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Drees C, Afra P, Verner R, Kaye L, Keith A, Jiang M, Szaflarski JP, Nichol K. Feasibility study of microburst VNS therapy in drug-resistant focal and generalized epilepsy. Brain Stimul 2024; 17:382-391. [PMID: 38499287 DOI: 10.1016/j.brs.2024.03.010] [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: 09/20/2023] [Revised: 01/31/2024] [Accepted: 03/12/2024] [Indexed: 03/20/2024] Open
Abstract
BACKGROUND Vagus nerve stimulation (VNS) at low frequencies (≤30 Hz) has been an established treatment for drug-resistant epilepsy (DRE) for over 25 years. OBJECTIVE To examine the initial safety and efficacy performance of an investigational, high-frequency (≥250 Hz) VNS paradigm herein called "Microburst VNS" (μVNS). μVNS consists of short, high-frequency bursts of electrical pulses believed to preferentially modulate certain brain regions. METHODS Thirty-three (33) participants were enrolled into an exploratory feasibility study, 21 with focal-onset seizures and 12 with generalized-onset seizures. Participants were titrated to a personalized target dose of μVNS using an investigational fMRI protocol. Participants were then followed for up to 12 months, with visits every 3 months, and monitored for side-effects at all time points. This study was registered as NCT03446664 on February 27th, 2018. RESULTS The device was well-tolerated. Reported adverse events were consistent with typical low frequency VNS outcomes and tended to diminish in severity over time, including dysphonia, cough, dyspnea, and implant site pain. After 12 months of μVNS, the mean seizure frequency reduction for all seizures was 61.3% (median reduction: 70.4%; 90% CI of median: 48.9%-83.3%). The 12-month responder rate (≥50% reduction) was 63.3% (90% CI: 46.7%-77.9%) and the super-responder rate (≥80% reduction) was 40% (90% CI: 25.0%-56.6%). Participants with focal-onset seizures appeared to benefit similarly to participants with generalized-onset seizures (mean reduction in seizures at 12 months: 62.6% focal [n = 19], versus 59.0% generalized [n = 11]). CONCLUSION Overall, μVNS appears to be safe and potentially a promising therapeutic alternative to traditional VNS. It merits further investigation in randomized controlled trials which will help determine the impact of investigational variables and which patients are most suitable for this novel therapy.
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Affiliation(s)
- Cornelia Drees
- Mayo Clinic Arizona, Department of Neurology, Phoenix, AZ, USA; University of Colorado School of Medicine, Department of Neurology, Aurora, CO, USA
| | - Pegah Afra
- University of Utah School of Medicine, Department of Neurology, Salt Lake City, UT, USA; Weill-Cornell Medicine, Department of Neurology, New York, NY, USA; University of Massachusetts Chan Medical School, Worcester, MA, USA
| | - Ryan Verner
- LivaNova PLC (or a Subsidiary), Department of Clinical and Medical Affairs, London, UK
| | - Lesley Kaye
- University of Colorado School of Medicine, Department of Neurology, Aurora, CO, USA
| | - Amy Keith
- LivaNova PLC (or a Subsidiary), Department of Clinical and Medical Affairs, London, UK
| | - Mei Jiang
- LivaNova PLC (or a Subsidiary), Department Statistics and Data Science, London, UK
| | - Jerzy P Szaflarski
- University of Alabama at Birmingham School of Medicine, Department of Neurology, Birmingham, AL, USA
| | - Kathryn Nichol
- LivaNova PLC (or a Subsidiary), Department of Clinical and Medical Affairs, London, UK.
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Verner R, Szaflarski JP, Allendorfer JB, Vonck K, Giannicola G. Modulation of the thalamus by microburst vagus nerve stimulation: a feasibility study protocol. Front Neurol 2023; 14:1169161. [PMID: 37384278 PMCID: PMC10299807 DOI: 10.3389/fneur.2023.1169161] [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: 02/18/2023] [Accepted: 05/04/2023] [Indexed: 06/30/2023] Open
Abstract
Vagus nerve stimulation (VNS) was the first device-based therapy for epilepsy, having launched in 1994 in Europe and 1997 in the United States. Since then, significant advances in the understanding of the mechanism of action of VNS and the central neurocircuitry that VNS modulates have impacted how the therapy is practically implemented. However, there has been little change to VNS stimulation parameters since the late 1990s. Short bursts of high frequency stimulation have been of increasing interest to other neuromodulation targets e.g., the spine, and these high frequency bursts elicit unique effects in the central nervous system, especially when applied to the vagus nerve. In the current study, we describe a protocol design that is aimed to assess the impact of high frequency bursts of stimulation, called "Microburst VNS", in subjects with refractory focal and generalized epilepsies treated with this novel stimulation pattern in addition to standard anti-seizure medications. This protocol also employed an investigational, fMRI-guided titration protocol that permits personalized dosing of Microburst VNS among the treated population depending on the thalamic blood-oxygen-level-dependent signal. The study was registered on clinicaltrials.gov (NCT03446664). The first subject was enrolled in 2018 and the final results are expected in 2023.
