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Nobili L, Cordani R, Arnaldi D, Mattioli P, Veneruso M, Ng M. Rapid eye movement sleep and epilepsy: exploring interactions and therapeutic prospects. J Sleep Res 2024:e14251. [PMID: 38842061 DOI: 10.1111/jsr.14251] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2024] [Revised: 03/21/2024] [Accepted: 05/07/2024] [Indexed: 06/07/2024]
Abstract
While research interest in the relationship between sleep and epilepsy is growing, it primarily centres on the effects of non-rapid eye movement (NREM) sleep in favouring seizures. Nonetheless, a noteworthy aspect is the observation that, in the lives of patients with epilepsy, REM sleep represents the moment with the least epileptic activity and the lowest probability of having a seizure. Studies demonstrate a suppressive effect of phasic REM sleep on interictal epileptiform discharges, potentially offering insights into epilepsy localisation and management. Furthermore, epilepsy impacts REM sleep, with successful treatment correlating with improved REM sleep quality. Novel therapeutic strategies aim to harness REM's anti-epileptic effects, including pharmacological approaches targeting orexinergic systems and neuromodulation techniques promoting cortical desynchronisation. These findings underscore the intricate relationship between REM sleep and epilepsy, highlighting avenues for further research and therapeutic innovation in epilepsy management.
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Affiliation(s)
- Lino Nobili
- Child Neuropsychiatry Unit, IRCCS Istituto Giannina Gaslini, Member of the European Reference Network EpiCARE, Genoa, Italy
- Department of Neuroscience, Rehabilitation, Ophthalmology, Genetics, Child and Maternal Health (DINOGMI), University of Genoa, Genoa, Italy
| | - Ramona Cordani
- Child Neuropsychiatry Unit, IRCCS Istituto Giannina Gaslini, Member of the European Reference Network EpiCARE, Genoa, Italy
- Department of Neuroscience, Rehabilitation, Ophthalmology, Genetics, Child and Maternal Health (DINOGMI), University of Genoa, Genoa, Italy
| | - Dario Arnaldi
- Department of Neuroscience, Rehabilitation, Ophthalmology, Genetics, Child and Maternal Health (DINOGMI), University of Genoa, Genoa, Italy
- Neurophysiopathology Unit, IRCCS Ospedale Policlinico San Martino, Genoa, Italy
| | - Pietro Mattioli
- Department of Neuroscience, Rehabilitation, Ophthalmology, Genetics, Child and Maternal Health (DINOGMI), University of Genoa, Genoa, Italy
- Neurophysiopathology Unit, IRCCS Ospedale Policlinico San Martino, Genoa, Italy
| | - Marco Veneruso
- Child Neuropsychiatry Unit, IRCCS Istituto Giannina Gaslini, Member of the European Reference Network EpiCARE, Genoa, Italy
- Department of Neuroscience, Rehabilitation, Ophthalmology, Genetics, Child and Maternal Health (DINOGMI), University of Genoa, Genoa, Italy
| | - Marcus Ng
- Biomedical Engineering, University of Manitoba, Winnipeg, Manitoba, Canada
- Section of Neurology, University of Manitoba, Winnipeg, Manitoba, Canada
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Marano M, Anzini G, Saltarocchi L, Ricciuti R, Capone F, Tan H, Torrecillos F, Lanzone J, Lazzaro VD. Left Vagus Stimulation Modulates Contralateral Subthalamic β Power Improving the Gait in Parkinson's Disease. Mov Disord 2024; 39:424-428. [PMID: 38111224 PMCID: PMC7615838 DOI: 10.1002/mds.29690] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2023] [Revised: 11/09/2023] [Accepted: 11/28/2023] [Indexed: 12/20/2023] Open
Abstract
BACKGROUND Transcutaneous vagus nerve stimulation (VNS) showed early evidence of efficacy for the gait treatment of Parkinson's disease (PD). OBJECTIVES Providing data on neurophysiological and clinical effects of transauricular VNS (taVNS). METHODS Ten patients with recording deep brain stimulation (DBS) have been enrolled in a within participant design pilot study, double-blind crossover sham-controlled trial of taVNS. Subthalamic local field potentials (β band power), Unified Parkinson's Disease Rating Scales (UPDRS), and a digital timed-up-and-go test (TUG) were measured and compared with real versus sham taVNS during medication-off/DBS-OFF condition. RESULTS The left taVNS induced a reduction of the total β power in the contralateral (ie, right) subthalamic nucleus and an improvement of TUG time, speed, and variability. The taVNS-induced β reduction correlated with the improvement of gait speed. No major clinical changes were observed at UPDRS. CONCLUSIONS taVNS is a promising strategy for the management of PD gait, deserving prospective trials of chronic neuromodulation. © 2023 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.
