Vagus Nerve Stimulation Implantation Research Articles

Early Implantation as a Main Predictor of Response to Vagus Nerve Stimulation in Childhood-Onset Refractory Epilepsy.

We describe a multicenter experience with vagus nerve stimulator implantation in pediatric patients with drug-resistant epilepsy. Our goal was to assess vagus nerve stimulation efficacy and identify potential predictors of favorable outcome. This is a retrospective study. Inclusion criteria: ≤18 years at time of vagus nerve stimulator implantation, at least 1 year of follow-up. All patients were previously found to be unsuitable for an excisional procedure. Favorable clinical outcome and effective vagus nerve stimulation therapy were defined as seizure reduction >50%. Outcome data were reviewed at 1, 2, 3, and 5 years after vagus nerve stimulator implantation. Fisher exact test and multiple logistic regression analysis were employed. Eighty-nine patients met inclusion criteria. Responder rate (seizure frequency reduction >50%) at 1-year follow-up was 25.8% (4.5% seizure-free). At last follow-up, 31.5% had a favorable outcome and 5.2% were seizure free. The only factor significantly predicting favorable outcome was time to vagus nerve stimulator implantation, with the best outcome achieved when vagus nerve stimulator implantation was performed within 3 years of seizure onset. Implantation between 3 and 5 years after epilepsy onset correlated with better long-term seizure freedom (13.3% at T5). Overall, 65.2% of patients evidenced improved quality of life at last follow-up. However, 12.4% had adverse events, but most were mild and disappeared after 3-4 months. Early vagus nerve stimulator implantation within 5 years of seizure onset was the only predictor of favorable clinical outcome in pediatric patients. Improved quality of life and a low incidence of significant adverse events were observed.

The cholinergic anti-inflammatory pathway in chronic kidney disease-review and vagus nerve stimulation clinical pilot study.

Inflammation and autonomic dysfunction are common findings in chronic and end-stage kidney disease and contribute to a markedly increased risk of mortality in this patient population. The cholinergic anti-inflammatory pathway (CAP) is a vagal neuro-immune circuit that upholds the homoeostatic balance of inflammatory activity in response to cell injury and pathogens. CAP models have been examined in preclinical studies to investigate its significance in a range of clinical inflammatory conditions and diseases. More recently, cervical vagus nerve stimulation (VNS) implants have been shown to be of potential benefit for patients with chronic autoimmune diseases such as rheumatoid arthritis and inflammatory bowel disease. We have previously shown that dialysis patients have a functional CAP ex vivo. Here we review the field and the potential role of the CAP in acute kidney injury and chronic kidney disease (CKD) as well as in hypertension. We also present a VNS pilot study in haemodialysis patients. Controlling inflammation by neuroimmune modulation may lead to new therapeutic modalities for improved treatment, outcome, prognosis and quality of life for patients with CKD.

Vagus Nerve Stimulation in Patients Receiving Maintenance Therapy With Electroconvulsive Therapy: A Series of 10 Cases.

Electroconvulsive therapy (ECT) is a mainstay in both acute and long-term management of difficult-to-treat depression. However, frequent acute courses of ECT or prolonged maintenance ECT treatment may increase adverse-effect burden and/or reduce patient acceptability. Therefore, we investigated the effectiveness of adjunctive vagus nerve stimulation (VNS) therapy as an alternative strategy for long-term maintenance treatment in ECT-responsive patients. This retrospective chart review identified maintenance ECT patients with unipolar (n = 5) and bipolar depression (n = 5) from 2 large hospital systems who had a history of ECT response, but the patients had significant residual incapacitating symptoms or increasing concerns regarding the burden associated with ECT and opted to receive adjunctive VNS therapy. The patients were followed for 2 years after VNS implantation. Response and remission were defined as Clinical Global Impression-Severity scale scores of ≤2 and 1, respectively, obtained at 1- and 2-year postimplantation compared with just before VNS implantation. One-year postimplantation, 6 of 10 had responded of which 5 met remission criteria. All 10 patients benefited from adjunctive VNS therapy with either fewer hospitalizations and/or ECT sessions. Seven of 10 stopped maintenance ECT by the end of year 1; an additional patient stopped maintenance ECT by year 2. No patients required an acute course of ECT during the 2-year follow-up. There was a statistically significant reduction (P < 0.0001) in mean (SD) Clinical Global Impression-Severity scale scores between baseline (5.4 [0.51]) and the 1-year postimplantation (2.1 [1.37]) time points, and between baseline and the 2-year postimplantation (2.3 [1.16]) time points, whereas no difference existed between the 1- and 2-year postimplantation time points. Vagus nerve stimulation therapy may be a useful maintenance strategy in patients with difficult-to-treat depression receiving maintenance ECT.

