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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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Tatum WO, Freund B, Middlebrooks EH, Lundstrom BN, Feyissa AM, Van Gompel JJ, Grewal SS. CM-Pf deep brain stimulation in polyneuromodulation for epilepsy. Epileptic Disord 2024. [PMID: 39078093 DOI: 10.1002/epd2.20255] [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: 01/31/2024] [Accepted: 06/09/2024] [Indexed: 07/31/2024]
Abstract
OBJECTIVE Neuromodulation is a viable option for patients with drug-resistant epilepsies. We reviewed the management of patients with two deep brain neurostimulators. In addition, patients implanted with a device targeting the centromedian-parafascicular (CM-Pf) nuclear complex supplements this report to provide an illustrative case to implantation and programming a patient with three active devices. METHODS A narrative review using PubMed and Embase identified patients with drug-resistant epilepsy implanted with more than one neurostimulator was performed. Combinations of vagus nerve stimulation (VNS), deep brain stimulation (DBS), and responsive neurostimulation (RNS) were identified. We provide a background of a newly reported case of an adult with a triple implant eventually responding to CM-Pf DBS as the third implant following suboptimal benefit from VNS and RNS. RESULTS In review of the literature, dual-device therapy is increasing in reports of use with combinations of VNS, RNS, and DBS to treat patients with drug-resistant epilepsy. We review dual-device implants with thalamic DBS device combinations, functional neural networks, and programming patients with dual devices. CM-Pf is a new target for DBS and has shown a variable response in focal epilepsy. We report the unique case of 28-year-old male with drug-resistant focal epilepsy who experienced a 75% seizure reduction with CM-Pf DBS as his third device after suboptimal responses to VNS and RNS. After 9 months, he also experienced seizure freedom from recurrent focal to bilateral tonic-clonic seizures. No medical or surgical complications or safety issues were encountered. CONCLUSION We demonstrate safety and feasibility in an adult combining active VNS, RNS, and CM-Pf DBS. Patients with dual-device therapy who experience a suboptimal response to initial device use at optimized settings should not be considered a neuromodulation "failure." Strategies to combine devices require a working knowledge of brain networks.
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Affiliation(s)
- W O Tatum
- Department of Neurology, Mayo Clinic, Jacksonville, Florida, USA
| | - B Freund
- Department of Neurology, Mayo Clinic, Jacksonville, Florida, USA
| | - E H Middlebrooks
- Department of Radiology, Division of Neuroradiology, Mayo Clinic, Jacksonville, Florida, USA
| | - B N Lundstrom
- Department of Neurology, Mayo Clinic, Rochester, Minnesota, USA
| | - A M Feyissa
- Department of Neurology, Mayo Clinic, Jacksonville, Florida, USA
| | - J J Van Gompel
- Department of Neurosurgery, Mayo Clinic, Rochester, Minnesota, USA
| | - S S Grewal
- Department of Neurosurgery, Mayo Clinic, Jacksonville, Florida, USA
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3
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Jordán Z, Szabó JP, Sákovics A, Kelemen A, Halász L, Erőss L, Fabó D. Epileptiform discharges in the anterior thalamus of epilepsy patients. iScience 2024; 27:109582. [PMID: 38726366 PMCID: PMC11079473 DOI: 10.1016/j.isci.2024.109582] [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: 04/19/2023] [Revised: 07/25/2023] [Accepted: 03/25/2024] [Indexed: 05/12/2024] Open
Abstract
Anterior thalamus (ANT) deep-brain stimulation (DBS) is an approved therapy for drug resistant epilepsy. We aimed to identify interictal epileptiform discharges (IED) in the ANT and to investigate their relationship with surface IEDs. Fifteen patients were monitored for two consecutive nights with externalized thalamic leads to analyze the intrathalamic epileptiform activities (TIED). Forty-six % of all contacts were located within the ANT. We found that all the responders had TIEDs within the ANT, while this held true only for 44% of the non-responders. The overall response rate (RR) at 1-year follow-up was 40%, while it was 44% in bilateral ANT hit patients and 45% in epileptic focus side hit. However, in case of TIEDs present in the focus side the RR reached as high as 71%. TIED activity may prove the pathophysiological connection to the seizure focus, and stimulation of this area might have a better suppressing effect on seizures.
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Affiliation(s)
- Zsófia Jordán
- Epilepsy Unit, Department of Neurosurgery and Neurointervention, Faculty of Medicine, Semmelweis University, 1145 Budapest, Hungary
- Member of the ERN EpiCARE, Budapest, Hungary
| | - Johanna-Petra Szabó
- Epilepsy Unit, Department of Neurosurgery and Neurointervention, Faculty of Medicine, Semmelweis University, 1145 Budapest, Hungary
- Member of the ERN EpiCARE, Budapest, Hungary
- János Szentágothai Neuroscience Program, School of PhD Studies, Semmelweis University, 1085 Budapest, Hungary
- Lendület Laboratory of Systems Neuroscience, Institute of Experimental Medicine, 1083 Budapest, Hungary
| | - Anna Sákovics
- Epilepsy Unit, Department of Neurosurgery and Neurointervention, Faculty of Medicine, Semmelweis University, 1145 Budapest, Hungary
- Member of the ERN EpiCARE, Budapest, Hungary
- János Szentágothai Neuroscience Program, School of PhD Studies, Semmelweis University, 1085 Budapest, Hungary
| | - Anna Kelemen
- Epilepsy Unit, Department of Neurosurgery and Neurointervention, Faculty of Medicine, Semmelweis University, 1145 Budapest, Hungary
- Member of the ERN EpiCARE, Budapest, Hungary
- András Pető Faculty, Semmelweis University, 1125 Budapest, Hungary
| | - László Halász
- Functional Neurosurgery Unit, Department of Neurosurgery and Neurointervention, Faculty of Medicine, Semmelweis University, 1145 Budapest, Hungary
| | - Loránd Erőss
- Functional Neurosurgery Unit, Department of Neurosurgery and Neurointervention, Faculty of Medicine, Semmelweis University, 1145 Budapest, Hungary
| | - Dániel Fabó
- Epilepsy Unit, Department of Neurosurgery and Neurointervention, Faculty of Medicine, Semmelweis University, 1145 Budapest, Hungary
- Member of the ERN EpiCARE, Budapest, Hungary
- Department of Neurology, University of Szeged, 6720 Szeged, Hungary
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Abstract
Intracranial neuromodulation is an evolving therapy for patients with drug-resistant epilepsy (DRE). Deep brain stimulation (DBS) is now available as a therapy for patients with DRE and focal-onset seizures in select health care systems; however, there remains a substantial need of efficacy data before DBS can be more widely adopted into routine clinical practice. This review and commentary focuses on a particular shifting paradigm: DBS as a therapy for children with generalized-onset seizures.
