Active Vagus Nerve Stimulation Research Articles

Vagus Nerve Stimulation Paired With Rehabilitation for Chronic Stroke: Characterizing Responders.

Implantable vagus nerve stimulation (VNS) paired with volitional upper extremity rehabilitation can improve impairment and function among moderately to severely impaired, chronic stroke survivors. This study is a retrospective analysis of the in-clinic rehabilitation phase of the blinded, placebo-controlled, randomized pivotal VNS-REHAB trial to determine whether dosing parameters during in-clinic paired VNS therapy were associated with responder status and whether covariates might impact that determination. Data were limited to 53 participants in the active VNS group who had received VNS implants prior to undergoing 6weeks of in-clinic rehabilitation paired with VNS. Tasks were standardized across all participants. Dosing parameters included number of stimulations and task time. The primary outcome was the Fugl-Meyer Upper Extremity Assessment (FMA-UE), evaluated at the end of 6weeks (Post-1). Participants were classified a priori as responders based on an improvement of≥6 points on the FMA-UE from baseline to Post-1. Dosing parameters were not associated with FMA-UE responder status at the end of 6weeks. Covariates including age, gender, paretic hand, baseline severity, and chronicity of stroke were also not significant associations of response. While responders to VNS could be defined, therapy dosing and participant attributes did not provide greater specification for association of responder status. Limitations of this study include small sample size and non-linearity of the FMA-UE. Future studies will include reassessing responder categorization using more linear scales and examining stroke lesion characteristics to determine whether these measures are more sensitive to dosing parameters. for more insights from the authors (see the Video, Supplemental Digital Content 1, available at: http://www.w3.org/1999/xlink).

Vagus Nerve Stimulation Paired With Upper Extremity Rehabilitation for Chronic Ischemic Stroke: Contribution of Dosage Parameters.

Vagus nerve stimulation (VNS) combined with rehabilitation is a Food and Drug Administration approved intervention for moderate to severe upper extremity deficits in chronic ischemic stroke patients. Previous studies demonstrated that VNS improves upper extremity motor impairments, using the Fugl Meyer Assessment of Upper Extremity (FMA-UE); however, delineating where these improvements occur, and the role of VNS dosage parameters were not reported. This study explored the relationship between dosing (time over which task repetitions were executed and number of VNS stimulations) and changes within proximal and distal components of the FMA-UE. Participants underwent VNS implantation, with 1 group receiving VNS paired with rehabilitation (Active VNS) and the other group receiving rehabilitation with sham stimulation (Controls). Both groups received 6 weeks of in-clinic therapy followed by a 90-day at-home, self-rehabilitation program. Participants who completed at least 12 of 18 in-clinic sessions were included in the analyses (n = l06). Pearson correlations and analysis of covariance were used to investigate the relationship between dosing and FMA-UE outcome change along with the effect of covariates including baseline severity, time since stroke, age, and paretic side. Compared to Controls, active VNS favorably influenced distal function with sustained improvement after the home program. Significant improvements were observed in only distal components (FMdist) at both post day-1 (1.80 points, 95% Cl [0.85, 2.73], P < .001) and post-day 90 (1.62 points, 95% CI [0.45, 2.80], P < .007). VNS paired with rehabilitation resulted in significant improvements in wrist and hand impairment compared to Controls, despite similar in-clinic dosing across both groups.NCT03131960.

Direct vagus nerve stimulation: A new tool to control allergic airway inflammation through α7 nicotinic acetylcholine receptor.

Asthma is characterized by airway inflammation, mucus hypersecretion, and airway hyperresponsiveness. The use of nicotinic agents to mimic the cholinergic anti-inflammatory pathway (CAP) controls experimental asthma. Yet, the effects of vagus nerve stimulation (VNS)-induced CAP on allergic inflammation remain unknown. BALB/c mice were sensitized and challenged with house dust mite (HDM) extract and treated with active VNS (5Hz, 0.5ms, 0.05-1mA). Bronchoalveolar lavage (BAL) fluid was assessed for total and differential cell counts and cytokine levels. Lungs were examined by histopathology and electron microscopy. In the HDM mouse asthma model, VNS at intensities equal to or above 0.1mA (VNS 0.1) but not sham VNS reduced BAL fluid differential cell counts and alveolar macrophages expressing α7 nicotinic receptors (α7nAChR), goblet cell hyperplasia, and collagen deposition. Besides, VNS 0.1 also abated HDM-induced elevation of type 2 cytokines IL-4 and IL-5 and was found to block the phosphorylation of transcription factor STAT6 and expression level of IRF4 in total lung lysates. Finally, VNS 0.1 abrogated methacholine-induced hyperresponsiveness in asthma mice. Prior administration of α-bungarotoxin, a specific inhibitor of α7nAChR, but not propranolol, a specific inhibitor of β2-adrenoceptors, abolished the therapeutic effects of VNS 0.1. Our data revealed the protective effects of VNS on various clinical features in allergic airway inflammation model. VNS, a clinically approved therapy for depression and epilepsy, appears to be a promising new strategy for controlling allergic asthma.