Efficacy of vagus nerve stimulation for drug-resistant epilepsy in children age six and younger

ObjectivesThe objective of the study were to examine the safety and efficacy of vagus nerve stimulation (VNS) for reducing seizure frequency and antiepileptic drugs (AEDs) in children younger than six years and to examine long-term VNS efficacy for children who receive the device at ages 1–3 and at ages 4–6. MethodsWe conducted a 10-year retrospective analysis of VNS implantations at UPMC Children's Hospital of Pittsburgh. Relevant data were collected within 12 months of VNS implantation and at six months, one, two, and four years after VNS implantation. ResultsThis analysis included 99 patients ages 0–3 (n = 40) and 4–6 (n = 59) at first VNS implantation. Eighty-six patients followed up for ≥4 years. There were no significant differences between age at VNS implant (0–3 vs. 4–6) and seizure etiology or most seizure semiologies. Patients took an average of 3.01 ± 1.29 AEDs prior to VNS and 3.84 ± 1.68 AEDs at their latest follow-up. The overall response to VNS therapy (≥50% seizure reduction) at one year, two years, and four years after VNS implantation was 55%, 60%, and 52%, respectively. At two years, 59% of 0- to 3-year-old patients responded to VNS and 52% of 4- to 6-year-old patients responded to VNS. The overall major complication rate was 5.6%, consistent with VNS use for older age groups. SignificanceThis study demonstrates the safety and efficacy of VNS for children with drug-resistant epilepsy (DRE) younger than six. One, two, and four years after VNS implantation, 55%, 60%, and 52% of these patients, respectively, achieved ≥50% reduction in seizure frequency. The safety of VNS is also comparable with older, better studied, age groups. Based on these data, VNS therapy should be considered for children younger than six.

Secondary epileptogenesis on gradient magnetic-field topography correlates with seizure outcomes after vagus nerve stimulation

ObjectiveTo determine the correlation between secondary unilateral or bilateral spreading on gradient magnetic-field topography (GMFT) before and after vagus nerve stimulation (VNS), and postoperative seizure outcomes. MethodsWe analyzed pre- and post-VNS magnetoencephalography (MEG) in 15 patients with VNS implants. We applied McHugh classification to evaluate seizure outcomes. GMFT visualized the spatiotemporal spread of the gradient magnetic field from MEG (>300 fT/cm) before and after the spike peak. We compared the proportion of bilaterally spreading (PBS) MEG spikes and seizure outcomes. We also compared the interhemispheric time difference (ITD) between patients with and without corpus callosotomy. ResultsWe allocated patients with favorable seizure outcomes of class I and II to group A (9 patients) and poor outcomes of class III–V to group B (6 patients). The number of post-VNS MEG spikes was significantly reduced compared to pre-VNS MEG spikes in group A, but not in group B. Group A showed significantly higher preoperative PBS than group B. Postoperative ITD significantly decreased in 5 patients who underwent corpus callosotomy compared to 10 patients without. ConclusionGMFT can detect the inter- and intrahemispheric spreading of spikes with high spatiotemporal resolution on the brain surface. Frequent interictal MEG spikes propagating bilaterally on GMFT may reflect a favorable seizure outcome after VNS. GMFT can identify dependent secondary epileptogenic spikes responding to VNS, which may be used to control generalized seizures in a subset of patients with pharmaco-resistant epilepsy.