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Affiliation(s)
- Rory J Piper
- Developmental Neurosciences, UCL Great Ormond Street Institute of Child Health, London, UK; Department of Neurosurgery, Great Ormond Street Hospital, London, UK.
| | - George M Ibrahim
- Division of Neurosurgery, Hospital for Sick Children, University of Toronto, Ontario, Canada
| | - Martin M Tisdall
- Developmental Neurosciences, UCL Great Ormond Street Institute of Child Health, London, UK; Department of Neurosurgery, Great Ormond Street Hospital, London, UK
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Stavropoulos I, Pak HL, Alarcon G, Valentin A. Neuromodulation Techniques in Children with Super-Refractory Status Epilepticus. Brain Sci 2023; 13:1527. [PMID: 38002487 PMCID: PMC10670094 DOI: 10.3390/brainsci13111527] [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] [Received: 09/29/2023] [Revised: 10/18/2023] [Accepted: 10/24/2023] [Indexed: 11/26/2023] Open
Abstract
Status epilepticus (SE) is a life-threatening condition and medical emergency which can have lifelong consequences, including neuronal death and alteration of neuronal networks, resulting in long-term neurologic and cognitive deficits in children. When standard pharmacological treatment for SE is not successful in controlling seizures, the condition evolves to refractory SE (rSE) and finally to super-refractory SE (srSE) if it exceeds 24 h despite using anaesthetics. In this systematic review, we present literature data on the potential uses of clinical neuromodulation techniques for the management of srSE in children, including electroconvulsive therapy, vagus nerve stimulation, and deep brain stimulation. The evaluation of these techniques is limited by the small number of published paediatric cases (n = 25, one with two techniques) in peer-reviewed articles (n = 18). Although neuromodulation strategies have not been tested through randomised, prospective controlled clinical trials, this review presents the existing data and the potential benefits of neuromodulation therapy, suggesting that these techniques, when available, could be considered at earlier stages within the course of srSE intending to prevent long-term neurologic complications. Clinical trials aiming to establish whether early intervention can prevent long-term sequelae are necessary in order to establish the potential clinical value of neuromodulation techniques for the treatment of srSE in children.
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Affiliation(s)
- Ioannis Stavropoulos
- Department of Clinical Neurophysiology, King’s College Hospital, London SE5 9RS, UK;
- Department of Basic and Clinical Neuroscience, Institute of Psychiatry, Psychology and Neuroscience, King’s College London, London SE5 8AB, UK
| | - Ho Lim Pak
- Faculty of Life Sciences and Medicine, King’s College London, London SE1 1UL, UK;
| | - Gonzalo Alarcon
- Royal Manchester Children’s Hospital, Manchester M13 9WL, UK;
- Alder Hey Children’s Hospital, Liverpool L12 2AP, UK
| | - Antonio Valentin
- Department of Clinical Neurophysiology, King’s College Hospital, London SE5 9RS, UK;
- Department of Basic and Clinical Neuroscience, Institute of Psychiatry, Psychology and Neuroscience, King’s College London, London SE5 8AB, UK
- Alder Hey Children’s Hospital, Liverpool L12 2AP, UK
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Edmonds B, Miyakoshi M, Gianmaria Remore L, Ahn S, Westley Phillips H, Daida A, Salamon N, Bari A, Sankar R, Matsumoto JH, Fallah A, Nariai H. Characteristics of ictal thalamic EEG in pediatric-onset neocortical focal epilepsy. Clin Neurophysiol 2023; 154:116-125. [PMID: 37595481 PMCID: PMC10529874 DOI: 10.1016/j.clinph.2023.07.007] [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: 03/13/2023] [Revised: 07/09/2023] [Accepted: 07/24/2023] [Indexed: 08/20/2023]
Abstract
OBJECTIVE To characterize ictal EEG change in the centromedian (CM) and anterior nucleus (AN) of the thalamus, using stereoelectroencephalography (SEEG) recordings. METHODS Forty habitual seizures were analyzed in nine patients with pediatric-onset neocortical drug-resistant epilepsy who underwent SEEG (age 2-25 y) with thalamic coverage. Both visual and quantitative analysis was used to evaluate ictal EEG signal in the cortex and thalamus. The amplitude and cortico-thalamic latencies of broadband frequencies at ictal onset were measured. RESULTS Visual analysis demonstrated consistent detection of ictal EEG changes in both the CM nucleus and AN nucleus with latency to thalamic ictal EEG changes of less than 400 ms in 95% of seizures, with low-voltage fast activity being the most common ictal pattern. Quantitative broadband amplitude analysis showed consistent power changes across the frequency bands, corresponding to ictal EEG onset, while while ictal EEG latency was variable from -18.0 seconds to 13.2 seconds. There was no significant difference between detection of CM and AN ictal activity on visual or amplitude analysis. Four patients with subsequent thalamic responsive neurostimulation (RNS) demonstrated ictal EEG changes consistent with SEEG findings. CONCLUSIONS Ictal EEG changes were consistently seen at the CM and AN of the thalamus during neocortical seizures. SIGNIFICANCE It may be feasible to use a closed-loop system in the thalamus to detect and modulate seizure activity for neocortical epilepsy.
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Affiliation(s)
- Benjamin Edmonds
- Division of Pediatric Neurology, Department of Pediatrics, UCLA Mattel Children's Hospital, David Geffen School of Medicine, Los Angeles, CA, USA.
| | - Makoto Miyakoshi
- Division of Child and Adolescent Psychiatry, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, USA; Department of Psychiatry, University of Cincinnati College of Medicine, Cincinnati, OH, USA; Swartz Center for Computational Neuroscience, Institute for Neural Computation, University of California San Diego, UCSD Medical Center, San Diego, CA, USA.
| | - Luigi Gianmaria Remore
- Department of Neurosurgery, UCLA Medical Center, David Geffen School of Medicine, Los Angeles, CA, USA
| | - Samuel Ahn
- Division of Pediatric Neurology, Department of Pediatrics, UCLA Mattel Children's Hospital, David Geffen School of Medicine, Los Angeles, CA, USA
| | - H Westley Phillips
- Department of Neurosurgery, UCLA Medical Center, David Geffen School of Medicine, Los Angeles, CA, USA
| | - Atsuro Daida
- Division of Pediatric Neurology, Department of Pediatrics, UCLA Mattel Children's Hospital, David Geffen School of Medicine, Los Angeles, CA, USA
| | - Noriko Salamon
- Department of Radiological Sciences, University of California, Los Angeles, CA, USA
| | - Ausaf Bari
- Department of Neurosurgery, UCLA Medical Center, David Geffen School of Medicine, Los Angeles, CA, USA
| | - Raman Sankar
- Division of Pediatric Neurology, Department of Pediatrics, UCLA Mattel Children's Hospital, David Geffen School of Medicine, Los Angeles, CA, USA; The UCLA Children's Discovery and Innovation Institute, Los Angeles, CA, USA
| | - Joyce H Matsumoto
- Division of Pediatric Neurology, Department of Pediatrics, UCLA Mattel Children's Hospital, David Geffen School of Medicine, Los Angeles, CA, USA
| | - Aria Fallah
- Department of Neurosurgery, UCLA Medical Center, David Geffen School of Medicine, Los Angeles, CA, USA
| | - Hiroki Nariai
- Division of Pediatric Neurology, Department of Pediatrics, UCLA Mattel Children's Hospital, David Geffen School of Medicine, Los Angeles, CA, USA; The UCLA Children's Discovery and Innovation Institute, Los Angeles, CA, USA.
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7
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Edmonds B, Miyakoshi M, Remore LG, Ahn S, Phillips HW, Daida A, Salamon N, Bari A, Sankar R, Matsumoto JH, Fallah A, Nariai H. Characteristics of ictal thalamic EEG in pediatric-onset neocortical focal epilepsy. MEDRXIV : THE PREPRINT SERVER FOR HEALTH SCIENCES 2023:2023.06.22.23291714. [PMID: 37425697 PMCID: PMC10327240 DOI: 10.1101/2023.06.22.23291714] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/11/2023]
Abstract
Objective To characterize ictal EEG change in the centromedian (CM) and anterior nucleus (AN) of the thalamus, using stereoelectroencephalography (SEEG) recordings. Methods Forty habitual seizures were analyzed in nine patients with pediatric-onset neocortical drug-resistant epilepsy who underwent SEEG (age 2-25 y) with thalamic coverage. Both visual and quantitative analysis was used to evaluate ictal EEG signal in the cortex and thalamus. The amplitude and cortico-thalamic latencies of broadband frequencies at ictal onset were measured. Results Visual analysis demonstrated consistent detection of ictal EEG changes in both the CM nucleus and AN nucleus with latency to thalamic ictal EEG changes of less than 400ms in 95% of seizures, with low-voltage fast activity being the most common ictal pattern. Quantitative broadband amplitude analysis showed consistent power changes across the frequency bands, corresponding to ictal EEG onset, while while ictal EEG latency was variable from -18.0 seconds to 13.2 seconds. There was no significant difference between detection of CM and AN ictal activity on visual or amplitude analysis. Four patients with subsequent thalamic responsive neurostimulation (RNS) demonstrated ictal EEG changes consistent with SEEG findings. Conclusions Ictal EEG changes were consistently seen at the CM and AN of the thalamus during neocortical seizures. Significance It may be feasible to use a closed-loop system in the thalamus to detect and modulate seizure activity for neocortical epilepsy.
