1
|
Wessel CR, Karakas C, Haneef Z, Mutchnick I. Vagus nerve stimulation and heart rate variability: A scoping review of a somatic oscillatory signal. Clin Neurophysiol 2024; 160:95-107. [PMID: 38412747 DOI: 10.1016/j.clinph.2024.02.011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2023] [Revised: 02/01/2024] [Accepted: 02/11/2024] [Indexed: 02/29/2024]
Abstract
The goal of this review is to synthesize the literature on vagus nerve stimulator (VNS)-related changes in heart rate variability (HRV) in patients with drug-resistant epilepsy (DRE) and assess the role of these changes in seizure relief. A scoping literature review was performed with the following inclusion criteria: primary articles written in English, involved implantable VNS in humans, and had HRV as a primary outcome. Twenty-nine studies were retrieved, however with considerable heterogeneity in study methods. The overall depression in HRV seen in DRE patients compared to healthy controls persisted even after VNS implant, indicating that achieving "healthy" HRV is not necessary for VNS therapeutic success. Within DRE patients, changes in frequency domain parameters six months after VNS implant returned to baseline after a year. The mechanism of how VNS reduces seizure burden does not appear to be significantly related to alterations in baseline HRV. However, the subtlety of sympathetic/parasympathetic signaling likely requires a more structured approach to experimental and analytic techniques than currently found in the literature.
Collapse
Affiliation(s)
- Caitlin R Wessel
- University of Louisville School of Medicine, Louisville KY 40202, USA.
| | - Cemal Karakas
- University of Louisville School of Medicine, Louisville KY 40202, USA; Division of Pediatric Neurology, Department of Neurology, University of Louisville, Louisville KY 40202, USA; Norton Neuroscience Institute and Children's Hospital, Louisville KY 40241, USA
| | - Zulfi Haneef
- Department of Neurology, Baylor College, Houston TX 77030, USA; Michael E. DeBakey VA Medical Center, Houston, TX 77030, USA
| | - Ian Mutchnick
- University of Louisville School of Medicine, Louisville KY 40202, USA; Norton Neuroscience Institute and Children's Hospital, Louisville KY 40241, USA; University of Louisville Department of Neurosurgery, Louisville KY 40202, USA
| |
Collapse
|
2
|
Jigo M, Carmel JB, Wang Q, Rodenkirch C. Transcutaneous cervical vagus nerve stimulation improves sensory performance in humans: a randomized controlled crossover pilot study. Sci Rep 2024; 14:3975. [PMID: 38368486 PMCID: PMC10874458 DOI: 10.1038/s41598-024-54026-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2023] [Accepted: 02/07/2024] [Indexed: 02/19/2024] Open
Abstract
Accurate senses depend on high-fidelity encoding by sensory receptors and error-free processing in the brain. Progress has been made towards restoring damaged sensory receptors. However, methods for on-demand treatment of impaired central sensory processing are scarce. Prior invasive studies demonstrated that continuous vagus nerve stimulation (VNS) in rodents can activate the locus coeruleus-norepinephrine system to rapidly improve central sensory processing. Here, we investigated whether transcutaneous VNS improves sensory performance in humans. We conducted three sham-controlled experiments, each with 12 neurotypical adults, that measured the effects of transcutaneous VNS on metrics of auditory and visual performance, and heart rate variability (HRV). Continuous stimulation was delivered to cervical (tcVNS) or auricular (taVNS) branches of the vagus nerve while participants performed psychophysics tasks or passively viewed a display. Relative to sham stimulation, tcVNS improved auditory performance by 37% (p = 0.00052) and visual performance by 23% (p = 0.038). Participants with lower performance during sham conditions experienced larger tcVNS-evoked improvements (p = 0.0040). Lastly, tcVNS increased HRV during passive viewing, corroborating vagal engagement. No evidence for an effect of taVNS was observed. These findings validate the effectiveness of tcVNS in humans and position it as a method for on-demand interventions of impairments associated with central sensory processing dysfunction.
Collapse
Affiliation(s)
| | - Jason B Carmel
- Sharper Sense, Inc., New York, NY, USA
- Department of Neurology and Orthopedics, Columbia University Medical Center, New York, NY, USA
| | - Qi Wang
- Sharper Sense, Inc., New York, NY, USA
- Department of Biomedical Engineering, Columbia University, New York, NY, USA
| | - Charles Rodenkirch
- Sharper Sense, Inc., New York, NY, USA.