The clinical effect of vagus nerve stimulation in the treatment of patients with a minimally conscious state

Objective:Vagus nerve stimulation (VNS) has recently been used in neurorehabilitation and the recovery of consciousness based on its effects on cortical plasticity. The aim of this study was to examine the therapeutic effects of VNS on patients with a minimally conscious state (MCS).Methods:All patients included in the study were assessed more than 5 months after injury and were receiving regular rehabilitation at our hospital from August 2018 to October 2019. Ten patients diagnosed with MCS by Coma Recovery Scale-Revised (CRS-R) test who underwent VNS surgery were enrolled. The scores on CRS-R evaluation at baseline (before VNS implantation) and 1, 3, and 6 months after VNS treatment were recorded. The stimulation parameters were chosen according to a previous study. All clinical rehabilitation protocols remained unchanged during the study. Furthermore, safety was assessed by analyzing treatment-emergent adverse events (TEAEs).Results:No significant improvement in the total CRS-R scores at the end of the 1-month follow-up was observed (p &gt; 0.05). After 3 months of stimulation, a significant difference (p = 0.0078) was observed in the total CRS-R scores compared with the baseline. After 6 months of VNS treatment, CRS-R assessments showed a continuous significant improvement (p = 0.0039); one patient emerged from the MCS and recovered functional communication and object use. Interestingly, one item of CRS-R scores on visual domain was sensitive to VNS treatment (p = 0.0039). Furthermore, no serious adverse event occurred throughout the study.Conclusion:This exploratory study provides preliminary evidence suggesting that VNS is a safe and effective tool for consciousness recovery in patients with MCS.

Vagal nerve stimulation is effective in pre-school children with intractable epilepsy: A report of two cases

There is lack of prospective evidence regarding vagal nerve stimulator (VNS) in younger children with intractable epilepsy. Here, we report the outcomes of using VNS in two pre-school patients for pediatric intractable epilepsy (VNS-PIE) study. Medical treatment was ineffective in both the patients, and they underwent VNS implantation. Seizure frequency, score on the Gesell scale, and heart rate variability (HRV) were assessed following VNS therapy. After 6 months VNS treatment, the seizure frequency in the two patients decreased by 50% from that at baseline, based on the records in their epileptic diary. Video electroencephalography (EEG) examinations showed that abnormal fast waves diminished in the background in Patient 1, and captured seizure frequency in Patient 2 remarkably decreased. The adaptability, language, and individual and social interaction on their Gesell scales increased slightly, suggesting that VNS had a positive effect on the development of these two children. Moreover, the changes in the different HRV indices indicated improved cardiac autonomic function. In conclusion, these two cases indicated that VNS may not only be a superior therapy for pre-school children with intractable epilepsy, but also may exert a positive effect on their mental development and cardiac autonomic function.

Transcutaneous Vagus Nerve Stimulation in Patients With Severe Traumatic Brain Injury: A Feasibility Trial

Preclinical studies have shown that surgically implanted vagus nerve stimulation (VNS) promotes recovery of consciousness and cognitive function following experimental traumatic brain injury (TBI). The aim of this study is to report the feasibility and safety of a noninvasive transcutaneous vagus nerve stimulation (tVNS) in patients with persistent impairment of consciousness following severe TBI. The feasibility of tVNS was evaluated in five patients presenting with diffuse axonal injury and reduced dominant EEG activity one month following severe TBI. tVNS was applied to the left cymba conchae of the external ear using a skin electrode four hours daily for eight weeks. Possible effects of tVNS on physiological parameters and general side effects were recorded. In addition, we report the rate of recovery using coma recovery scale revised (CRS-R). The tVNS regime of four hours daily for eight weeks was feasible and well tolerated with little side effects and no clinically relevant effects on physiological parameters. Three patients showed improvements (>3 points) in the CRS-R following eight weeks tVNS. We demonstrated that tVNS is a feasible and safe VNS strategy for patients following severe TBI. Controlled studies are needed to clarify whether tVNS has a potential to promote recovery of consciousness following severe TBI.