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Affiliation(s)
- Benjamin Edmonds
- Division of Pediatric Neurology, Department of Pediatrics, UCLA Mattel Children’s Hospital, David Geffen School of Medicine, Los Angeles, CA, USA
| | - Makoto Miyakoshi
- Division of Child and Adolescent Psychiatry, Cincinnati Children’s Hospital Medical Center, Cincinnati, OH, USA
- Department of Psychiatry, University of Cincinnati College of Medicine, Cincinnati, OH, USA
- Swartz Center for Computational Neuroscience, Institute for Neural Computation, University of California San Diego, UCSD Medical Center, San Diego, CA, USA
| | - Luigi Gianmaria Remore
- Department of Neurosurgery, UCLA Medical Center, David Geffen School of Medicine, Los Angeles, CA, USA
| | - Samuel Ahn
- Division of Pediatric Neurology, Department of Pediatrics, UCLA Mattel Children’s Hospital, David Geffen School of Medicine, Los Angeles, CA, USA
| | - H. Westley Phillips
- Department of Neurosurgery, UCLA Medical Center, David Geffen School of Medicine, Los Angeles, CA, USA
| | - Atsuro Daida
- Division of Pediatric Neurology, Department of Pediatrics, UCLA Mattel Children’s Hospital, David Geffen School of Medicine, Los Angeles, CA, USA
| | - Noriko Salamon
- Department of Radiological Sciences, University of California, Los Angeles, CA, USA
| | - Ausaf Bari
- Department of Neurosurgery, UCLA Medical Center, David Geffen School of Medicine, Los Angeles, CA, USA
| | - Raman Sankar
- Division of Pediatric Neurology, Department of Pediatrics, UCLA Mattel Children’s Hospital, David Geffen School of Medicine, Los Angeles, CA, USA
- The UCLA Children’s Discovery and Innovation Institute, Los Angeles, CA, USA
| | - Joyce H. Matsumoto
- Division of Pediatric Neurology, Department of Pediatrics, UCLA Mattel Children’s Hospital, David Geffen School of Medicine, Los Angeles, CA, USA
| | - Aria Fallah
- Department of Neurosurgery, UCLA Medical Center, David Geffen School of Medicine, Los Angeles, CA, USA
| | - Hiroki Nariai
- Division of Pediatric Neurology, Department of Pediatrics, UCLA Mattel Children’s Hospital, David Geffen School of Medicine, Los Angeles, CA, USA
- The UCLA Children’s Discovery and Innovation Institute, Los Angeles, CA, USA
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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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Deep brain stimulation of thalamic nuclei for the treatment of drug-resistant epilepsy: Are we confident with the precise surgical target? Seizure 2023; 105:22-28. [PMID: 36657225 DOI: 10.1016/j.seizure.2023.01.009] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2022] [Revised: 01/10/2023] [Accepted: 01/12/2023] [Indexed: 01/16/2023] Open
Abstract
Deep brain stimulation (DBS) of the thalamic nuclei for the treatment of drug-resistant epilepsy (DRE) has been investigated for decades. In recent years, DBS targeting the anterior nucleus of the thalamus (ANT) was approved by CE and FDA for the treatment of focal-onset DRE in light of the results from the multicentric randomized controlled SANTE trial. However, stereotactic targeting of thalamic nuclei is not straightforward because of the low contrast definition among thalamic nuclei on the current MRI sequences. When the FGATIR sequence is added to the preoperative MRI protocol, the mammillothalamic tract can be identified and used as a visible landmark to directly target ANT. According to the current evidence, the trans-ventricular trajectory allows the placement of stimulating contact into the nucleus more frequently than the trans-cortical trajectory. Another thalamic nucleus whose stimulation for the treatment of generalized DRE is receiving increasing attention is the centromedian nucleus (CM). CM-DBS seems to be particularly efficacious in patients suffering from Lennox-Gastault syndrome (LGS) and the recent monocentric randomized controlled ESTEL trial also described a beneficial "sweet-spot". However, CM targeting is still based on indirect stereotactic coordinates, since acquisition times and post-processing techniques of the actual MRI sequences are not applicable in clinical practice. Moreover, the results of the ESTEL trial await confirmation from similar studies accounting for epileptic syndromes other than LGS. Therefore, novel neuroimaging approaches are advisable to improve the surgical targeting of CM and potentially tailor the stimulation based on the patient's specific epileptic phenotype.
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10
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Hu B, Wang Z, Xu M, Zhang D, Wang D. The adjustment mechanism of the spike and wave discharges in thalamic neurons: a simulation analysis. Cogn Neurodyn 2022; 16:1449-1460. [PMID: 36408065 PMCID: PMC9666587 DOI: 10.1007/s11571-022-09788-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2021] [Revised: 01/18/2022] [Accepted: 01/25/2022] [Indexed: 11/28/2022] Open
Abstract
Different from many previous theoretical studies, this paper explores the regulatory mechanism of the spike and wave discharges (SWDs) in the reticular thalamic nucleus (TRN) by a dynamic computational model. We observe that the SWDs appears in the TRN by changing the coupling weights and delays in the thalamocortical circuit. The abundant poly-spikes wave discharges is also induced when the delay increases to large enough. These discharges can be inhibited by tuning the inhibitory output from the basal ganglia to the thalamus. The mechanisms of these waves can be explained in this model together with simulation results, which are different from the mechanisms in the cortex. The TRN is an important target in treating epilepsy, and the results may be a theoretical evidence for experimental study in the future.
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Affiliation(s)
- Bing Hu
- Department of Applied Mathematics, Zhejiang University of Technology, Hangzhou, 310023 China
| | - Zhizhi Wang
- Department of Applied Mathematics, Zhejiang University of Technology, Hangzhou, 310023 China
| | - Minbo Xu
- Department of Applied Mathematics, Zhejiang University of Technology, Hangzhou, 310023 China
| | - Dongmei Zhang
- Department of Applied Mathematics, Zhejiang University of Technology, Hangzhou, 310023 China
| | - Dingjiang Wang
- Department of Applied Mathematics, Zhejiang University of Technology, Hangzhou, 310023 China
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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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12
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Qin Y, Li S, Yao D, Luo C. Causality Analysis to the Abnormal Subcortical–Cortical Connections in Idiopathic-Generalized Epilepsy. Front Neurosci 2022; 16:925968. [PMID: 35844218 PMCID: PMC9280354 DOI: 10.3389/fnins.2022.925968] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2022] [Accepted: 06/06/2022] [Indexed: 11/13/2022] Open
Abstract
Idiopathic generalized epilepsy (IGE) was characterized by 3–6 Hz generalized spike-wave discharges (GSWDs), and extensive altered interactions in subcortical-cortical circuit. However, the dynamics and the causal relationship among these interactions were less studied. Using resting-state functional magnetic resonance imaging (fMRI) data, the abnormal connections in the subcortical-cortical pathway in IGE were examined. Then, we proposed a novel method of granger causal analysis based on the dynamic functional connectivity, and the predictive effects among these abnormal connections were calculated. The results showed that the thalamus, and precuneus were key regions representing abnormal functional network connectivity (FNC) in the subcortical-cortical circuit. Moreover, the connectivity between precuneus and adjacent regions had a causal effect on the widespread dysfunction of the thalamocortical circuit. In addition, the connection between the striatum and thalamus indicated the modulation role on the cortical connection in epilepsy. These results described the causality of the widespread abnormality of the subcortical-cortical circuit in IGE in terms of the dynamics of functional connections, which provided additional evidence for understanding the potential modulation pattern of the abnormal epileptic pathway.
