effects in suppressing both high voltage electroencephalogram signals propagation and behavioral seizure stage and neuroprotection of the hippocampus mediated via the Papez circuit similar to conventional wired-in DBS. This work establishes an advanced antiepilepsy strategy and provides a perspective for other neurological disorder treatment.
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Affiliation(s)
- Yusheng Zhang
- National Engineering Research Center for Biomaterials, College of Biomedical Engineering, Sichuan University, Chengdu 610064, Sichuan, China
| | - Xiaoyang Wu
- National Engineering Research Center for Biomaterials, College of Biomedical Engineering, Sichuan University, Chengdu 610064, Sichuan, China
| | - Jie Ding
- National Engineering Research Center for Biomaterials, College of Biomedical Engineering, Sichuan University, Chengdu 610064, Sichuan, China
| | - Borui Su
- National Engineering Research Center for Biomaterials, College of Biomedical Engineering, Sichuan University, Chengdu 610064, Sichuan, China
| | - Zhihong Chen
- National Engineering Research Center for Biomaterials, College of Biomedical Engineering, Sichuan University, Chengdu 610064, Sichuan, China
| | - Zhanwen Xiao
- National Engineering Research Center for Biomaterials, College of Biomedical Engineering, Sichuan University, Chengdu 610064, Sichuan, China
| | - Chengheng Wu
- National Engineering Research Center for Biomaterials, College of Biomedical Engineering, Sichuan University, Chengdu 610064, Sichuan, China
- Institute of Regulatory Science for Medical Devices, Sichuan University, Chengdu 610064, Sichuan, China
| | - Dan Wei
- National Engineering Research Center for Biomaterials, College of Biomedical Engineering, Sichuan University, Chengdu 610064, Sichuan, China
| | - Jing Sun
- National Engineering Research Center for Biomaterials, College of Biomedical Engineering, Sichuan University, Chengdu 610064, Sichuan, China
| | - Fang Luo
- The Center of Gerontology and Geriatrics, West China Hospital, Sichuan University, Chengdu 610064, Sichuan, China
| | - Huabing Yin
- James Watt School of Engineering, University of Glasgow, Glasgow G12 8LT, U.K
| | - Hongsong Fan
- National Engineering Research Center for Biomaterials, College of Biomedical Engineering, Sichuan University, Chengdu 610064, Sichuan, China
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12
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Zhang F, Yang Y, Xin Y, Sun Y, Wang C, Zhu J, Tang T, Zhang J, Xu K. Efficacy of different strategies of responsive neurostimulation on seizure control and their association with acute neurophysiological effects in rats. Epilepsy Behav 2023; 143:109212. [PMID: 37172446 DOI: 10.1016/j.yebeh.2023.109212] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/08/2023] [Accepted: 04/01/2023] [Indexed: 05/15/2023]
Abstract
Responsive neurostimulation (RNS) has shown promising but limited efficacy in the treatment of drug-resistant epilepsy. The clinical utility of RNS is hindered by the incomplete understanding of the mechanism behind its therapeutic effects. Thus, assessing the acute effects of responsive stimulation (AERS) based on intracranial EEG recordings in the temporal lobe epilepsy rat model may provide a better understanding of the potential therapeutic mechanisms underlying the antiepileptic effect of RNS. Furthermore, clarifying the correlation between AERS and seizure severity may help guide the optimization of RNS parameter settings. In this study, RNS with high (130 Hz) and low frequencies (5 Hz) was applied to the subiculum (SUB) and CA1. To quantify the changes induced by RNS, we calculated the AERS during synchronization by Granger causality and analyzed the band power ratio in the classic power band after different stimulations were delivered in the interictal and seizure onset periods, respectively. This demonstrates that only targets combined with an appropriate stimulation frequency could be efficient for seizure control. High-frequency stimulation of CA1 significantly shortened the ongoing seizure duration, which may be causally related to increased synchronization after stimulation. Both high-frequency stimulation of the CA1 and low-frequency stimulation delivered to the SUB reduced seizure frequency, and the reduced seizure risk may correlate with the change in power ratio near the theta band. It indicated that different stimulations may control seizures in diverse manners, perhaps with disparate mechanisms. More focus should be placed on understanding the correlation between seizure severity and synchronization and rhythm around theta bands to simplify the process of parameter optimization.
