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Warren AEL, Butson CR, Hook MP, Dalic LJ, Archer JS, Macdonald-Laurs E, Schaper FLWVJ, Hart LA, Singh H, Johnson L, Bullinger KL, Gross RE, Morrell MJ, Rolston JD. Targeting thalamocortical circuits for closed-loop stimulation in Lennox-Gastaut syndrome. Brain Commun 2024; 6:fcae161. [PMID: 38764777 PMCID: PMC11099664 DOI: 10.1093/braincomms/fcae161] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2023] [Revised: 03/26/2024] [Accepted: 05/06/2024] [Indexed: 05/21/2024] Open
Abstract
This paper outlines the therapeutic rationale and neurosurgical targeting technique for bilateral, closed-loop, thalamocortical stimulation in Lennox-Gastaut syndrome, a severe form of childhood-onset epilepsy. Thalamic stimulation can be an effective treatment for Lennox-Gastaut syndrome, but complete seizure control is rarely achieved. Outcomes may be improved by stimulating areas beyond the thalamus, including cortex, but the optimal targets are unknown. We aimed to identify a cortical target by synthesizing prior neuroimaging studies, and to use this knowledge to advance a dual thalamic (centromedian) and cortical (frontal) approach for closed-loop stimulation. Multi-modal brain network maps from three group-level studies of Lennox-Gastaut syndrome were averaged to define the area of peak overlap: simultaneous EEG-functional MRI of generalized paroxysmal fast activity, [18F]fluorodeoxyglucose PET of cortical hypometabolism and diffusion MRI structural connectivity associated with clinical efficacy in a previous trial of thalamic deep brain stimulation. The resulting 'hotspot' was used as a seed in a normative functional MRI connectivity analysis to identify connected networks. Intracranial electrophysiology was reviewed in the first two trial patients undergoing bilateral implantations guided by this hotspot. Simultaneous recordings from cortex and thalamus were analysed for presence and synchrony of epileptiform activity. The peak overlap was in bilateral premotor cortex/caudal middle frontal gyrus. Functional connectivity of this hotspot revealed a distributed network of frontoparietal cortex resembling the diffuse abnormalities seen on EEG-functional MRI and PET. Intracranial electrophysiology showed characteristic epileptiform activity of Lennox-Gastaut syndrome in both the cortical hotspot and thalamus; most detected events occurred first in the cortex before appearing in the thalamus. Premotor frontal cortex shows peak involvement in Lennox-Gastaut syndrome and functional connectivity of this region resembles the wider epileptic brain network. Thus, it may be an optimal target for a range of neuromodulation therapies, including thalamocortical stimulation and emerging non-invasive treatments like focused ultrasound or transcranial magnetic stimulation. Compared to thalamus-only approaches, the addition of this cortical target may allow more rapid detections of seizures, more diverse stimulation paradigms and broader modulation of the epileptic network. A prospective, multi-centre trial of closed-loop thalamocortical stimulation for Lennox-Gastaut syndrome is currently underway.
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Affiliation(s)
- Aaron E L Warren
- Department of Neurosurgery, Brigham and Women’s Hospital, Harvard Medical School, Boston, MA 02115, USA
| | - Christopher R Butson
- Normal Fixel Institute for Neurological Diseases, University of Florida, Gainesville, FL 32608, USA
| | - Matthew P Hook
- Normal Fixel Institute for Neurological Diseases, University of Florida, Gainesville, FL 32608, USA
| | - Linda J Dalic
- University of Melbourne, Parkville, VIC 3052, Australia
- Department of Neurology, Austin Health, Heidelberg, VIC 3084, Australia
| | - John S Archer
- University of Melbourne, Parkville, VIC 3052, Australia
- Department of Neurology, Austin Health, Heidelberg, VIC 3084, Australia
| | - Emma Macdonald-Laurs
- University of Melbourne, Parkville, VIC 3052, Australia
- Department of Neurology, Royal Children’s Hospital, Parkville, VIC 3052, Australia
- Murdoch Children’s Research Institute, Parkville, VIC 3052, Australia
| | - Frederic L W V J Schaper
- Department of Neurology, Brigham and Women’s Hospital, Harvard Medical School, Boston, MA 02115, USA
| | - Lauren A Hart
- Department of Neurology, Brigham and Women’s Hospital, Harvard Medical School, Boston, MA 02115, USA
| | - Hargunbir Singh
- Department of Neurosurgery, Brigham and Women’s Hospital, Harvard Medical School, Boston, MA 02115, USA
| | | | - Katie L Bullinger
- Department of Neurology, Emory University Hospital, Atlanta, GA 30322, USA
| | - Robert E Gross
- Department of Neurosurgery, Emory University Hospital, Atlanta, GA 30322, USA
| | - Martha J Morrell
- NeuroPace, Mountain View, CA 94043, USA
- Department of Neurology and Neurological Science, Stanford University, Palo Alto, CA 94304, USA
| | - John D Rolston
- Department of Neurosurgery, Brigham and Women’s Hospital, Harvard Medical School, Boston, MA 02115, USA
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Panchavati S, Daida A, Edmonds B, Miyakoshi M, Oana S, Ahn SS, Arnold C, Salamon N, Sankar R, Fallah A, Speier W, Nariai H. Uncovering spatiotemporal dynamics of the corticothalamic network at ictal onset. Epilepsia 2024. [PMID: 38662128 DOI: 10.1111/epi.17990] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2023] [Revised: 04/08/2024] [Accepted: 04/08/2024] [Indexed: 04/26/2024]
Abstract
OBJECTIVE Although the clinical efficacy of deep brain stimulation targeting the anterior nucleus (AN) and centromedian nucleus (CM) of the thalamus has been actively investigated for the treatment of medication-resistant epilepsy, few studies have investigated dynamic ictal changes in corticothalamic connectivity in human electroencephalographic (EEG) recording. This study aims to establish the complex spatiotemporal dynamics of the ictal corticothalamic network associated with various seizure foci. METHODS We analyzed 10 patients (aged 2.7-28.1 years) with medication-resistant focal epilepsy who underwent stereotactic EEG evaluation with thalamic sampling. We examined both undirected and directed connectivity, incorporating coherence and spectral Granger causality analysis (GCA) between the diverse seizure foci and thalamic nuclei (AN and CM) at ictal onset. RESULTS In our analysis of 36 seizures, coherence between seizure onset and thalamic nuclei increased across all frequencies, especially in slower bands (delta, theta, alpha). GCA showed increased information flow from seizure onset to the thalamus across all frequency bands, but outflows from the thalamus were mainly in slower frequencies, particularly delta. In the subgroup analysis based on various seizure foci, the delta coherence showed a more pronounced increase at CM than at AN during frontal lobe seizures. Conversely, in limbic seizures, the delta coherence increase was greater at AN compared to CM. SIGNIFICANCE It appears that the delta frequency plays a pivotal role in modulating the corticothalamic network during seizures. Our results underscore the significance of comprehending the spatiotemporal dynamics of the corticothalamic network at ictal onset, and this knowledge could guide personalized responsive neuromodulation treatment strategies.