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Affiliation(s)
- Yun Qin
- Sichuan Provincial People’s Hospital, MOE Key Lab for Neuroinformation, School of Life Science and Technology, University of Electronic Science and Technology of China, Chengdu, China
- Sichuan Institute for Brain Science and Brain-Inspired Intelligence, Chengdu, China
| | - Sipei Li
- Glasgow College, University of Electronic Science and Technology of China, Chengdu, China
| | - Dezhong Yao
- Sichuan Provincial People’s Hospital, MOE Key Lab for Neuroinformation, School of Life Science and Technology, University of Electronic Science and Technology of China, Chengdu, China
- Sichuan Institute for Brain Science and Brain-Inspired Intelligence, Chengdu, China
| | - Cheng Luo
- Sichuan Provincial People’s Hospital, MOE Key Lab for Neuroinformation, School of Life Science and Technology, University of Electronic Science and Technology of China, Chengdu, China
- *Correspondence: Cheng Luo,
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13
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Nowakowska M, Üçal M, Charalambous M, Bhatti SFM, Denison T, Meller S, Worrell GA, Potschka H, Volk HA. Neurostimulation as a Method of Treatment and a Preventive Measure in Canine Drug-Resistant Epilepsy: Current State and Future Prospects. Front Vet Sci 2022; 9:889561. [PMID: 35782557 PMCID: PMC9244381 DOI: 10.3389/fvets.2022.889561] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2022] [Accepted: 05/23/2022] [Indexed: 11/28/2022] Open
Abstract
Modulation of neuronal activity for seizure control using various methods of neurostimulation is a rapidly developing field in epileptology, especially in treatment of refractory epilepsy. Promising results in human clinical practice, such as diminished seizure burden, reduced incidence of sudden unexplained death in epilepsy, and improved quality of life has brought neurostimulation into the focus of veterinary medicine as a therapeutic option. This article provides a comprehensive review of available neurostimulation methods for seizure management in drug-resistant epilepsy in canine patients. Recent progress in non-invasive modalities, such as repetitive transcranial magnetic stimulation and transcutaneous vagus nerve stimulation is highlighted. We further discuss potential future advances and their plausible application as means for preventing epileptogenesis in dogs.
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Affiliation(s)
- Marta Nowakowska
- Research Unit of Experimental Neurotraumatology, Department of Neurosurgery, Medical University of Graz, Graz, Austria
| | - Muammer Üçal
- Research Unit of Experimental Neurotraumatology, Department of Neurosurgery, Medical University of Graz, Graz, Austria
| | - Marios Charalambous
- Department of Small Animal Medicine and Surgery, University of Veterinary Medicine Hannover, Hanover, Germany
| | - Sofie F. M. Bhatti
- Small Animal Department, Faculty of Veterinary Medicine, Small Animal Teaching Hospital, Ghent University, Merelbeke, Belgium
| | - Timothy Denison
- Department of Engineering Science, Institute of Biomedical Engineering, University of Oxford, Oxford, United Kingdom
| | - Sebastian Meller
- Department of Small Animal Medicine and Surgery, University of Veterinary Medicine Hannover, Hanover, Germany
| | | | - Heidrun Potschka
- Faculty of Veterinary Medicine, Institute of Pharmacology, Toxicology and Pharmacy, Ludwig-Maximilians-University, Munich, Germany
| | - Holger A. Volk
- Department of Small Animal Medicine and Surgery, University of Veterinary Medicine Hannover, Hanover, Germany
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14
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Aung T, Tenney JR, Bagić AI. Contributions of Magnetoencephalography to Understanding Mechanisms of Generalized Epilepsies: Blurring the Boundary Between Focal and Generalized Epilepsies? Front Neurol 2022; 13:831546. [PMID: 35572923 PMCID: PMC9092024 DOI: 10.3389/fneur.2022.831546] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2021] [Accepted: 03/08/2022] [Indexed: 12/31/2022] Open
Abstract
According to the latest operational 2017 ILAE classification of epileptic seizures, the generalized epileptic seizure is still conceptualized as "originating at some point within and rapidly engaging, bilaterally distributed networks." In contrast, the focal epileptic seizure is defined as "originating within networks limited to one hemisphere." Hence, one of the main concepts of "generalized" and "focal" epilepsy comes from EEG descriptions before the era of source localization, and a presumed simultaneous bilateral onset and bi-synchrony of epileptiform discharges remains a hallmark for generalized seizures. Current literature on the pathophysiology of generalized epilepsy supports the concept of a cortical epileptogenic focus triggering rapidly generalized epileptic discharges involving intact corticothalamic and corticocortical networks, known as the cortical focus theory. Likewise, focal epilepsy with rich connectivity can give rise to generalized spike and wave discharges resulting from widespread bilateral synchronization. Therefore, making this key distinction between generalized and focal epilepsy may be challenging in some cases, and for the first time, a combined generalized and focal epilepsy is categorized in the 2017 ILAE classification. Nevertheless, treatment options, such as the choice of antiseizure medications or surgical treatment, are the reason behind the importance of accurate epilepsy classification. Over the past several decades, plentiful scientific research on the pathophysiology of generalized epilepsy has been conducted using non-invasive neuroimaging and postprocessing of the electromagnetic neural signal by measuring the spatiotemporal and interhemispheric latency of bi-synchronous or generalized epileptiform discharges as well as network analysis to identify diagnostic and prognostic biomarkers for accurate diagnosis of the two major types of epilepsy. Among all the advanced techniques, magnetoencephalography (MEG) and multiple other methods provide excellent temporal and spatial resolution, inherently suited to analyzing and visualizing the propagation of generalized EEG activities. This article aims to provide a comprehensive literature review of recent innovations in MEG methodology using source localization and network analysis techniques that contributed to the literature of idiopathic generalized epilepsy in terms of pathophysiology and clinical prognosis, thus further blurring the boundary between focal and generalized epilepsy.
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Affiliation(s)
- Thandar Aung
- Department of Neurology, University of Pittsburgh Comprehensive Epilepsy Center (UPCEC), University of Pittsburgh Medical Center (UPMC), Pittsburgh, PA, United States
| | - Jeffrey R. Tenney
- Division of Neurology, Department of Pediatrics, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, United States
| | - Anto I. Bagić
- Department of Neurology, University of Pittsburgh Comprehensive Epilepsy Center (UPCEC), University of Pittsburgh Medical Center (UPMC), Pittsburgh, PA, United States
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15
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Warsi NM, Yan H, Suresh H, Wong SM, Arski ON, Gorodetsky C, Zhang K, Gouveia FV, Ibrahim GM. The anterior and centromedian thalamus: anatomy, function, and dysfunction in epilepsy. Epilepsy Res 2022; 182:106913. [DOI: 10.1016/j.eplepsyres.2022.106913] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2021] [Revised: 02/07/2022] [Accepted: 03/21/2022] [Indexed: 01/21/2023]
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16
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Richardson RM. Closed-Loop Brain Stimulation and Paradigm Shifts in Epilepsy Surgery. Neurol Clin 2022; 40:355-373. [PMID: 35465880 PMCID: PMC9271409 DOI: 10.1016/j.ncl.2021.12.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
Advances in device technology have created greater flexibility in treating seizures as emergent properties of networks that exist on a local to global continuum. All patients with drug-resistant epilepsy are potential surgical candidates, given that intracranial neuromodulation through deep brain stimulation and responsive neurostimulation can reduce seizures and improve quality of life, even in multifocal and generalized epilepsies. To achieve this goal, indications and strategies for diagnostic epilepsy surgery are evolving. This article describes the state-of-the-art in epilepsy surgery and related changes in how we define indications for diagnostic and therapeutic surgical intervention.