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Affiliation(s)
- Fang Zhang
- Qiushi Academy for Advanced Studies (QAAS), Zhejiang University, Hangzhou, China; The State Key Lab of Brain-Machine Intelligence, Zhejiang University, Hangzhou, China; Zhejiang Provincial Key Laboratory of Cardio-Cerebral Vascular Detection Technology and Medicinal Effectiveness Appraisal, Key Laboratory of Biomedical Engineering of Education Ministry, Department of Biomedical Engineering, Zhejiang University, Hangzhou, China
| | - Yufang Yang
- Qiushi Academy for Advanced Studies (QAAS), Zhejiang University, Hangzhou, China; The State Key Lab of Brain-Machine Intelligence, Zhejiang University, Hangzhou, China; Zhejiang Provincial Key Laboratory of Cardio-Cerebral Vascular Detection Technology and Medicinal Effectiveness Appraisal, Key Laboratory of Biomedical Engineering of Education Ministry, Department of Biomedical Engineering, Zhejiang University, Hangzhou, China
| | - Yanjie Xin
- Qiushi Academy for Advanced Studies (QAAS), Zhejiang University, Hangzhou, China; The State Key Lab of Brain-Machine Intelligence, Zhejiang University, Hangzhou, China; Zhejiang Provincial Key Laboratory of Cardio-Cerebral Vascular Detection Technology and Medicinal Effectiveness Appraisal, Key Laboratory of Biomedical Engineering of Education Ministry, Department of Biomedical Engineering, Zhejiang University, Hangzhou, China
| | - Yuting Sun
- Qiushi Academy for Advanced Studies (QAAS), Zhejiang University, Hangzhou, China; The State Key Lab of Brain-Machine Intelligence, Zhejiang University, Hangzhou, China; Zhejiang Provincial Key Laboratory of Cardio-Cerebral Vascular Detection Technology and Medicinal Effectiveness Appraisal, Key Laboratory of Biomedical Engineering of Education Ministry, Department of Biomedical Engineering, Zhejiang University, Hangzhou, China
| | - Chang Wang
- Qiushi Academy for Advanced Studies (QAAS), Zhejiang University, Hangzhou, China; The State Key Lab of Brain-Machine Intelligence, Zhejiang University, Hangzhou, China; Zhejiang Provincial Key Laboratory of Cardio-Cerebral Vascular Detection Technology and Medicinal Effectiveness Appraisal, Key Laboratory of Biomedical Engineering of Education Ministry, Department of Biomedical Engineering, Zhejiang University, Hangzhou, China
| | - Junming Zhu
- The State Key Lab of Brain-Machine Intelligence, Zhejiang University, Hangzhou, China; The MOE Frontier Science Center for Brain Science and Brain-machine Integration, China; Department of Neurosurgery, Second Affiliated Hospital Zhejiang University School of Medicine, Zhejiang University, Zhejiang, China
| | - Tao Tang
- Zhejiang Lab, Hangzhou 311100, China
| | - Jianmin Zhang
- The State Key Lab of Brain-Machine Intelligence, Zhejiang University, Hangzhou, China; The MOE Frontier Science Center for Brain Science and Brain-machine Integration, China; Department of Neurosurgery, Second Affiliated Hospital Zhejiang University School of Medicine, Zhejiang University, Zhejiang, China
| | - Kedi Xu
- Qiushi Academy for Advanced Studies (QAAS), Zhejiang University, Hangzhou, China; The State Key Lab of Brain-Machine Intelligence, Zhejiang University, Hangzhou, China; The MOE Frontier Science Center for Brain Science and Brain-machine Integration, China; Zhejiang Provincial Key Laboratory of Cardio-Cerebral Vascular Detection Technology and Medicinal Effectiveness Appraisal, Key Laboratory of Biomedical Engineering of Education Ministry, Department of Biomedical Engineering, Zhejiang University, Hangzhou, China.