Abstract 118: Vagus Nerve Stimulation Paired With Rehabilitation for Post-Stroke Arm Impairment: One Year Follow-Up of the VNS-REHAB Pivotal Trial

Background: Persistent post-stroke impairment of the arm and hand is debilitating after stroke. Pairing vagus nerve stimulation (VNS) with upper extremity (UE) rehabilitation improves such deficits after 5 months and was approved by the FDA in 2021. Here, we present 1-year outcomes from the VNS-REHAB pivotal trial. Methods: Stroke participants with moderate-to-severe UE impairment were randomized to task-specific rehabilitation plus either active VNS (n=53, VNS) or sham VNS (n=55, Control). After baseline assessment (Pre-therapy), both groups did 6 wk. of in-clinic therapy followed by a 3-mo. home exercise program combined with active or sham VNS (post90). Controls then crossed over to receive 6 wk. of active VNS followed by a 3-mo. home exercise program (Cross-over post90). Both groups continued active VNS with a home exercise program through 1 year, after which change from Pre-therapy baseline in Fugl-Meyer Assessment-Upper Extremity (FMA-UE) and Wolf Motor Function Test (WMFT) scores were obtained. To determine whether participants made additional gains, 1 year outcome scores (n=70) were also compared to post90 (n=38, VNS) and Cross-over post90 (n=32, Control) scores. Data was available from 74 participants at one year, with others not available mainly due to COVID-19. Results: At 1-year, both FMA-UE and WMFT scores improved from Pre-therapy baseline by 5.3±6.9 (CI=3.7-6.9, p&lt;0.001) and 0.51±0.52 (CI=0.39-0.63, p&lt;0.001) points, respectively. FMA-UE change at 1-year was not significantly different from the post90 (VNS) and Cross-over post90 (control) timepoints (n=70, mean difference: -0.3±4.1, CI=-1.3-0.67, p=0.52), but WMFT was, by an additional 0.09 points (n=70, mean difference: 0.09±0.35, CI=0.01-0.18, p=0.03), indicating that participants either improved or maintained motor gains through 1 year. Conclusion: Improvements in arm and hand function with VNS were maintained at 1-year follow-up, supporting use of VNS paired with rehabilitation as a long-term treatment option for individuals with post-stroke UE impairment. Limitations include sample size and lack of details of therapeutic regimens over the long term. Future studies and an ongoing clinical registry will explore the long-term impact of active VNS in real-world settings.

Safety of vagus nerve stimulation and responsive neurostimulation used in combination for multifocal and generalized onset epilepsy in pediatric patients.

The aim of this study was to assess the safety and efficacy of combined active responsive neurostimulation (RNS) and vagus nerve stimulation (VNS) therapies in pediatric patients with drug-resistant epilepsy. A single-center retrospective chart review was conducted on pediatric patients implanted with the RNS System with a concomitant active VNS System (VNS+RNS) between 2015 and 2021. Patients with at least 1 month of overlapping concomitant VNS and RNS treatment were included. Patients who had an RNS device implanted after 21 years of age, those who had responsive neurostimulators implanted after their VNS was inactivated, or those in whom the VNS battery died and was not replaced before RNS System implantation were excluded. Seven pediatric VNS+RNS patients were identified, and their courses of treatment were evaluated. All patients tolerated concurrent VNS and RNS treatment well, no device-device interactions were identified, and no major treatment-related adverse effects were noted. The median follow-up after RNS System implantation was 1.2 years. By electroclinical criteria, all 7 patients achieved 75%-99% reductions in the frequency of disabling seizures after RNS System implantation. By patient and caregiver report, 2 patients (28.6%) had 75%-99% reductions in the frequency of their disabling seizures, 2 patients (28.6%) achieved 50%-74% reductions, 2 patients achieved 1%-24% reduction in frequency of disabling seizures, and 1 patient (14.3%) experienced a 1%-24% increase in seizure frequency. The available VNS magnet swipe data identified 2 patients with 75%-99% reductions in seizure frequency as measured by magnet swipes, one with 25%-49% reductions and the other with 1%-24% increases in seizure frequency as measured by magnet swipes. This study demonstrated that RNS and VNS therapies can safely be used simultaneously in pediatric patients. RNS may potentially augment the therapeutic effects of VNS treatment. Patients in whom a response to VNS has been suboptimal should still be considered for RNS therapy.