- The Jacobs Technion-Cornell Institute at Cornell Tech, New York, NY, USA.
| |
Collapse
|
3
|
Jigo M, Carmel JB, Wang Q, Rodenkirch C. Transcutaneous cervical vagus nerve stimulation improves sensory performance in humans. bioRxiv 2024:2023.08.08.552508. [PMID: 37609169 PMCID: PMC10441305 DOI: 10.1101/2023.08.08.552508] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/24/2023]
Abstract
Accurate senses depend on high-fidelity encoding by sensory receptors and error-free processing in the brain. Progress has been made towards restoring damaged sensory receptors. However, methods for on-demand treatment of impaired central sensory processing are scarce. Prior invasive studies demonstrated that continuous vagus nerve stimulation (VNS) in rodents can activate the locus coeruleus-norepinephrine system to rapidly improve central sensory processing. Here, we investigated whether transcutaneous VNS improves sensory performance in humans. We conducted three sham-controlled experiments, each with 12 neurotypical adults, that measured the effects of transcutaneous VNS on metrics of auditory and visual performance, and heart rate variability (HRV). Continuous stimulation was delivered to cervical (tcVNS) or auricular (taVNS) branches of the vagus nerve while participants performed psychophysics tasks or passively viewed a display. Relative to sham stimulation, tcVNS improved auditory performance by 37% (p=0.00052) and visual performance by 23% (p=0.038). Participants with lower performance during sham conditions experienced larger tcVNS-evoked improvements (p=0.0040). Lastly, tcVNS increased HRV during passive viewing, corroborating vagal engagement. No evidence for an effect of taVNS was observed. These findings validate the effectiveness of tcVNS in humans and position it as a method for on-demand interventions of impairments associated with central sensory processing dysfunction.
Collapse
Affiliation(s)
| | - Jason B. Carmel
- Sharper Sense, Inc., New York, NY
- Department of Neurology and Orthopedics, Columbia University Medical Center, New York, NY
| | - Qi Wang
- Sharper Sense, Inc., New York, NY
- Department of Biomedical Engineering, Columbia University, New York, NY
| | - Charles Rodenkirch
- Sharper Sense, Inc., New York, NY
- The Jacobs Technion-Cornell Institute at Cornell Tech, New York, NY
| |
Collapse
|
4
|
Yaghouby F, Jang K, Hoang U, Asgari S, Vasudevan S. Sex Differences in Vagus Nerve Stimulation Effects on Rat Cardiovascular and Immune Systems. Front Neurosci 2020; 14:560668. [PMID: 33240036 PMCID: PMC7677457 DOI: 10.3389/fnins.2020.560668] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2020] [Accepted: 09/22/2020] [Indexed: 01/09/2023] Open
Abstract
Background Investigations into the benefits of vagus nerve stimulation (VNS) through pre-clinical and clinical research have led to promising findings for treating several disorders. Despite proven effectiveness of VNS on conditions such as epilepsy and depression, understanding of off-target effects and contributing factors such as sex differences can be beneficial to optimize therapy design. New Methods In this article, we assessed longitudinal effects of VNS on cardiovascular and immune systems, and studied potential sex differences using a rat model of long-term VNS. Rats were implanted with cuff electrodes around the left cervical vagus nerve for VNS, and wireless physiological monitoring devices for continuous monitoring of cardiovascular system using electrocardiogram (ECG) signals. ECG morphology and heart rate variability (HRV) features were extracted to assess cardiovascular changes resulting from VNS in short-term and long-term timescales. We also assessed VNS effects on expression of inflammatory cytokines in blood during the course of the experiment. Statistical analysis was performed to compare results between Treatment and Sham groups, and between male and female animals from Treatment and Sham groups. Results Considerable differences between male and female rats in cardiovascular effects of VNS were observed in multiple cardiovascular features. However, the effects seemed to be transient with approximately 1-h recovery after VNS. While short-term cardiovascular effects were mainly observed in male rats, females in general showed more significant long-term effects even after VNS stopped. We did not observe notable changes or sex differences in systemic cytokine levels resulting from VNS. Comparison With Existing Methods Compared to existing methods, our study design incorporated wireless physiological monitoring and systemic blood cytokine level analysis, along with long-term VNS experiments in unanesthetized rats to study sex differences. Conclusion The contribution of sex differences for long-term VNS off-target effects on cardiovascular and immune systems was assessed using awake behaving rats. Although VNS did not change the concentration of inflammatory biomarkers in systemic circulation for male and female rats, we observed significant differences in cardiovascular effects of VNS characterized using ECG morphology and HRV analyses.