Therapeutic effects of children with refractory epilepsy after vagus nerve stimulation in Taiwan

Vagus nerve stimulation (VNS) is used as an add-on treatment for epilepsy. This study aimed to use Taiwanese nationwide registry data to analyze the therapeutic effects of VNS in children with refractory epilepsy (RE) and try to explore predictive factors of VNS treatment effectiveness. This retrospective study collected data from December 2007 to December 2014. Patient variables included gender, age, VNS implantation date, epilepsy duration, seizure frequency, seizure type, etiology, and antiepileptic drug (AED) history. We divided patients into three groups: Group I as seizure frequency >80 times per month, Group II as seizure frequency 24-80 times per month, and Group III as seizure frequency <24 times per month. Multivariate regression analysis was performed to determine predictors of seizure frequency reduction after VNS treatment. A total of 80 patients were included in this study. Three or more AED types were prescribed for 61 (77.1%) patients. Seizure frequency decreased significantly at 12 and 24 months after VNS treatment. The mean seizure reduction rates were 44.6% and 50.1% at 12 and 24 months after VNS treatment, with the difference between them reaching statistical significance (p=0.001). In multivariate linear regression, high seizure frequency (Group I) was a positive predictor of seizure frequency reduction (p<0.001). The most common complication was coughing (eight patients, 10%) and no patient had early withdrawal or premature termination of VNS use due to complications. VNS is an effective palliative treatment for children with RE for different seizure types. Seizure reduction rate at 24 months after VNS was better than at 12 months after VNS. High seizure frequency can be regarded as a positive predictor for seizure frequency reduction in children with RE treated with VNS.

Implanted vagus nerve stimulation in 126 patients: surgical technique and complications.

Vagus nerve stimulation is apalliative treatment for patients with refractory epilepsy to reduce the frequency and intensity of seizures. Abipolar helical electrode is placed around the left vagus nerve at the cervical level and is connected to the pulse generator placed in asubcutaneous pocket, most commonly in the subclavian region. Between March 1998 and October 2019, we performed 196 procedures related to the vagal nerve stimulation at the Neurosurgery Department in Motol University Hospital. Of these, 126 patients were vagal nerve stimulator implantation surgeries for intractable epilepsy. The cases included 69 female and 57 male patients with mean age at the time of the implantation surgery 22±12.4 years (range 2.158.4 years). Nine patients (7.1%) were afflicted by complications related to implantation. Surgical complications included postoperative infection in 1.6%, VNS-associated arrhythmias in 1.6%, jugular vein bleeding in 0.8% and vocal cord paresis in 2.4%. One patient with vocal cord palsy also suffered from severe dysphagia. One patient (0.8%) did not tolerate extra stimulation with magnet due to aprolonged spasm in his throat. The extra added benefit of vagus stimulation in one patient was asignificant reduction of previously regular severe headaches. Vagus nerve stimulation is an appropriate treatment for patients with drug-resistant epilepsy who are not candidates for focal resective surgery. Implantation of the vagus nerve stimulator is arelatively safe operative procedure.