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Affiliation(s)
- Saarang Panchavati
- Department of Bioengineering, University of California, Los Angeles, Los Angeles, California, USA
- Department of Radiological Sciences, University of California, Los Angeles, Los Angeles, California, USA
| | - Atsuro Daida
- Division of Pediatric Neurology, Department of Pediatrics, UCLA Mattel Children's Hospital, David Geffen School of Medicine, Los Angeles, California, USA
| | - Benjamin Edmonds
- Division of Pediatric Neurology, Department of Pediatrics, UCLA Mattel Children's Hospital, David Geffen School of Medicine, Los Angeles, California, USA
| | - Makoto Miyakoshi
- Department of Psychiatry and Behavioral Neuroscience, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio, USA
- Department of Psychiatry, University of Cincinnati College of Medicine, Cincinnati, Ohio, USA
| | - Shingo Oana
- Division of Pediatric Neurology, Department of Pediatrics, UCLA Mattel Children's Hospital, David Geffen School of Medicine, Los Angeles, California, USA
| | - Samuel S Ahn
- Division of Pediatric Neurology, Department of Pediatrics, UCLA Mattel Children's Hospital, David Geffen School of Medicine, Los Angeles, California, USA
| | - Corey Arnold
- Department of Bioengineering, University of California, Los Angeles, Los Angeles, California, USA
- Department of Radiological Sciences, University of California, Los Angeles, Los Angeles, California, USA
| | - Noriko Salamon
- Department of Radiology, UCLA Medical Center, David Geffen School of Medicine, Los Angeles, California, USA
| | - Raman Sankar
- Division of Pediatric Neurology, Department of Pediatrics, UCLA Mattel Children's Hospital, David Geffen School of Medicine, Los Angeles, California, USA
- UCLA Children's Discovery and Innovation Institute, Los Angeles, California, USA
| | - Aria Fallah
- Department of Neurosurgery, UCLA Medical Center, David Geffen School of Medicine, Los Angeles, California, USA
| | - William Speier
- Department of Bioengineering, University of California, Los Angeles, Los Angeles, California, USA
- Department of Radiological Sciences, University of California, Los Angeles, Los Angeles, California, USA
| | - Hiroki Nariai
- Division of Pediatric Neurology, Department of Pediatrics, UCLA Mattel Children's Hospital, David Geffen School of Medicine, Los Angeles, California, USA
- Department of Radiology, UCLA Medical Center, David Geffen School of Medicine, Los Angeles, California, USA
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3
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Schulze-Bonhage A, Nitsche MA, Rotter S, Focke NK, Rao VR. Neurostimulation targeting the epileptic focus: Current understanding and perspectives for treatment. Seizure 2024; 117:183-192. [PMID: 38452614 DOI: 10.1016/j.seizure.2024.03.001] [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: 02/06/2024] [Revised: 02/29/2024] [Accepted: 03/02/2024] [Indexed: 03/09/2024] Open
Abstract
For the one third of people with epilepsy whose seizures are not controlled with medications, targeting the seizure focus with neurostimulation can be an effective therapeutic strategy. In this focused review, we summarize a discussion of targeted neurostimulation modalities during a workshop held in Frankfurt, Germany in September 2023. Topics covered include: available devices for seizure focus stimulation; alternating current (AC) and direct current (DC) stimulation to reduce focal cortical excitability; modeling approaches to simulate DC stimulation; reconciling the efficacy of focal stimulation with the network theory of epilepsy; and the emerging concept of 'neurostimulation zones,' which are defined as cortical regions where focal stimulation is most effective for reducing seizures and which may or may not directly involve the seizure onset zone. By combining experimental data, modeling results, and clinical outcome analysis, rational selection of target regions and stimulation parameters is increasingly feasible, paving the way for a broader use of neurostimulation for epilepsy in the future.
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Affiliation(s)
- Andreas Schulze-Bonhage
- Epilepsy Center, University Medical Center, University of Freiburg, Germany; European Reference Network EpiCare, Belgium; NeuroModul Basic, University of Freiburg, Freiburg, Germany.