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Affiliation(s)
- Ryan Verner
- Clinical and Medical Affairs, LivaNova PLC (or a subsidiary), London, United Kingdom
| | - Jerzy P. Szaflarski
- Department of Neurology, University of Alabama at Birmingham Heersink School of Medicine, Birmingham, AL, United States
| | - Jane B. Allendorfer
- Department of Neurology, University of Alabama at Birmingham Heersink School of Medicine, Birmingham, AL, United States
| | - Kristl Vonck
- Department of Neurology, 4Brain, Ghent University Hospital, Ghent, Belgium
| | - Gaia Giannicola
- Clinical and Medical Affairs, LivaNova PLC (or a subsidiary), London, United Kingdom
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Sant'Anna FM, Resende RCL, Sant'Anna LB, Couceiro SLM, Pinto RBS, Sant'Anna MB, Chao LW, Szeles JC, Kaniusas E. Auricular vagus nerve stimulation: a new option to treat inflammation in COVID-19? REVISTA DA ASSOCIACAO MEDICA BRASILEIRA (1992) 2023; 69:e20230345. [PMID: 37283364 DOI: 10.1590/1806-9282.20230345] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/21/2023] [Accepted: 04/19/2023] [Indexed: 06/08/2023]
Affiliation(s)
- Fernando Mendes Sant'Anna
- Universidade Federal do Rio de Janeiro - Macaé (RJ), Brazil
- Hospital Santa Izabel - Cabo Frio (RJ), Brazil
| | | | | | | | | | | | - Liaw Wen Chao
- Universidade de São Paulo, Hospital das Clínicas - São Paulo (SP), Brazil
| | - Jozsef Constantin Szeles
- Medical University of Vienna, Department of Surgery, Division of Vascular Surgery - Vienna, Austria
| | - Eugenijus Kaniusas
- Vienna Universit y of Technology, Institute of Biomedical Electronics, Faculty of Electrical Engineering and Information Technology - Vienna, Austria
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Charalambous M, Fischer A, Potschka H, Walker MC, Raedt R, Vonck K, Boon P, Lohi H, Löscher W, Worrell G, Leeb T, McEvoy A, Striano P, Kluger G, Galanopoulou AS, Volk HA, Bhatti SFM. Translational veterinary epilepsy: A win-win situation for human and veterinary neurology. Vet J 2023; 293:105956. [PMID: 36791876 DOI: 10.1016/j.tvjl.2023.105956] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2022] [Revised: 02/07/2023] [Accepted: 02/09/2023] [Indexed: 02/15/2023]
Abstract
Epilepsy is a challenging multifactorial disorder with a complex genetic background. Our current understanding of the pathophysiology and treatment of epilepsy has substantially increased due to animal model studies, including canine studies, but additional basic and clinical research is required. Drug-resistant epilepsy is an important problem in both dogs and humans, since seizure freedom is not achieved with the available antiseizure medications. The evaluation and exploration of pharmacological and particularly non-pharmacological therapeutic options need to remain a priority in epilepsy research. Combined efforts and sharing knowledge and expertise between human medical and veterinary neurologists are important for improving the treatment outcomes or even curing epilepsy in dogs. Such interactions could offer an exciting approach to translate the knowledge gained from people and rodents to dogs and vice versa. In this article, a panel of experts discusses the similarities and knowledge gaps in human and animal epileptology, with the aim of establishing a common framework and the basis for future translational epilepsy research.
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Affiliation(s)
- Marios Charalambous
- Department of Small Animal Medicine and Surgery, University of Veterinary Medicine Hannover, Hannover 30559, Germany.
| | - Andrea Fischer
- Centre for Clinical Veterinary Medicine, Ludwig-Maximilians-University Munich, Munich 80539, Germany
| | - Heidrun Potschka
- Institute of Pharmacology, Toxicology and Pharmacy, Ludwig-Maximilians-University, Munich 80539, Germany
| | - Matthew C Walker
- Institute of Neurology, University College London, London WC1N 3JD, UK
| | - Robrecht Raedt
- Department of Neurology, 4brain, Ghent University, Ghent 9000, Belgium
| | - Kristl Vonck
- Department of Neurology, 4brain, Ghent University, Ghent 9000, Belgium
| | - Paul Boon
- Department of Neurology, 4brain, Ghent University, Ghent 9000, Belgium
| | - Hannes Lohi
- Department of Veterinary Biosciences, Department of Medical and Clinical Genetics, and Folkhälsan Research Center, University of Helsinki, Helsinki 00014, Finland
| | - Wolfgang Löscher
- Department of Pharmacology, Toxicology, and Pharmacy, University of Veterinary Medicine Hannover, Hannover 30559, Germany
| | | | - Tosso Leeb
- Institute of Genetics, University of Bern, Bern 3001, Switzerland
| | - Andrew McEvoy
- Institute of Neurology, University College London, London WC1N 3JD, UK
| | - Pasquale Striano
- IRCCS 'G. Gaslini', Genova 16147, Italy; Department of Neurosciences, Rehabilitation, Ophthalmology, Genetics, Maternal and Child Health, University of Genova, Genova, Italy
| | - Gerhard Kluger
- Research Institute, Rehabilitation, Transition-Palliation', PMU Salzburg, Salzburg 5020, Austria; Clinic for Neuropediatrics and Neurorehabilitation, Epilepsy Center for Children and Adolescents, Schoen Clinic Vogtareuth, Vogtareuth 83569, Germany
| | - Aristea S Galanopoulou
- Saul R Korey Department of Neurology, Isabelle Rapin Division of Child Neurology, Dominick P. Purpura Department of Neuroscience, Montefiore Medical Center, Albert Einstein College of Medicine, Bronx, NY 10461, USA
| | - Holger A Volk
- Department of Small Animal Medicine and Surgery, University of Veterinary Medicine Hannover, Hannover 30559, Germany
| | - Sofie F M Bhatti
- Faculty of Veterinary Medicine, Small Animal Department, Ghent University, Merelbeke 9820, Belgium
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Farrand A, Jacquemet V, Verner R, Owens M, Beaumont E. Vagus nerve stimulation parameters evoke differential neuronal responses in the locus coeruleus. Physiol Rep 2023; 11:e15633. [PMID: 36905173 PMCID: PMC10006695 DOI: 10.14814/phy2.15633] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2023] [Revised: 02/13/2023] [Accepted: 02/15/2023] [Indexed: 03/12/2023] Open
Abstract
Vagus nerve stimulation (VNS) is used to treat drug-resistant epilepsy and depression, with additional applications under investigation. The noradrenergic center locus coeruleus (LC) is vital for VNS effects; however, the impact of varying stimulation parameters on LC activation is poorly understood. This study characterized LC activation across VNS parameters. Extracellular activity was recorded in rats' left LC while 11 VNS paradigms, utilizing variable frequencies and bursting characteristics, were pseudorandomly delivered to the left cervical vagus for five cycles. Neurons' change from baseline firing rate and timing response profiles were assessed. The proportion of neurons categorized as responders over 5 VNS cycles doubled in comparison to the first VNS cycle (p < 0.001) for all VNS paradigms, demonstrating an amplification effect. The percentage of positively consistent/positive responders increased for standard VNS paradigms with frequencies ≥10 Hz and for bursting paradigms with shorter interburst intervals and more pulses per burst. The synchrony between pairs of LC neurons increased during bursting VNS but not standard paradigms. Also, the probability of evoking a direct response during bursting VNS was higher with longer interburst intervals and a higher number of pulses per burst. Standard paradigms between 10-30 Hz best positively activates LC with consistency to VNS while the best bursting paradigm to increase activity was 300 Hz, seven pulses per burst separated by 1 s. Bursting VNS was effective in increasing synchrony between pairs of neurons, suggesting a common network recruitment originating from vagal afferents. These results indicate differential activation of LC neurons depending on the VNS parameters delivered.