Collapse
Affiliation(s)
- Farid Yaghouby
- U.S. Food and Drug Administration, Center for Devices and Radiological Health (CDRH), Office of Science and Engineering Laboratory (OSEL), Division of Biomedical Physics (DBP), Silver Spring, MD, United States
| | - Kee Jang
- U.S. Food and Drug Administration, Center for Devices and Radiological Health (CDRH), Office of Science and Engineering Laboratory (OSEL), Division of Biomedical Physics (DBP), Silver Spring, MD, United States
| | - Uyen Hoang
- U.S. Food and Drug Administration, Center for Devices and Radiological Health (CDRH), Office of Science and Engineering Laboratory (OSEL), Division of Biomedical Physics (DBP), Silver Spring, MD, United States
| | - Sepideh Asgari
- U.S. Food and Drug Administration, Center for Devices and Radiological Health (CDRH), Office of Science and Engineering Laboratory (OSEL), Division of Biomedical Physics (DBP), Silver Spring, MD, United States
| | - Srikanth Vasudevan
- U.S. Food and Drug Administration, Center for Devices and Radiological Health (CDRH), Office of Science and Engineering Laboratory (OSEL), Division of Biomedical Physics (DBP), Silver Spring, MD, United States
| |
Collapse
|
5
|
Potruch A, Khoury ST, Ilan Y. The role of chronobiology in drug-resistance epilepsy: The potential use of a variability and chronotherapy-based individualized platform for improving the response to anti-seizure drugs. Seizure 2020; 80:201-11. [DOI: 10.1016/j.seizure.2020.06.032] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2020] [Revised: 06/27/2020] [Accepted: 06/30/2020] [Indexed: 12/16/2022] Open
|
6
|
|
7
|
Boswijk E, Franssen R, Vijgen GHEJ, Wierts R, van der Pol JAJ, Mingels AMA, Cornips EMJ, Majoie MHJM, van Marken Lichtenbelt WD, Mottaghy FM, Wildberger JE, Bucerius J. Short-term discontinuation of vagal nerve stimulation alters 18F-FDG blood pool activity: an exploratory interventional study in epilepsy patients. EJNMMI Res 2019; 9:101. [PMID: 31773320 PMCID: PMC6879675 DOI: 10.1186/s13550-019-0567-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2019] [Accepted: 10/16/2019] [Indexed: 11/15/2022] Open
Abstract
Background Vagus nerve activation impacts inflammation. Therefore, we hypothesized that vagal nerve stimulation (VNS) influenced arterial wall inflammation as measured by 18F-FDG uptake. Results Ten patients with left-sided VNS for refractory epilepsy were studied during stimulation (VNS-on) and in the hours after stimulation was switched off (VNS-off). In nine patients, 18F-FDG uptake was measured in the right carotid artery, aorta, bone marrow, spleen, and adipose tissue. Target-to-background ratios (TBRs) were calculated to normalize the respective standardized uptake values (SUVs) for venous blood pool activity. Median values are shown with interquartile range and compared using the Wilcoxon signed-rank test. Arterial SUVs tended to be higher during VNS-off than VNS-on [SUVmax all vessels 1.8 (1.5–2.2) vs. 1.7 (1.2–2.0), p = 0.051]. However, a larger difference was found for the venous blood pool at this time point, reaching statistical significance in the vena cava superior [meanSUVmean 1.3 (1.1–1.4) vs. 1.0 (0.8–1.1); p = 0.011], resulting in non-significant lower arterial TBRs during VNS-off than VNS-on. Differences in the remaining tissues were not significant. Insulin levels increased after VNS was switched off [55.0 pmol/L (45.9–96.8) vs. 48.1 pmol/L (36.9–61.8); p = 0.047]. The concurrent increase in glucose levels was not statistically significant [4.8 mmol/L (4.7–5.3) vs. 4.6 mmol/L (4.5–5.2); p = 0.075]. Conclusions Short-term discontinuation of VNS did not show a consistent change in arterial wall 18F-FDG-uptake. However, VNS did alter insulin and 18F-FDG blood levels, possibly as a result of sympathetic activation.