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Affiliation(s)
- Massimo Marano
- Unit of Neurology, Neurophysiology, Neurobiology and Psychiatry, Department of Medicine and Surgery, Università Campus Bio-Medico di Roma, Roma, Italy
- Fondazione Policlinico Universitario Campus Bio-Medico, Roma, Italy
| | - Gaia Anzini
- Unit of Neurology, Neurophysiology, Neurobiology and Psychiatry, Department of Medicine and Surgery, Università Campus Bio-Medico di Roma, Roma, Italy
- Fondazione Policlinico Universitario Campus Bio-Medico, Roma, Italy
| | - Luca Saltarocchi
- Unit of Neurology, Neurophysiology, Neurobiology and Psychiatry, Department of Medicine and Surgery, Università Campus Bio-Medico di Roma, Roma, Italy
| | - Riccardo Ricciuti
- Neurosurgery Unit, Ospedale Belcolle, ASL di Viterbo, Viterbo, Italy
| | - Fioravante Capone
- Unit of Neurology, Neurophysiology, Neurobiology and Psychiatry, Department of Medicine and Surgery, Università Campus Bio-Medico di Roma, Roma, Italy
- Fondazione Policlinico Universitario Campus Bio-Medico, Roma, Italy
| | - Huiling Tan
- Medical Research Council Brain Network Dynamics Unit, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, United Kingdom
| | - Flavie Torrecillos
- Medical Research Council Brain Network Dynamics Unit, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, United Kingdom
| | - Jacopo Lanzone
- Department of the Neurorehabilitation, Istituti Clinici Scientifici Maugeri IRCCS, Milano Institute, Milan, Italy
| | - Vincenzo Di Lazzaro
- Unit of Neurology, Neurophysiology, Neurobiology and Psychiatry, Department of Medicine and Surgery, Università Campus Bio-Medico di Roma, Roma, Italy
- Fondazione Policlinico Universitario Campus Bio-Medico, Roma, Italy
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3
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Khambhati AN. Utility of Chronic Intracranial Electroencephalography in Responsive Neurostimulation Therapy. Neurosurg Clin N Am 2024; 35:125-133. [PMID: 38000836 DOI: 10.1016/j.nec.2023.09.004] [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] [Indexed: 11/26/2023]
Abstract
Responsive neurostimulation (RNS) therapy is an effective treatment for reducing seizures in some patients with focal epilepsy. Utilizing a chronically implanted device, RNS involves monitoring brain activity signals for user-defined patterns of seizure activity and delivering electrical stimulation in response. Devices store chronic data including counts of detected activity patterns and brief recordings of intracranial electroencephalography signals. Data platforms for reviewing stored chronic data retrospectively may be used to evaluate therapy performance and to fine-tune detection and stimulation settings. New frontiers in RNS research can leverage raw chronic data to reverse engineer neurostimulation mechanisms and improve therapy effectiveness.
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Affiliation(s)
- Ankit N Khambhati
- Department of Neurosurgery, Weill Institute for Neurosciences, University of California, San Francisco, Joan and Sanford I. Weill Neurosciences Building, 1651 4th Street, 671C, San Francisco, CA 94158, USA.