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Affiliation(s)
- Ariana Farrand
- Department of Biomedical SciencesQuillen College of Medicine, East Tennessee State UniversityJohnson CityTennesseeUSA
| | - Vincent Jacquemet
- Department of Pharmacology and PhysiologyInstitute of Biomedical Engineering, University of MontrealMontrealQuebecCanada
- Research CenterSacred Heart Hospital of MontrealMontrealQuebecCanada
| | - Ryan Verner
- Neuromodulation DivisionLivaNova PLCHoustonTexasUSA
| | - Misty Owens
- Department of Biomedical SciencesQuillen College of Medicine, East Tennessee State UniversityJohnson CityTennesseeUSA
| | - Eric Beaumont
- Department of Biomedical SciencesQuillen College of Medicine, East Tennessee State UniversityJohnson CityTennesseeUSA
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Xue T, Chen S, Bai Y, Han C, Yang A, Zhang J. Neuromodulation in drug-resistant epilepsy: A review of current knowledge. Acta Neurol Scand 2022; 146:786-797. [PMID: 36063433 DOI: 10.1111/ane.13696] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2022] [Accepted: 08/16/2022] [Indexed: 11/30/2022]
Abstract
Nearly 1% of the global population suffers from epilepsy. Drug-resistant epilepsy (DRE) affects one-third of epileptic patients who are unable to treat their condition with existing drugs. For the treatment of DRE, neuromodulation offers a lot of potential. The background, mechanism, indication, application, efficacy, and safety of each technique are briefly described in this narrative review, with an emphasis on three approved neuromodulation therapies: vagus nerve stimulation (VNS), deep brain stimulation of the anterior nucleus of the thalamus (ANT-DBS), and closed-loop responsive neurostimulation (RNS). Neuromodulatory approaches involving direct or induced electrical currents have been developed to lessen seizure frequency and duration in patients with DRE since the notion of electrical stimulation as a therapy for neurologic diseases originated in the early nineteenth century. Although few people have attained total seizure independence for more than 12 months using these treatments, more than half have benefitted from a 50% drop in seizure frequency over time. Although promising outcomes in adults and children with DRE have been achieved, challenges such as heterogeneity among epilepsy types and etiologies, optimization of stimulation parameters, a lack of biomarkers to predict response to neuromodulation therapies, high-level evidence to aid decision-making, and direct comparisons between neuromodulatory approaches remain. To solve these existing gaps, authorize new kinds of neuromodulation, and develop personalized closed-loop treatments, further research is needed. Finally, both invasive and non-invasive neuromodulation seems to be safe. Implantation-related adverse events for invasive stimulation primarily include infection and pain at the implant site. Intracranial hemorrhage is a frequent adverse event for DBS and RNS. Other stimulation-specific side-effects are mild with non-invasive stimulation.
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Affiliation(s)
- Tao Xue
- Department of Neurosurgery, Beijing Tiantan Hospital, Capital Medical University, Beijing, China
| | - Shujun Chen
- Department of Neurology, Beijing Tiantan Hospital, Capital Medical University, Beijing, China
| | - Yutong Bai
- Department of Neurosurgery, Beijing Tiantan Hospital, Capital Medical University, Beijing, China
| | - Chunlei Han
- Department of Neurosurgery, Beijing Tiantan Hospital, Capital Medical University, Beijing, China
| | - Anchao Yang
- Department of Neurosurgery, Beijing Tiantan Hospital, Capital Medical University, Beijing, China
| | - Jianguo Zhang
- Department of Neurosurgery, Beijing Tiantan Hospital, Capital Medical University, Beijing, China
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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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Sevcencu C. Single-interface bioelectronic medicines - concept, clinical applications and preclinical data. J Neural Eng 2022; 19. [PMID: 35533654 DOI: 10.1088/1741-2552/ac6e08] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2022] [Accepted: 05/08/2022] [Indexed: 11/12/2022]
Abstract
Presently, large groups of patients with various diseases are either intolerant, or irresponsive to drug therapies and also intractable by surgery. For several diseases, one option which is available for such patients is the implantable neurostimulation therapy. However, lacking closed-loop control and selective stimulation capabilities, the present neurostimulation therapies are not optimal and are therefore used as only "third" therapeutic options when a disease cannot be treated by drugs or surgery. Addressing those limitations, a next generation class of closed-loop controlled and selective neurostimulators generically named bioelectronic medicines seems within reach. A sub-class of such devices is meant to monitor and treat impaired functions by intercepting, analyzing and modulating neural signals involved in the regulation of such functions using just one neural interface for those purposes. The primary objective of this review is to provide a first broad perspective on this type of single-interface devices for bioelectronic therapies. For this purpose, the concept, clinical applications and preclinical studies for further developments with such devices are here analyzed in a narrative manner.