Vagus Nerve Stimulation Paired With Rehabilitation for Upper Limb Motor Impairment and Function After Chronic Ischemic Stroke: Subgroup Analysis of the Randomized, Blinded, Pivotal, VNS-REHAB Device Trial

Background Vagus Nerve Stimulation (VNS) paired with rehabilitation improved upper extremity impairment and function in a recent pivotal, randomized, triple-blind, sham-controlled trial in people with chronic arm weakness after stroke. Objective We aimed to determine whether treatment effects varied across candidate subgroups, such as younger age or less injury. Methods Participants were randomized to receive rehabilitation paired with active VNS or rehabilitation paired with sham stimulation (Control). The primary outcome was the change in impairment measured by the Fugl–Meyer Assessment Upper Extremity (FMA-UE) score on the first day after completion of 6-weeks in-clinic therapy. We explored the effect of VNS treatment by sex, age (≥62 years), time from stroke (>2 years), severity (baseline FMA-UE score >34), paretic side of body, country of enrollment (USA vs UK) and presence of cortical involvement of the index infarction. We assessed whether there was any interaction with treatment. Findings The primary outcome increased by 5.0 points (SD 4.4) in the VNS group and by 2.4 points (SD 3.8) in the Control group (P = .001, between group difference 2.6, 95% CI 1.03-4.2). The between group difference was similar across all subgroups and there were no significant treatment interactions. There was no important difference in rates of adverse events across subgroups. Conclusion The response was similar across subgroups examined. The findings suggest that the effects of paired VNS observed in the VNS-REHAB trial are likely to be consistent in wide range of stroke survivors with moderate to severe upper extremity impairment.

Vagus Nerve Stimulation Modulates Phase-Amplitude Coupling in Thalamic Local Field Potentials

ObjectiveThe antiseizure effects of vagus nerve stimulation (VNS) are thought to be mediated by the modulation of afferent thalamocortical circuitry. Cross-frequency phase-amplitude coupling (PAC) is a mechanism of hierarchical network coordination across multiple spatiotemporal scales. In this study, we leverage local field potential (LFP) recordings from the centromedian (CM) (n = 3) and anterior (ATN) (n = 2) nuclei in five patients with tandem thalamic deep brain stimulation and VNS to study neurophysiological changes in the thalamus in response to VNS. Materials and MethodsBipolar LFP data were recorded from contact pairs spanning target nuclei in VNS “on” and “off” states. ResultsActive VNS was associated with increased PAC between theta, alpha, and beta phase and gamma amplitude in CM (q < 0.05). Within the ATN, PAC changes also were observed, although these were less robust. In both nuclei, active VNS also modulated interhemispheric bithalamic functional connectivity. ConclusionsWe report that VNS is associated with enhanced PAC and coordinated interhemispheric interactions within and between thalamic nuclei, respectively. These findings advance understanding of putative neurophysiological effects of acute VNS and contextualize previous animal and human studies showing distributed cortical synchronization after VNS.