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13
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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: 17] [Impact Index Per Article: 17.0] [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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14
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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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15
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Bae S, Lim HK, Jeong Y, Kim SG, Park SM, Shon YM, Suh M. Deep brain stimulation of the anterior nuclei of the thalamus can alleviate seizure severity and induce hippocampal GABAergic neuronal changes in a pilocarpine-induced epileptic mouse brain. Cereb Cortex 2022; 32:5530-5543. [PMID: 35258078 DOI: 10.1093/cercor/bhac033] [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: 11/09/2021] [Revised: 01/17/2022] [Accepted: 01/24/2022] [Indexed: 01/25/2023] Open
Abstract
Deep brain stimulation (DBS) of the anterior nucleus of the thalamus (ANT) has been widely used as an effective treatment for refractory temporal lobe epilepsy. Despite its promising clinical outcome, the exact mechanism of how ANT-DBS alleviates seizure severity has not been fully understood, especially at the cellular level. To assess effects of DBS, the present study examined electroencephalography (EEG) signals and locomotor behavior changes and conducted immunohistochemical analyses to examine changes in neuronal activity, number of neurons, and neurogenesis of inhibitory neurons in different hippocampal subregions. ANT-DBS alleviated seizure activity, abnormal locomotor behaviors, reduced theta-band, increased gamma-band EEG power in the interictal state, and increased the number of neurons in the dentate gyrus (DG). The number of parvalbumin- and somatostatin-expressing inhibitory neurons was recovered to the level in DG and CA1 of naïve mice. Notably, BrdU-positive inhibitory neurons were increased. In conclusion, ANT-DBS not only could reduce the number of seizures, but also could induce neuronal changes in the hippocampus, which is a key region involved in chronic epileptogenesis. Importantly, our results suggest that ANT-DBS may lead to hippocampal subregion-specific cellular recovery of GABAergic inhibitory neurons.
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Affiliation(s)
- Sungjun Bae
- Center for Neuroscience Imaging Research (CNIR), Institute for Basic Science (IBS), Suwon 16419, South Korea.,Department of Biomedical Engineering, Sungkyunkwan University, Suwon 16419, South Korea.,IMNEWRUN Inc., N Center Bldg. A 5F, Sungkyunkwan University, Suwon 16419, South Korea
| | - Hyun-Kyoung Lim
- Center for Neuroscience Imaging Research (CNIR), Institute for Basic Science (IBS), Suwon 16419, South Korea.,Biomedical Institute for Convergence at SKKU (BICS), Sungkyunkwan University, Suwon 16419, South Korea
| | - Yoonyi Jeong
- Center for Neuroscience Imaging Research (CNIR), Institute for Basic Science (IBS), Suwon 16419, South Korea.,Department of Biomedical Engineering, Sungkyunkwan University, Suwon 16419, South Korea
| | - Seong-Gi Kim
- Center for Neuroscience Imaging Research (CNIR), Institute for Basic Science (IBS), Suwon 16419, South Korea.,Department of Biomedical Engineering, Sungkyunkwan University, Suwon 16419, South Korea
| | - Sung-Min Park
- Department of Creative IT Engineering, Pohang University of Science and Technology (POSTECH), Pohang 37673, South Korea
| | - Young-Min Shon
- Department of Neurology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul 06351, South Korea.,Samsung Advanced Institute for Health Sciences & Technology (SAIHST), Sungkyunkwan University, Suwon 16419, South Korea
| | - Minah Suh
- Center for Neuroscience Imaging Research (CNIR), Institute for Basic Science (IBS), Suwon 16419, South Korea.,Department of Biomedical Engineering, Sungkyunkwan University, Suwon 16419, South Korea.,IMNEWRUN Inc., N Center Bldg. A 5F, Sungkyunkwan University, Suwon 16419, South Korea.,Biomedical Institute for Convergence at SKKU (BICS), Sungkyunkwan University, Suwon 16419, South Korea.,Samsung Advanced Institute for Health Sciences & Technology (SAIHST), Sungkyunkwan University, Suwon 16419, South Korea
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16
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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: 58] [Impact Index Per Article: 29.0] [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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17
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Xue T, Chen S, Bai Y, Han C, Yang A, Zhang J. Neuromodulation in drug-resistant epilepsy: A review of current knowledge. Acta Neurol Scand 2022; 146:786-797. [PMID: 36063433 DOI: 10.1111/ane.13696] [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: 08/05/2022] [Accepted: 08/16/2022] [Indexed: 11/30/2022]
Abstract