Vagus nerve stimulation in epilepsy: Efficiency and safety of outpatient practice

IntroductionOver the past 20 years, Vagus Nerve Stimulation (VNS) has become one of the tools for surgical treatment of patients with refractory cryptogenic epilepsy. The objective of this study was to determine the feasibility of implanting a Vagus Nerve Stimulation in ambulatory patients with chronic epilepsy. Patients and methodsVNS procedure was consecutively performed in outpatient surgery between November 2016 and November 2018 in patients with refractory epilepsy. The main endpoints were complications, prolonged hospitalization and readmission during the first postoperative month. This information was collected by retrospective analysis of clinical files. ResultsOf the 22 patients included, the majority were autonomous (77%) with only 5 institutionalized patients. Retrospective analysis revealed a single complication of temporary dysphonia (4.5%) and an unplanned hospitalisation for immediate post-operative vomiting (4.5%). No readmissions were observed during the postoperative month but an emergency room visit for generalized seizure disorder was reported for one patient. ConclusionThe outpatient implantation of VNS in patients with epilepsy is a valid strategy for 95% of patients.

Vagus nerve stimulation in patients with therapy-resistant generalized epilepsy

BackgroundFor patients with generalized epilepsy who do not respond to antiseizure medications, the therapeutic options are limited. Vagus nerve stimulation (VNS) is a treatment mainly approved for therapy-resistant focal epilepsy. There is limited information on the use of VNS on generalized epilepsies, including Lennox–Gastaut Syndrome (LGS) and genetic generalized epilepsy (GGE). MethodsWe identified patients with a diagnosis of generalized epilepsy (including LGS and GGE), who underwent VNS implantation at the London Health Sciences Centre and Western University, London, Ontario, since this treatment became available in Canada in 1997 until July 2018. We assessed response to the treatment, including admissions to hospital and complications. ResultsA total of 46 patients were included in this study with a history of therapy-resistant generalized epilepsy. The mean age at implantation was 24 years (interquartile range [IQR] = 17.8–31 years), significantly younger in the LGS group (p = 0.02) and 50% (n = 23) were female. The most common etiologies were GGE in 37% (n = 17) and LGS in 63% (n = 29). Median follow-up since VNS implantation was 63 months (IQR: 31–112.8 months). Of the LGS group 41.7% (n = 12) of patients had an overall seizure reduction of 50% or more, and 64.7% (n = 11) in the GGE group without statistical significance between the groups. The best response in seizure reduction was seen in generalized tonic–clonic seizures, with a significant reduction in the GGE group (p = 0.043). There was a reduction of seizure-related hospital admissions from 91.3% (N = 42) preimplantation, to 43.5% (N = 20) postimplantation (p < 0.05). The frequency of side effects due to the stimulation was almost equal in both groups (62.1% in LGS and 64.7% in GGE). ConclusionsVagus nerve stimulation should be considered as a treatment in patients with therapy-resistant generalized epilepsy, especially in cases with GGE.

Refractory Status Epilepticus in Genetic Epilepsy—Is Vagus Nerve Stimulation an Option?

Refractory and super-refractory status epilepticus (RSE, SRSE) are severe conditions that can have long-term neurological consequences with high morbidity and mortality rates. The usefulness of vagus nerve-stimulation (VNS) implantation during RSE has been documented by anecdotal cases and in systematic reviews; however, the use of VNS in RSE has not been widely adopted. We successfully implanted VNS in two patients with genetic epilepsy admitted to hospital for SRSE; detailed descriptions of the clinical findings and VNS parameters are provided. Our patients were implanted 25 and 58 days after status epilepticus (SE) onset, and a stable remission of SE was observed from the seventh and tenth day after VNS implantation, respectively, without change in anti-seizure medication. We used a fast ramp-up of stimulation without evident side effects. Our results support the consideration of VNS implantation as a safe and effective adjunctive treatment for SRSE.