| | - Michael A Nitsche
- Dept. Psychology and Neurosciences, Leibniz Research Centre for Working Environment and Human Factors, Dortmund, Germany; Bielefeld University, University Hospital OWL, Protestant Hospital of Bethel Foundation, University Clinic of Psychiatry and Psychotherapy, Germany; German Center for Mental Health (DZPG), Germany
| | - Stefan Rotter
- Bernstein Center Freiburg & Faculty of Biology, University of Freiburg, Germany
| | - Niels K Focke
- Epilepsy Center, Clinic for Neurology, University Medical Center Göttingen, Germany
| | - Vikram R Rao
- Department of Neurology and Weill Institute for Neurosciences, University of California, San Francisco, USA
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4
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Gouveia FV, Warsi NM, Suresh H, Matin R, Ibrahim GM. Neurostimulation treatments for epilepsy: Deep brain stimulation, responsive neurostimulation and vagus nerve stimulation. Neurotherapeutics 2024; 21:e00308. [PMID: 38177025 PMCID: PMC11103217 DOI: 10.1016/j.neurot.2023.e00308] [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: 09/05/2023] [Revised: 11/29/2023] [Accepted: 12/06/2023] [Indexed: 01/06/2024] Open
Abstract
Epilepsy is a common and debilitating neurological disorder, and approximately one-third of affected individuals have ongoing seizures despite appropriate trials of two anti-seizure medications. This population with drug-resistant epilepsy (DRE) may benefit from neurostimulation approaches, such as vagus nerve stimulation (VNS), deep brain stimulation (DBS) and responsive neurostimulation (RNS). In some patient populations, these techniques are FDA-approved for treating DRE. VNS is used as adjuvant therapy for children and adults. Acting via the vagus afferent network, VNS modulates thalamocortical circuits, reducing seizures in approximately 50 % of patients. RNS uses an adaptive (closed-loop) system that records intracranial EEG patterns to activate the stimulation at the appropriate time, being particularly well-suited to treat seizures arising within eloquent cortex. For DBS, the most promising therapeutic targets are the anterior and centromedian nuclei of the thalamus, with anterior nucleus DBS being used for treating focal and secondarily generalized forms of DRE and centromedian nucleus DBS being applied for treating generalized epilepsies such as Lennox-Gastaut syndrome. Here, we discuss the indications, advantages and limitations of VNS, DBS and RNS in treating DRE and summarize the spatial distribution of neuroimaging observations related to epilepsy and stimulation using NeuroQuery and NeuroSynth.
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Affiliation(s)
| | - Nebras M Warsi
- Neuroscience and Mental Health, The Hospital for Sick Children, Toronto, ON, Canada; Division of Neurosurgery, The Hospital for Sick Children, Toronto, ON, Canada
| | - Hrishikesh Suresh
- Neuroscience and Mental Health, The Hospital for Sick Children, Toronto, ON, Canada; Division of Neurosurgery, The Hospital for Sick Children, Toronto, ON, Canada
| | - Rafi Matin
- Neuroscience and Mental Health, The Hospital for Sick Children, Toronto, ON, Canada; Institute of Medical Science, University of Toronto, Toronto, ON, Canada
| | - George M Ibrahim
- Neuroscience and Mental Health, The Hospital for Sick Children, Toronto, ON, Canada; Division of Neurosurgery, The Hospital for Sick Children, Toronto, ON, Canada; Institute of Medical Science, University of Toronto, Toronto, ON, Canada.
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5
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Warren AEL, Tobochnik S, Chua MMJ, Singh H, Stamm MA, Rolston JD. Neurostimulation for Generalized Epilepsy: Should Therapy be Syndrome-specific? Neurosurg Clin N Am 2024; 35:27-48. [PMID: 38000840 PMCID: PMC10676463 DOI: 10.1016/j.nec.2023.08.001] [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] [Indexed: 11/26/2023]
Abstract
Current applications of neurostimulation for generalized epilepsy use a one-target-fits-all approach that is agnostic to the specific epilepsy syndrome and seizure type being treated. The authors describe similarities and differences between the 2 "archetypes" of generalized epilepsy-Lennox-Gastaut syndrome and Idiopathic Generalized Epilepsy-and review recent neuroimaging evidence for syndrome-specific brain networks underlying seizures. Implications for stimulation targeting and programming are discussed using 5 clinical questions: What epilepsy syndrome does the patient have? What brain networks are involved? What is the optimal stimulation target? What is the optimal stimulation paradigm? What is the plan for adjusting stimulation over time?
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Affiliation(s)
- Aaron E L Warren
- Department of Neurosurgery, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA.
| | - Steven Tobochnik
- Department of Neurology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA
| | - Melissa M J Chua
- Department of Neurosurgery, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA
| | - Hargunbir Singh
- Department of Neurosurgery, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA
| | - Michaela A Stamm
- Department of Neurosurgery, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA
| | - John D Rolston
- Department of Neurosurgery, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA
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6
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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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7
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Frauscher B, Bartolomei F, Baud MO, Smith RJ, Worrell G, Lundstrom BN. Stimulation to probe, excite, and inhibit the epileptic brain. Epilepsia 2023; 64 Suppl 3:S49-S61. [PMID: 37194746 PMCID: PMC10654261 DOI: 10.1111/epi.17640] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2023] [Revised: 05/01/2023] [Accepted: 05/02/2023] [Indexed: 05/18/2023]
Abstract
Direct cortical stimulation has been applied in epilepsy for nearly a century and has experienced a renaissance, given unprecedented opportunities to probe, excite, and inhibit the human brain. Evidence suggests stimulation can increase diagnostic and therapeutic utility in patients with drug-resistant epilepsies. However, choosing appropriate stimulation parameters is not a trivial issue, and is further complicated by epilepsy being characterized by complex brain state dynamics. In this article derived from discussions at the ICTALS 2022 Conference (International Conference on Technology and Analysis for Seizures), we succinctly review the literature on cortical stimulation applied acutely and chronically to the epileptic brain for localization, monitoring, and therapeutic purposes. In particular, we discuss how stimulation is used to probe brain excitability, discuss evidence on the usefulness of stimulation to trigger and stop seizures, review therapeutic applications of stimulation, and finally discuss how stimulation parameters are impacted by brain dynamics. Although research has advanced considerably over the past decade, there are still significant hurdles to optimizing use of this technique. For example, it remains unclear to what extent short timescale diagnostic biomarkers can predict long-term outcomes and to what extent these biomarkers add information to already existing biomarkers from passive electroencephalographic recordings. Further questions include the extent to which closed loop stimulation offers advantages over open loop stimulation, what the optimal closed loop timescales may be, and whether biomarker-informed stimulation can lead to seizure freedom. The ultimate goal of bioelectronic medicine remains not just to stop seizures but rather to cure epilepsy and its comorbidities.