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Furlanis GM, Favaro J, Bresolin N, Grioni D, Baro V, D’Amico A, Sartori S, Denaro L, Landi A. Role of Vagus Nerve Stimulation in Refractory and Super Refractory Status Epilepticus: A Pediatric Case Series. Brain Sci 2023; 13:1589. [PMID: 38002548 PMCID: PMC10669853 DOI: 10.3390/brainsci13111589] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2023] [Revised: 10/31/2023] [Accepted: 11/08/2023] [Indexed: 11/26/2023] Open
Abstract
BACKGROUND Status epilepticus is a life-threatening condition that is defined as refractory (RSE) when the seizure activity continues despite treatment with benzodiazepine and a second appropriate treatment. Super refractory status epilepticus (SRSE) is an RSE that persists or recurs for ≥24 h. Few papers have reported the outcomes of pediatric patients affected by RSE and SRSE and treated with neuromodulation therapies. Vagus nerve stimulation (VNS) is an approved treatment for drug-resistant epilepsy. We present our findings of pediatric patients treated with VNS for RSE/SRSE. METHODS We present a case series of seven consecutive pediatric patients treated with VNS for SRSE since 2012 by a single surgeon in Monza and Padua. A rapid titration was started soon after implantation. We considered electroclinical data before and after VNS implantation and at the last follow-up. RESULTS We achieved the resolution of SRSE in five out of seven patients in a mean time of two weeks. At the last follow-up, these patients had a significant reduction of seizure burden without any relapse of SE. DISCUSSION AND CONCLUSIONS Based on our limited findings, we discuss the potential role of VNS therapy in similar but distinct clinical contexts. For patients with drug-resistant epilepsy and RSE/SRSE, prompt VNS consideration is suggested, offering rapid responses and potentially reducing pharmacological load. Meanwhile, in NORSE/FIRES, we suggest early neuromodulation during the acute phase if standard treatments prove ineffective or not tolerated. This approach may leverage VNS's potential anti-inflammatory effects and neuromodulation, enhancing patient-specific treatments. Expanding case studies and prolonged follow-ups are recommended to strengthen these clinical insights.
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Affiliation(s)
- Giulia Melinda Furlanis
- Pediatric and Functional Neurosurgery, Department of Neuroscience, Padua University Hospital, via Giustiniani 5, 35127 Padova, Italy; (G.M.F.); (A.L.)
| | - Jacopo Favaro
- Neurology and Neurophysiology Unit, Department of Women’s and Children’s Health, Padua University Hospital, 35128 Padova, Italy; (J.F.)
| | - Nicola Bresolin
- Pediatric and Functional Neurosurgery, Department of Neuroscience, Padua University Hospital, via Giustiniani 5, 35127 Padova, Italy; (G.M.F.); (A.L.)
| | | | - Valentina Baro
- Pediatric and Functional Neurosurgery, Department of Neuroscience, Padua University Hospital, via Giustiniani 5, 35127 Padova, Italy; (G.M.F.); (A.L.)
| | - Alberto D’Amico
- Pediatric and Functional Neurosurgery, Department of Neuroscience, Padua University Hospital, via Giustiniani 5, 35127 Padova, Italy; (G.M.F.); (A.L.)
| | - Stefano Sartori
- Neurology and Neurophysiology Unit, Department of Women’s and Children’s Health, Padua University Hospital, 35128 Padova, Italy; (J.F.)
| | - Luca Denaro
- Pediatric and Functional Neurosurgery, Department of Neuroscience, Padua University Hospital, via Giustiniani 5, 35127 Padova, Italy; (G.M.F.); (A.L.)
| | - Andrea Landi
- Pediatric and Functional Neurosurgery, Department of Neuroscience, Padua University Hospital, via Giustiniani 5, 35127 Padova, Italy; (G.M.F.); (A.L.)