Collapse
Affiliation(s)
- Ellen Boswijk
- Department of Radiology and Nuclear Medicine, Maastricht University Medical Center (MUMC+), P. Debyelaan 25, 6229 HX, Maastricht, The Netherlands.,Cardiovascular Research Institute Maastricht (CARIM), Maastricht University, Universiteitssingel 50, 6229 ER, Maastricht, The Netherlands
| | - Renee Franssen
- Department of Radiology and Nuclear Medicine, Maastricht University Medical Center (MUMC+), P. Debyelaan 25, 6229 HX, Maastricht, The Netherlands
| | - Guy H E J Vijgen
- School of Nutrition and Translational Research in Metabolism (NUTRIM), Maastricht University, Universiteitssingel 40, 6229 ER, Maastricht, The Netherlands.,Department of Surgery, Erasmus Medical Center (EMC), Postbus 2040, 3000 CA, Rotterdam, The Netherlands
| | - Roel Wierts
- Department of Radiology and Nuclear Medicine, Maastricht University Medical Center (MUMC+), P. Debyelaan 25, 6229 HX, Maastricht, The Netherlands
| | - Jochem A J van der Pol
- Department of Radiology and Nuclear Medicine, Maastricht University Medical Center (MUMC+), P. Debyelaan 25, 6229 HX, Maastricht, The Netherlands
| | - Alma M A Mingels
- Department of Clinical Chemistry, Maastricht University Medical Center (MUMC+), P. Debyelaan 25, 6229 HX, Maastricht, The Netherlands
| | - Erwin M J Cornips
- Department of Neurosurgery, Maastricht University Medical Center (MUMC+), P. Debyelaan 25, 6229 HX, Maastricht, The Netherlands
| | - Marian H J M Majoie
- Department of Research & Development, Epilepsy Center Kempenhaeghe, Sterkselseweg 65, 5591 VE, Heeze, The Netherlands.,Department of Neurology, Academic Center for Epileptology, Epilepsy Center Kempenhaeghe & Maastricht University Medical Center (MUMC+), P. Debyelaan 25, 6229 HX, Maastricht, The Netherlands.,MHENS School of Mental Health & Neuroscience, Maastricht University, Universiteitssingel 40, 6229 ER, Maastricht, The Netherlands.,School of Health Professions Education, Faculty of Health, Medicine and Life Sciences, Maastricht University, Universiteitssingel 60, 6229 ER, Maastricht, The Netherlands
| | - Wouter D van Marken Lichtenbelt
- School of Nutrition and Translational Research in Metabolism (NUTRIM), Maastricht University, Universiteitssingel 40, 6229 ER, Maastricht, The Netherlands
| | - Felix M Mottaghy
- Department of Radiology and Nuclear Medicine, Maastricht University Medical Center (MUMC+), P. Debyelaan 25, 6229 HX, Maastricht, The Netherlands.,Department of Nuclear Medicine, University Hospital RWTH Aachen, Pauwelsstraße 30, 52074, Aachen, Germany
| | - Joachim E Wildberger
- Department of Radiology and Nuclear Medicine, Maastricht University Medical Center (MUMC+), P. Debyelaan 25, 6229 HX, Maastricht, The Netherlands.,Cardiovascular Research Institute Maastricht (CARIM), Maastricht University, Universiteitssingel 50, 6229 ER, Maastricht, The Netherlands
| | - Jan Bucerius
- Department of Radiology and Nuclear Medicine, Maastricht University Medical Center (MUMC+), P. Debyelaan 25, 6229 HX, Maastricht, The Netherlands. .,Cardiovascular Research Institute Maastricht (CARIM), Maastricht University, Universiteitssingel 50, 6229 ER, Maastricht, The Netherlands. .,Department of Nuclear Medicine, Georg-August University Göttingen, Robert-Koch-Strasse 40, 37075, Göttingen, Germany.
| |
Collapse
|
8
|
Constantinescu V, Matei D, Constantinescu I, Cuciureanu DI. Heart Rate Variability and Vagus Nerve Stimulation in Epilepsy Patients. Transl Neurosci 2019; 10:223-232. [PMID: 31497318 PMCID: PMC6708288 DOI: 10.1515/tnsci-2019-0036] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2019] [Accepted: 07/23/2019] [Indexed: 01/01/2023] Open
Abstract
Background Vagus nerve stimulation (VNS) exerts a cortical modulating effect through its diffuse projections, especially involving cerebral structures related to autonomic regulation. The influence of VNS on cardiovascular autonomic function in drug-resistant epilepsy patients is still debated. We aimed to evaluate the impact of VNS on cardiovascular autonomic function in drug-resistant epilepsy patients, after three months of neurostimulation, using the heart rate variability (HRV) analysis. Methodology Multiple Trigonometric Regressive Spectral analysis enables a precise assessment of the autonomic control on the heart rate. We evaluated time and frequency-domain HRV parameters in resting condition and during sympathetic and parasympathetic activation tests in five epilepsy patients who underwent VNS procedure. Results We found appropriate cardiac autonomic responses to sympathetic and parasympathetic activation tests, described by RMSSD, pNN50, HF and LF/HF dynamics after three months of VNS. ON period of the neurostimulation may generate a transient vagal activation reflected on heart rate and RMSSD values, as observed in one of our cases. Conclusion VNS therapy in epilepsy patients seems not to disrupt the cardiac autonomic function. HRV represents a useful tool in evaluating autonomic activity. More extensive studies are needed to further explore cardiac autonomic response after neurostimulation.