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Affiliation(s)
- Birgit Frauscher
- Analytical Neurophysiology Lab, Montreal Neurological Institute and Hospital, Montreal, Quebec, Canada
| | - Fabrice Bartolomei
- Institut de Neurosciences des Systèmes, Aix Marseille University, Marseille, France. AP-HM, Service de Neurophysiologie Clinique, Hôpital de la Timone, Marseille, France
| | - Maxime O. Baud
- Sleep-Wake-Epilepsy Center, NeuroTec and Center for Experimental Neurology, Department of Neurology, Inselspital Bern, University Hospital, University of Bern, Bern
| | - Rachel J. Smith
- University of Alabama at Birmingham, Electrical and Computer Engineering Department, Birmingham, Alabama, US. University of Alabama at Birmingham, Neuroengineering Program, Birmingham, Alabama, US
| | - Greg Worrell
- Department of Neurology, Mayo Clinic, Rochester, US
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8
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Rao VR, Rolston JD. Unearthing the mechanisms of responsive neurostimulation for epilepsy. COMMUNICATIONS MEDICINE 2023; 3:166. [PMID: 37974025 PMCID: PMC10654422 DOI: 10.1038/s43856-023-00401-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2023] [Accepted: 11/03/2023] [Indexed: 11/19/2023] Open
Abstract
Responsive neurostimulation (RNS) is an effective therapy for people with drug-resistant focal epilepsy. In clinical trials, RNS therapy results in a meaningful reduction in median seizure frequency, but the response is highly variable across individuals, with many receiving minimal or no benefit. Understanding why this variability occurs will help improve use of RNS therapy. Here we advocate for a reexamination of the assumptions made about how RNS reduces seizures. This is now possible due to large patient cohorts having used this device, some long-term. Two foundational assumptions have been that the device's intracranial leads should target the seizure focus/foci directly, and that stimulation should be triggered only in response to detected epileptiform activity. Recent studies have called into question both hypotheses. Here, we discuss these exciting new studies and suggest future approaches to patient selection, lead placement, and device programming that could improve clinical outcomes.
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Affiliation(s)
- Vikram R Rao
- Department of Neurology and Weill Institute for Neurosciences, University of California, San Francisco, CA, USA.
| | - John D Rolston
- Department of Neurosurgery, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA
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9
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Rissardo JP, Vora NM, Tariq I, Mujtaba A, Caprara ALF. Deep Brain Stimulation for the Management of Refractory Neurological Disorders: A Comprehensive Review. MEDICINA (KAUNAS, LITHUANIA) 2023; 59:1991. [PMID: 38004040 PMCID: PMC10673515 DOI: 10.3390/medicina59111991] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/17/2023] [Revised: 11/04/2023] [Accepted: 11/10/2023] [Indexed: 11/26/2023]
Abstract
In recent decades, deep brain stimulation (DBS) has been extensively studied due to its reversibility and significantly fewer side effects. DBS is mainly a symptomatic therapy, but the stimulation of subcortical areas by DBS is believed to affect the cytoarchitecture of the brain, leading to adaptability and neurogenesis. The neurological disorders most commonly studied with DBS were Parkinson's disease, essential tremor, obsessive-compulsive disorder, and major depressive disorder. The most precise approach to evaluating the location of the leads still relies on the stimulus-induced side effects reported by the patients. Moreover, the adequate voltage and DBS current field could correlate with the patient's symptoms. Implantable pulse generators are the main parts of the DBS, and their main characteristics, such as rechargeable capability, magnetic resonance imaging (MRI) safety, and device size, should always be discussed with patients. The safety of MRI will depend on several parameters: the part of the body where the device is implanted, the part of the body scanned, and the MRI-tesla magnetic field. It is worth mentioning that drug-resistant individuals may have different pathophysiological explanations for their resistance to medications, which could affect the efficacy of DBS therapy. Therefore, this could explain the significant difference in the outcomes of studies with DBS in individuals with drug-resistant neurological conditions.
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Affiliation(s)
| | - Nilofar Murtaza Vora
- Medicine Department, Terna Speciality Hospital and Research Centre, Navi Mumbai 400706, India;
| | - Irra Tariq
- Medicine Department, United Medical & Dental College, Karachi 75600, Pakistan;
| | - Amna Mujtaba
- Medicine Department, Karachi Medical & Dental College, Karachi 74700, Pakistan;
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10
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Remore LG, Rifi Z, Nariai H, Eliashiv DS, Fallah A, Edmonds BD, Matsumoto JH, Salamon N, Tolossa M, Wei W, Locatelli M, Tsolaki EC, Bari AA. Structural connections of the centromedian nucleus of thalamus and their relevance for neuromodulation in generalized drug-resistant epilepsy: insight from a tractography study. Ther Adv Neurol Disord 2023; 16:17562864231202064. [PMID: 37822361 PMCID: PMC10563482 DOI: 10.1177/17562864231202064] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2023] [Accepted: 09/01/2023] [Indexed: 10/13/2023] Open
Abstract
Background Epilepsy is a widespread neurologic disorder and almost one-third of patients suffer from drug-resistant epilepsy (DRE). Neuromodulation targeting the centromediannucleus of the thalamus (CM) has been showing promising results for patients with generalized DRE who are not surgical candidates. Recently, the effect of CM- deep brain stimulation (DBS) in DRE patients was investigated in the Electrical Stimulation of Thalamus for Epilepsy of Lennox-Gastaut phenotype (ESTEL) trial, a monocentric randomized-controlled study. The same authors described a 'cold-spot' and a 'sweet-spot', which are defined as the volume of stimulation in the thalamus yielding the least and the best clinical response, respectively. However, it remains unclear which structural connections may contribute to the anti-seizure effect of the stimulation. Objective We investigated the differences in structural connectivity among CM, the sweet-spot and the cold-spot. Furthermore, we tried to validate our results in a cohort of DRE patients who underwent CM-DBS or CM-RNS (responsive neurostimulation). We hypothesized that the sweet-spot would share similar structural connectivity with responder patients. Methods By using the software FMRIB Software Library (FSL), probabilistic tractography was performed on 100 subjects from the Human Connectome Project to calculate the probability of connectivity of the whole CM, the sweet-spot and the cold-spot to 45 cortical and subcortical areas. Results among the three seeds were compared with multivariate analysis of variance (MANOVA). Similarly, the structural connectivity of volumes of tissue activated (VTAs) from eight DRE patients was investigated. Patients were divided into responders and non-responders based on the degree of reduction in seizure frequency, and the mean probabilities of connectivity were similarly compared between the two groups. Results The sweet-spot demonstrated a significantly higher probability of connectivity (p < 0.001) with the precentral gyrus, superior frontal gyrus, and the cerebellum than the whole CM and the cold-spot. Responder patients displayed a higher probability of connectivity with both ipsilateral (p = 0.011) and contralateral cerebellum (p = 0.04) than the non-responders. Conclusion Cerebellar connections seem to contribute to the beneficial effects of CM-neuromodulation in patients with drug-resistant generalized epilepsy.