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Sklenarova B, Chladek J, Macek M, Brazdil M, Chrastina J, Jurkova T, Burilova P, Plesinger F, Zatloukalova E, Dolezalova I. Entropy in scalp EEG can be used as a preimplantation marker for VNS efficacy. Sci Rep 2023; 13:18849. [PMID: 37914788 PMCID: PMC10620210 DOI: 10.1038/s41598-023-46113-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2023] [Accepted: 10/27/2023] [Indexed: 11/03/2023] Open
Abstract
Vagus nerve stimulation (VNS) is a therapeutic option in drug-resistant epilepsy. VNS leads to ≥ 50% seizure reduction in 50 to 60% of patients, termed "responders". The remaining 40 to 50% of patients, "non-responders", exhibit seizure reduction < 50%. Our work aims to differentiate between these two patient groups in preimplantation EEG analysis by employing several Entropy methods. We identified 59 drug-resistant epilepsy patients treated with VNS. We established their response to VNS in terms of responders and non-responders. A preimplantation EEG with eyes open/closed, photic stimulation, and hyperventilation was found for each patient. The EEG was segmented into eight time intervals within four standard frequency bands. In all, 32 EEG segments were obtained. Seven Entropy methods were calculated for all segments. Subsequently, VNS responders and non-responders were compared using individual Entropy methods. VNS responders and non-responders differed significantly in all Entropy methods except Approximate Entropy. Spectral Entropy revealed the highest number of EEG segments differentiating between responders and non-responders. The most useful frequency band distinguishing responders and non-responders was the alpha frequency, and the most helpful time interval was hyperventilation and rest 4 (the end of EEG recording).
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Affiliation(s)
- B Sklenarova
- Brno Epilepsy Center, First Department of Neurology, Member of ERN-Epicar, St. Anne's University Hospital and Faculty of Medicine, Masaryk University, Pekařská 53, 602 00, Brno, Czech Republic
- International Clinical Research Center, St. Anne's University Hospital, Brno, Czech Republic
| | - J Chladek
- Brno Epilepsy Center, First Department of Neurology, Member of ERN-Epicar, St. Anne's University Hospital and Faculty of Medicine, Masaryk University, Pekařská 53, 602 00, Brno, Czech Republic
- Institute of Scientific Instruments, Czech Academy of Sciences, Brno, Czech Republic
- Behavioral and Social Neuroscience Research Group, CEITEC-Central European Institute of Technology, Masaryk University, Brno, Czech Republic
| | - M Macek
- Institute of Scientific Instruments, Czech Academy of Sciences, Brno, Czech Republic
| | - M Brazdil
- Brno Epilepsy Center, First Department of Neurology, Member of ERN-Epicar, St. Anne's University Hospital and Faculty of Medicine, Masaryk University, Pekařská 53, 602 00, Brno, Czech Republic
- Behavioral and Social Neuroscience Research Group, CEITEC-Central European Institute of Technology, Masaryk University, Brno, Czech Republic
| | - J Chrastina
- Brno Epilepsy Center, Department of Neurosurgery, St. Anne's University Hospital and Masaryk University, Brno, Czech Republic
| | - T Jurkova
- Institute of Biostatistics and Analyses, Faculty of Medicine, Masaryk University, Brno, Czech Republic
| | - P Burilova
- Department of Health Sciences, Faculty of Medicine, Masaryk University, Brno, Czech Republic
| | - F Plesinger
- Institute of Scientific Instruments, Czech Academy of Sciences, Brno, Czech Republic
| | - E Zatloukalova
- Brno Epilepsy Center, First Department of Neurology, Member of ERN-Epicar, St. Anne's University Hospital and Faculty of Medicine, Masaryk University, Pekařská 53, 602 00, Brno, Czech Republic
- International Clinical Research Center, St. Anne's University Hospital, Brno, Czech Republic
| | - I Dolezalova
- Brno Epilepsy Center, First Department of Neurology, Member of ERN-Epicar, St. Anne's University Hospital and Faculty of Medicine, Masaryk University, Pekařská 53, 602 00, Brno, Czech Republic.
