Non-Invasive Vagus Nerve Stimulation Improves Brain Lesion Volume and Neurobehavioral Outcomes in a Rat Model of Traumatic Brain Injury.

Abstract Traumatic brain injury (TBI) continues to be a major cause of death and disability worldwide. This study assessed the effectiveness of non-invasive vagus nerve stimulation (nVNS) in reducing brain lesion volume and improving neurobehavioral performance in a rat model of TBI. Animals were randomized into three experimental groups: (1) TBI with sham stimulation treatment (Control), (2) TBI treated with five lower doses (2-min) nVNS, and (3) TBI treated with five higher doses (2 × 2-min) nVNS. We used the gammaCore nVNS device to deliver stimulations. Magnetic resonance imaging studies were performed 1 and 7 days post-injury to confirm lesion volume. We observed smaller brain lesion volume in the lower dose nVNS group compared with the control group on days 1 and 7. The lesion volume for the higher dose nVNS group was significantly smaller than either the lower dose nVNS or the control groups on days 1 and 7 post-injury. The apparent diffusion coefficient differences between the ipsilateral and contralateral hemispheres on day 1 were significantly smaller for the higher dose (2 × 2 min) nVNS group than for the control group. Voxel-based morphometry analysis revealed an increase in the ipsilateral cortical volume in the control group caused by tissue deformation and swelling. On day 1, these abnormal volume changes were 13% and 55% smaller in the lower dose and higher dose nVNS groups, respectively, compared with the control group. By day 7, nVNS dampened cortical volume loss by 35% and 89% in the lower dose and higher dose nVNS groups, respectively, compared with the control group. Rotarod, beam walking, and anxiety performances were significantly improved in the higher-dose nVNS group on day 1 compared with the control group. The anxiety indices were also improved on day 7 post-injury compared with the control and the lower-dose nVNS groups. In conclusion, the higher dose nVNS (five 2 × 2-min stimulations) reduced brain lesion volume to a level that further refined the role of nVNS therapy for the acute treatment of TBI. Should nVNS prove effective in additional pre-clinical TBI models and later in clinical settings, it would have an enormous impact on the clinical practice of TBI in both civilian and military settings, as it can easily be adopted into routine clinical practice.

Non-invasive Vagus Nerve Stimulation for COVID-19: Results From a Randomized Controlled Trial (SAVIOR I).

Background: Severe coronavirus disease 2019 (COVID-19) is characterized, in part, by an excessive inflammatory response. Evidence from animal and human studies suggests that vagus nerve stimulation can lead to reduced levels of various biomarkers of inflammation. We conducted a prospective randomized controlled study (SAVIOR-I) to assess the feasibility, efficacy, and safety of non-invasive vagus nerve stimulation (nVNS) for the treatment of respiratory symptoms and inflammatory markers among patients who were hospitalized for COVID-19 (ClinicalTrials.gov identifier: NCT04368156). Methods: Participants were randomly assigned in a 1:1 allocation to receive either the standard of care (SoC) alone or nVNS therapy plus the SoC. The nVNS group received 2 consecutive 2-min doses of nVNS 3 times daily as prophylaxis. Efficacy and safety were evaluated via the incidence of specific clinical events, inflammatory biomarker levels, and the occurrence of adverse events. Results: Of the 110 participants who were enrolled and randomly assigned, 97 (nVNS, n = 47; SoC, n = 50) had sufficient available data and comprised the evaluable population. C-reactive protein (CRP) levels decreased from baseline to a significantly greater degree in the nVNS group than in the SoC group at day 5 and overall (i.e., all postbaseline data points collected through day 5, combined). Procalcitonin level also showed significantly greater decreases from baseline to day 5 in the nVNS group than in the SoC group. D-dimer levels were decreased from baseline for the nVNS group and increased from baseline for the SoC group at day 5 and overall, although the difference between the treatment groups did not reach statistical significance. No significant treatment differences were seen for clinical respiratory outcomes or any of the other biochemical markers evaluated. No serious nVNS-related adverse events occurred during the study. Conclusions: nVNS therapy led to significant reductions in levels of inflammatory markers, specifically CRP and procalcitonin. Because nVNS has multiple mechanisms of action that may be relevant to COVID-19, additional research into its potential use earlier in the course of COVID-19 and its potential to mitigate some of the symptoms associated with post-acute sequelae of COVID-19 is warranted.