Alteration in brain connectivity in patients with Dravet syndrome after vagus nerve stimulation (VNS): exploration of its effectiveness using graph theory analysis with electroencephalography

Objective. Vagus nerve stimulation (VNS) is a nonpharmacologic therapeutic option for patients who have pharmaco-resistant Dravet syndrome (DS). Plentiful efforts have been made for delivering VNS to DS patients, but its effectiveness still requires further verification. We investigated the effectiveness of the VNS treatment of DS patients using brain connectivity analysis with electroencephalography (EEG). Approach. Twenty pharmaco-resistant DS patients were selected to undergo VNS implantation and classified into responder and non-responder groups after 24 months post-VNS. The effect of VNS between 6 months pre- and 6, 12, and 24 months post-VNS in all patients, responders, and non-responders on four different frequency categories of four brain parameters were compared using resting-state EEG. Main results. In alpha and beta bands, all patients showed positive results for characteristic path length (CPL), global efficiency (GE), and transitivity after VNS treatment, and changes in betweenness centrality (BC) were not significant. The difference in transitivity between responders and non-responders is more pronounced than those in CPL and GE are, in both the alpha (p < 0.015) and beta (p < 0.001) bands. There was an obvious change in BC, especially in the alpha band, as the hubs tended to move from frontal lobe to parietal lobe for responders; however, there was no change for the non-responders. Significance. We investigated the alteration in brain connectivity of DS patients in alpha and beta bands during a long-term follow-up and found the responders have a decreased transitivity after the VNS treatment. Moreover, the hubs with high values in the alpha band tended to move from frontal lobe to parietal lobe for responders after VNS treatment.

Chronic vagus nerve stimulation for drug-resistant epilepsy may influence fasting blood glucose concentration

BackgroundCervical vagus nerve stimulation (VNS) has been widely accepted as adjunctive therapy for drug-resistant epilepsy and major depression. Its effects on glycemic control in humans were however poorly understood. The aim of our study was to investigate the potential effects of VNS on fasting blood glucose (FBG) in patients with drug-resistant epilepsy.MethodsPatients with drug-resistant epilepsy who had received VNS implants at the same hospital were retrospectively studied. Effects on FBG, weight, body mass index and blood pressure were evaluated at 4, 8 and 12 months of follow-up.Results32 subjects (11 females/21 males, 19 ± 9 years, body mass index 22.2 ± 4.0 kg/m2) completed 12-month follow-up. At the 4 months, there were no significant changes in FBG concentrations from baseline to follow-up in both Sham-VNS (4.89 ± 0.54 vs. 4.56 ± 0.54 mmol/L, N = 13, p = 0.101) and VNS (4.80 ± 0.54 vs. 4.50 ± 0.56 mmol/L, N = 19, p = 0.117) groups. However, after 8 (4.90 ± 0.42 mmol/L, N = 32, p = 0.001) and 12 (4.86 ± 0.40 mmol/L, N = 32, p = 0.002) months of VNS, FBG levels significantly increased compared to baseline values (4.52 ± 0.54 mmol/L, N = 32). Changes in FBG concentrations at both 8 (R2 = 0.502, N = 32, p < 0.001) and 12 (R2 = 0.572, N = 32, p < 0.001) months were negatively correlated with baseline FBG levels.ConclusionsOur study suggests that chronic cervical VNS elevates FBG levels with commonly used stimulation parameters in patients with epilepsy.Trial registration VNSRE, NCT02378792. Registered 4 March 2015—Retrospectively registered, https://clinicaltrials.gov/ct2/show/NCT02378792

Subgroup analysis of seizure and cognitive outcome after vagal nerve stimulator implantation in children.