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Affiliation(s)
- Cristian Sevcencu
- National Institute for Research and Development of Isotopic and Molecular Technologies, 67-103 Donat Street, Cluj-Napoca, 400293, ROMANIA
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Szabó CÁ, Akopian M, Papanastassiou AM, Salinas FS. Cerebral blood flow differences between high- vs low-frequency VNS therapy in the epileptic baboon. Epilepsy Res 2022; 180:106862. [PMID: 35114431 DOI: 10.1016/j.eplepsyres.2022.106862] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2021] [Revised: 12/24/2021] [Accepted: 01/17/2022] [Indexed: 01/24/2023]
Abstract
PURPOSE Cerebral blood flow (CBF) tracks physiological effects of ictal or interictal epileptic discharges (IEDs) and neurostimulation. This study compared CBF changes between high-frequency (HF; 300 Hz) microburst, and standard, low-frequency (LF; 30 Hz) vagal nerve stimulation (VNS) Therapy in 2 baboons with genetic generalized epilepsy (GGE), including one with photosensitivity. METHODS The baboons were selected based on video recordings and scalp EEG studies. They were both implanted with Sentiva™ 1000 devices capable of stimulating at standard and microburst frequencies. Nine H215O (10-20 mCi) positron emission tomographic (PET) scans were performed each session (two PET sessions acquired for each animal). The baboons were sedated with ketamine, paralyzed, and monitored with scalp EEG. CBF changes were compared between the two modes of stimulation and resting scans in the first study, while in the second, VNS Therapy trials were combined with intermittent light stimulation (ILS) at 25 Hz and compared to CBF changes induced by ILS alone. RESULTS ILS-associated IED rates were slightly reduced by HF- and LF-VNS Therapies in B1, while spontaneous IEDs were completely suppressed by HF-VNS Therapy in B2. Regional CBF changes were consistent between the two modes of therapy in each baboon, in particular with respect to the activation of the superior colliculus and cerebellum. Neither VNS mode suppressed the photoepileptic response in B1. In B2, IED suppression was associated with bilateral deactivations of the frontal and temporal cortices, cingulate and anterior striatum, as well as bilateral cerebellar activations. CONCLUSIONS This pilot study reveals similar activation/deactivation patterns between LF- and HF-VNS Therapies, but the most pronounced CBF differences between the two baboons and the two modes of stimulation may have been driven by the suppression of the epileptic network by HF-VNS Therapy in B2. Some therapeutic targets appear to be subcortical, including the putamen, superior colliculus, brainstem nuclei, as well as the cerebellum, all of which modulate corticothalamic networks, which is particularly reflected by CBF changes associated with HF-VNS Therapy. These findings need to be replicated in larger samples and correlated with long-term clinical outcomes.
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Affiliation(s)
- C Ákos Szabó
- Department of Neurology, University of Texas Health San Antonio, San Antonio, TX, USA.
| | - Margarita Akopian
- Neurodiagnostic Center, University Health System, San Antonio, TX, USA
| | | | - Felipe S Salinas
- Research Imaging Institute, USA; Department of Radiology, University of Texas Health San Antonio, San Antonio, TX, USA
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The baboon in epilepsy research: Revelations and challenges. Epilepsy Behav 2021; 121:108012. [PMID: 34022622 PMCID: PMC8238811 DOI: 10.1016/j.yebeh.2021.108012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/11/2021] [Accepted: 04/17/2021] [Indexed: 11/23/2022]
Abstract
The baboon offers a natural model for genetic generalized epilepsy with photosensitivity. In this review, we will summarize some of the more important clinical, neuroimaging, and elctrophysiological findings form recent work performed at the Southwest National Primate Research Center (SNPRC, Texas Biomedical Research Institute, San Antonio, Texas), which houses the world's largest captive baboon pedigree. Due to the phylogenetic proximity of the baboon to humans, many of the findings are readily translatable, but there may be some important differences, such as the mutlifocality of the ictal and interictal epileptic discharges (IEDs) on intracranial electroencephalography (EEG) and greater parieto-occipital connectivity of baboon brain networks compared to juvenile myoclonic epilepsy in humans. Furthermore, there is still limited knowledge of the natural history of the epilepsy, which could be transformative for research into epileptogenesis in genetic generalized epilepsy (GGE) and sudden unexpected death in epilepsy (SUDEP).
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Ákos Szabó C, De La Garza M, Shade R, Papanastassiou AM, Nathanielsz P. Cortical responsive neurostimulation in a baboon with genetic generalized epilepsy. Epilepsy Behav 2021; 120:107973. [PMID: 33962250 PMCID: PMC8483259 DOI: 10.1016/j.yebeh.2021.107973] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/25/2021] [Revised: 03/25/2021] [Accepted: 04/01/2021] [Indexed: 10/21/2022]
Abstract
OBJECTIVE To evaluate the efficacy of cortical responsive neurostimulation (CRN) in a male baboon with epilepsy and with genetic generalized epilepsy (GGE), as well as the alteration of seizure patterns and their circadian rhythms due to treatment. METHODS The baboon was implanted with two subdural frontoparietal strips, bridging the medial central sulci bilaterally. Electrocorticography (ECoG) data were downloaded daily during a three-month baseline, then every 2-3 days over a five-month treatment period. Long episodes, reflecting ictal or interictal epileptic discharges, were also quantified. RESULTS Twenty-three generalized tonic-clonic seizures (GTCS) and 2 episodes of nonconvulsive status epilepticus (NCSE) were recorded at baseline (median 8 events/month), whereas 26 GTCS were recorded under treatment (median 5/month). Similarly, daily indices of long episodes decreased from 0.46 at baseline to 0.29 with treatment. Ictal ECoG patterns and the circadian distribution of GTCS were also altered by RNS therapy. SIGNIFICANCE This case study provides the proof-of-concept for RNS therapy in the baboon model of GGE. Cortical responsive neurostimulation (CRN) demonstrated a 38% median reduction in GTCS. Distinct ictal patterns were identified, which changed over the treatment period; the circadian pattern of his GTCS also shifted gradually from night to daytime with treatment. Future studies targeting the thalamic nuclei, or combining cortical and subcortical sites, may further improve detection and control of GTCS as well as other generalized seizure types. More broadly, this study demonstrates opportunities for evaluating seizure detection as well as chronic therapeutic interventions over long term in the baboon.