Nearly 1% of the global population suffers from epilepsy. Drug-resistant epilepsy (DRE) affects one-third of epileptic patients who are unable to treat their condition with existing drugs. For the treatment of DRE, neuromodulation offers a lot of potential. The background, mechanism, indication, application, efficacy, and safety of each technique are briefly described in this narrative review, with an emphasis on three approved neuromodulation therapies: vagus nerve stimulation (VNS), deep brain stimulation of the anterior nucleus of the thalamus (ANT-DBS), and closed-loop responsive neurostimulation (RNS). Neuromodulatory approaches involving direct or induced electrical currents have been developed to lessen seizure frequency and duration in patients with DRE since the notion of electrical stimulation as a therapy for neurologic diseases originated in the early nineteenth century. Although few people have attained total seizure independence for more than 12 months using these treatments, more than half have benefitted from a 50% drop in seizure frequency over time. Although promising outcomes in adults and children with DRE have been achieved, challenges such as heterogeneity among epilepsy types and etiologies, optimization of stimulation parameters, a lack of biomarkers to predict response to neuromodulation therapies, high-level evidence to aid decision-making, and direct comparisons between neuromodulatory approaches remain. To solve these existing gaps, authorize new kinds of neuromodulation, and develop personalized closed-loop treatments, further research is needed. Finally, both invasive and non-invasive neuromodulation seems to be safe. Implantation-related adverse events for invasive stimulation primarily include infection and pain at the implant site. Intracranial hemorrhage is a frequent adverse event for DBS and RNS. Other stimulation-specific side-effects are mild with non-invasive stimulation.
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Affiliation(s)
- Tao Xue
- Department of Neurosurgery, Beijing Tiantan Hospital, Capital Medical University, Beijing, China
| | - Shujun Chen
- Department of Neurology, Beijing Tiantan Hospital, Capital Medical University, Beijing, China
| | - Yutong Bai
- Department of Neurosurgery, Beijing Tiantan Hospital, Capital Medical University, Beijing, China
| | - Chunlei Han
- Department of Neurosurgery, Beijing Tiantan Hospital, Capital Medical University, Beijing, China
| | - Anchao Yang
- Department of Neurosurgery, Beijing Tiantan Hospital, Capital Medical University, Beijing, China
| | - Jianguo Zhang
- Department of Neurosurgery, Beijing Tiantan Hospital, Capital Medical University, Beijing, China
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18
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Johnson GW, Doss DJ, Englot DJ. Network dysfunction in pre and postsurgical epilepsy: connectomics as a tool and not a destination. Curr Opin Neurol 2022; 35:196-201. [PMID: 34799514 PMCID: PMC8891078 DOI: 10.1097/wco.0000000000001008] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
PURPOSE OF REVIEW Patients with focal drug-resistant epilepsy (DRE) sometimes continue to have seizures after surgery. Recently, there is increasing interest in using advanced network analyses (connectomics) to better understand this problem. Connectomics has changed the way researchers and clinicians view DRE, but it must be applied carefully in a hypothesis-driven manner to avoid spurious results. This review will focus on studies published in the last 18 months that have thoughtfully used connectomics to advance our fundamental understanding of network dysfunction in DRE - hopefully for the eventual direct benefit to patient care. RECENT FINDINGS Impactful recent findings have centered on using patient-specific differences in network dysfunction to predict surgical outcome. These works span functional and structural connectivity and include the modalities of functional and diffusion magnetic resonance imaging (MRI) and electrophysiology. Using functional MRI, many groups have described an increased functional segregation outside of the surgical resection zone in patients who fail surgery. Using electrophysiology, groups have reported network characteristics of resected tissue that suggest whether a patient will respond favorably to surgery. SUMMARY If we can develop accurate models to outline functional and structural network characteristics that predict failure of standard surgical approaches, then we can not only improve current clinical decision-making; we can also begin developing alternative treatments including network approaches to improve surgical success rates.
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Affiliation(s)
- Graham W. Johnson
- Department of Biomedical Engineering at Vanderbilt University
- Vanderbilt University Institute of Imaging Science at Vanderbilt University Medical Center
| | - Derek J. Doss
- Department of Biomedical Engineering at Vanderbilt University
- Vanderbilt University Institute of Imaging Science at Vanderbilt University Medical Center
| | - Dario J. Englot
- Department of Biomedical Engineering at Vanderbilt University
- Vanderbilt University Institute of Imaging Science at Vanderbilt University Medical Center
- Department of Neurological Surgery
- Department of Neurology
- Department of Radiology and Radiological Sciences at Vanderbilt University Medical Center
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19
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Abstract
Three neuromodulation therapies, all using implanted device and electrodes, have been
approved to treat adults with drug-resistant focal epilepsy, namely, the vagus nerve
stimulation in 1995, deep brain stimulation of the anterior nucleus of the thalamus
(ANT-DBS) in 2018 (2010 in Europe), and responsive neurostimulation (RNS) in 2014.