Dual-Device Neuromodulation in Epilepsy

Current methods of neuromodulation have been shown to reduce seizures in patients with drug-resistant epilepsy, and in a small percentage of patients it has rendered them seizure-free when surgical resection is not feasible. While polytherapy with antiseizure medication is not uncommon, dual neurostimulation has received limited attention. We set out to identify trends and changes in the use of dual neurostimulation to understand choosing device combinations. We reviewed the Mayo Clinic database in Florida of patients who underwent vagus nerve stimulation (VNS), deep brain stimulation (DBS), and responsive neurostimulation (RNS) from October 1998 through September 2021. The prevalence of active VNS with DBS or RNS was considered dual therapy. In total, 131 patients (71 female) underwent 164 VNS-associated procedures, 28 received RNS, and 8 received DBS (6 anterior thalamic DBS; 2 thalamic centromedian nucleus DBS). Active dual stimulation occurred in 3 of 28 patients who received RNS and 8 of 8 patients who received DBS (P= 0.006), mean duration of 28 and 16.3 months, respectively. Patients who received VNS-DBS were more likely to have a previous response to VNS (P= 0.025) and were unresponsive to more antiseizure medications (P= 0.020). The VNS-RNS group had focal seizures more likely to have electroclinical localization (P= 0.005) and more frequently underwent invasive electroencephalographic monitoring (P= 0.026). The ability to localize was the primary decision-maker in prompting RNS versus DBS. RNS surgery was more likely to be preceded by invasive electroencephalographic monitoring. Previous VNS responsiveness was more prominent in patients with DBS. Dual therapy was safe. Prospective multicenter studies of dual-device neuromodulation are needed.

Abstract 1: Vagus Nerve Stimulation Paired With Rehabilitation For Upper Limb Motor Function After Ischaemic Stroke: Sub-group Analysis Of The Randomised, Blinded, Pivotal, Vns-Rehab Device Trial.

Background: Vagus Nerve Stimulation (VNS) paired with rehabilitation improved upper extremity impairment and function in a recent pivotal, randomised, blinded, sham-controlled trial. Here we report post-hoc sub-group analyses from the VNS Rehab trial. We aimed to determine whether treatment effects were consistent across subgroups. Methods: VNS Rehab included 108 participants with moderate to severe arm /hand weakness, at least nine months after ischaemic stroke. They were randomised to receive rehabilitation paired with active VNS or rehabilitation paired with sham stimulation (Control). The primary outcome was the change in iFugl-Meyer Assessment Upper Extremity (FMA-UE) score on the first day after completion of in-clinic therapy. The trial was registered on ClinicalTrials.gov (NCT03131960). We explored the effect of VNS treatment by sex (n=70 males; n=38 females), age (≤ 65 or &gt;65 years)), time from stroke (median time, 2 years) and baseline FMA-UE score (&lt;=33 severe, &gt;33 moderate). We assessed whether there was any interaction with treatment. No hypotheses were specified prior to this analysis and no formal adjustment was made for multiplicity. Findings: On the first day after completion of in-clinic therapy, the mean (±SD) FMA-UE score increased by 5.0 points (SD 4.4) in the VNS group and by 2.4 points (SD 3.8) in the Control group (p=0.001, between group difference 2.6, 95% CI 1.03 to 4.2). The between group difference was similar across all subgroups (figure). No significant treatment interactions were observed with baseline characteristics. Interpretation: Participants with moderate to severe arm and hand impairment after ischaemic stroke showed clinically meaningful improvements in motor impairment and function with rehabilitation paired with VNS compared to rehabilitation with sham VNS. The response appeared similar across pre-defined subgroups of interest.

Pregnancy Outcomes in Refractory Epilepsy Patients with Vagus Nerve Stimulation: Long-Term Single-Center Experience.

Vagus nerve stimulation (VNS) has been employed worldwide as an adjunctive therapy in drug-resistant epilepsy patients. However, the mechanisms of VNS action potentially increase the risk of obstetric complications. The study presents the long-term single-center experience with pregnancies and childbirth in women with VNS for refractory epilepsy based on prospectively collected epileptologic data and a retrospective analysis of pregnancy, childbirth, and data about long-term child development. From a group of patients with VNS implanted for refractory epilepsy between October 1999 and January 2018, all the women of childbearing age (younger than 40 years) were identified. After checking their hospital records for data about any pregnancies, the women with confirmed childbirth during active VNS stimulation and their general practitioners were interviewed based on a prepared questionnaire regarding their gynecologic history, the course of pregnancy and childbirth, gestational week, birth weight and length, any congenital anomalies of the child, and the child's psychomotor development, school performance, and somatic health problems. From the group of 257 patients implanted with VNS for refractory epilepsy, 4 women (1.5%) became pregnant and gave birth (all on polypharmacotherapy). The mean interval from VNS implantation to birth was 44.3 months. Slight seizure worsening during the last trimester was reported in one woman. In one patient, acute caesarean section was required due to placental separation. Planned birth induction and caesarean section were used in the other two women because of their seizure disorder. No malfunction of the stimulation system was detected during pregnancy or after birth. No congenital malformations were observed. The two children who were of school age at the time of this study require special schooling. The study results confirmed a high rate of obstetric interventions in patients with VNS. Although no teratogenic effect of VNS has been proven, the higher incidence of children exposed to VNS needing special education requires attention.