NOn-invasive Vagus nerve stimulation in acute Ischemic Stroke (NOVIS): a study protocol for a randomized clinical trial.

BACKGROUND: Secondary damage due to neurochemical and inflammatory changes in the penumbra in the first days after ischemic stroke contributes substantially to poor clinical outcome. In animal models, vagus nerve stimulation (VNS) inhibits these detrimental changes and thereby reduces tissue injury. The aim of this study is to investigate whether non-invasive cervical VNS (nVNS) in addition to the current standard treatment can improve penumbral recovery and limit final infarct volume. METHODS: NOVIS is a single-center prospective randomized clinical trial with blinded outcome assessment. One hundred fifty patients will be randomly allocated (1:1) within 12 h from clinical stroke onset to nVNS for 5 days in addition to standard treatment versus standard treatment alone. The primary endpoint is the final infarct volume on day 5 assessed with MRI. DISCUSSION: We hypothesize that nVNS will result in smaller final infarct volumes as compared to standard treatment due to improved penumbral recovery. The results of this study will be used to assess the viability and approach to power a larger trial to more definitively assess the clinical efficacy of nVNS after stroke. TRIAL REGISTRATION: ClinicalTrials.gov NCT04050501 . Registered on 8 August 2019.

A Randomized Sham-Controlled Cross-Over Study on the Short-Term Effect of Non-Invasive Cervical Vagus Nerve Stimulation on Spinal and Supraspinal Nociception in Healthy Subjects.

OBJECTIVE: The aim of the present study was to test the effects of vagus nerve stimulation (VNS) on the descending pain inhibition, quantified by the nociceptive flexor (RIII) reflex and the conditioned pain modulation (CPM) paradigm, and on supraspinal nociceptive responses, assessed by pain intensity and unpleasantness ratings and late somatosensory evoked potentials (SEPs), in healthy subjects. BACKGROUND: Non-invasive vagus nerve stimulation (nVNS) showed promising effects on headache and pain treatment. Underlying mechanisms are only incompletely understood but may include the activation of the descending pain inhibitory system and/or the modification of emotional responses to pain. METHODS: Twenty-seven adult, healthy, and pain-free subjects participated in this double-blind cross-over study conducted at a university research center. They received 4 minutes of cervical nVNS or sham stimulation in randomized order. RIII reflexes, pain ratings, and SEPs were assessed before, during, and 5, 15, 30, and 60 minutes after nVNS/sham stimulation, followed by CPM testing. The primary outcome was the nVNS effect on the RIII reflex size. Three subjects were excluded after the preparatory session (before randomization), 1 subject was excluded after outlier analysis, leaving 23 for analysis. RESULTS: RIII reflex areas were 917.1 ± 563.8 µV × ms (mean ± SD) before, 952.4 ± 467.4 µV × ms during and 929.2 ± 484.0 µV × ms immediately after nVNS and 858.4 ± 489.2 µV × ms before, 913.9 ± 539.7 µV × ms during and 862.4 ± 476.0 µV × ms after sham stimulation, revealing no differences between the immediate effects of nVNS and sham stimulation (F [3,66]  = 0.67, P = .574). There also were no effects of nVNS over sham on RIII reflex areas up to 60 minutes after nVNS (F [1.7,37.4]  = 1.29, P = .283). Similarly, there was no statistically significant effect of nVNS on pain intensity ratings and thresholds, RIII reflex thresholds, late SEP amplitudes, and the CPM effect, compared to sham. Pain unpleasantness ratings statistically significantly decreased from 4.4 ± 2.4 (NRS 0-10) to 4.1 ± 2.5 during nVNS compared to sham stimulation (F [1,22]  = 8.74, P = .007), but there were no longer lasting effects (5-60 minutes after stimulation). CONCLUSIONS: The present study does not support an acute effect of nVNS on descending pain inhibition, pain intensity perception or supraspinal nociception in healthy adults. However, there was a small effect on pain unpleasantness during nVNS, suggesting that nVNS may preferentially act on affective, not somatosensory pain components.