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Affiliation(s)
- C. Ákos Szabó
- Department of Neurology, UT Health San Antonio, San Antonio, Texas
| | - Melissa De La Garza
- Southwest National Primate Research Center, Texas Biomedical Research Institute, San Antonio, Texas
| | - Robert Shade
- Southwest National Primate Research Center, Texas Biomedical Research Institute, San Antonio, Texas
| | | | - Peter Nathanielsz
- Southwest National Primate Research Center, Texas Biomedical Research Institute, San Antonio, Texas,Department of Animal Science, University of Wyoming, Laramie, WY
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Levitsky A, Klein J, Artemiadis PK, Buneo CA. Effects of Transcutaneous Electric Nerve Stimulation on Upper Extremity Proprioceptive Function. ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. ANNUAL INTERNATIONAL CONFERENCE 2020; 2020:3577-3580. [PMID: 33018776 DOI: 10.1109/embc44109.2020.9176210] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Electrical stimulation of the vagus nerve has been shown to enhance cortical plasticity and may benefit upper extremity rehabilitation following stroke. As an initial step towards assessing the potential of other craniocervical nerves as neuromodulation targets during rehabilitation, we explored the ability of non-invasive stimulation of cervical spine afferents, paired with a proprioceptive discrimination task, to improve sensory function in neurologically intact human subjects. On each trial, subjects' arms were moved by a robot from a test position, along a random path, to a judgment position located 1-4 cm away. Subjects responded 'same' if the judgment position was the same as the test or 'different' if it was not. These responses were used to compute proprioceptive sensitivity and bias. Three groups of 20 subjects received transcutaneous electric nerve stimulation to the C3/C4 cervical spine at one of three frequencies (30 Hz, 300 Hz, 3 kHz) for 10 minutes prior to task performance. A fourth group served as a sham. We found a statistically significant interaction between stimulation frequency and displacement distance on proprioceptive sensitivity. In summary, stimulation of cervical spine afferents may enhance arm proprioceptive function, though in unimpaired subjects these gains depend on both stimulation frequency and discrimination distance.Clinical Relevance- This study provides preliminary data on the potential for non-invasive stimulation of cervical spine afferents to enhance recovery of function following stroke and other neurological disorders.
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Farrand AQ, Verner RS, McGuire RM, Helke KL, Hinson VK, Boger HA. Differential effects of vagus nerve stimulation paradigms guide clinical development for Parkinson's disease. Brain Stimul 2020; 13:1323-1332. [PMID: 32629028 DOI: 10.1016/j.brs.2020.06.078] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2020] [Revised: 06/15/2020] [Accepted: 06/30/2020] [Indexed: 01/06/2023] Open
Abstract
BACKGROUND Vagus nerve stimulation (VNS) modifies brain rhythms in the locus coeruleus (LC) via the solitary nucleus. Degeneration of the LC in Parkinson's disease (PD) is an early catalyst of the spreading neurodegenerative process, suggesting that stimulating LC output with VNS has the potential to modify disease progression. We previously showed in a lesion PD model that VNS delivered twice daily reduced neuroinflammation and motor deficits, and attenuated tyrosine hydroxylase (TH)-positive cell loss. OBJECTIVE The goal of this study was to characterize the differential effects of three clinically-relevant VNS paradigms in a PD lesion model. METHODS Eleven days after DSP-4 (N-(2-chloroethyl)-N-ethyl-2-bromobenzylamine, noradrenergic lesion, administered systemically)/6-OHDA (6-hydroxydopamine, dopaminergic lesion, administered intrastriatally) rats were implanted with VNS devices, and received either low-frequency VNS, standard-frequency VNS, or high-frequency microburst VNS. After 10 days of treatment and behavioral assessment, rats were euthanized, right prefrontal cortex (PFC) was dissected for norepinephrine assessment, and the left striatum, bilateral substantia nigra (SN), and LC were sectioned for immunohistochemical detection of catecholamine neurons, α-synuclein, astrocytes, and microglia. RESULTS At higher VNS frequencies, specifically microburst VNS, greater improvements occurred in motor function, attenuation of TH-positive cell loss in SN and LC, and norepinephrine concentration in the PFC. Additionally, higher VNS frequencies resulted in lower intrasomal α-synuclein accumulation and glial density in the SN. CONCLUSIONS These data indicate that higher stimulation frequencies provided the greatest attenuation of behavioral and pathological markers in this PD model, indicating therapeutic potential for these VNS paradigms.
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Affiliation(s)
- Ariana Q Farrand
- Department of Neuroscience and Center on Aging, Medical University of South Carolina, 173 Ashley Ave, BSB Suite 403, MSC 510, Charleston, SC, 29425, USA
| | - Ryan S Verner
- Neuromodulation Division of LivaNova, PLC, 100 Cyberonics Blvd, Houston, TX, 77058, USA
| | - Ryan M McGuire
- Neuromodulation Division of LivaNova, PLC, 100 Cyberonics Blvd, Houston, TX, 77058, USA
| | - Kristi L Helke
- Department of Comparative Medicine, 114 Doughty St, STB 648, MSC 777; Department of Pathology and Laboratory Medicine, 165 Ashley Ave, Children's Hospital 309, MSC 908, Medical University of South Carolina, Charleston, SC, 29425, USA
| | - Vanessa K Hinson
- Department of Neurology, Medical University of South Carolina, 96 Jonathan Lucas St, CSB 309, MSC 606, Charleston, SC, 29425, USA
| | - Heather A Boger
- Department of Neuroscience and Center on Aging, Medical University of South Carolina, 173 Ashley Ave, BSB Suite 403, MSC 510, Charleston, SC, 29425, USA.
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Specchio N, Ferretti A, Pietrafusa N, Trivisano M, Calabrese C, Carfì Pavia G, De Benedictis A, Marras CE, de Palma L, Vigevano F. Refractory Status Epilepticus in Genetic Epilepsy-Is Vagus Nerve Stimulation an Option? Front Neurol 2020; 11:443. [PMID: 32595584 PMCID: PMC7303322 DOI: 10.3389/fneur.2020.00443] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2020] [Accepted: 04/27/2020] [Indexed: 11/13/2022] Open
Abstract
Refractory and super-refractory status epilepticus (RSE, SRSE) are severe conditions that can have long-term neurological consequences with high morbidity and mortality rates. The usefulness of vagus nerve-stimulation (VNS) implantation during RSE has been documented by anecdotal cases and in systematic reviews; however, the use of VNS in RSE has not been widely adopted. We successfully implanted VNS in two patients with genetic epilepsy admitted to hospital for SRSE; detailed descriptions of the clinical findings and VNS parameters are provided. Our patients were implanted 25 and 58 days after status epilepticus (SE) onset, and a stable remission of SE was observed from the seventh and tenth day after VNS implantation, respectively, without change in anti-seizure medication. We used a fast ramp-up of stimulation without evident side effects. Our results support the consideration of VNS implantation as a safe and effective adjunctive treatment for SRSE.