Indications for VNS have more recently extended to children down to age of 4. Limited or
anecdotal data are available in other epilepsy syndromes and refractory/super-refractory
status epilepticus. Overall, neuromodulation therapies are palliative, with only a
minority of patients achieving long-term seizure freedom, justifying favoring such
treatments in patients who are not good candidates for curative epilepsy surgery. About
half of patients implanted with VNS, ANT-DBS, and RNS have 50% or greater reduction in
seizures, with long-term data suggesting increased efficacy over time. Besides their
impact on seizure frequency, neuromodulation therapies are associated with various
benefits and drawbacks in comparison to antiseizure drugs. Yet, we lack high-level
evidence to best position each neuromodulation therapy in the treatment pathways of
persons with difficult-to-treat epilepsy.
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Affiliation(s)
- Philippe Ryvlin
- Department of Clinical Neurosciences, Lausanne University Hospital (CHUV) and University of Lausanne (UNIL), Lausanne, Switzerland
| | - Lara E. Jehi
- Epilepsy Center, Cleveland Clinic, Cleveland, OH, USA
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Ryvlin P, Rheims S, Hirsch LJ, Sokolov A, Jehi L. Neuromodulation in epilepsy: state-of-the-art approved therapies. Lancet Neurol 2021; 20:1038-1047. [PMID: 34710360 DOI: 10.1016/s1474-4422(21)00300-8] [Citation(s) in RCA: 108] [Impact Index Per Article: 36.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2021] [Revised: 08/22/2021] [Accepted: 09/03/2021] [Indexed: 12/20/2022]
Abstract
Three neuromodulation therapies have been appropriately tested and approved in refractory focal epilepsies: vagus nerve stimulation (VNS), deep brain stimulation of the anterior nucleus of the thalamus (ANT-DBS), and closed-loop responsive neurostimulation of the epileptogenic zone or zones. These therapies are primarily palliative. Only a few individuals have achieved complete freedom from seizures for more than 12 months with these therapies, whereas more than half have benefited from long-term reduction in seizure frequency of more than 50%. Implantation-related adverse events primarily include infection and pain at the implant site. Intracranial haemorrhage is a frequent adverse event for ANT-DBS and responsive neurostimulation. Other stimulation-specific side-effects are observed with VNS and ANT-DBS. Biomarkers to predict response to neuromodulation therapies are not available, and high-level evidence to aid decision making about when and for whom these therapies should be preferred over other antiepileptic treatments is scant. Future studies are thus needed to address these shortfalls in knowledge, approve other forms of neuromodulation, and develop personalised closed-loop therapies with embedded machine learning. Until then, neuromodulation could be considered for individuals with intractable seizures, ideally after the possibility of curative surgical treatment has been carefully assessed and ruled out or judged less appropriate.
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Affiliation(s)
- Philippe Ryvlin
- Department of Clinical Neurosciences, Lausanne University Hospital and University of Lausanne, Lausanne, Switzerland.