Real-world assessment of concomitant opioid utilization and associated trends in patients with migraine.

Migraine is a debilitating condition that affects approximately 16% of adults and is the fifth leading cause of emergency department visits in the United States. There are several treatment options for migraines; opioids are frequently prescribed. Results from a recent study showed that more than half of the patients with chronic migraine and a third of the patients with episodic migraine received an opioid prescription in the past year. The American Headache Society recognizes the magnitude of this issue and is working to educate providers on the danger of prescribing opioids in the migraine population The objective of this article is to assess the utilization trends of prescription opioid products and evaluate the impact of opioid utilization on healthcare costs in this patient population. This retrospective claims database analysis used real-world medical claims from multiple health plans. The study period was from January 1, 2009, to September 30, 2017. Patients were included if they were 18 years or older and continuously enrolled in the study period for at least 3 years. Patients were included in the migraine cohort if they had any diagnosis of migraine headache during the study period, while patients without a headache related diagnosis were included in the control cohort. Control patients were propensity matched 1:1 to migraine patients. Discrete (count) data are represented by frequencies and percentages. Continuous results are presented as means, medians, and standard deviations. In the study, 107,216 patients met the inclusion criteria, with 53,608 assigned to each cohort. In the migraine and control cohorts, respectively, 28% and 11% were prescribed opioids. In both cohorts, a majority of the patients were female (81.8%). In both cohorts, opioid use was associated with higher total costs compared with patients who were not prescribed opioids: $82,007 for 200 morphine milligram equivalents (MME)/day or more versus $19,792 for no opioid in patients with migraine; and $54,200 for 200 MME/day or more versus $12,060 for no opioid use in control patients; P <.0001. Patients with more than 2 comorbidities who were prescribed opioids had higher costs than patients with more than 2 comorbidities who were not prescribed opioids and patients with less than 2 comorbidities who were prescribed opioids ($65,980, $32,152, and $35,964, respectively, for patients with migraine, and $52,883, $24,641, and $35,748, respectively, for control patients; P <.0001). Patients with migraine have more than twice the healthcare costs as patients without migraines. The additional increase in healthcare costs in patients with migraine who use opioids for treatment and/or have 2 or more comorbidities is significant. Control of the pain associated with migraine, specifically among those with multiple comorbid conditions, may contribute to substantial reductions in healthcare costs.

Patient experience with non-invasive vagus nerve stimulator: gammaCore patient registry.