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Affiliation(s)
- Nicola Specchio
- Rare and Complex Epilepsy Unit, Department of Neuroscience, Bambino Gesù Children's Hospital, IRCCS, Member of European Reference Network EpiCARE, Rome, Italy
| | - Alessandro Ferretti
- Rare and Complex Epilepsy Unit, Department of Neuroscience, Bambino Gesù Children's Hospital, IRCCS, Member of European Reference Network EpiCARE, Rome, Italy
| | - Nicola Pietrafusa
- Rare and Complex Epilepsy Unit, Department of Neuroscience, Bambino Gesù Children's Hospital, IRCCS, Member of European Reference Network EpiCARE, Rome, Italy
| | - Marina Trivisano
- Rare and Complex Epilepsy Unit, Department of Neuroscience, Bambino Gesù Children's Hospital, IRCCS, Member of European Reference Network EpiCARE, Rome, Italy
| | - Costanza Calabrese
- Rare and Complex Epilepsy Unit, Department of Neuroscience, Bambino Gesù Children's Hospital, IRCCS, Member of European Reference Network EpiCARE, Rome, Italy
| | - Giusy Carfì Pavia
- Rare and Complex Epilepsy Unit, Department of Neuroscience, Bambino Gesù Children's Hospital, IRCCS, Member of European Reference Network EpiCARE, Rome, Italy
| | - Alessandro De Benedictis
- Neurosurgery Unit, Department of Neuroscience, Bambino Gesù Children's Hospital, IRCCS, Rome, Italy
| | - Carlo Efisio Marras
- Neurosurgery Unit, Department of Neuroscience, Bambino Gesù Children's Hospital, IRCCS, Rome, Italy
| | - Luca de Palma
- Rare and Complex Epilepsy Unit, Department of Neuroscience, Bambino Gesù Children's Hospital, IRCCS, Member of European Reference Network EpiCARE, Rome, Italy
| | - Federico Vigevano
- Department of Neuroscience, Bambino Gesù Children's Hospital, IRCCS, Member of European Reference Network EpiCARE, Rome, Italy
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15
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Szabó CÁ, González DA, Koneru S. Semiology of spontaneous generalized tonic-clonic seizures in the epileptic baboon. Epilepsia Open 2020; 5:213-219. [PMID: 32524046 PMCID: PMC7278549 DOI: 10.1002/epi4.12388] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2020] [Accepted: 02/24/2020] [Indexed: 01/14/2023] Open
Abstract
Objective The epileptic baboon provides an animal model for juvenile myoclonic epilepsy (JME), demonstrating spontaneous generalized tonic‐clonic seizures (GTCS) in addition to generalized myoclonic, absence and multifocal seizures. While photoconvulsive responses have been described in this model, spontaneous GTCS have not been characterized. Methods In this study, we characterized 46 seizures in 7 epileptic baboons (5 females, 12 ± 3 years old) by video recording. While housed in single cages, the baboons were monitored for a median of 2 (range 1‐10) weeks, with high‐resolution, infrared‐capable camera systems. Each GTCS was evaluated for evidence of preconvulsive ictal symptoms, focal convulsive behaviors, duration of the preconvulsive and convulsive periods, postictal immobility, and recovery of an upright posture. The circadian pattern of GTCS was also for each baboon. Results More than half of GTCS occurred in sleep, beginning from an upright position in all but one tethered baboon. Focal semiological findings were noted in 19 (41%) GTCS, and these included preconvulsive focal ictal motor behaviors as well as lateralized motor activity during the convulsions. The convulsive portion lasted 47 ± 10 seconds, whereas the entire seizure lasted 54 ± 21 seconds. Postictally, the baboons remained immobile for a median latency of 40 (range 14‐347) seconds, recovering an upright posture after 173 (range 71‐1980) seconds. GTCS demonstrated circadian patterns in all but one baboon, with 34 (74%) all seizures occurring between 1‐9 am. Significance GTCS in the baboon revealed intersubject variability, but semiology remained stereotyped in a given baboon. Similar to GTCS in people with JME, focal symptoms were also observed in epileptic baboons. The postictal recovery period, characterized by postictal immobility and myoclonus as well as time to recumbency, also varied among baboons.
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Affiliation(s)
- Charles Ákos Szabó
- South Texas Comprehensive Epilepsy Center San Antonio Texas.,Department of Neurology UT Health San Antonio San Antonio Texas
| | - David Andrés González
- South Texas Comprehensive Epilepsy Center San Antonio Texas.,Department of Neurology UT Health San Antonio San Antonio Texas
| | - Sreekanth Koneru
- South Texas Comprehensive Epilepsy Center San Antonio Texas.,Department of Neurology UT Health San Antonio San Antonio Texas
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16
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Kaniusas E, Samoudi AM, Kampusch S, Bald K, Tanghe E, Martens L, Joseph W, Szeles JC. Stimulation Pattern Efficiency in Percutaneous Auricular Vagus Nerve Stimulation: Experimental Versus Numerical Data. IEEE Trans Biomed Eng 2019; 67:1921-1935. [PMID: 31675313 DOI: 10.1109/tbme.2019.2950777] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
OBJECTIVE Percutaneous electrical stimulation of the auricular vagus nerve (pVNS) is an electroceutical technology. The selection of stimulation patterns is empirical, which may lead to under-stimulation or over-stimulation. The objective is to assess the efficiency of different stimulation patterns with respect to individual perception and to compare it with numerical data based on in-silico ear models. METHODS Monophasic (MS), biphasic (BS) and triphasic stimulation (TS) patterns were tested in volunteers. Different clinically-relevant perception levels were assessed. In-silico models of the human ear were created with embedded fibers and vessels to assess different excitation levels. RESULTS TS indicates experimental superiority over BS which is superior to MS while reaching different perception levels. TS requires about 57% and 35% of BS and MS magnitude, respectively, to reach the comfortable perception. Experimental thresholds decrease from non-bursted to bursted stimulation. Numerical results indicate a slight superiority of BS and TS over MS while reaching different excitation levels, whereas the burst length has no influence. TS yields the highest number of asynchronous action impulses per stimulation symbol for the used tripolar electrode set-up. CONCLUSION The comparison of experimental and numerical data favors the novel TS pattern. The analysis separates excitatory pVNS effects in the auricular periphery, as accounted by in-silico data, from the combination of peripheral and central pVNS effects in the brain, as accounted by experimental data. SIGNIFICANCE The proposed approach moves from an empirical selection of stimulation patterns towards efficient and optimized pVNS settings.