Collapse
Affiliation(s)
- Victor Constantinescu
- Neurology Department, Faculty of Medicine, University of Medicine and Pharmacy Iasi, Iasi Romania
| | - Daniela Matei
- Department of Biomedical Sciences, Faculty of Medical Bioengineering, University of Medicine and Pharmacy Iasi, Iasi Romania
| | | | - Dan Iulian Cuciureanu
- Neurology Department, Faculty of Medicine, University of Medicine and Pharmacy Iasi, Iasi Romania
| |
Collapse
|
9
|
Hirfanoglu T, Serdaroglu A, Cetin I, Kurt G, Capraz IY, Ekici F, Arhan E, Bilir E. Effects of vagus nerve stimulation on heart rate variability in children with epilepsy. Epilepsy Behav 2018; 81:33-40. [PMID: 29462779 DOI: 10.1016/j.yebeh.2018.01.036] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/22/2017] [Revised: 01/22/2018] [Accepted: 01/26/2018] [Indexed: 11/16/2022]
Abstract
PURPOSE The aim of this study was to evaluate the effects of vagus nerve stimulation (VNS) on heart rate variability (HRV) in children with epilepsy. METHODS The subgroups of HRV, namely time domain (Standard deviation of NN interval (SDNN), SDNN index, Standard deviation of the averages of NN intervals (SDANN), Root mean square of successive differences (RMMSD), Adjacent NN intervals differing by more than 50 ms in the entire recording divided by the total number of all NN intervals (PNN50), triangular index) and frequency domain (Low-frequency (LF), High-frequency (HF), LF/HF), were investigated in 20 pediatric patients before and after 6 and 12months of VNS treatment during day and night by comparing their data with those of 20 control subjects. In addition, subgroups of age, epilepsy duration and localization, and antiepileptic drugs (AEDs) were also evaluated if they had further effects on basal HRV levels. RESULTS Increased heart rates (HRs); decreased SDNN, SDANN, RMMSD, and PNN50; and increased LF/HF ratios were identified before VNS therapy (p<0.05). Even though remarkable improvement was seen after 6months of VNS treatment (p<0.05), no further changes were observed in 12-month compared with 6-month levels (p>0.05) in all parameters, still even significantly lower than those of controls (p<0.05). Longer duration of epilepsy and localization of epileptic focus, such as in the temporal lobe, were also found to further contribute to diminished basal HRV levels (p<0.05). CONCLUSION The cardiovascular system is under deep sympathetic influence in children with epilepsy. Although VNS seems to provide a substantial improvement by achieving increased parasympathetic effects in short-term therapy, the levels were still lower than those of healthy children after either short- or long-term therapy. Therefore, impaired cardiovascular autonomic regulation may be associated with the epileptic process itself as well as with the contribution of some additional factors. Overall, different aspects such as age, epilepsy duration, epileptic focus, seizure frequency, and AEDs should also be considered for their further possible effects on HRV during VNS therapy.
Collapse
Affiliation(s)
- Tugba Hirfanoglu
- Gazi University School of Medicine, Department of Pediatric Neurology, Ankara, Turkey.