Vagal nerve stimulator (VNS) implantation at an early age seems to lead to improved quality of life and cognitive outcome. The aim of this analysis is to evaluate whether specific patient or seizure characteristics might lead to better seizure control, cognitive outcome, and higher quality of life in children undergoing VNS implantation. Primary outcome measure was reduction in seizure frequency. Secondary outcome measures were epilepsy outcome assessed by McHugh and Engel classifications, reduction in antiepileptic drugs (AED), developmental and cognitive outcome, as well as quality of life assessed through the pediatric quality of life (PEDSQL™) questionnaire and care giver impression (CGI) scale. Forty-five consecutive children undergoing VNS implantation were analyzed for the following subgroups: age (categorized to 1-2years old, 3-5years old, 6-12years old, and 13-18years old), sex, underlying cause (categorized to idiopathic, encephalitis, stroke, syndromic), duration of preoperative seizures (dichotomized to under or above 89months, corresponding to the median of the whole cohort), and preoperative seizure frequency (dichotomized to under and above 360 seizures per month). Encephalitis as the underlying cause for seizures was the only variable significantly associated with higher reduction rate of seizure frequency. Patients with VNS implantation at the age of ≤ 2years showed a strong association with better developmental and cognitive outcome, as well as quality of life. Shorter duration of preoperative seizures and higher preoperative seizure frequency showed a strong association with better developmental outcome, as well as quality of life. Engel outcome scores were significantly better in patients with epilepsy due to encephalitis (100% Engel I-III). However, patients with epilepsy due to encephalitis showed significantly higher complication rates (71.4%, p = 0.045). Children suffering from epilepsy due to encephalitis show higher seizure reduction rates after VNS implantation when compared with children suffering from epilepsy due to other causes. Developmental and cognitive outcomes as well as quality of life of children undergoing VNS implantation is strongly associated with shorter duration of preoperative seizures and implantation at a young age.

(Invited) Self-Powered Wearable and Implantable Electrical Stimulation Devices for Biomedical Applications

Electrical stimulation (ES) is a widely used therapeutic treatment strategy. It showed significantly positive results in treating a variety of diseases, biological disorders, and neurological problems. Today, the emergence of wearable devices is rapidly reshaping the development of medical devices, pushing them from conventional bulky and rigid silicon electronics to flexible and primarily polymer-based systems. Among many types of functions, nanogenerators are developed as a unique device for converting biomechanical energy into electrical pulses. This talk will fist introduce the application of flexible nanogenerators as an implantable power source and its biosafety and compatibility. In addition, the pulsed electricity from nanogenerators can be applied directly as a ES signal for therapeutic treatment. In our recent research, we successfully implemented such an electromechanical system for skin wound healing, hair growth, and vagus nerve stimulation for obesity control. An electrical stimulation bandage was developed by integrating a flexible nanogenerator and a pair of dressing electrodes on a flexible substrate. Rat studies demonstrated rapid closure of a full-thickness rectangular skin wound within 3 days as compared to 12 days of usual contraction-based healing processes in rodents. From in vitro studies, the accelerated skin wound healing was attributed to the electric field-facilitated fibroblast migration, proliferation and transdifferentiation. Via a similar design, the electrical pulses were applied to stimulate hair growth. Significantly facilitated hair regeneration results were obtained from Sprague-Dawley rats and nude mice, which was attributed to the improved secretion of vascular endothelial growth factor and keratinocyte growth factor. In another work, an implanted vagus nerve stimulation system was developed. The device comprises a flexible and biocompatible nanogenerator that is attached on the surface of stomach. It generates biphasic electric pulses in responsive to the peristalsis of stomach. The electric signals generated by this device stimulates the vagal afferent fibers to reduce food intake and achieve weight control. This strategy is successfully demonstrated on rat models. Within 100 days, the average body weight is controlled at 350 g, 38% less than the control groups. All the results bring a new concept in electrical therapeutic technology that is battery-free, self-activated and directly responsive to body activities. Keywords: Nanogenerator; Implantable medical devices; Wearable devices; Self-powered systems; Electrical stimulation;

Vagus nerve stimulation in pediatric patients with failed epilepsy surgery.