Hypercapnic ventilatory response in epilepsy patients treated with VNS: A case-control study.

Central CO2 chemoreception (CCR), a major chemical drive for breathing, can be quantified with a CO2 re-breathing test to measure the hypercapnic ventilatory response (HCVR). An attenuated HCVR correlates with the severity of respiratory dysfunction after generalized convulsive seizures and is a potential biomarker for sudden unexpected death in epilepsy (SUDEP) risk. Vagus nerve stimulation (VNS) may reduce SUDEP risk, but for unclear reasons the risk remains higher during the first 2 years after implantation. The vagus nerve has widespread connections in the brainstem, including key areas related to CCR. Here we examined whether chronic electrical stimulation of the vagus nerve induces changes in CCR. We compared the HCVR in epilepsy patients with or without an active VNS in a sex- and age-matched case-control study. Eligible subjects were selected from a cohort of patients who previously underwent HCVR testing. The HCVR slope, change in minute ventilation (VE) with respect to change in end tidal (ET) CO2 (∆ VE/ ∆ ETCO2) during the test was calculated for each subject. Key variables were compared between the two groups. Univariate and multivariate analyses were carried out for HCVR slope as dependent variable. A total of 86subjects were in the study. HCVR slope was significantly lower in the cases compared to the controls. Cases had longer duration of epilepsy and higher number of anti-epileptic drugs (AEDs) tried during lifetime. Having active VNS and ETCO2 were associated with a low HCVR slope while high BMI was associated with high HCVR slope in both univariate and multivariate analyses. We found having an active VNS was associated with relatively attenuated HCVR slope. Although duration of epilepsy and number of AEDs tried during lifetime was significantly different between the groups, they were not predictors of HCVR slope in subsequent analysis. Chronic electrical stimulation of the vagus nerve by VNS may be associated with an attenuated CCR [Correction added on 24 November 2021, after first online publication: The preceding sentence has been revised from “Chronic electrical stimulation of VNS nerve by VNS…”]. A larger prospective study may help to establish the time course of this effect in relation to the time of VNS implantation, whether there is a causal relationship, and determine how it affects SUDEP risk.

Randomized Cross Over Study Assessing the Efficacy of Non-invasive Stimulation of the Vagus Nerve in Patients With Axial Spondyloarthritis Resistant to Biotherapies: The ESNV-SPA Study Protocol.

Axial spondyloarthritis (SpA), is a major cause of chronic pain and disability that profoundly alters the quality of life of patients. Nearly half of patients with SpA usually develop drug resistance. Non-pharmacological treatments targeting inflammation are an attractive alternative to drug administration. Vagus nerve stimulation (VNS), by promoting a cholinergic anti-inflammatory reflex holds promise for treating inflammatory disease. Inflammatory reflex signaling, which is enhanced by electrically stimulating the vagus nerve, significantly reduces cytokine production and attenuates disease severity in animal models of endotoxemia, sepsis, colitis, and other preclinical models of inflammatory diseases. It has been proposed that vagal efferent fibers release acetylcholine (Ach), which can interact with α7-subunit-containing nicotinic receptors expressed by tissue macrophages and other immune cells to rapidly inhibit the synthesis/release of pro-inflammatory cytokines such as TNFα, IL-1β, IL-6, and IL-18. External vagal nerve stimulation devices are now available that do not require surgery nor implantation to non-invasively stimulate the vagal nerve. This double-blind randomized cross-over clinical trial aims to study the change in SpA disease activity, according to Assessment in Ankylosing Spondylitis 20 (ASAS20) definition, after 12 weeks of non-invasive VNS treatment vs. non-specific dummy stimulation (control group). One hundred and twenty adult patients with drug resistant SpA, meeting the ASAS classification criteria, will be included in the study. Patients will be randomized into two parallel groups according to a cross over design: either active VNS for 12 weeks, then dummy stimulation for 12 weeks, or dummy stimulation for 12 weeks, then active VNS for 12 weeks. The two stimulation periods will be separated by a 4 weeks wash-out period. A transcutaneous auricular vagus nerve stimulator Tens Eco Plus SCHWA MEDICOTM France will be used in this study. The active VNS stimulation will be applied in the cymba conchae of the left ear upon the auricular branch of the vagus nerve, using low intensity (2–5 mA), once à week, during 1 h. Dummy stimulation will be performed under the same conditions and parameters as active VNS stimulation, but at an irrelevant anatomical site: the left ear lobule. This multicenter study was registered on ClinicalTrials.gov: NCT04286373.