| | - Ayse Serdaroglu
- Gazi University School of Medicine, Department of Pediatric Neurology, Ankara, Turkey
| | - Ilker Cetin
- Ankara Children's Hematology Oncology Training and Research Hospital, Department of Pediatric Cardiology, Ankara, Turkey
| | - Gokhan Kurt
- Gazi University School of Medicine, Department of Neurosurgery, Ankara, Turkey
| | - Irem Y Capraz
- Gazi University School of Medicine, Department of Neurology, Ankara, Turkey
| | - Filiz Ekici
- Akdeniz University School of Medicine, Department of Pediatric Cardiology, Antalya, Turkey
| | - Ebru Arhan
- Gazi University School of Medicine, Department of Pediatric Neurology, Ankara, Turkey
| | - Erhan Bilir
- Gazi University School of Medicine, Department of Neurology, Ankara, Turkey
| |
Collapse
|
10
|
Garamendi-Ruiz I, Gómez-Esteban JC. Cardiovascular autonomic effects of vagus nerve stimulation. Clin Auton Res 2017; 29:183-194. [DOI: 10.1007/s10286-017-0477-8] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2017] [Accepted: 10/09/2017] [Indexed: 12/15/2022]
|
11
|
Abstract
BACKGROUND: The vagus nerve stimulation (VNS) is an approach mainly used in cases of intractable epilepsy despite all the efforts. Also, its benefits have been shown in severe cases of depression resistant to typical treatment. AIM: The aim of this study was to present current knowledge of vagus nerve stimulation. MATERIAL AND METHODS: A new value has emerged just at this stage: VNS aiming the ideal treatment with new hopes. It is based on the placement of a programmable generator on the chest wall. Electric signals from the generator are transmitted to the left vagus nerve through the connection cable. Control on the cerebral bioelectrical activity can be achieved by way of these signal sent from there in an effort for controlling the epileptic discharges. RESULTS: The rate of satisfactory and permanent treatment in epilepsy with monotherapy is around 50%. This rate will increase by one-quarters (25%) with polytherapy. However, there is a patient group roughly constituting one-thirds of this population, and this group remains unresponsive or refractory to all the therapies and combined regimes. The more the number of drugs used, the more chaos and side effects are observed. The anti-epileptic drugs (AEDs) used will have side effects on both the brain and the systemic organs. Cerebral resection surgery can be required in some patients. The most commonly encountered epilepsy type is the partial one, and the possibility of benefiting from invasive procedures is limited in most patients of this type. Selective amygdala-hippocampus surgery is a rising value in complex partial seizures. Therefore, as epilepsy surgery can be performed in very limited numbers and rather developed centres, success can also be achieved in limited numbers of patients. The common ground for all the surgical procedures is the target of preservation of memory, learning, speaking, temper and executive functions as well as obtaining a good control on seizures. However, the action mechanism of VNS is still not exactly known. On the other hand, it appears to be a reliable method that is tolerated well in partial resistant seizures. It has been observed that adverse effects are generally of mild-medium severity, and most of the problems can be eliminated easily through the re-adjustment of the stimulator. CONCLUSION: VNS, which is a treatment modality that will take place it deserves in epilepsy treatment with “the correct patient” and “correct reason”, must be known better and its applications must be developed.
Collapse
Affiliation(s)
- Hakan Ekmekçi
- Selcuk University, Faculty of Medicine, Department of Neurology, Konya, Turkey
| | - Hülagu Kaptan
- Dokuz Eylül University, Medical Faculty, Inciralti 35340, Izmir, Turkey
| |
Collapse
|
12
|
Garamendi I, Acera M, Agundez M, Galbarriatu L, Marinas A, Pomposo I, Valle E, Palma JA, Gomez-Esteban JC. Cardiovascular autonomic and hemodynamic responses to vagus nerve stimulation in drug-resistant epilepsy. Seizure 2016; 45:56-60. [PMID: 27919011 DOI: 10.1016/j.seizure.2016.11.018] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2016] [Revised: 11/20/2016] [Accepted: 11/22/2016] [Indexed: 10/20/2022] Open
Abstract
PURPOSE Vagus nerve stimulation (VNS) is used as an adjunctive therapy for treating patients with drug-resistant epilepsy. The impact of VNS on cardiovascular autonomic function remains to be fully understood. We determined changes in cardiovascular sympathetic and parasympathetic, and hemodynamic function in association with VNS in patients with drug-resistant focal epilepsy. METHOD Longitudinal (n=15) evaluation of beat-to-beat blood pressure (BP) and heart rate variability (HRV), baroreflex sensibility, and hemodynamic function performed before VNS implantation, 6-months after implantation, and a mean of 12-months after implantation; and cross-sectional study (n=14) of BP and HR variability and baroreflex sensitivity during VNS on and VNS off. RESULTS In the longitudinal study, no differences were observed between the baseline, the 6-month visit, and the final visit in markers of parasympathetic cardiovagal tone or baroreflex sensitivity. Systolic and diastolic BP upon 5-min of head-up tilt increased significantly after VNS implantation (Systolic BP: -16.69±5.65mmHg at baseline, 2.86±16.54mmHg at 6-month, 12.25±12.95mmHg at final visit, p=0.01; diastolic BP: -14.84±24.72mmHg at baseline, 0.86±16.97mmHg at 6-month, and 17±12.76mmHg at final visit, p=0.001). CONCLUSION VNS does not seem to produce alterations in parasympathetic cardiovagal tone, regardless of the laterality of the stimulus. We observed a slight increase in sympathetic cardiovascular modulations. These changes had no significant hemodynamic implications. These findings contribute to the understanding of potential mechanisms of action of VNS.