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17
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de la Garza MA, Poldiak D, Shade R, Salinas FS, Papanastassiou AM, Szabó CÁ. Cardiac changes in epileptic baboons with high-frequency microburst VNS therapy: A pilot study. Epilepsy Res 2019; 155:106156. [PMID: 31284120 PMCID: PMC6684821 DOI: 10.1016/j.eplepsyres.2019.106156] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2019] [Revised: 05/21/2019] [Accepted: 06/11/2019] [Indexed: 10/26/2022]
Abstract
The epileptic baboon provides a natural model of idiopathic generalized epilepsy and sudden unexpected death in epilepsy (SUDEP). We sought to evaluate autonomic differences, including heart rate (HR), heart rate variability (HRV) and corrected QT-duration (QTc) between two epileptic (EB1, EB2) and one control (CB) baboon, and the autonomic effects of high-frequency (HF) microburst Vagal Nerve Stimulation (VNS) Therapy in the epileptic baboons. At baseline, EB2's HR was increased over both EB1 and CB, and EB1's HRV was decreased compared to the others. QTc-intervals were significantly prolonged in both epileptic baboons. EB1 became free of generalized tonic-clonic seizures (GTCS) with VNS therapy, whereas EB2's GTCS were reduced by a third. HR decreased in both epileptic baboons, but while HRV improved in EB1, it decreased in EB2. EB2 succumbed to SUDEP after 9 months. This pilot study demonstrates abnormalities in HR, HRV and QTc-intervals in epileptic baboons. HF VNS Therapy demonstrated different effects on HRV in the two epileptic baboons, which, in addition to persistent GTCS and elevated HR, may have contributed to SUDEP risk in EB2. Future studies are needed to establish normative values for HRV and determine variability of HR, HRV and QTc-intervals in epileptic baboons.
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Affiliation(s)
- Melissa A de la Garza
- Southwest National Primate Research Center, Texas Biomedical Research Institute, San Antonio, TX, United States.
| | - David Poldiak
- emka TECHNOLOGIES, Inc., Falls Church, VA, United States
| | - Robert Shade
- Southwest National Primate Research Center, Texas Biomedical Research Institute, San Antonio, TX, United States
| | - Felipe S Salinas
- Research Imaging Institute, UT Health San Antonio, San Antonio, TX, United States; South Texas Veterans Health Care System, San Antonio, TX, United States
| | | | - C Ákos Szabó
- Departments of Neurology and South Texas Comprehensive Epilepsy Center, UT Health San Antonio, San Antonio, TX, United States
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18
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Croll L, Szabo CA, Abou-Madi N, Devinsky O. Epilepsy in nonhuman primates. Epilepsia 2019; 60:1526-1538. [PMID: 31206636 PMCID: PMC6779127 DOI: 10.1111/epi.16089] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2018] [Revised: 05/22/2019] [Accepted: 05/27/2019] [Indexed: 01/05/2023]
Abstract
OBJECTIVES Nonhuman primates (NHPs) are model organisms for understanding the pathophysiology and treatment of epilepsy in humans, while data from human patients informs the diagnosis and treatment of NHP with seizures and epilepsy. We reviewed the literature and surveyed veterinarians at zoos and NHP research centers to (a) better define the range of seizures and epilepsy in NHP, (b) understand how NHPs can inform our knowledge of the pathophysiology and treatment of epilepsy in humans, and (c) identify gaps of knowledge and develop more effective guidelines to treat seizures and epilepsy in NHP. METHODS We searched PrimateLit, PubMed, and Google Scholar for studies on experimental models of epilepsy in NHPs and on naturally occurring seizures and epilepsy in NHPs in captivity. In addition, we created a survey to assess methods to diagnose and treat epilepsy in NHPs. This survey was sent to 41 veterinarians at major international zoos and research facilities with NHP populations to study seizure phenomenology, diagnostic criteria for seizures and epilepsy, etiology, and antiseizure therapies in NHPs. RESULTS We summarize the data from experimental and natural models of epilepsy in NHPs and case reports of epilepsy of unknown origin in captive primates. In addition, we present survey data collected from veterinarians at eight zoos and one research facility. Experimental data from NHP epilepsy models is abundant, whereas data from primates who develop epilepsy in the wild or in zoos is very limited, constraining our ability to advance evidence-based medicine. SIGNIFICANCE Characterization of seizure or epilepsy models in NHPs will provide insights into mechanisms and new therapies that cannot be addressed by other animal models. NHP research will better inform species-specific diagnoses and outcomes.
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Affiliation(s)
| | | | - Noha Abou-Madi
- Department of Clinical Sciences, Cornell University College of Veterinary Medicine, Ithaca, New York
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19
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Kaniusas E, Kampusch S, Tittgemeyer M, Panetsos F, Gines RF, Papa M, Kiss A, Podesser B, Cassara AM, Tanghe E, Samoudi AM, Tarnaud T, Joseph W, Marozas V, Lukosevicius A, Ištuk N, Lechner S, Klonowski W, Varoneckas G, Széles JC, Šarolić A. Current Directions in the Auricular Vagus Nerve Stimulation II - An Engineering Perspective. Front Neurosci 2019; 13:772. [PMID: 31396044 PMCID: PMC6667675 DOI: 10.3389/fnins.2019.00772] [Citation(s) in RCA: 64] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2019] [Accepted: 07/09/2019] [Indexed: 01/05/2023] Open
Abstract
Electrical stimulation of the auricular vagus nerve (aVNS) is an emerging electroceutical technology in the field of bioelectronic medicine with applications in therapy. Artificial modulation of the afferent vagus nerve - a powerful entrance to the brain - affects a large number of physiological processes implicating interactions between the brain and body. Engineering aspects of aVNS determine its efficiency in application. The relevant safety and regulatory issues need to be appropriately addressed. In particular, in silico modeling acts as a tool for aVNS optimization. The evolution of personalized electroceuticals using novel architectures of the closed-loop aVNS paradigms with biofeedback can be expected to optimally meet therapy needs. For the first time, two international workshops on aVNS have been held in Warsaw and Vienna in 2017 within the scope of EU COST Action "European network for innovative uses of EMFs in biomedical applications (BM1309)." Both workshops focused critically on the driving physiological mechanisms of aVNS, its experimental and clinical studies in animals and humans, in silico aVNS studies, technological advancements, and regulatory barriers. The results of the workshops are covered in two reviews, covering physiological and engineering aspects. The present review summarizes on engineering aspects - a discussion of physiological aspects is provided by our accompanying article (Kaniusas et al., 2019). Both reviews build a reasonable bridge from the rationale of aVNS as a therapeutic tool to current research lines, all of them being highly relevant for the promising aVNS technology to reach the patient.