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17
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Hect JL, Fernandez LD, Welch WP, Abel TJ. Deep brain stimulation of the centromedian thalamic nucleus for the treatment of FIRES. Epilepsia Open 2021; 7:187-193. [PMID: 34862854 PMCID: PMC8886094 DOI: 10.1002/epi4.12568] [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: 09/03/2021] [Revised: 11/16/2021] [Accepted: 11/28/2021] [Indexed: 11/10/2022] Open
Abstract
Febrile infection‐related epilepsy syndrome (FIRES) is a rare, life‐threatening complication of febrile illness in previously healthy individuals followed by super‐refractory status epilepticus. Deep brain stimulation (DBS) has been demonstrated to be a promising therapy for the treatment of intractable epilepsy. Here, we present a pediatric patient with FIRES whose seizures were mitigated by acute DBS of the bilateral centromedian thalamic nucleus (CMTN). This is a previously healthy 11‐year‐old female who presented emergently with altered mental status, fever, and malaise after 1 week of lethargy, anorexia, fever, and abdominal pain. The patient began having seizures shortly after admission. After thorough workup for encephalitis and other potential etiologies, this patient was diagnosed with FIRES due to super‐refractory status epilepticus. Status epilepticus persisted despite pharmacologic management, immunotherapy, and vagus nerve stimulation. DBS of the bilateral CMTN (CM‐DBS) was pursued after 56 days of hospitalization, and she demonstrated considerable improvement in baseline mental status 30 days after DBS insertion. This report highlights application of CM‐DBS for super‐refractory status epilepticus in FIRES. This region is a diffusely connected brain region and has been shown to modulate neural networks contributing to seizure propagation and consciousness; therefore, neurostimulation is a potential therapeutic intervention for patients with super‐refractory status epilepticus.
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Affiliation(s)
- Jasmine L Hect
- Department of Neurological Surgery, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
| | - Luis D Fernandez
- Division of Pediatric Neurology, Department of Pediatrics, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
| | - William P Welch
- Division of Pediatric Neurology, Department of Pediatrics, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
| | - Taylor J Abel
- Department of Neurological Surgery, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA.,Department of Bioengineering, University of Pittsburgh Swanson School of Engineering, Pittsburgh, Pennsylvania, USA
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18
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Zamora M, Meller S, Kajin F, Sermon JJ, Toth R, Benjaber M, Dijk DJ, Bogacz R, Worrell GA, Valentin A, Duchet B, Volk HA, Denison T. Case Report: Embedding "Digital Chronotherapy" Into Medical Devices-A Canine Validation for Controlling Status Epilepticus Through Multi-Scale Rhythmic Brain Stimulation. Front Neurosci 2021; 15:734265. [PMID: 34630021 PMCID: PMC8498587 DOI: 10.3389/fnins.2021.734265] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2021] [Accepted: 08/24/2021] [Indexed: 01/15/2023] Open
Abstract
Circadian and other physiological rhythms play a key role in both normal homeostasis and disease processes. Such is the case of circadian and infradian seizure patterns observed in epilepsy. However, these rhythms are not fully exploited in the design of active implantable medical devices. In this paper we explore a new implantable stimulator that implements chronotherapy as a feedforward input to supplement both open-loop and closed-loop methods. This integrated algorithm allows for stimulation to be adjusted to the ultradian, circadian and infradian patterns observed in patients through slowly-varying temporal adjustments of stimulation and algorithm sub-components, while also enabling adaption of stimulation based on immediate physiological needs such as a breakthrough seizure or change of posture. Embedded physiological sensors in the stimulator can be used to refine the baseline stimulation circadian pattern as a "digital zeitgeber," i.e., a source of stimulus that entrains or synchronizes the subject's natural rhythms. This algorithmic approach is tested on a canine with severe drug-resistant idiopathic generalized epilepsy exhibiting a characteristic diurnal pattern correlated with sleep-wake cycles. Prior to implantation, the canine's cluster seizures evolved to status epilepticus (SE) and required emergency pharmacological intervention. The cranially-mounted system was fully-implanted bilaterally into the centromedian nucleus of the thalamus. Using combinations of time-based modulation, thalamocortical rhythm-specific tuning of frequency parameters as well as fast-adaptive modes based on activity, the canine experienced no further SE events post-implant as of the time of writing (7 months). Importantly, no significant cluster seizures have been observed either, allowing the reduction of rescue medication. The use of digitally-enabled chronotherapy as a feedforward signal to augment adaptive neurostimulators could prove a useful algorithmic method in conditions where sensitivity to temporal patterns are characteristics of the disease state, providing a novel mechanism for tailoring a more patient-specific therapy approach.
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Affiliation(s)
- Mayela Zamora
- Institute of Biomedical Engineering, Department of Engineering Science, University of Oxford, Oxford, United Kingdom
| | - Sebastian Meller
- Department of Small Animal Medicine and Surgery, University of Veterinary Medicine Hannover, Hanover, Germany
| | - Filip Kajin
- Department of Small Animal Medicine and Surgery, University of Veterinary Medicine Hannover, Hanover, Germany
| | - James J. Sermon
- Institute of Biomedical Engineering, Department of Engineering Science, University of Oxford, Oxford, United Kingdom
- MRC Brain Network Dynamics Unit, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, United Kingdom
| | - Robert Toth
- MRC Brain Network Dynamics Unit, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, United Kingdom
| | - Moaad Benjaber
- Institute of Biomedical Engineering, Department of Engineering Science, University of Oxford, Oxford, United Kingdom
- MRC Brain Network Dynamics Unit, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, United Kingdom
| | - Derk-Jan Dijk
- Surrey Sleep Research Centre, University of Surrey, Guildford, United Kingdom
- UK Dementia Research Institute, Care Research and Technology Centre, Imperial College London and The University of Surrey, Guildford, United Kingdom
| | - Rafal Bogacz
- MRC Brain Network Dynamics Unit, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, United Kingdom
| | | | - Antonio Valentin
- Department of Clinical Neurophysiology, King's College Hospital NHS Trust, London, United Kingdom
| | - Benoit Duchet
- MRC Brain Network Dynamics Unit, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, United Kingdom
| | - Holger A. Volk
- Department of Small Animal Medicine and Surgery, University of Veterinary Medicine Hannover, Hanover, Germany
| | - Timothy Denison
- Institute of Biomedical Engineering, Department of Engineering Science, University of Oxford, Oxford, United Kingdom
- MRC Brain Network Dynamics Unit, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, United Kingdom
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19
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Tukker AM, Westerink RHS. Novel test strategies for in vitro seizure liability assessment. Expert Opin Drug Metab Toxicol 2021; 17:923-936. [PMID: 33595380 PMCID: PMC8367052 DOI: 10.1080/17425255.2021.1876026] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2020] [Accepted: 01/11/2021] [Indexed: 12/18/2022]
Abstract
INTRODUCTION The increasing incidence of mental illnesses and neurodegenerative diseases results in a high demand for drugs targeting the central nervous system (CNS). These drugs easily reach the CNS, have a high affinity for CNS targets, and are prone to cause seizures as an adverse drug reaction. Current seizure liability assessment heavily depends on in vivo or ex vivo animal models and is therefore ethically debated, labor intensive, expensive, and not always predictive for human risk. AREAS COVERED The demand for CNS drugs urges the development of alternative safety assessment strategies. Yet, the complexity of the CNS hampers reliable detection of compound-induced seizures. This review provides an overview of the requirements of in vitro seizure liability assays and highlights recent advances, including micro-electrode array (MEA) recordings using rodent and human cell models. EXPERT OPINION Successful and cost-effective replacement of in vivo and ex vivo models for seizure liability screening can reduce animal use for drug development, while increasing the predictive value of the assays, particularly if human cell models are used. However, these novel test strategies require further validation and standardization as well as additional refinements to better mimic the human in vivo situation and increase their predictive value.