- International Clinical Research Center, St. Anne's University Hospital, Brno, Czech Republic.
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Carron R, Roncon P, Lagarde S, Dibué M, Zanello M, Bartolomei F. Latest Views on the Mechanisms of Action of Surgically Implanted Cervical Vagal Nerve Stimulation in Epilepsy. Neuromodulation 2022; 26:498-506. [PMID: 36064522 DOI: 10.1016/j.neurom.2022.08.447] [Citation(s) in RCA: 19] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2022] [Revised: 07/05/2022] [Accepted: 08/01/2022] [Indexed: 11/25/2022]
Abstract
BACKGROUND Vagus nerve stimulation (VNS) is approved as an adjunctive treatment for drug-resistant epilepsy. Although there is a substantial amount of literature aiming at unraveling the mechanisms of action of VNS in epilepsy, it is still unclear how the cascade of events triggered by VNS leads to its antiepileptic effect. OBJECTIVE In this review, we integrated available peer-reviewed data on the effects of VNS in clinical and experimental research to identify those that are putatively responsible for its therapeutic effect. The topic of transcutaneous VNS will not be covered owing to the current lack of data supporting the differences and commonalities of its mechanisms of action in relation to invasive VNS. SUMMARY OF THE MAIN FINDINGS There is compelling evidence that the effect is obtained through the stimulation of large-diameter afferent myelinated fibers that project to the solitary tract nucleus, then to the parabrachial nucleus, which in turn alters the activity of the limbic system, thalamus, and cortex. VNS-induced catecholamine release from the locus coeruleus in the brainstem plays a pivotal role. Functional imaging studies tend to point toward a common vagal network that comes into play, made up of the amygdalo-hippocampal regions, left thalamus, and insular cortex. CONCLUSIONS Even though some crucial pieces are missing, neurochemical, molecular, cellular, and electrophysiological changes occur within the vagal afferent network at three main levels (the brainstem, the limbic system [amygdala and hippocampus], and the cortex). At this final level, VNS notably alters functional connectivity, which is known to be abnormally high within the epileptic zone and was shown to be significantly decreased by VNS in responders. The effect of crucial VNS parameters such as frequency or current amplitude on functional connectivity metrics is of utmost importance and requires further investigation.
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Concurrent brain-responsive and vagus nerve stimulation for treatment of drug-resistant focal epilepsy. Epilepsy Behav 2022; 129:108653. [PMID: 35305525 PMCID: PMC9339206 DOI: 10.1016/j.yebeh.2022.108653] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/21/2021] [Revised: 02/12/2022] [Accepted: 02/26/2022] [Indexed: 02/08/2023]
Abstract
OBJECTIVE Clinical trials of a brain-responsive neurostimulator, RNS® System (RNS), excluded patients with a vagus nerve stimulator, VNS® System (VNS). The goal of this study was to evaluate seizure outcomes and safety of concurrent RNS and VNS stimulation in adults with drug-resistant focal-onset seizures. METHODS A retrospective multicenter chart review was performed on all patients with an active VNS and RNS who were treated for a minimum of 6 months with both systems concurrently. Frequency of disabling seizures at baseline before RNS, at 1 year after RNS placement, and at last follow-up were used to calculate the change in seizure frequency after treatment. Data on adverse events and complications related to each device were collected. RESULTS Sixty-four patients from 10 epilepsy centers met inclusion criteria. All but one patient received RNS after VNS. The median follow-up time after RNS implantation was 28 months. Analysis of the entire population of patients with active VNS and RNS systems revealed a median reduction in seizure frequency at 1 year post-RNS placement of 43% with a responder rate of 49%, and at last follow-up a 64% median reduction with a 67% responder rate. No negative interactions were reported from the concurrent use of VNS and RNS. Stimulation-related side-effects were reported more frequently in association with VNS (30%) than with RNS (2%). SIGNIFICANCE Our findings suggest that concurrent treatment with VNS and RNS is safe and that the addition of RNS to VNS can further reduce seizure frequency.