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Affiliation(s)
- Eugenijus Kaniusas
- Institute of Electrodynamics, Microwave and Circuit Engineering, Vienna University of Technology, Vienna, Austria
| | - Stefan Kampusch
- Institute of Electrodynamics, Microwave and Circuit Engineering, Vienna University of Technology, Vienna, Austria
- SzeleSTIM GmbH, Vienna, Austria
| | - Marc Tittgemeyer
- Max Planck Institute for Metabolism Research, Cologne, Germany
- Cologne Cluster of Excellence in Cellular Stress and Aging Associated Disease (CECAD), Cologne, Germany
| | - Fivos Panetsos
- Neurocomputing & Neurorobotics Research Group, Complutense University of Madrid, Madrid, Spain
| | - Raquel Fernandez Gines
- Neurocomputing & Neurorobotics Research Group, Complutense University of Madrid, Madrid, Spain
| | - Michele Papa
- Laboratory of Neuronal Networks, Department of Mental and Physical Health and Preventive Medicine, University of Campania “Luigi Vanvitelli”, Naples, Italy
| | - Attila Kiss
- Ludwig Boltzmann Cluster for Cardiovascular Research at Center for Biomedical Research, Medical University of Vienna, Vienna, Austria
| | - Bruno Podesser
- Ludwig Boltzmann Cluster for Cardiovascular Research at Center for Biomedical Research, Medical University of Vienna, Vienna, Austria
| | | | - Emmeric Tanghe
- Department of Information Technology, Ghent University/IMEC, Ghent, Belgium
| | | | - Thomas Tarnaud
- Department of Information Technology, Ghent University/IMEC, Ghent, Belgium
| | - Wout Joseph
- Department of Information Technology, Ghent University/IMEC, Ghent, Belgium
| | - Vaidotas Marozas
- Biomedical Engineering Institute, Kaunas University of Technology, Kaunas, Lithuania
| | - Arunas Lukosevicius
- Biomedical Engineering Institute, Kaunas University of Technology, Kaunas, Lithuania
| | - Niko Ištuk
- Faculty of Electrical Engineering, Mechanical Engineering and Naval Architecture, University of Split, Split, Croatia
| | | | - Wlodzimierz Klonowski
- Nalecz Institute of Biocybernetics and Biomedical Engineering, Polish Academy of Sciences, Warsaw, Poland
| | - Giedrius Varoneckas
- Sleep Medicine Centre, Klaipeda University Hospital, Klaipėda, Lithuania
- Institute of Neuroscience, Lithuanian University of Health Sciences, Palanga, Lithuania
| | | | - Antonio Šarolić
- Faculty of Electrical Engineering, Mechanical Engineering and Naval Architecture, University of Split, Split, Croatia
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20
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Effects of ketamine on EEG in baboons with genetic generalized epilepsy. Epilepsy Res 2019; 154:50-54. [PMID: 31048260 DOI: 10.1016/j.eplepsyres.2019.04.008] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2018] [Revised: 04/12/2019] [Accepted: 04/17/2019] [Indexed: 11/21/2022]
Abstract
Ketamine, a noncompetitive N-methyl-D-aspartate receptor (NMDAR) antagonist, used as an anesthetic has been reported to induce seizures both in humans and baboons predisposed to epilepsy. In this study, we aimed to characterize the acute effects of ketamine on scalp (sc-EEG) and intracranial EEG (ic-EEG) in the baboon, which offers a natural model of genetic generalized epilepsy (GGE). We evaluated the electroclinical response to ketamine in three epileptic baboons. The raw EEG data were analyzed within 10 min of intramuscular ketamine (5-6 mg/kg) administration. Earliest EEG changes occurred after 30 s in sc-EEG and after 15 s in ic-EEG of ketamine administration. These initial changes involved increased paroxysmal fast activity (PFA) followed by slowing, the latter emerging first occipitally, and then spreading more anteriorly. Generalized spike-and-wave discharges (GSWDs) were evident on both sc-EEG and ic-EEG within two minutes, but focal occipital discharges were already increased on ic-EEG after 15 s. Occipital slowing emerged on ic-EEG after 30 s, before spreading fronto-centrally and orbito-frontally. By 60-120 seconds post-injection, ic-EEG demonstrated a parieto-occipital burst suppression (BS), which was not noted on sc-EEG. Ketamine waves and seizures, especially if the latter were subclinical, also appeared earlier on ic-EEG. This study highlights the anesthetic and proconvulsant effects of ketamine originate in the occipital lobes before fronto-central regions. We speculate that NMDAR concentration difference in cortical regions, such as the occipital and frontal cortices, are mainly involved in the expression of ketamine's EEG effects, both physiological and epileptic.
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Mertens A, Raedt R, Gadeyne S, Carrette E, Boon P, Vonck K. Recent advances in devices for vagus nerve stimulation. Expert Rev Med Devices 2018; 15:527-539. [DOI: 10.1080/17434440.2018.1507732] [Citation(s) in RCA: 41] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Affiliation(s)
- Ann Mertens
- Department of Neurology, Ghent University Hospital, Gent, Belgium
| | - Robrecht Raedt
- Department of Neurology, Ghent University Hospital, Gent, Belgium
| | - Stefanie Gadeyne
- Department of Neurology, Ghent University Hospital, Gent, Belgium
| | - Evelien Carrette
- Department of Neurology, Ghent University Hospital, Gent, Belgium
| | - Paul Boon
- Department of Neurology, Ghent University Hospital, Gent, Belgium
| | - Kristl Vonck
- Department of Neurology, Ghent University Hospital, Gent, Belgium
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