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Affiliation(s)
- Anke M. Tukker
- School of Health Sciences, Purdue University, Hall for Discovery and Learning Research (DLR 339), INUSA
| | - Remco H. S. Westerink
- Neurotoxicology Research Group, Toxicology Division, Institute for Risk Assessment Sciences (IRAS), Faculty of Veterinary Medicine, Utrecht University, TD Utrecht, The Netherlands
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20
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Successful Hemispherotomy in a Patient with Encephalopathy with Continuous Spikes and Waves during Sleep Related to Neonatal Thalamic Hemorrhage: A Case Report with Intracranial Electroencephalogram Findings. Brain Sci 2021; 11:brainsci11070827. [PMID: 34206592 PMCID: PMC8301857 DOI: 10.3390/brainsci11070827] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2021] [Revised: 06/19/2021] [Accepted: 06/20/2021] [Indexed: 11/17/2022] Open
Abstract
Neonatal thalamic hemorrhage is a strong risk factor for developing encephalopathy with continuous spikes and waves during sleep (ECSWS), even when not accompanied by widespread cortical destruction. The efficacy and indication of resective epilepsy surgery in such patients has not yet been reported. A 4-year-old boy was diagnosed with ECSWS based on strong epileptiform activation during sleep and neurocognitive deterioration. He had a history of left thalamic hemorrhage related to a straight sinus thrombosis during the newborn period. He presented with daily absence seizures that were refractory to medical treatment. At age 5, he underwent intracranial electroencephalogram (EEG) recording using depth and subdural strip electrodes placed in the left thalamus and over bilateral cortex, respectively. Interictal and ictal epileptiform discharges were observed in the thalamus, always preceded by discharges in the left or right parietal lobe. Left hemispherotomy successfully normalized the EEG of his unaffected hemisphere and extinguished his seizures. This is the first case report documenting resective epilepsy surgery in a patient with ECSWS due to neonatal thalamic injury without widespread cerebral destruction. Based on intracranial EEG findings, his injured thalamus did not directly generate the EEG abnormalities or absence seizures on its own. Patients with ipsilateral neonatal thalamic injury and even mild lateralized cortical changes may be candidates for resective or disconnective surgery for ECSWS.
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21
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Deep Versus Lobar Intraparenchymal Hemorrhage: Seizures, Hyperexcitable Patterns, and Clinical Outcomes. Crit Care Med 2021; 48:e505-e513. [PMID: 32301843 DOI: 10.1097/ccm.0000000000004317] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
OBJECTIVES To compare electrographic seizures, hyperexcitable patterns, and clinical outcomes in lobar and deep intraparenchymal hemorrhage. Additionally, to characterize electrographic seizure and hyperexcitable pattern predictors in each group and determine seizure risk with thalamic involvement. DESIGN Retrospective cohort study. SETTING Tertiary academic medical center. PATIENTS Consecutive adult patients with nontraumatic intraparenchymal hemorrhage undergoing continuous electroencephalography at our center between January 2013 and December 2016. INTERVENTIONS Not applicable. MEASUREMENTS AND MAIN RESULTS Based on head CT closest to the initial continuous electroencephalography session, we classified intraparenchymal hemorrhage as isolated deep (no insular, subarachnoid, subdural extension) or lobar. Hyperexcitable patterns included the following: periodic discharges, spike-wave complexes, any rhythmic delta other than generalized. We used Fisher exact test for categorical and Mann-Whitney U test for continuous variables. Multivariable regression identified predictors of electrographic seizures, hyperexcitable patterns, and poor outcomes (score of 1-2 on Glasgow Outcome Scale) in lobar intraparenchymal hemorrhage. The cohort comprised of 128 patients, 88 lobar, and 40 deep intraparenchymal hemorrhage. Electrographic seizures occurred in 17% of lobar and 5% of deep intraparenchymal hemorrhage (p = 0.09). Hyperexcitable patterns were more frequent in the lobar group (44.3% vs 17.5%; p = 0.005). In multivariable analyses in the lobar group, lateralized rhythmic delta activity predicted electrographic seizures (odds ratio, 6.24; CI, 1.49-26.08; p = 0.012); insular involvement predicted hyperexcitable patterns (odds ratio, 4.88; CI, 1.36-17.57; p = 0.015); coma, temporal lobe involvement, intraparenchymal hemorrhage volume, and electrographic seizures predicted poor outcome. Thalamic involvement did not affect electrographic seizures or hyperexcitable patterns in either group. CONCLUSIONS Electrographic seizures are frequent in lobar intraparenchymal hemorrhage, occurring in one in six monitored patients, as opposed to only 5% in isolated deep intraparenchymal hemorrhage not extending to cortex/insula, subarachnoid, or subdural spaces. Patients with lobar intraparenchymal hemorrhage and lateralized rhythmic delta activity were six times as likely to have electrographic seizures, which were associated with 5.47 higher odds of a poor outcome. Coma, temporal lobe involvement, hematoma volume, and electrographic seizures predicted poor outcome in lobar intraparenchymal hemorrhage.
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22
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Kokkinos V, Urban A, Sisterson ND, Li N, Corson D, Richardson RM. Responsive Neurostimulation of the Thalamus Improves Seizure Control in Idiopathic Generalized Epilepsy: A Case Report. Neurosurgery 2021; 87:E578-E583. [PMID: 32023343 DOI: 10.1093/neuros/nyaa001] [Citation(s) in RCA: 40] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2019] [Accepted: 12/01/2019] [Indexed: 11/13/2022] Open
Abstract
BACKGROUND AND IMPORTANCE At least 25% of patients with idiopathic generalized epilepsy do not obtain adequate seizure control with medication. This report describes the first use of responsive neurostimulation (RNS), bilaterally targeting the centromedian/ventrolateral (CM/VL) region in a patient with drug-refractory Jeavons syndrome (eyelid myoclonia with absences). CLINICAL PRESENTATION A patient, diagnosed with eyelid myoclonia with absences (EMA) and refractory to medication, was offered RNS treatment in the CM/VL region of the thalamus. Stimulation was triggered by thalamic neural activity having morphological, spectral, and synchronous features that corresponded to 3- to 5-Hz spike-wave discharges recorded on prior scalp electroencephalography. CONCLUSION RNS decreased daily absence seizures from a mean of 60 to ≤10 and maintained the patient's level of consciousness during the occurring episodes. This therapy should be evaluated further for its potential to treat patients with pharmaco-refractory generalized epilepsy.
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Affiliation(s)
- Vasileios Kokkinos
- Department of Neurosurgery, Massachusetts General Hospital, Boston, Massachusetts.,Harvard Medical School, Boston, Massachusetts
| | - Alexandra Urban
- University of Pittsburgh Comprehensive Epilepsy Center, Pittsburgh, Pennsylvania.,Department of Neurology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania
| | - Nathaniel D Sisterson
- Department of Neurological Surgery, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania
| | - Ningfei Li
- Department for Neurology, Charité - University Medicine Berlin, Berlin, Germany
| | - Danielle Corson
- University of Pittsburgh Comprehensive Epilepsy Center, Pittsburgh, Pennsylvania.,Department of Neurological Surgery, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania
| | - R Mark Richardson
- Department of Neurosurgery, Massachusetts General Hospital, Boston, Massachusetts.,Harvard Medical School, Boston, Massachusetts
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23
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Abstract
Neuromodulation, including first-generation open-loop devices and second-generation closed-loop devices, is a valuable but poorly understood therapeutic option for patients with drug-refractory epilepsy. The precise therapy a patient receives is contingent on the relationship between the patient's own unique neurophysiology and the custom programming of detection and stimulation parameters. Recent evidence demonstrates that therapeutic efficacy can be achieved through neuromodulation of seizure networks, rather than simple disruption of seizure evolution. Nevertheless, the improvement in outcomes achieved combined with its minimally invasive, nondestructive nature make closed-loop stimulation a promising therapy for additional indications, such as generalized and pediatric epilepsy.