gammaCore is cleared by the FDA for acute and preventive treatment of cluster headache and the acute treatment of migraine in adults. Previously, only 2 treatments were approved for acute treatment of cluster headache while none were approved for preventive treatment. Following the initial FDA clearance, based on the ACT-1 and ACT-2 studies, a gammaCore Patient Registry (GPR) was designed to provide insights on the use of gammaCore and prescription patterns in the real-world setting and to characterize respective benefits and challenges during the acute treatment of episodic cluster headache. GPR was a prospective observational registry in which patients with episodic cluster headache (3rd edition of the International Classification of Headache Disorders criteria) who were prescribed gammaCore were invited to voluntarily enroll and provide information on their experiences between July 2017 and June 2018. Participants provided baseline information and were trained to self-administer treatment with gammaCore for cluster pain. Participants were also requested to record information for each cluster attack. Of the 182 patients who provided baseline demographic and cluster headache characteristics, 152 provided health index baseline data using EuroQol Health Index tool, 5-level format (EQ5D-5L) and 17 patients provided attack data on a total of 192 cluster headache attacks. The mean age was 49 years; 65% were male and 82% were white; the mean number of months of known diagnosis of cluster headache was 57; the mean number of attacks per cluster headache 4-week period was 14; and the mean pain score was 3.7 (0-4 scale) with a mean attack duration of 74 minutes. Sixty-seven percent of patients had used preventive treatments and 83% had used abortive treatments for cluster headaches; 25% of participants reported at least 1 comorbidity. The mean EQ5D-5L score (scale 0-1) was 0.83. Of the 192 cluster headache attacks reported, gammaCore was used in 116 (60%) attacks. Within this group, the mean pain score at the start of the attacks was 2.7, the mean number of stimulations used was 3.6, and the pain score after 30 minutes was 1.3. At 30 minutes, the pain of 81 (70%) attacks was reduced to none (27%) or mild (43%) (a pain score of 0 or 1) and in 94 (81%) attacks, patients experienced a reduction of at least 1 point in the pain score. This real-world observational evidence suggests that gammaCore adds clinically meaningful value to patients with episodic cluster headache by providing rapid pain relief and confirms that there is significant interest among prescribers in providing this new treatment and technology. This evidence further supports the need to redefine gammaCore as no longer investigational or experimental during considerations for reimbursement.

Review of non-invasive vagus nerve stimulation (gammaCore): efficacy, safety, potential impact on comorbidities, and economic burden for episodic and chronic cluster headache.

The FDA has cleared gammaCore (non-invasive vagus nerve stimulator [nVNS]) for the treatment of episodic cluster headache (eCH). With the exception of subcutaneous sumatriptan, all other treatments are used off label and have many limitations. The FDA approval process for devices differs from that of drugs. We performed a review of the literature to evaluate new evidence on various aspects of gammaCore treatment and impact. The ACute Treatment of Cluster Headache Studies (ACT1 and ACT2), both double-blind sham-controlled randomized trials, did not meet the primary endpoints of the trials but each demonstrated significant superiority of gammaCore among patients with eCH. In ACT1, gammaCore resulted in a higher response rate (RR) (RR, 3.2; 95% CI, 1.6-8.2; P = .014), higher pain-free rate for >50% of attacks (RR, 2.3; 95% CI, 1.1-5.2; P = .045), and shorter duration of attacks (mean difference [MD], -30 minutes; P <.01) compared with the sham group. In ACT2, gammaCore resulted in higher odds of achieving pain-free attacks in 15 minutes (OR, 9.8; 95% CI, 2.2-44.1; P = .01), lower pain intensity in 15 minutes (MD, -1.1; P <.01), and higher rate of achieving responder status at 15 minutes for ≥50% of treated attacks (RR, 2.8; 95% CI, 1.0-8.1; P = .058) compared with the sham group. The PREVention and Acute Treatment of Chronic Cluster Headache (PREVA) study also demonstrated that gammaCore plus standard of care (SOC) was superior to SOC alone in patients with chronic cluster headache (CH). Medical costs, pharmacy refills, and pharmacy costs were higher in patients coded for CH in claims data compared with controls with nonheadache codes. gammaCore is easy to use, practical, and safe; delivery cannot be wasted; and patients prefer using gammaCore compared with SOC. The treatment improves symptoms and reduces the need for CH rescue medications. Current US reimbursement policies, which predate nVNS and are based on expensive, surgically implanted, and permanent implanted vagus nerve stimulation (iVNS), need to be modified to distinguish nVNS from iVNS. gammaCore, cleared by the FDA in April 2017, provides substantial value to patients and also to payers. There is sufficient evidence to support the need to modify current reimbursement policies to include coverage for gammaCore (nVNS) for eCH.