Vagus nerve stimulation paired with rehabilitation for upper limb motor function after ischaemic stroke (VNS-REHAB): a randomised, blinded, pivotal, device trial

Long-term loss of arm function after ischaemic stroke is common and might be improved by vagus nerve stimulation paired with rehabilitation. We aimed to determine whether this strategy is a safe and effective treatment for improving arm function after stroke. In this pivotal, randomised, triple-blind, sham-controlled trial, done in 19 stroke rehabilitation services in the UK and the USA, participants with moderate-to-severe arm weakness, at least 9 months after ischaemic stroke, were randomly assigned (1:1) to either rehabilitation paired with active vagus nerve stimulation (VNS group) or rehabilitation paired with sham stimulation (control group). Randomisation was done by ResearchPoint Global (Austin, TX, USA) using SAS PROC PLAN (SAS Institute Software, Cary, NC, USA), with stratification by region (USA vs UK), age (≤30 years vs >30 years), and baseline Fugl-Meyer Assessment-Upper Extremity (FMA-UE) score (20-35 vs 36-50). Participants, outcomes assessors, and treating therapists were masked to group assignment. All participants were implanted with a vagus nerve stimulation device. The VNS group received 0·8 mA, 100 μs, 30 Hz stimulation pulses, lasting 0·5 s. The control group received 0 mA pulses. Participants received 6 weeks of in-clinic therapy (three times per week; total of 18 sessions) followed by a home exercise programme. The primary outcome was the change in impairment measured by the FMA-UE score on the first day after completion of in-clinic therapy. FMA-UE response rates were also assessed at 90 days after in-clinic therapy (secondary endpoint). All analyses were by intention to treat. This trial is registered at ClinicalTrials.gov, NCT03131960. Between Oct 2, 2017, and Sept 12, 2019, 108 participants were randomly assigned to treatment (53 to the VNS group and 55 to the control group). 106 completed the study (one patient for each group did not complete the study). On the first day after completion of in-clinic therapy, the mean FMA-UE score increased by 5·0 points (SD 4·4) in the VNS group and by 2·4 points (3·8) in the control group (between group difference 2·6, 95% CI 1·0-4·2, p=0·0014). 90 days after in-clinic therapy, a clinically meaningful response on the FMA-UE score was achieved in 23 (47%) of 53 patients in the VNS group versus 13 (24%) of 55 patients in the control group (between group difference 24%, 6-41; p=0·0098). There was one serious adverse event related to surgery (vocal cord paresis) in the control group. Vagus nerve stimulation paired with rehabilitation is a novel potential treatment option for people with long-term moderate-to-severe arm impairment after ischaemic stroke. MicroTransponder.

Vagus Nerve Stimulation Paired With Upper-Limb Rehabilitation After Stroke: One-Year Follow-up

Background. Vagus nerve stimulation (VNS) paired with rehabilitation may improve upper-limb impairment and function after ischemic stroke. Objective. To report 1-year safety, feasibility, adherence, and outcome data from a home exercise program paired with VNS using long-term follow-up data from a randomized double-blind study of rehabilitation therapy paired with Active VNS (n = 8) or Control VNS (n = 9). Methods. All people were implanted with a VNS device and underwent 6 weeks in clinic therapy with Control or Active VNS followed by home exercises through day 90. Thereafter, participants and investigators were unblinded. The Control VNS group then received 6 weeks in-clinic Active VNS (Cross-VNS group). All participants then performed an individualized home exercise program with self-administered Active VNS. Data from this phase are reported here. Outcome measures were Fugl-Meyer Assessment—Upper Extremity (FMA-UE), Wolf Motor Function Test (Functional and Time), Box and Block Test, Nine-Hole Peg Test, Stroke Impact Scale, and Motor Activity Log. Results. There were no VNS treatment–related serious adverse events during the long-term therapy. Two participants discontinued prior to receiving the full crossover VNS. On average, participants performed 200 ± 63 home therapy sessions, representing device use on 57.4% of home exercise days available for each participant. Pooled analysis revealed that 1 year after randomization, the FMA-UE score increased by 9.2 points (95% CI = 4.7 to 13.7; P = .001; n = 15). Other functional measures were also improved at 1 year. Conclusions. VNS combined with rehabilitation is feasible, with good long-term adherence, and may improve arm function after ischemic stroke.