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Afra P, Adamolekun B, Aydemir S, Watson GDR. Evolution of the Vagus Nerve Stimulation (VNS) Therapy System Technology for Drug-Resistant Epilepsy. FRONTIERS IN MEDICAL TECHNOLOGY 2022; 3:696543. [PMID: 35047938 PMCID: PMC8757869 DOI: 10.3389/fmedt.2021.696543] [Citation(s) in RCA: 24] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2021] [Accepted: 06/10/2021] [Indexed: 12/14/2022] Open
Abstract
The vagus nerve stimulation (VNS) Therapy® System is the first FDA-approved medical device therapy for the treatment of drug-resistant epilepsy. Over the past two decades, the technology has evolved through multiple iterations resulting in software-related updates and implantable lead and generator hardware improvements. Healthcare providers today commonly encounter a range of single- and dual-pin generators (models 100, 101, 102, 102R, 103, 104, 105, 106, 1000) and related programming systems (models 250, 3000), all of which have their own subtle, but practical differences. It can therefore be a daunting task to go through the manuals of these implant models for comparison, some of which are not readily available. In this review, we highlight the technological evolution of the VNS Therapy System with respect to device approval milestones and provide a comparison of conventional open-loop vs. the latest closed-loop generator models. Battery longevity projections and an in-depth examination of stimulation mode interactions are also presented to further differentiate amongst generator models.
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Affiliation(s)
- Pegah Afra
- Department of Neurology, Weill-Cornell Medicine, New York, NY, United States.,Department of Neurology, University of Utah School of Medicine, Salt Lake City, UT, United States
| | - Bola Adamolekun
- Department of Neurology, University of Tennessee Health Science Center, Memphis, TN, United States
| | - Seyhmus Aydemir
- Department of Neurology, Weill-Cornell Medicine, New York, NY, United States
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Human intracranial recordings reveal distinct cortical activity patterns during invasive and non-invasive vagus nerve stimulation. Sci Rep 2021; 11:22780. [PMID: 34815529 PMCID: PMC8611055 DOI: 10.1038/s41598-021-02307-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2021] [Accepted: 11/12/2021] [Indexed: 12/26/2022] Open
Abstract
Vagus nerve stimulation (VNS) is being used increasingly to treat a wide array of diseases and disorders. This growth is driven in part by the putative ability to stimulate the nerve non-invasively. Despite decades of use and a rapidly expanding application space, we lack a complete understanding of the acute effects of VNS on human cortical neurophysiology. Here, we investigated cortical responses to sub-perceptual threshold cervical implanted (iVNS) and transcutaneous auricular (taVNS) vagus nerve stimulation using intracranial neurophysiological recordings in human epilepsy patients. To understand the areas that are modulated by VNS and how they differ depending on invasiveness and stimulation parameters, we compared VNS-evoked neural activity across a range of stimulation modalities, frequencies, and amplitudes. Using comparable stimulation parameters, both iVNS and taVNS caused subtle changes in low-frequency power across broad cortical networks, which were not the same across modalities and were highly variable across participants. However, within at least some individuals, it may be possible to elicit similar responses across modalities using distinct sets of stimulation parameters. These results demonstrate that both invasive and non-invasive VNS cause evoked changes in activity across a set of highly distributed cortical networks that are relevant to a diverse array of clinical, rehabilitative, and enhancement applications.