Cost-effectiveness of gammaCore (non-invasive vagus nerve stimulation) for acute treatment of episodic cluster headache.

Cluster headache is a debilitating disease characterized by excruciatingly painful attacks that affects 0.15% to 0.4% of the US population. Episodic cluster headache manifests as circadian and circannual seasonal bouts of attacks, each lasting 15 to 180 minutes, with periods of remission. In chronic cluster headache, the attacks occur throughout the year with no periods of remission. While existing treatments are effective for some patients, many patients continue to suffer. There are only 2 FDA-approved medications for episodic cluster headache in the United States, while others, such as high-flow oxygen, are used off-label. Episodic cluster headache is associated with comorbidities and affects work, productivity, and daily functioning. The economic burden of episodic cluster headache is considerable, costing more than twice that of nonheadache patients. gammaCore adjunct to standard of care (SoC) was found to have superior efficacy in treatment of acute episodic cluster headaches compared with sham-gammaCore used with SoC in ACT1 and ACT2 trials. However, the economic impact has not been characterized for this indication. We conducted a cost-effectiveness analysis of gammaCore adjunct to SoC compared with SoC alone for the treatment of acute pain associated with episodic cluster headache attacks. The model structure was based on treatment of acute attacks with 3 outcomes: failures, nonresponders, and responders. The time horizon of the model is 1 year using a payer perspective with uncertainty incorporated. Parameter inputs were derived from primary data from the randomized controlled trials for gammaCore. The mean annual costs associated with the gammaCore-plus-SoC arm was $9510, and mean costs for the SoC-alone arm was $10,040. The mean quality-adjusted life years for gammaCore-plus-SoC arm were 0.83, and for the SoC-alone arm, they were 0.74. The gammaCore-plus-SoC arm was dominant over SoC alone. All 1-way and multiway sensitivity analyses were cost-effective using a threshold of $20,000. gammaCore dominance, representing savings, was driven by superior efficacy, improvement in quality of life (QoL), and reduction in costs associated with successful and consistent abortion of episodic attacks. These findings serve as additional economic evidence to support coverage for gammaCore. Additional real-world data are needed to characterize the long-term impact of gammaCore on comorbidities, utilization, QoL, daily functioning, productivity, and social engagement of these patients, and for other indications.

Non-Invasive Vagus Nerve Stimulation for the ACute Treatment of Cluster Headache: Findings From the Randomized, Double-Blind, Sham-Controlled ACT1 Study.

OBJECTIVE: To evaluate non-invasive vagus nerve stimulation (nVNS) as an acute cluster headache (CH) treatment. BACKGROUND: Many patients with CH experience excruciating attacks at a frequency that is not sufficiently addressed by current symptomatic treatments. METHODS: One hundred fifty subjects were enrolled and randomized (1:1) to receive nVNS or sham treatment for ≤1 month during a double-blind phase; completers could enter a 3-month nVNS open-label phase. The primary end point was response rate, defined as the proportion of subjects who achieved pain relief (pain intensity of 0 or 1) at 15 minutes after treatment initiation for the first CH attack without rescue medication use through 60 minutes. Secondary end points included the sustained response rate (15-60 minutes). Subanalyses of episodic cluster headache (eCH) and chronic cluster headache (cCH) cohorts were prespecified. RESULTS: The intent-to-treat population comprised 133 subjects: 60 nVNS-treated (eCH, n = 38; cCH, n = 22) and 73 sham-treated (eCH, n = 47; cCH, n = 26). A response was achieved in 26.7% of nVNS-treated subjects and 15.1% of sham-treated subjects (P = .1). Response rates were significantly higher with nVNS than with sham for the eCH cohort (nVNS, 34.2%; sham, 10.6%; P = .008) but not the cCH cohort (nVNS, 13.6%; sham, 23.1%; P = .48). Sustained response rates were significantly higher with nVNS for the eCH cohort (P = .008) and total population (P = .04). Adverse device effects (ADEs) were reported by 35/150 (nVNS, 11; sham, 24) subjects in the double-blind phase and 18/128 subjects in the open-label phase. No serious ADEs occurred. CONCLUSIONS: In one of the largest randomized sham-controlled studies for acute CH treatment, the response rate was not significantly different (vs sham) for the total population; nVNS provided significant, clinically meaningful, rapid, and sustained benefits for eCH but not for cCH, which affected results in the total population. This safe and well-tolerated treatment represents a novel and promising option for eCH. ClinicalTrials.gov identifier: NCT01792817.