Study protocol for a pivotal randomised study assessing vagus nerve stimulation during rehabilitation for improved upper limb motor function after stroke.

Vagus nerve stimulation (VNS) paired with a motor task improves motor outcome in rat stroke models. It is hypothesised that VNS delivered during rehabilitation will improve upper limb function compared to control rehabilitation therapy. Two pilot clinical studies demonstrated acceptable safety and feasibility of VNS paired with rehabilitation for improved upper limb function after stroke. Participants who received rehabilitation paired with VNS demonstrated clinically meaningful improvements in motor function that exceed gains seen among controls who received similar rehabilitation without VNS. These preliminary data support a larger pivotal trial. VNS-REHAB (VNS-Rehabilitation) is a pivotal, multi-site, double-blinded, randomised trial designed to evaluate safety and efficacy of VNS paired with upper limb rehabilitation after ischaemic stroke. The study will include up to 120 participants with upper limb weakness due to stroke nine months to 10 years prior. All participants will be implanted with a VNS device and randomised to receive either Active (0.8 mA) or Control VNS (0.0 mA) paired with upper limb rehabilitation. All participants receive 18 sessions of in-clinic therapy for six weeks, followed by a home-based therapy for three months. The rehabilitation therapy involves progressive, functionally based and intensive practice of hand and arm tasks. VNS is delivered during each movement repetition. After blinded follow-up is completed, the Active vagus nerve stimulation group continues with home-based Active VNS and the Control group receive six weeks of in-clinic therapy with Active VNS followed by home-based Active VNS. The primary efficacy endpoint will be the difference in Fugl-Meyer assessment-upper extremity scores between the Active VNS and Control VNS groups at the end of six weeks of in-clinic therapy. Additional secondary endpoints will also be measured. Safety will be assessed with analysis of adverse events and device complications during study participation. This pivotal trial will determine whether VNS paired with rehabilitation is a safe and effective treatment for improving arm function after stroke.Trial Registration: ClinicalTrials.gov, NCT03131960. Registered on 27 April 2017.

Magnetoencephalographic Source Localization of the Eye Area of the Motor Homunculus.

A patient with intractable epilepsy, previous right frontal resection, and active vagus nerve stimulation (VNS) developed new onset quasi-continuous twitching around the left eye. Electroencephalography showed no correlate to the orbicularis oculi twitches apart from myographic potentials at the left supraorbital and anterior frontal electrodes. Magnetoencephalography was performed using spatiotemporal signal space separation to suppress magnetic artifacts associated with the VNS apparatus. Magnetoencephalographic source imaging performed on the data back-averaged from the left supraorbital myographic potentials revealed an intrasulcal cortical generator situated in the posterior wall of the right precentral gyrus representing the eye area of the motor homunculus.

Vagus Nerve Stimulation Paired With Upper Limb Rehabilitation After Chronic Stroke

Background and Purpose- We assessed safety, feasibility, and potential effects of vagus nerve stimulation (VNS) paired with rehabilitation for improving arm function after chronic stroke. Methods- We performed a randomized, multisite, double-blinded, sham-controlled pilot study. All participants were implanted with a VNS device and received 6-week in-clinic rehabilitation followed by a home exercise program. Randomization was to active VNS (n=8) or control VNS (n=9) paired with rehabilitation. Outcomes were assessed at days 1, 30, and 90 post-completion of in-clinic therapy. Results- All participants completed the course of therapy. There were 3 serious adverse events related to surgery. Average FMA-UE scores increased 7.6 with active VNS and 5.3 points with control at day 1 post-in-clinic therapy (difference, 2.3 points; CI, -1.8 to 6.4; P=0.20). At day 90, mean scores increased 9.5 points from baseline with active VNS, and the control scores improved by 3.8 (difference, 5.7 points; CI, -1.4 to 11.5; P=0.055). The clinically meaningful response rate of FMA-UE at day 90 was 88% with active VNS and 33% with control VNS ( P<0.05). Conclusions- VNS paired with rehabilitation was acceptably safe and feasible in participants with upper limb motor deficit after chronic ischemic stroke. A pivotal study of this therapy is justified. Clinical Trial Registration- URL: https://www.clinicaltrials.gov . Unique identifier: NCT02243020.