Collapse
Affiliation(s)
- Iñigo Garamendi
- Epilepsy Unit, Biocruces Research Institute, Barakado, Bizkaia, Spain.
| | - Marian Acera
- Epilepsy Unit, Biocruces Research Institute, Barakado, Bizkaia, Spain
| | - Marta Agundez
- Epilepsy Unit, Biocruces Research Institute, Barakado, Bizkaia, Spain
| | | | - Ainhoa Marinas
- Epilepsy Unit, Biocruces Research Institute, Barakado, Bizkaia, Spain
| | - Iñigo Pomposo
- Department of Neurosurgery, Cruces University Hospital, Spain
| | - Elena Valle
- Epilepsy Unit, Biocruces Research Institute, Barakado, Bizkaia, Spain
| | - Jose-Alberto Palma
- Dysautonomia Center, Department of Neurology, New York University Medical Center, New York, NY, USA
| | - Juan C Gomez-Esteban
- Autonomic and Movement Disorders Unit, Biocruces Research Institute, Barakado, Bizkaia, Spain; Department of Neurosciences, University of Basque Country, Leioa, Spain.
| |
Collapse
|
13
|
Jansen K, Vandeput S, Milosevic M, Ceulemans B, Van Huffel S, Brown L, Penders J, Lagae L. Autonomic effects of refractory epilepsy on heart rate variability in children: influence of intermittent vagus nerve stimulation. Dev Med Child Neurol 2011; 53:1143-9. [PMID: 21883174 DOI: 10.1111/j.1469-8749.2011.04103.x] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
AIM Vagus nerve stimulation (VNS) is a therapeutic option for individuals with refractory epilepsy. Individuals with refractory epilepsy are prone to dysfunction of the autonomic nervous system. Reduced heart rate variability is a marker of dysfunction of the autonomic nervous system. Our goal was to study heart rate variability in children with refractory epilepsy and the influence of VNS on this parameter. METHODS In 17 children (13 male; four female; mean age 7 y 6 mo; age range 3-16 y) with refractory epilepsy, electroencephalographic and electrocardiographic data were obtained before and after implantation of VNS during stage 2 and slow-wave sleep. Time and frequency domain parameters were calculated and the results were compared with an age- and sex-matched group of individuals without refractory epilepsy. RESULTS Our results show that autonomic cardiac control is affected in individuals with refractory epilepsy. There is a striking reduction in vagal tone during slow-wave sleep and modulation capacity is smaller than in individuals without refractory epilepsy. Implantation of VNS induces a shift in sympathovagal balance towards sympathetic predominance and an improvement in autonomic modulation. INTERPRETATION Heart rate variability is affected in children with refractory epilepsy, and changes after implantation of VNS. The observed changes could be of importance in the cardiac complications of individuals with epilepsy and should be explored in more detail.
Collapse
Affiliation(s)
- Katrien Jansen
- Department of Pediatric Neurology, University Hospitals Leuven, Leuven, Belgium
| | | | | | | | | | | | | | | |
Collapse
|
14
|
Cadeddu C, Deidda M, Mercuro G, Tuveri A, Muroni A, Nocco S, Puligheddu M, Maleci A, Marrosu F. Cardiovascular modulation during vagus nerve stimulation therapy in patients with refractory epilepsy. Epilepsy Res 2010; 92:145-52. [DOI: 10.1016/j.eplepsyres.2010.08.012] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2010] [Revised: 07/12/2010] [Accepted: 08/22/2010] [Indexed: 11/21/2022]
|
15
|
Abstract
Epilepsy and seizures can have a dramatic effect on the autonomic nervous system by involvement of the central autonomic control centers. The peri-ictal changes can lead to short-term alteration of cardiac functions in patients with seizures, and are partially hemispheric specific. Changes in heart rhythm, conduction and even subtle signs of ischemia have been reported. Ictal asystole and the lock-step phenomenon during seizures play an important role in the pathophysiology of SUDEP. In patients with longlasting epilepsy and multiple seizures, there are now convincing arguments for a chronic dysfunction of the autonomic nervous system. In this sense, heart rate variability can be considered as a biomarker of autonomic dysfunction in epilepsy. Early recognition of these short- and long-term cardiac effects will become useful in predicting seizures and in guiding more individualized treatment in the near future.