| | - Sylvain Rheims
- Department of Functional Neurology and Epileptology, Hospices Civils de Lyon, Lyon 1 University Lyon Neuroscience Research Center, Institut National de la Santé et de la Recherche Médicale U1028/CNRS UMR 5292 Epilepsy Institute, Lyon, France
| | - Lawrence J Hirsch
- Comprehensive Epilepsy Center, Department of Neurology, Yale University School of Medicine, New Haven, CT, USA
| | - Arseny Sokolov
- Department of Clinical Neurosciences, Lausanne University Hospital and University of Lausanne, Lausanne, Switzerland
| | - Lara Jehi
- Epilepsy Center, Cleveland Clinic, Cleveland, OH, USA
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21
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Fasano A, Eliashiv D, Herman ST, Lundstrom BN, Polnerow D, Henderson JM, Fisher RS. Experience and consensus on stimulation of the anterior nucleus of thalamus for epilepsy. Epilepsia 2021; 62:2883-2898. [PMID: 34697794 DOI: 10.1111/epi.17094] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2021] [Revised: 08/31/2021] [Accepted: 09/27/2021] [Indexed: 12/11/2022]
Abstract
Deep brain stimulation of the anterior nuclei of thalamus (ANT-DBS) is effective for reduction of seizures, but little evidence is available to guide practitioners in the practical use of this therapy. In an attempt to fill this gap, a questionnaire with 37 questions was circulated to 578 clinicians who were either engaged in clinical trials of or known users of DBS for epilepsy, with responses from 141, of whom 58.2% were epileptologists and 28.4% neurosurgeons. Multiple regions of the world were represented. The survey found that the best candidates for DBS were considered those with temporal or frontal seizures, refractory to at least two medicines. Motivations for renewing therapy upon battery depletion were reduced convulsive, impaired awareness, and severe seizures and improved quality of life. Targeting of leads mainly was by magnetic resonance imaging, sometimes with intraoperative imaging or microelectrode recording. The majority used transventricular approaches. Stimulation parameters mostly imitated the SANTE study parameters, except for initial stimulation amplitudes in the 2-3-V or -mA range, versus 5 V in the SANTE study. Stimulation intensity was most often increased or reduced, respectively, for lack of efficacy or side effects, but changes in active contacts, cycle time, and pulse duration were also employed. Mood or memory problems or paresthesias were the side effects most responsible for adjustments. Off-label sites stimulated included centromedian thalamus, hippocampus, neocortex, and a few others. Several physicians used DBS in conjunction with vagus nerve stimulation or responsive neurostimulation, although our study did not track efficacy for combined use. Experienced users varied more from published parameters than did inexperienced users. In conclusion, surveys of experts can provide Class IV evidence for the most prevalent practical use of ANT-DBS. We present a flowchart for one protocol combining common practices. Controlled comparisons will be needed to choose the best approach.
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Affiliation(s)
- Alfonso Fasano
- Edmond J. Safra Program in Parkinson's Disease, Morton and Gloria Shulman Movement Disorders Clinic, Toronto Western Hospital, University Health Network, Toronto, Ontario, Canada.,Division of Neurology, University of Toronto, Toronto, Ontario, Canada.,Krembil Brain Institute, Toronto, Ontario, Canada.,Center for Advancing Neurotechnological Innovation to Application, Toronto, Ontario, Canada
| | - Dawn Eliashiv
- Department of Neurology, UCLA Seizure Disorders Center, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, California, USA
| | - Susan T Herman
- Epilepsy Program, Department of Neurology at Barrow Neurological Institute, Phoenix, Arizona, USA
| | | | | | - Jaimie M Henderson
- Department of Neurosurgery and, by courtesy, Neurology and Neurological Sciences, Wu Tsai Neurosciences Institute and Bio-X Institute, Stanford University, Stanford, California, USA
| | - Robert S Fisher
- Department of Neurology & Neurological Sciences and, by courtesy, Department of Neurosurgery, Stanford University School of Medicine, Stanford, California, USA
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22
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Vespa S, Heyse J, Stumpp L, Liberati G, Ferrao Santos S, Rooijakkers H, Nonclercq A, Mouraux A, van Mierlo P, El Tahry R. Vagus Nerve Stimulation Elicits Sleep EEG Desynchronization and Network Changes in Responder Patients in Epilepsy. Neurotherapeutics 2021; 18:2623-2638. [PMID: 34668148 PMCID: PMC8804116 DOI: 10.1007/s13311-021-01124-4] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/06/2021] [Indexed: 12/23/2022] Open
Abstract
Neural desynchronization was shown as a key mechanism of vagus nerve stimulation (VNS) action in epilepsy, and EEG synchronization measures are explored as possible response biomarkers. Since brain functional organization in sleep shows different synchrony and network properties compared to wakefulness, we aimed to explore the effects of acute VNS on EEG-derived measures in the two different states of vigilance. EEG epochs were retrospectively analyzed from twenty-four VNS-treated epileptic patients (11 responders, 13 non-responders) in calm wakefulness and stage N2 sleep. Weighted Phase Lag Index (wPLI) was computed as connectivity measure of synchronization, for VNS OFF and VNS ON conditions. Global efficiency (GE) was computed as a network measure of integration. Ratios OFF/ON were obtained as desynchronization/de-integration index. Values were compared between responders and non-responders, and between EEG states. ROC curve and area-under-the-curve (AUC) analysis was performed for response classification. In responders, stronger VNS-induced theta desynchronization (p < 0.05) and decreased GE (p < 0.05) were found in sleep, but not in wakefulness. Theta sleep wPLI Ratio OFF/ON yielded an AUC of 0.825, and 79% accuracy as a response biomarker if a cut-off value is set at 1.05. Considering all patients, the VNS-induced GE decrease was significantly more important in sleep compared to awake EEG state (p < 0.01). In conclusion, stronger sleep EEG desynchronization in theta band distinguishes responders to VNS therapy from non-responders. VNS-induced reduction of network integration occurs significantly more in sleep than in wakefulness.