Right Vagus Nerve Stimulation With a Novel Self-Sizing Cuff Electrode Improves Left Ventricular Function in Dogs With Heart Failure

Background: Autonomic imbalance namely high sympathetic and low parasympathetic drive, is a maladaptive feature of chronic heart failure (HF) that contributes to progressive left ventricular (LV) dysfunction and remodeling. Electrical right cervical Vagus nerve stimulation (VNS) has been shown to restore autonomic balance and improve LV function in animals with experimentally-induced HF. In this study, we examined the effects of long-term VNS with a novel, self-sizing cuff electrode on LV function and remodeling in dogs with HF. Methods: Studies were performed in 12 dogs with HF (LV ejection fraction, EF !35%) produced by coronary microembolizations. All dogs underwent surgical implantation of the self-sizing cuff electrode around the right Vagus nerve connected to an implantable pulse generator. Delivery of VNS pulses was synchronized to cardiac rhythm assessed from a lead placed in the right ventricle. Dogs were then randomized to no therapy (control, n57) or to active VNS therapy (n55) maintained for 3 months. LV end-diastolic (EDV), end-systolic (ESV) volumes and EF were measured from ventriculograms taken at time of randomization (PRE) and after 3 months of therapy (POST). Results: Results are shown in the table. In controls, heart rate (HR), mean aortic pressure (mAoP), systemic vascular resistance (SVR), EDV, ESV and EF were essentially unchanged between PRE and POST. In VNS-treated dogs, SVR tended to decrease and mAoP and EDV were unchanged. In this group, HR and ESV decreased and EF increased significantly. In 4 dogs, surgical removal of the self-sizing cuff was attempted at the end of 3 months of follow-up and was easily accomplished in every case. Conclusions: Long-term VNS therapy using a novel self-sizing cuff electrode improves LV systolic function in dogs with chronic HF.

Review and Comparison of Somatic Therapies

Over the past two decades, the number of somatic treatments for psychiatric disorders has expanded, leading to new insights into the complex relationship between chemical and electric transmission of signals in the brain. In this article, the authors discuss the different device-based treatments currently available in psychiatry. They review clinical indications; putative mechanism of action; efficacy and adverse effects; the results and limitations of salient clinical trials; and active areas of research into the neurobiology of device-based stimuli.

Vagus Nerve Stimulation for Treatment-Resistant Depression: Behavioral and Neural Effects on Encoding Negative Material

Vagus nerve stimulation (VNS) can improve depression. Cognitive models of depression highlight an over-representation of negative thoughts and memories, with depressed individuals showing memory facilitation for negative material. We hypothesized that the antidepressant action of VNS may emerge through corrective influences on 'negativity bias' in memory. We therefore examined the impact of VNS on emotional memory and its underlying brain activity. We tested a single patient undergoing VNS for treatment-resistant depression (TRD). Stimulation was set at a 30/66-second on/off cycle during three encoding blocks when the patient viewed randomly presented positive, negative, and neutral words. Following each block, VNS was switched off and the patient identified previously seen words from distractors in a subsequent recognition memory task. The patient was scanned using functional magnetic resonance imaging (fMRI) during the first encoding block. There was robust recall of negative material viewed during 'off' cycles of VNS but subsequent memory of negative words was attenuated during active VNS ('on' cycles). VNS did not influence memory for neutral and positive words. With neuroimaging, direct modulatory effects of VNS were observed in dorsomedial, dorsolateral, and orbital regions of the prefrontal cortex. Moreover, during encoding of negative words, compared with positive and neutral words, VNS also modulated activity within orbitofrontal, ventromedial and polar prefrontal cortices, midcingulate cortex, and brain stem. Our observations show that VNS can interfere with memory of negative information, an effect that may contribute to its antidepressant role. Neuroimaging implicated regions including the ventral and medial prefrontal cortex as an underlying neural substrate.