Adequate control of pharmacoresistant epilepsy continues to be a challenge. Multiple studies have reported the benefits of epilepsy surgery and vagus nerve stimulation for children with pharmacoresistant epilepsy. Little is known about the role of vagus nerve stimulation for children with failed epilepsy surgeries. The aim of this study was to examine the effects of vagus nerve stimulation on seizure frequency reduction for children with failed epilepsy surgeries. We retrospectively reviewed 85 children with pharmacoresistant epilepsy who underwent vagus nerve stimulation. Six of these patients underwent epilepsy surgery before vagus nerve stimulation (group I) and 79 patients received only vagus nerve stimulation (group II). We recorded seizure frequency at 3, 12, 24 and 36months after vagus nerve stimulator implantation. Both groups had reduced seizure frequencies at the 3-, 12-, 24- and 36-month follow-up (p = 0.044 for group I trends and 0.008 for group II trends). Vagus nerve stimulator implantations significantly improve seizure frequency for children with or without previous epilepsy surgery at 3, 12, 24 and 36months. These findings suggest that vagus nerve stimulation should be considered an alternative therapy for pediatric patients with previous failed surgeries.

Vagus Nerve Stimulator implantation in a pregnant woman with drug resistant epilepsy

The aim is to present a case of successful implantation of Vagus Nerve Stimulator (VNS) in a woman with drug resistant epilepsy (DRE) during pregnancy. It is the first case of VNS implantation in the Russian Federation. The implantation, follow-up, and programming were carried out in the Bekhterev National Research Medical Centre of Psychiatry and Neurology, Saint-Petersburg. Material and method . Female patient, 28 y.o., was diagnosed with DRE more than 11 years ago. The course of her epilepsy deteriorated during pregnancy despite of the appropriate antiepileptic treatment. The EEG, MRI, and laboratory tests did not reveal any focal brain lesion that could necessitate surgical resection. After multidisciplinary consultations, no contraindications to VNS procedure were found. Results . The VNS system was implanted in this patient when she was 18-week-pregnant. The procedure resulted in a seizure reduction and allowed the patient to preserve her pregnancy and deliver a healthy child. Conclusion s. VNS Therapy® is safe and effective for the treatment of DRE. This successful case of VNS implantation in pregnancy opens new venues for the treatment of DRE in this group of patients. The authors declare the absence of conflict of interest with respect to this publication. All authors contributed equally to this article.

Surgical Outcomes in Post-Traumatic Epilepsy: A Single Institutional Experience.

Post-traumatic epilepsy (PTE) is a debilitating sequela of traumatic brain injury (TBI), occurring in up to 20% of severe cases. This entity is generally thought to be more difficult to treat with surgical intervention. To detail our experience with the surgical treatment of PTE. Patients with a history of head injury undergoing surgical treatment for epilepsy were retrospectively enrolled. Engel classification at the last follow-up was used to assess outcome of patients that underwent surgical resection of an epileptic focus. Reduction in seizure frequency was assessed for patients who underwent vagal nerve stimulator (VNS) or responsive neurostimulator (RNS) implantation. A total of 23 patients met inclusion criteria. Nineteen (82.6%) had mesial temporal sclerosis, 3 had lesional neocortical epilepsy (13.0%), and 1 had nonlesional neocortical epilepsy (4.3%). Fourteen patients (60.9%) underwent temporal lobectomy (TL), 2 underwent resection of a cortical focus (8.7%), and 7 underwent VNS implantation (30.4%). Three patients underwent RNS implantation after VNS failed to reduce seizure frequency more than 50%. In the patients treated with resection, 11 (68.8%) were Engel I, 3 (18.8%) were Engel II, and 2 (12.5%) were Engel III at follow-up. Average seizure frequency reduction in the VNS group was 30.6%±25.6%. RNS patients had reduction of seizure severity but seizure frequency was only reduced 9.6%±13.6%. Surgical outcomes of PTE patients treated with TL were similar to reported surgical outcomes of patients with nontraumatic epilepsy treated with TL. Patients who were not candidates for resection demonstrated variable response rates to VNS or RNS implantation.