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10
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Rao VR. Chronic electroencephalography in epilepsy with a responsive neurostimulation device: current status and future prospects. Expert Rev Med Devices 2021; 18:1093-1105. [PMID: 34696676 DOI: 10.1080/17434440.2021.1994388] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
INTRODUCTION Implanted neurostimulation devices are gaining traction as therapeutic options for people with certain forms of drug-resistant focal epilepsy. Some of these devices enable chronic electroencephalography (cEEG), which offers views of the dynamics of brain activity in epilepsy over unprecedented time horizons. AREAS COVERED This review focuses on clinical insights and basic neuroscience discoveries enabled by analyses of cEEG from an exemplar device, the NeuroPace RNS® System. Applications of RNS cEEG covered here include counting and lateralizing seizures, quantifying medication response, characterizing spells, forecasting seizures, and exploring mechanisms of cognition. Limitations of the RNS System are discussed in the context of next-generation devices in development. EXPERT OPINION The wide temporal lens of cEEG helps capture the dynamism of epilepsy, revealing phenomena that cannot be appreciated with short duration recordings. The RNS System is a vanguard device whose diagnostic utility rivals its therapeutic benefits, but emerging minimally invasive devices, including those with subscalp recording electrodes, promise to be more applicable within a broad population of people with epilepsy. Epileptology is on the precipice of a paradigm shift in which cEEG is a standard part of diagnostic evaluations and clinical management is predicated on quantitative observations integrated over long timescales.
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Affiliation(s)
- Vikram R Rao
- Associate Professor of Clinical Neurology, Chief, Epilepsy Division, Department of Neurology and Weill Institute for Neurosciences, University of California, San Francisco, CA, USA
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11
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Vespa S, Heyse J, Stumpp L, Liberati G, Ferrao Santos S, Rooijakkers H, Nonclercq A, Mouraux A, van Mierlo P, El Tahry R. Vagus Nerve Stimulation Elicits Sleep EEG Desynchronization and Network Changes in Responder Patients in Epilepsy. Neurotherapeutics 2021; 18:2623-2638. [PMID: 34668148 PMCID: PMC8804116 DOI: 10.1007/s13311-021-01124-4] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/06/2021] [Indexed: 12/23/2022] Open
Abstract
Neural desynchronization was shown as a key mechanism of vagus nerve stimulation (VNS) action in epilepsy, and EEG synchronization measures are explored as possible response biomarkers. Since brain functional organization in sleep shows different synchrony and network properties compared to wakefulness, we aimed to explore the effects of acute VNS on EEG-derived measures in the two different states of vigilance. EEG epochs were retrospectively analyzed from twenty-four VNS-treated epileptic patients (11 responders, 13 non-responders) in calm wakefulness and stage N2 sleep. Weighted Phase Lag Index (wPLI) was computed as connectivity measure of synchronization, for VNS OFF and VNS ON conditions. Global efficiency (GE) was computed as a network measure of integration. Ratios OFF/ON were obtained as desynchronization/de-integration index. Values were compared between responders and non-responders, and between EEG states. ROC curve and area-under-the-curve (AUC) analysis was performed for response classification. In responders, stronger VNS-induced theta desynchronization (p < 0.05) and decreased GE (p < 0.05) were found in sleep, but not in wakefulness. Theta sleep wPLI Ratio OFF/ON yielded an AUC of 0.825, and 79% accuracy as a response biomarker if a cut-off value is set at 1.05. Considering all patients, the VNS-induced GE decrease was significantly more important in sleep compared to awake EEG state (p < 0.01). In conclusion, stronger sleep EEG desynchronization in theta band distinguishes responders to VNS therapy from non-responders. VNS-induced reduction of network integration occurs significantly more in sleep than in wakefulness.
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Affiliation(s)
- Simone Vespa
- Institute of Neuroscience (IONS), Université Catholique de Louvain, Avenue Mounier, 53 - 1200, Brussels, Belgium.