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Affiliation(s)
- Luigi G. Remore
- Surgical Neuromodulation and Brain Mapping Laboratory, ULCA
- Department of Neurosurgery, 300 Stein Plaza, Los Angeles, CA 90095, USA
- University of Milan ‘La Statale’, Milan, Italy
- Department of Neurosurgery, Fondazione IRCCS Ca’Granda Ospedale Maggiore Policlinico, Milan, Italy
| | - Ziad Rifi
- Department of Neurosurgery, University of California Los Angeles, Los Angeles, CA, USA
| | - Hiroki Nariai
- Division of Pediatric Neurology, Department of Pediatrics, University of California Los Angeles, Los Angeles, CA, USA
- David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA, USA
| | - Dawn S. Eliashiv
- David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA, USA
- Department of Neurology, University of California Los Angeles, Los Angeles, CA, USA
| | - Aria Fallah
- Department of Neurosurgery, University of California Los Angeles, Los Angeles, CA, USA
- Division of Pediatric Neurology, Department of Pediatrics, University of California Los Angeles, Los Angeles, CA, USA
- David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA, USA
| | - Benjamin D. Edmonds
- Division of Pediatric Neurology, Department of Pediatrics, University of California Los Angeles, Los Angeles, CA, USA
| | - Joyce H. Matsumoto
- Division of Pediatric Neurology, Department of Pediatrics, University of California Los Angeles, Los Angeles, CA, USA
| | - Noriko Salamon
- David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA, USA
- Department of Radiology, University of California Los Angeles, Los Angeles, CA, USA
| | - Meskerem Tolossa
- Department of Neurosurgery, University of California Los Angeles, Los Angeles, CA, USA
| | - Wexin Wei
- Department of Neurosurgery, University of California Los Angeles, Los Angeles, CA, USA
| | - Marco Locatelli
- University of Milan ‘La Statale’, Milan, Italy
- Department of Neurosurgery, Fondazione IRCCS Ca’Granda Ospedale Maggiore Policlinico, Milan, Italy
- Department of Pathophysiology and Transplantation, University of Milan, Milan, Italy
- ‘Aldo Ravelli’ Research Center for Neurotechnology and Experimental Brain Therapeutics, University of Milan, Milan, Italy
| | - Evangelia C. Tsolaki
- Department of Neurosurgery, University of California Los Angeles, Los Angeles, CA, USA
| | - Ausaf A. Bari
- Department of Neurosurgery, University of California Los Angeles, Los Angeles, CA, USA
- Geffen School of Medicine David California Los Angeles University of Angeles Los CA, USA
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Chua MMJ, Vissani M, Liu DD, Schaper FLWVJ, Warren AEL, Caston R, Dworetzky BA, Bubrick EJ, Sarkis RA, Cosgrove GR, Rolston JD. Initial case series of a novel sensing deep brain stimulation device in drug-resistant epilepsy and consistent identification of alpha/beta oscillatory activity: A feasibility study. Epilepsia 2023; 64:2586-2603. [PMID: 37483140 DOI: 10.1111/epi.17722] [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: 03/27/2023] [Revised: 07/18/2023] [Accepted: 07/18/2023] [Indexed: 07/25/2023]
Abstract
OBJECTIVE Here, we report a retrospective, single-center experience with a novel deep brain stimulation (DBS) device capable of chronic local field potential (LFP) recording in drug-resistant epilepsy (DRE) and explore potential electrophysiological biomarkers that may aid DBS programming and outcome tracking. METHODS Five patients with DRE underwent thalamic DBS, targeting either the bilateral anterior (n = 3) or centromedian (n = 2) nuclei. Postoperative electrode lead localizations were visualized in Lead-DBS software. Local field potentials recorded over 12-18 months were tracked, and changes in power were associated with patient events, medication changes, and stimulation. We utilized a combination of lead localization, in-clinic broadband LFP recordings, real-time LFP response to stimulation, and chronic recordings to guide DBS programming. RESULTS Four patients (80%) experienced a >50% reduction in seizure frequency, whereas one patient had no significant reduction. Peaks in the alpha and/or beta frequency range were observed in the thalamic LFPs of each patient. Stimulation suppressed these LFP peaks in a dose-dependent manner. Chronic timeline data identified changes in LFP amplitude associated with stimulation, seizure occurrences, and medication changes. We also noticed a circadian pattern of LFP amplitudes in all patients. Button-presses during seizure events via a mobile application served as a digital seizure diary and were associated with elevations in LFP power. SIGNIFICANCE We describe an initial cohort of patients with DRE utilizing a novel sensing DBS device to characterize potential LFP biomarkers of epilepsy that may be associated with seizure control after DBS in DRE. We also present a new workflow utilizing the Percept device that may optimize DBS programming using real-time and chronic LFP recording.