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Affiliation(s)
- Simone Vespa
- Institute of Neuroscience (IONS), Université Catholique de Louvain, Avenue Mounier, 53 - 1200, Brussels, Belgium.
| | - Jolan Heyse
- Medical Image and Signal Processing Group (MEDISIP), Ghent University, Ghent, Belgium
| | - Lars Stumpp
- Institute of Neuroscience (IONS), Université Catholique de Louvain, Avenue Mounier, 53 - 1200, Brussels, Belgium
| | - Giulia Liberati
- Institute of Neuroscience (IONS), Université Catholique de Louvain, Avenue Mounier, 53 - 1200, Brussels, Belgium
| | - Susana Ferrao Santos
- Institute of Neuroscience (IONS), Université Catholique de Louvain, Avenue Mounier, 53 - 1200, Brussels, Belgium
- Centre for Refractory Epilepsy, Department of Neurology, Cliniques Universitaires Saint-Luc, Brussels, Belgium
| | - Herbert Rooijakkers
- Centre for Refractory Epilepsy, Department of Neurology, Cliniques Universitaires Saint-Luc, Brussels, Belgium
| | - Antoine Nonclercq
- Bio, Electro and Mechanical Systems (BEAMS), Université Libre de Bruxelles, Brussels, Belgium
| | - André Mouraux
- Institute of Neuroscience (IONS), Université Catholique de Louvain, Avenue Mounier, 53 - 1200, Brussels, Belgium
| | - Pieter van Mierlo
- Medical Image and Signal Processing Group (MEDISIP), Ghent University, Ghent, Belgium
| | - Riëm El Tahry
- Institute of Neuroscience (IONS), Université Catholique de Louvain, Avenue Mounier, 53 - 1200, Brussels, Belgium
- Centre for Refractory Epilepsy, Department of Neurology, Cliniques Universitaires Saint-Luc, Brussels, Belgium
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23
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Christenson Wick Z, Shuman T. To Stop the Seizure, You Must Become the Seizure: Closed-Loop Stimulation Phase Locked to Seizure Waves Disrupts Kindled Seizures While Open-Loop Stimulation Fails. Epilepsy Curr 2021; 21:293-294. [PMID: 34690571 PMCID: PMC8512909 DOI: 10.1177/15357597211014187] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Closed-Loop Stimulation of the Medial Septum Terminates Epileptic Seizures Takeuchi Y, Harangozó M, Pedraza L, Földi T, Kozák G, Li Q, Berényi A. Brain . 2021;144(3):885-908. doi:10.1093/brain/awaa450 Temporal lobe epilepsy with distributed hippocampal seizure foci is often intractable and its secondary generalization might lead to sudden death. Early termination through spatially extensive hippocampal intervention is not feasible directly, because of the large size and irregular shape of the hippocampus. In contrast, the medial septum is a promising target to govern hippocampal oscillations through its divergent connections to both hippocampi. Combining this “proxy intervention” concept and precisely timed stimulation, we report here that closed-loop medial septum electrical stimulation can quickly terminate intrahippocampal seizures and suppress secondary generalization in a rat kindling model. Precise stimulus timing governed by internal seizure rhythms was essential. Cell type-specific stimulation revealed that the precisely timed activation of medial septum GABAergic neurons underlaid the effects. Our concept of time-targeted proxy stimulation for intervening pathological oscillations can be extrapolated to other neurological and psychiatric disorders, and has potential for clinical translation.
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