| | - Jolan Heyse
- Medical Image and Signal Processing Group (MEDISIP), Ghent University, Ghent, Belgium
| | - Lars Stumpp
- Institute of Neuroscience (IONS), Université Catholique de Louvain, Avenue Mounier, 53 - 1200, Brussels, Belgium
| | - Giulia Liberati
- Institute of Neuroscience (IONS), Université Catholique de Louvain, Avenue Mounier, 53 - 1200, Brussels, Belgium
| | - Susana Ferrao Santos
- Institute of Neuroscience (IONS), Université Catholique de Louvain, Avenue Mounier, 53 - 1200, Brussels, Belgium
- Centre for Refractory Epilepsy, Department of Neurology, Cliniques Universitaires Saint-Luc, Brussels, Belgium
| | - Herbert Rooijakkers
- Centre for Refractory Epilepsy, Department of Neurology, Cliniques Universitaires Saint-Luc, Brussels, Belgium
| | - Antoine Nonclercq
- Bio, Electro and Mechanical Systems (BEAMS), Université Libre de Bruxelles, Brussels, Belgium
| | - André Mouraux
- Institute of Neuroscience (IONS), Université Catholique de Louvain, Avenue Mounier, 53 - 1200, Brussels, Belgium
| | - Pieter van Mierlo
- Medical Image and Signal Processing Group (MEDISIP), Ghent University, Ghent, Belgium
| | - Riëm El Tahry
- Institute of Neuroscience (IONS), Université Catholique de Louvain, Avenue Mounier, 53 - 1200, Brussels, Belgium
- Centre for Refractory Epilepsy, Department of Neurology, Cliniques Universitaires Saint-Luc, Brussels, Belgium
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Silva AB, Khambhati AN, Speidel BA, Chang EF, Rao VR. Effects of anterior thalamic nuclei stimulation on hippocampal activity: Chronic recording in a patient with drug-resistant focal epilepsy. Epilepsy Behav Rep 2021; 16:100467. [PMID: 34458713 PMCID: PMC8379668 DOI: 10.1016/j.ebr.2021.100467] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2021] [Revised: 06/24/2021] [Accepted: 06/26/2021] [Indexed: 11/12/2022] Open
Abstract
Devices for RNS and thalamic DBS were implanted in a single person with epilepsy. RNS electrocorticography enabled characterization of acute and chronic DBS effects. DBS caused acute, phasic, frequency-dependent responses in hippocampus and cortex. DBS modulated functional connectivity and suppressed epileptiform activity over time. Chronic electrocorticography elucidates progressive effects of thalamic stimulation.
Implanted neurostimulation devices are gaining traction as palliative treatment options for certain forms of drug-resistant epilepsy, but clinical utility of these devices is hindered by incomplete mechanistic understanding of their therapeutic effects. Approved devices for anterior thalamic nuclei deep brain stimulation (ANT DBS) are thought to work at a network level, but limited sensing capability precludes characterization of neurophysiological effects outside the thalamus. Here, we describe a patient with drug-resistant temporal lobe epilepsy who was implanted with a responsive neurostimulation device (RNS System), involving hippocampal and ipsilateral temporal neocortical leads, and subsequently received ANT DBS. Over 1.5 years, RNS System electrocorticography enabled multiscale characterization of neurophysiological effects of thalamic stimulation. In brain regions sampled by the RNS System, ANT DBS produced acute, phasic, frequency-dependent responses, including suppression of hippocampal low frequency local field potentials. ANT DBS modulated functional connectivity between hippocampus and neocortex. Finally, ANT DBS progressively suppressed hippocampal epileptiform activity in relation to the extent of hippocampal theta suppression, which informs stimulation parameter selection for ANT DBS. Taken together, this unique clinical scenario, involving hippocampal recordings of unprecedented chronicity alongside ANT DBS, sheds light on the therapeutic mechanism of thalamic stimulation and highlights capabilities needed in next-generation devices.
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Affiliation(s)
- Alexander B Silva
- Medical Scientist Training Program, University of California, San Francisco, USA
| | - Ankit N Khambhati
- Department of Neurological Surgery and Weill Institute for Neurosciences, University of California, San Francisco, USA
| | - Benjamin A Speidel
- Department of Neurology and Weill Institute for Neurosciences, University of California, San Francisco, United States
| | - Edward F Chang
- Department of Neurological Surgery and Weill Institute for Neurosciences, University of California, San Francisco, USA
| | - Vikram R Rao
- Department of Neurology and Weill Institute for Neurosciences, University of California, San Francisco, United States
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