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Affiliation(s)
- Melissa M J Chua
- Department of Neurosurgery, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts, USA
| | - Matteo Vissani
- Department of Neurosurgery, Massachusetts General Hospital, Harvard Medical School, Boston, Massachusetts, USA
| | - David D Liu
- Department of Neurosurgery, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts, USA
| | - Frederic L W V J Schaper
- Department of Neurology, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts, USA
| | - Aaron E L Warren
- Department of Neurosurgery, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts, USA
| | - Rose Caston
- Department of Biomedical Engineering, University of Utah, Salt Lake City, Utah, USA
- Department of Neurosurgery, University of Utah, Salt Lake City, Utah, USA
| | - Barbara A Dworetzky
- Department of Neurology, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts, USA
| | - Ellen J Bubrick
- Department of Neurology, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts, USA
| | - Rani A Sarkis
- Department of Neurology, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts, USA
| | - G Rees Cosgrove
- Department of Neurosurgery, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts, USA
| | - John D Rolston
- Department of Neurosurgery, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts, USA
- Department of Biomedical Engineering, University of Utah, Salt Lake City, Utah, USA
- Department of Neurosurgery, University of Utah, Salt Lake City, Utah, USA
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Besag FMC, Vasey MJ, Chin RFM. Current and emerging pharmacotherapy for the treatment of Lennox-Gastaut syndrome. Expert Opin Pharmacother 2023; 24:1249-1268. [PMID: 37212330 DOI: 10.1080/14656566.2023.2215924] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2023] [Accepted: 05/16/2023] [Indexed: 05/23/2023]
Abstract
INTRODUCTION Lennox-Gastaut syndrome (LGS) is a severe childhood-onset epileptic encephalopathy, characterized by multiple seizure types, generalized slow spike-and-wave complexes in the EEG, and cognitive impairment. Seizures in LGS are typically resistant to treatment with antiseizure medications (ASMs). Tonic/atonic ('drop') seizures are of particular concern, due to their liability to cause physical injury. AREAS COVERED We summarize evidence for current and emerging ASMs for the treatment of seizures in LGS. The review focuses on findings from randomized, double-blind, placebo-controlled trials (RDBCTs). For ASMs for which no double-blind trials were identified, lower quality evidence was considered. Novel pharmacological agents currently undergoing investigation for the treatment of LGS are also briefly discussed. EXPERT OPINION Evidence from RDBCTs supports the use of cannabidiol, clobazam, felbamate, fenfluramine, lamotrigine, rufinamide, and topiramate as adjunct treatments for drop seizures. Percentage decreases in drop seizure frequency ranged from 68.3% with high-dose clobazam to 14.8% with topiramate. Valproate continues to be considered the first-line treatment, despite the absence of RDBCTs specifically in LGS. Most individuals with LGS will require treatment with multiple ASMs. Treatment decisions should be individualized and take into account adverse effects, comorbidities, general quality of life, and drug interactions, as well as individual efficacy.
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Affiliation(s)
- Frank M C Besag
- East London NHS Foundation Trust, Bedford, UK
- School of Pharmacy, University College London, London, UK
- Department of Psychiatry, Psychology and Neuroscience, King's College London, London, UK
| | | | - Richard F M Chin
- Muir Maxwell Epilepsy Centre, The University of Edinburgh, Edinburgh, UK
- Department of Paediatric Neurosciences, Royal Hospital for Children and Young People, Edinburgh, UK
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Shlobin NA, Hofmann K, Cohen NT, Koubeissi MZ, Gaillard WD, Oluigbo CO. Deep Brain Stimulation of the Centromedian Nucleus of the Thalamus for Lennox-Gastaut Syndrome: A Systematic Review and Individual Patient Data Analysis. Neurosurgery 2023; 92:703-715. [PMID: 36700706 DOI: 10.1227/neu.0000000000002280] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2022] [Accepted: 09/29/2022] [Indexed: 01/27/2023] Open
Abstract
BACKGROUND Lennox-Gastaut syndrome (LGS) is a severe childhood-onset pharmacoresistant epilepsy. Deep brain stimulation (DBS) of the centromedian nucleus of the thalamus (CMN) has been utilized. OBJECTIVE To conduct a systematic review and individual patient data (IPD) analysis to characterize outcomes of DBS of CMN in LGS. METHODS PubMed, Embase, and Scopus were searched per Preferred Reporting Items for Systematic Reviews and Meta-Analyses. Articles were screened by title/abstract then full text. Included articles were reviewed for bibliographic, demographic, and outcome data. IPD were extracted from studies providing IPD for all patients. RESULTS Of 72 resultant articles, 10 studies (114 patients) were included. Six of 7 studies reporting the outcome of ≥50% seizure reduction indicated that ≥50% of patients achieved this, with improved functional ability. Seizure freedom rate was generally <10%. Six studies with 47 patients provided IPD. The mean ages at epilepsy onset and CMN DBS were 3.9 ± 4.5 years and 17.4 ± 8.8 years, respectively. Nineteen of 41 (46.3%) patients had positive MRI findings. Seizure types included atypical absence in 39 (83.0%) patients, generalized tonic-clonic in 32 (68.1%), tonic in 22 (46.8%), and atonic in 20 (42.6%). Thirty-eight (80.9%) patients experienced ≥50% reduction in seizure frequency, and only 3 (6.4%) experienced seizure freedom. The mean seizure reduction was 62.9% ± 31.2% overall. Quality of life improved in 30/34 (88.2%) and was unchanged in the remainder (11.8%). The complication rate was 2/41 (4.9%). The mean length of follow-up was 19.8 ± 26.1 months (IQR: 4-18 months). CONCLUSION Limited data indicate that DBS of the CMN may be effective and safe for people with LGS.