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Affiliation(s)
- Nathaniel D Sisterson
- Department of Neurological Surgery, University of Pittsburgh, 3550 Terrace Street, Pittsburgh, PA 15261, USA
| | - Vasileios Kokkinos
- Department of Neurosurgery, Massachusetts General Hospital, Harvard Medical School, 55 Fruit Street, 429A Thier, Boston, MA 02114, USA.
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24
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Low frequency centromedian thalamic nuclei deep brain stimulation for the treatment of super refractory status epilepticus: A case report and a review of the literature. Brain Stimul 2020; 14:226-229. [PMID: 33388465 DOI: 10.1016/j.brs.2020.12.013] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2020] [Revised: 11/26/2020] [Accepted: 12/28/2020] [Indexed: 11/21/2022] Open
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25
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Dalic LJ, Warren AEL, Young JC, Thevathasan W, Roten A, Bulluss KJ, Archer JS. Cortex leads the thalamic centromedian nucleus in generalized epileptic discharges in Lennox‐Gastaut syndrome. Epilepsia 2020; 61:2214-2223. [DOI: 10.1111/epi.16657] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2020] [Revised: 07/23/2020] [Accepted: 07/24/2020] [Indexed: 01/01/2023]
Affiliation(s)
- Linda J. Dalic
- Department of Medicine (Austin Health) University of Melbourne Heidelberg Victoria Australia
- Department of Neurology Austin Health Heidelberg Victoria Australia
| | - Aaron E. L. Warren
- Department of Medicine (Austin Health) University of Melbourne Heidelberg Victoria Australia
- Florey Institute of Neuroscience and Mental Health Heidelberg Victoria Australia
- Murdoch Children’s Research Institute Parkville Victoria Australia
| | - James C. Young
- Florey Institute of Neuroscience and Mental Health Heidelberg Victoria Australia
| | - Wesley Thevathasan
- Department of Medicine (Austin Health) University of Melbourne Heidelberg Victoria Australia
- Bionics Institute East Melbourne Victoria Australia
- Department of Medicine Royal Melbourne Hospital and Department of Neurology University of Melbourne Parkville Victoria Australia
| | - Annie Roten
- Department of Neurology Austin Health Heidelberg Victoria Australia
| | - Kristian J. Bulluss
- Bionics Institute East Melbourne Victoria Australia
- Department of Neurosurgery Austin Health Heidelberg Victoria Australia
- Department of Surgery University of Melbourne Parkville Victoria Australia
| | - John S. Archer
- Department of Medicine (Austin Health) University of Melbourne Heidelberg Victoria Australia
- Department of Neurology Austin Health Heidelberg Victoria Australia
- Florey Institute of Neuroscience and Mental Health Heidelberg Victoria Australia
- Murdoch Children’s Research Institute Parkville Victoria Australia
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Qin Y, Zhang N, Chen Y, Zuo X, Jiang S, Zhao X, Dong L, Li J, Zhang T, Yao D, Luo C. Rhythmic Network Modulation to Thalamocortical Couplings in Epilepsy. Int J Neural Syst 2020; 30:2050014. [PMID: 32308081 DOI: 10.1142/s0129065720500148] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Thalamus interacts with cortical areas, generating oscillations characterized by their rhythm and levels of synchrony. However, little is known of what function the rhythmic dynamic may serve in thalamocortical couplings. This work introduced a general approach to investigate the modulatory contribution of rhythmic scalp network to the thalamo-frontal couplings in juvenile myoclonic epilepsy (JME) and frontal lobe epilepsy (FLE). Here, time-varying rhythmic network was constructed using the adapted directed transfer function between EEG electrodes, and then was applied as a modulator in fMRI-based thalamocortical functional couplings. Furthermore, the relationship between corticocortical connectivity and rhythm-dependent thalamocortical coupling was examined. The results revealed thalamocortical couplings modulated by EEG scalp network have frequency-dependent characteristics. Increased thalamus- sensorimotor network (SMN) and thalamus-default mode network (DMN) couplings in JME were strongly modulated by alpha band. These thalamus-SMN couplings demonstrated enhanced association with SMN-related corticocortical connectivity. In addition, altered theta-dependent and beta-dependent thalamus-frontoparietal network (FPN) couplings were found in FLE. The reduced theta-dependent thalamus-FPN couplings were associated with the decreased FPN-related corticocortical connectivity. This study proposed interactive links between the rhythmic modulation and thalamocortical coupling. The crucial role of SMN and FPN in subcortical-cortical circuit may have implications for intervention in generalized and focal epilepsy.
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Affiliation(s)
- Yun Qin
- The Clinical Hospital of Chengdu Brain Science Institute, MOE Key Lab for Neuroinformation, High-Field Magnetic Resonance Brain Imaging Key Laboratory of Sichuan Province, University of Electronic Science and Technology of China, Chengdu 610054, P. R. China
| | - Nan Zhang
- The Clinical Hospital of Chengdu Brain Science Institute, MOE Key Lab for Neuroinformation, High-Field Magnetic Resonance Brain Imaging Key Laboratory of Sichuan Province, University of Electronic Science and Technology of China, Chengdu 610054, P. R. China
| | - Yan Chen
- The Clinical Hospital of Chengdu Brain Science Institute, MOE Key Lab for Neuroinformation, High-Field Magnetic Resonance Brain Imaging Key Laboratory of Sichuan Province, University of Electronic Science and Technology of China, Chengdu 610054, P. R. China
| | - Xiaojun Zuo
- The Clinical Hospital of Chengdu Brain Science Institute, MOE Key Lab for Neuroinformation, High-Field Magnetic Resonance Brain Imaging Key Laboratory of Sichuan Province, University of Electronic Science and Technology of China, Chengdu 610054, P. R. China
| | - Sisi Jiang
- The Clinical Hospital of Chengdu Brain Science Institute, MOE Key Lab for Neuroinformation, High-Field Magnetic Resonance Brain Imaging Key Laboratory of Sichuan Province, University of Electronic Science and Technology of China, Chengdu 610054, P. R. China
| | - Xiaole Zhao
- The Clinical Hospital of Chengdu Brain Science Institute, MOE Key Lab for Neuroinformation, High-Field Magnetic Resonance Brain Imaging Key Laboratory of Sichuan Province, University of Electronic Science and Technology of China, Chengdu 610054, P. R. China
| | - Li Dong
- The Clinical Hospital of Chengdu Brain Science Institute, MOE Key Lab for Neuroinformation, High-Field Magnetic Resonance Brain Imaging Key Laboratory of Sichuan Province, University of Electronic Science and Technology of China, Chengdu 610054, P. R. China
| | - Jianfu Li
- The Clinical Hospital of Chengdu Brain Science Institute, MOE Key Lab for Neuroinformation, High-Field Magnetic Resonance Brain Imaging Key Laboratory of Sichuan Province, University of Electronic Science and Technology of China, Chengdu 610054, P. R. China
| | - Tao Zhang
- The Clinical Hospital of Chengdu Brain Science Institute, MOE Key Lab for Neuroinformation, High-Field Magnetic Resonance Brain Imaging Key Laboratory of Sichuan Province, University of Electronic Science and Technology of China, Chengdu 610054, P. R. China
| | - Dezhong Yao
- The Clinical Hospital of Chengdu Brain Science Institute, MOE Key Lab for Neuroinformation, High-Field Magnetic Resonance Brain Imaging Key Laboratory of Sichuan Province, University of Electronic Science and Technology of China, Chengdu 610054, P. R. China.,Research Unit of NeuroInformation, Chinese Academy of Medical Sciences, 2019RU035, Chengdu, P. R. China
| | - Cheng Luo
- The Clinical Hospital of Chengdu Brain Science Institute, MOE Key Lab for Neuroinformation, High-Field Magnetic Resonance Brain Imaging Key Laboratory of Sichuan Province, University of Electronic Science and Technology of China, Chengdu 610054, P. R. China.,Research Unit of NeuroInformation, Chinese Academy of Medical Sciences, 2019RU035, Chengdu, P. R. China