Collapse
Affiliation(s)
- K Jansen
- University Hospitals Leuven, Herestraat 49, 3000 Leuven, Belgium
| | | |
Collapse
|
16
|
Müller H, Demling JH, Schütz P, Weigel D, Kornhuber J, Sperling W. Safety of vagus nerve stimulation in a patient with bipolar disorder and an implanted cardioverter-defibrillator. Acta Neurol Scand 2010; 121:285-6; author reply 287-8. [PMID: 20175760 DOI: 10.1111/j.1600-0404.2010.01328.x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
|
17
|
|
18
|
Abstract
Seizures frequently affect the heart rate and rhythm. In most cases, seizure-related cardiac changes are transient and do not appear to cause clinically significant abnormalities for the patient. Great interest in this area of research has been generated because of a possible connection with sudden unexpected death in epilepsy (SUDEP). While there are clear, but rare complications from seizure-related cardiac arrhythmias, such as ictal asystole that causes syncope, the overall risk of seizures on cardiac status and any potential connection between seizures and SUDEP still remain uncertain.
Collapse
Affiliation(s)
- Maromi Nei
- Jefferson Comprehensive Epilepsy Center Philadelphia, Pennsylvania, USA.
| |
Collapse
|
19
|
Borusiak P, Zilbauer M, Cagnoli S, Heldmann M, Jenke A. Late-onset cardiac arrhythmia associated with vagus nerve stimulation. J Neurol 2009; 256:1578-80. [PMID: 19430856 DOI: 10.1007/s00415-009-5162-y] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2008] [Revised: 04/16/2009] [Accepted: 04/27/2009] [Indexed: 10/20/2022]
|
20
|
Milby AH, Halpern CH, Baltuch GH. Vagus nerve stimulation in the treatment of refractory epilepsy. Neurotherapeutics 2009; 6:228-37. [PMID: 19332314 PMCID: PMC5084198 DOI: 10.1016/j.nurt.2009.01.010] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2008] [Revised: 01/16/2009] [Accepted: 01/17/2009] [Indexed: 10/21/2022] Open
Abstract
Many patients with epilepsy suffer from persistent seizures despite maximal anti-epileptic drug therapy. Chronic, intermittent vagus nerve stimulation has been proven to be an effective option for many patients suffering from refractory seizures who are not candidates for surgical resection. Although only a small minority of patients will be entirely seizure-free, vagus nerve stimulation, as an adjunct to medical therapy, may result in significant improvements in quality of life. Vagus nerve stimulation is generally well-tolerated, as device implantation is associated with a low rate of perioperative complications, and the majority of side effects are stimulation-dependent and thus reversible.
Collapse
Affiliation(s)
- Andrew H. Milby
- grid.412713.20000000404351019Department of Neurosurgery, Center for Functional and Restorative Neurosurgery, University of Pennsylvania Medical Center, 19104 Philadelphia, Pennsylvania
| | - Casey H. Halpern
- grid.412713.20000000404351019Department of Neurosurgery, Center for Functional and Restorative Neurosurgery, University of Pennsylvania Medical Center, 19104 Philadelphia, Pennsylvania
| | - Gordon H. Baltuch
- grid.412713.20000000404351019Department of Neurosurgery, Center for Functional and Restorative Neurosurgery, University of Pennsylvania Medical Center, 19104 Philadelphia, Pennsylvania
- grid.411115.10000000404350884Department of Neurosurgery, 3 Silverstein, Hospital of the University of Pennsylvania, 3400 Spruce Street, 19104 Philadelphia, PA
| |
Collapse
|
21
|
Abstract
Cardiac changes may occasionally occur during vagus nerve stimulation (VNS) used in epileptic patients. As they can be potentially life-threatening, it is important to detect them, and this is why an intraoperative test is performed during the implantation. Few cases of asystole during this test have been described. Only one patient with late-onset bradyarrythmia caused by VNS has been reported. This patient had been implanted 2 years and 4 months before the episode. We present another case of late asystole in a patient whose VNS had been implanted 9 years before the arrhythmia onset. In our patient, each run of stimulation produced bradyarrhythmias and very often severe asystolia due to atrium-ventricular block.
Collapse
Affiliation(s)
- Jorge Iriarte
- Epilepsy Section, Clinica Universitaria, University of Navarra, Pamplona, Spain.
| | | | | | | | | | | | | | | |
Collapse
|
22
|
|