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Affiliation(s)
- Nathan A Shlobin
- Department of Neurological Surgery, Northwestern University Feinberg School of Medicine, Chicago, Illinois, USA
| | - Katherine Hofmann
- Deparment of Neurosurgery, Children's National Hospital, Washington, District of Columbia, USA
| | - Nathan T Cohen
- Department of Neurology, Children's National Hospital, Washington, District of Columbia, USA
| | - Mohamad Z Koubeissi
- Department of Neurology, The George Washington University, Washington, District of Columbia, USA
| | - William D Gaillard
- Department of Neurology, Children's National Hospital, Washington, District of Columbia, USA
| | - Chima O Oluigbo
- Deparment of Neurosurgery, Children's National Hospital, Washington, District of Columbia, USA
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14
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Lundstrom BN, Osman GM, Starnes K, Gregg NM, Simpson HD. Emerging approaches in neurostimulation for epilepsy. Curr Opin Neurol 2023; 36:69-76. [PMID: 36762660 PMCID: PMC9992108 DOI: 10.1097/wco.0000000000001138] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/11/2023]
Abstract
PURPOSE OF REVIEW Neurostimulation is a quickly growing treatment approach for epilepsy patients. We summarize recent approaches to provide a perspective on the future of neurostimulation. RECENT FINDINGS Invasive stimulation for treatment of focal epilepsy includes vagus nerve stimulation, responsive neurostimulation of the cortex and deep brain stimulation of the anterior nucleus of the thalamus. A wide range of other targets have been considered, including centromedian, central lateral and pulvinar thalamic nuclei; medial septum, nucleus accumbens, subthalamic nucleus, cerebellum, fornicodorsocommissure and piriform cortex. Stimulation for generalized onset seizures and mixed epilepsies as well as increased efforts focusing on paediatric populations have emerged. Hardware with more permanently implanted lead options and sensing capabilities is emerging. A wider variety of programming approaches than typically used may improve patient outcomes. Finally, noninvasive brain stimulation with its favourable risk profile offers the potential to treat increasingly diverse epilepsy patients. SUMMARY Neurostimulation for the treatment of epilepsy is surprisingly varied. Flexibility and reversibility of neurostimulation allows for rapid innovation. There remains a continued need for excitability biomarkers to guide treatment and innovation. Neurostimulation, a part of bioelectronic medicine, offers distinctive benefits as well as unique challenges.
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Affiliation(s)
| | | | - Keith Starnes
- Department of Neurology, Mayo Clinic, Rochester, Minnesota, USA
| | | | - Hugh D Simpson
- Department of Neurology, Alfred Health
- Department of Neuroscience, Central Clinical School, Monash University, Melbourne, Victoria, Australia
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15
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Balfroid T, Warren AE, Dalic LJ, Aeby A, Berlangieri SU, Archer JS. Frontoparietal 18F-FDG-PET hypo-metabolism in Lennox-Gastaut syndrome: further evidence highlighting the key network. Epilepsy Res 2023; 192:107131. [PMID: 37054522 DOI: 10.1016/j.eplepsyres.2023.107131] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2023] [Revised: 03/20/2023] [Accepted: 03/27/2023] [Indexed: 03/31/2023]
Abstract
INTRODUCTION Lennox Gastaut syndrome (LGS) can be conceptualised as a "secondary network epilepsy", in which the shared electroclinical manifestations reflect epileptic recruitment of a common brain network, despite a range of underlying aetiologies. We aimed to identify the key networks recruited by the epileptic process of LGS using interictal 2-deoxy-2-(18F)fluoro-D-glucose positron emission tomography (18F-FDG-PET). METHODS Group analysis of cerebral 18F-FDG-PET, comparing 21 patients with LGS (mean age = 15 years) and 18 pseudo-controls (mean age = 19 years), studied at Austin Health Melbourne, between 2004 and 2015. To minimise the influence of individual patient lesions in the LGS group, we only studied brain hemispheres without structural MRI abnormalities. The pseudo-control group consisted of age- and sex-matched patients with unilateral temporal lobe epilepsy, using only the hemispheres contralateral to the side of epilepsy. Voxel-wise permutation testing compared 18F-FDG-PET uptake between groups. Associations were explored between areas of altered metabolism and clinical variables (age of seizure onset, proportion of life with epilepsy, and verbal/nonverbal ability). Penetrance maps were calculated to explore spatial consistency of altered metabolic patterns across individual patients with LGS. RESULTS Although not always readily apparent on visual inspection of individual patient scans, group analysis revealed hypometabolism in a network of regions including prefrontal and premotor cortex, anterior and posterior cingulate, inferior parietal lobule, and precuneus (p < 0.05, corrected for family-wise error). These brain regions tended to show a greater reduction in metabolism in non-verbal compared to verbal LGS patients, although this difference was not statistically significant. No areas of hypermetabolism were detected on group analysis, although ∼25 % of individual patients showed increased metabolism (relative to pseudo-controls) in the brainstem, putamen, thalamus, cerebellum, and pericentral cortex. DISCUSSION Interictal hypometabolism in frontoparietal cortex in LGS is compatible with our previous EEG-fMRI and SPECT studies showing that interictal bursts of generalised paroxysmal fast activity and tonic seizures recruit similar cortical regions. This study provides further evidence that these regions are central to the electroclinical expression of LGS.