Chronic migraine headache prevention with noninvasive vagus nerve stimulation: The EVENT study.

OBJECTIVE: To evaluate the feasibility, safety, and tolerability of noninvasive vagus nerve stimulation (nVNS) for the prevention of chronic migraine (CM) attacks. METHODS: In this first prospective, multicenter, double-blind, sham-controlled pilot study of nVNS in CM prophylaxis, adults with CM (≥15 headache d/mo) entered the baseline phase (1 month) and were subsequently randomized to nVNS or sham treatment (2 months) before receiving open-label nVNS treatment (6 months). The primary endpoints were safety and tolerability. Efficacy endpoints in the intent-to-treat population included change in the number of headache days per 28 days and acute medication use. RESULTS: Fifty-nine participants (mean age, 39.2 years; mean headache frequency, 21.5 d/mo) were enrolled. During the randomized phase, tolerability was similar for nVNS (n = 30) and sham treatment (n = 29). Most adverse events were mild/moderate and transient. Mean changes in the number of headache days were -1.4 (nVNS) and -0.2 (sham) (Δ = 1.2; p = 0.56). Twenty-seven participants completed the open-label phase. For the 15 completers initially assigned to nVNS, the mean change from baseline in headache days after 8 months of treatment was -7.9 (95% confidence interval -11.9 to -3.8; p < 0.01). CONCLUSIONS: Therapy with nVNS was well-tolerated with no safety issues. Persistent prophylactic use may reduce the number of headache days in CM; larger sham-controlled studies are needed. CLINICALTRIALSGOV IDENTIFIER: NCT01667250. CLASSIFICATION OF EVIDENCE: This study provides Class II evidence that for patients with CM, nVNS is safe, is well-tolerated, and did not significantly change the number of headache days. This pilot study lacked the precision to exclude important safety issues or benefits of nVNS.

Non-invasive vagus nerve stimulation for PREVention and Acute treatment of chronic cluster headache (PREVA): A randomised controlled study.

BACKGROUND: Chronic cluster headache (CH) is a debilitating disorder for which few well-controlled studies demon.strate effectiveness of available therapies. Non-invasive vagus nerve stimulation (nVNS) was examined as adjunctive prophylactic treatment of chronic CH. METHODS: PREVA was a prospective, open-label, randomised study that compared adjunctive prophylactic nVNS (n = 48) with standard of care (SoC) alone (control (n = 49)). A two-week baseline phase was followed by a four-week randomised phase (SoC plus nVNS vs control) and a four-week extension phase (SoC plus nVNS). The primary end point was the reduction in the mean number of CH attacks per week. Response rate, abortive medication use and safety/tolerability were also assessed. RESULTS: During the randomised phase, individuals in the intent-to-treat population treated with SoC plus nVNS (n = 45) had a significantly greater reduction in the number of attacks per week vs controls (n = 48) (-5.9 vs -2.1, respectively) for a mean therapeutic gain of 3.9 fewer attacks per week (95% CI: 0.5, 7.2; p = 0.02). Higher ≥50% response rates were also observed with SoC plus nVNS (40% (18/45)) vs controls (8.3% (4/48); p < 0.001). No serious treatment-related adverse events occurred. CONCLUSION: Adjunctive prophylactic nVNS is a well-tolerated novel treatment for chronic CH, offering clinical benefits beyond those with SoC.