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28
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Li Y, Yu Z, Chen Y, Yang C, Li Y, Allen Li X, Li B. Automatic Seizure Detection using Fully Convolutional Nested LSTM. Int J Neural Syst 2020; 30:2050019. [DOI: 10.1142/s0129065720500197] [Citation(s) in RCA: 56] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
The automatic seizure detection system can effectively help doctors to monitor and diagnose epilepsy thus reducing their workload. Many outstanding studies have given good results in the two-class seizure detection problems, but most of them are based on hand-wrought feature extraction. This study proposes an end-to-end automatic seizure detection system based on deep learning, which does not require heavy preprocessing on the EEG data or feature engineering. The fully convolutional network with three convolution blocks is first used to learn the expressive seizure characteristics from EEG data. Then these robust EEG features pertinent to seizures are presented as an input to the Nested Long Short-Term Memory (NLSTM) model to explore the inherent temporal dependencies in EEG signals. Lastly, the high-level features obtained from the NLSTM model are fed into the softmax layer to output predicted labels. The proposed method yields an accuracy range of 98.44–100% in 10 different experiments based on the Bonn University database. A larger EEG database is then used to evaluate the performance of the proposed method in real-life situations. The average sensitivity of 97.47%, specificity of 96.17%, and false detection rate of 0.487 per hour are yielded. For CHB–MIT Scalp EEG database, the proposed model also achieves a segment-level sensitivity of 94.07% with a false detection rate of 0.66 per hour. The excellent results obtained on three different EEG databases demonstrate that the proposed method has good robustness and generalization power under ideal and real-life conditions.
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Affiliation(s)
- Yang Li
- Laboratory of Image Science and Technology, School of Computer Science and Engineering, Southeast University, Nanjing, Jiangsu 210096, P. R. China
- Department of Radiation Oncology, Shandong Cancer Hospital and Institute, Shandong First Medical University and Shandong Academy of Medical Sciences, Jinan, Shandong 250117, P. R. China
| | - Zuyi Yu
- School of Information Science and Engineering, Shandong University, Jinan, Shandong 250100, P. R. China
| | - Yang Chen
- Laboratory of Image Science and Technology, Southeast University, Nanjing, Jiangsu 210096, P. R. China
| | - Chunfeng Yang
- Laboratory of Image Science and Technology, Southeast University, Nanjing, Jiangsu 210096, P. R. China
| | - Yue Li
- School of Clinical Medicine, Dali University, Dali, Yunnan 671000, P. R. China
| | - X. Allen Li
- Department of Radiation Oncology, Medical College of Wisconsin, Milwaukee, WI 53226, USA
| | - Baosheng Li
- Laboratory of Image Science and Technology, School of Computer Science and Engineering, Southeast University, Nanjing, Jiangsu 210096, P. R. China
- Department of Radiation Oncology, Shandong Cancer Hospital and Institute, Shandong First Medical University and Shandong Academy of Medical Sciences, Jinan, Shandong 250117, P. R. China
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Koutlis C, Kimiskidis VK, Kugiumtzis D. Identification of Hidden Sources by Estimating Instantaneous Causality in High-Dimensional Biomedical Time Series. Int J Neural Syst 2019; 29:1850051. [DOI: 10.1142/s012906571850051x] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
The study of connectivity patterns of a system’s variables, such as multi-channel electroencephalograms (EEG), is of utmost importance towards a better understanding of its internal evolutionary mechanisms. Here, the problem of estimating the connectivity network from multivariate time series in the presence of prominent unobserved variables is addressed. The causality measure of partial mutual information from mixed embedding (PMIME), designed to estimate direct lag-causal effects in the presence of many observed variables, is adapted to estimate also zero-lag effects, the so-called instantaneous causality. We term the proposed advanced method, PMIME0. The estimation of instantaneous causality by PMIME0 is a signature of the presence of hidden source in the observed system, as demonstrated analytically in a toy model. It is further demonstrated that the PMIME0 identifies the true instantaneous with great accuracy in a variety of high-dimensional dynamical systems. The method is applied to EEG data with epileptiform discharges (EDs), and the results imply a strong impact of unobserved confounders during the EDs. This finding comes as a possible explanation for the increased levels of causality during epileptic seizures estimated by some measures affected by the presence of a common source.
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Affiliation(s)
- Christos Koutlis
- Department of Electrical and Computer Engineering, Aristotle University of Thessaloniki, Thessaloniki 54124, Greece
| | - Vasilios K. Kimiskidis
- Laboratory of Clinical Neurophysiology, Medical School, Aristotle University of Thessaloniki, Thessaloniki 54124, Greece
| | - Dimitris Kugiumtzis
- Department of Electrical and Computer Engineering, Aristotle University of Thessaloniki, Thessaloniki 54124, Greece
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Martinez-Murcia FJ, Górriz JM, Ramírez J, Ortiz A. Convolutional Neural Networks for Neuroimaging in Parkinson's Disease: Is Preprocessing Needed? Int J Neural Syst 2018; 28:1850035. [PMID: 30215285 DOI: 10.1142/s0129065718500351] [Citation(s) in RCA: 37] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Spatial and intensity normalizations are nowadays a prerequisite for neuroimaging analysis. Influenced by voxel-wise and other univariate comparisons, where these corrections are key, they are commonly applied to any type of analysis and imaging modalities. Nuclear imaging modalities such as PET-FDG or FP-CIT SPECT, a common modality used in Parkinson's disease diagnosis, are especially dependent on intensity normalization. However, these steps are computationally expensive and furthermore, they may introduce deformations in the images, altering the information contained in them. Convolutional neural networks (CNNs), for their part, introduce position invariance to pattern recognition, and have been proven to classify objects regardless of their orientation, size, angle, etc. Therefore, a question arises: how well can CNNs account for spatial and intensity differences when analyzing nuclear brain imaging? Are spatial and intensity normalizations still needed? To answer this question, we have trained four different CNN models based on well-established architectures, using or not different spatial and intensity normalization preprocessings. The results show that a sufficiently complex model such as our three-dimensional version of the ALEXNET can effectively account for spatial differences, achieving a diagnosis accuracy of 94.1% with an area under the ROC curve of 0.984. The visualization of the differences via saliency maps shows that these models are correctly finding patterns that match those found in the literature, without the need of applying any complex spatial normalization procedure. However, the intensity normalization - and its type - is revealed as very influential in the results and accuracy of the trained model, and therefore must be well accounted.
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Affiliation(s)
| | - Juan M Górriz
- * Department of Signal Theory, Networking and Communications, University of Granada, Granada, Spain.,† Department of Psychiatry, University of Cambridge, Cambridge CB2 OSZ, UK
| | - Javier Ramírez
- * Department of Signal Theory, Networking and Communications, University of Granada, Granada, Spain
| | - Andres Ortiz
- ‡ Department of Communications Engineering, University of Malaga, Malaga, Spain
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