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16
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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: 4] [Impact Index Per Article: 4.0] [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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17
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Dalic LJ, Warren AEL, Spiegel C, Thevathasan W, Roten A, Bulluss KJ, Archer JS. Paroxysmal fast activity is a biomarker of treatment response in deep brain stimulation for Lennox-Gastaut syndrome. Epilepsia 2022; 63:3134-3147. [PMID: 36114808 PMCID: PMC10946931 DOI: 10.1111/epi.17414] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2022] [Revised: 09/15/2022] [Accepted: 09/16/2022] [Indexed: 01/11/2023]
Abstract
OBJECTIVE Epilepsy treatment trials typically rely on seizure diaries to determine seizure frequency, but these are time-consuming and difficult to maintain accurately. Fast, reliable, and objective biomarkers of treatment response are needed, particularly in Lennox-Gastaut syndrome (LGS), where high seizure frequency and comorbid cognitive and behavioral issues are additional obstacles to accurate diary-keeping. Here, we measured generalized paroxysmal fast activity (GPFA), a key interictal electrographic feature of LGS, and correlated GPFA burden with seizure diaries during a thalamic deep brain stimulation (DBS) treatment trial (Electrical Stimulation of the Thalamus in Epilepsy of Lennox-Gastaut Phenotype [ESTEL]). METHODS GPFA and electrographic seizure counts from intermittent, 24-h electroencephalograms (EEGs) were compared to 3-month diary-recorded seizure counts in 17 young adults with LGS (mean age ± SD = 24.9 ± 6.6) in the ESTEL study, a randomized clinical trial of DBS lasting 12 months (comprising a 3-month baseline and 9 months of postimplantation follow-up). RESULTS Baseline median seizures measured by diaries numbered 2.6 (interquartile range [IQR] = 1.4-5) per day, compared to 284 (IQR = 120.5-360) electrographic seizures per day, confirming that diaries capture only a small fraction of seizure burden. Across all patient EEGs, the average number of GPFA discharges per hour of sleep was 138 (IQR =72-258). GPFA duration and frequency, quantified over 2-h windows of sleep EEG, were significantly associated with diary-recorded seizure counts over 3-month intervals (p < .001, η2 p = .30-.48). For every GPFA discharge, there were 20-25 diary seizures witnessed over 3 months. There was high between-patient variability in the ratio between diary seizure burden and GPFA burden; however, within individual patients, the ratio was similar over time, such that the percentage change from pre-DBS baseline in seizure diaries strongly correlated with the percentage change in GPFA. SIGNIFICANCE When seeking to optimize treatment in patients with LGS, monitoring changes in GPFA may allow rapid titration of treatment parameters, rather than waiting for feedback from seizure diaries.
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Affiliation(s)
- Linda J. Dalic
- Department of Medicine, Austin HealthUniversity of MelbourneHeidelbergVictoriaAustralia
- Department of Neurology, Austin HealthHeidelbergVictoriaAustralia
| | - Aaron E. L. Warren
- Department of Medicine, Austin HealthUniversity of MelbourneHeidelbergVictoriaAustralia
- The Florey Institute of Neuroscience and Mental HealthHeidelbergVictoriaAustralia
- Murdoch Children's Research InstituteParkvilleVictoriaAustralia
| | - Chloe Spiegel
- Department of Neurology, Austin HealthHeidelbergVictoriaAustralia
| | - Wesley Thevathasan
- Department of Medicine, Austin HealthUniversity of MelbourneHeidelbergVictoriaAustralia
- Bionics InstituteEast MelbourneVictoriaAustralia
- Department of MedicineUniversity of Melbourne, and Department of Neurology, Royal Melbourne HospitalParkvilleVictoriaAustralia
| | - Annie Roten
- Department of Neurology, Austin HealthHeidelbergVictoriaAustralia
| | - Kristian J. Bulluss
- Bionics InstituteEast MelbourneVictoriaAustralia
- Department of Neurosurgery, Austin HealthHeidelbergVictoriaAustralia
- Department of SurgeryUniversity of MelbourneParkvilleVictoriaAustralia
| | - John S. Archer
- Department of Medicine, Austin HealthUniversity of MelbourneHeidelbergVictoriaAustralia
- Department of Neurology, Austin HealthHeidelbergVictoriaAustralia
- The Florey Institute of Neuroscience and Mental HealthHeidelbergVictoriaAustralia
- Murdoch Children's Research InstituteParkvilleVictoriaAustralia
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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: 48] [Impact Index Per Article: 24.0] [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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Alanazi RF, Alkhani AM. Management of Lennox-Gastaut syndrome with deep brain stimulation: A systematic literature review. NEUROSCIENCES (RIYADH, SAUDI ARABIA) 2022; 27:216-220. [PMID: 36252974 PMCID: PMC9749582 DOI: 10.17712/nsj.2022.4.20220043] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/17/2022] [Accepted: 07/06/2022] [Indexed: 12/31/2022]
Abstract
OBJECTIVES To review the current literature regarding the efficacy and safety of deep brain stimulation (DBS) in Lennox-Gastaut syndrome (LGS). METHODS The authors conducted a systematic review of PubMed databases using keywords relevant to the objective of this research. Titles and abstracts were reviewed, after which studies that met the inclusion criteria were selected. Findings were reported according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. RESULTS Thirteen studies were identified, and only 3 studies that reported 50 patients (age range from 3 to 65 years) met the inclusion criteria of DBS for LGS. Radiological imaging findings and neurophysiological findings were described in all studies. The thalamus nuclei, particularly the centromedian thalamic nucleus (CMN), were found to be highly active in LGS. By targeting this brain region, patients showed favorable outcomes. Overall, the mean seizure reduction was more than 50% in all patients (among whom 2 were seizure free) at a mean follow-up of 15 (12-18) months. CONCLUSION According to this systemic review, DBS for LGS showed satisfactory outcomes, indicating that DBS should be considered a valid treatment option. However, more studies are needed to ensure the role of DBS in LGS by establishing accurate targeting of the CMN using proper lead positioning and radiological imaging, a standard DBS intervention, and long-term outcomes.
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Affiliation(s)
- Rahaf F. Alanazi
- From the College of Medicine (Alanazi), King Saud Bin Abdulaziz University for Health Sciences, and from the Division of Neurosurgery (Alkhani), Department of Surgery, King Abdulaziz Medical City, Ministry of the National Guard–Health Affairs, Riyadh, Kingdom of Saudi Arabia.,Address correspondence and reprint request to: Dr. Rahaf F. Alanazi, College of Medicine, King Saud Bin Abdulaziz University for Health Sciences, Riyadh, Kingdom of Saudi Arabia. E-mail: ORCID ID: https://orcid.org/0000-0003-0094-5453
| | - Ahmed M. Alkhani
- From the College of Medicine (Alanazi), King Saud Bin Abdulaziz University for Health Sciences, and from the Division of Neurosurgery (Alkhani), Department of Surgery, King Abdulaziz Medical City, Ministry of the National Guard–Health Affairs, Riyadh, Kingdom of Saudi Arabia.
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