Nerve Stimulation For Epilepsy Research Articles

Role of vagus nerve stimulation in epilepsy

ABSTRACT Introduction and purpose: Epilepsy affects 1% globally, with 2.6 to 6 million cases in Europe. 30-40% of the 50 million epilepsy patients globally don't respond to drugs. For those ineligible for surgery, Vagus Nerve Stimulation (VNS) therapy offers an alternative for drug-resistant epilepsy and major depression. A brief description of the state of knowledge: Vagus Nerve Stimulation (VNS) is a modern therapy using implanted or non-invasive devices to regulate nerve activity with controlled electrical impulses. Vagus Nerve Stimulation (VNS) is effective for focal seizures, including simple partial seizures and auras. It also shows promise in reducing seizures in generalized tonic-clonic seizures and benefits patients with epileptic encephalopathies like Lennox-Gastaut syndrome. VNS effectively decreases both the frequency and duration of seizures in individuals contending with intractable epilepsy. The use of vagus nerve stimulation is generally a safe and well-tolerated form of treatment. VNS therapy improves psychomotor functions in patients with severe drug-resistant epilepsy, showing positive effects on cognitive aspects. The precise mechanism through which VNS affects the body is not fully understood, but it has demonstrated effectiveness, especially in cases of drug-resistant epilepsy. Conclusions: Extensive research backs Vagus Nerve Stimulation (VNS) as an effective palliative for intractable epilepsy, reducing seizures. Yet, identifying specific patients who would benefit most from VNS treatment lacks clear criteria. Neuromodulation remains crucial for healthcare professionals handling drug-resistant epilepsy.

Vagus nerve stimulation in epilepsy – literature review

Vagus nerve stimulation in epilepsy – literature review

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.

Vagal Nerve Stimulation in Epilepsy: Experiences of Participants with Cognitive Deficits.

IntroductionThe purpose of this study was to examine patients’ experiences of vagal nerve stimulation (VNS) with a special interest in patients with cognitive deficit (CD).Materials and MethodsAn open, retrospective study was conducted on 82 patients with pharmacoresistant epilepsy, who were treated with VNS for at least 10 months. Based on the inability to live independently, they were divided into two groups: patients with cognitive deficit (CD group) and patients without cognitive deficit (non-CD group). A specially designed questionnaire was used for semi-structured interviews about patients’ experiences of VNS treatment.ResultsApproximately one-third described a continuous reduction of seizure frequency of 50% or more and were regarded as responders. Fewer subjects in the CD group were responders than in the non-CD group. Approximately one-third of all subjects had no positive effect of VNS treatment. More CD patients described additional improvements and the most common were milder seizures and improved alertness. The most commonly reported adverse effect was hoarseness.DiscussionVNS treatment in patients without CD had better effect on seizure frequency reduction than in patients with CD, but many patients with CD reported other benefits from the treatment.ConclusionNon-CD patients had higher seizure frequency reduction than CD patients during VNS treatment, but many CD patients described other benefits.

Efficienc y of vag us nerve stim ulation in epilepsy (literat ure review and case report )

Despite significant advances in epileptology, approximately one-third of patients suffer from drug-resistant epilepsy. Numerous approaches are currently available to treat epilepsy; however, there are still many patients with treatment-resistant epilepsy, in whom antiepileptic drugs are ineffective and surgical treatment is impossible. Thus, searching for new effective antiepileptic drugs and alternative treatments (such as vagus nerve stimulation) for these patients remains highly relevant. This literature review covers the indications for and the efficacy and tolerability of vagus nerve stimulation in patients with epilepsy. We also report a case of successful treatment of a patient with drug-resistant epilepsy using this method.

F36. Imaging fascicle traffic in peripheral nerve using fast neural EIT

Fast neural Electrical Impedance Tomography (EIT) is a promising technique which can potentially be used for imaging neural activity over milliseconds with unprecedented spatial resolution without penetrating nervous tissue. Here we present the first cross-sectional images of fascicular neural activity measured during compound action potentials acquired in rat sciatic nerve in in vivo experiments. EIT was collected with a cylindrical cuff electrode wrapped around the sciatic nerve in the thigh in 4 adult Sprague-Dawley rats anaesthetized with Isoflurane nerve made of silicone rubber. 16 electrodes were placed around the circumference, each 2 × 0.1 mm, made of laser-cut stainless steel foil which was then platinised. Distal fibular and tibial branches were electrically stimulated with square pulses with 0.2 ms duration, 1 mA amplitude, and 200 ms inter–stimulus interval. EIT data was acquired during consecutive injection of alternating current, with amplitude 5–75 μA and frequency 3–15 kHz, through a pair of electrodes at a time with simultaneous voltage recordings on the remaining electrodes. 16 independent current injections with 50 pulses per injection were recorded, resulting in 160 s image acquisition time. Acquired data was demodulated with 4 kHz bandwidth, averaged, and reconstructed with >0.5 ms temporal resolution. 1M-element 3D forward mesh, and 20k-element inverse mesh was used for reconstruction; 0-th order Tikhonov regularisation with coefficient of variance correction was employed. Results were displayed as a Z-score with respect to the inter-stimulus noise. Reproducible time-series images were reconstructed in each experiment, showing neural activity onset in ∼0.3–0.6 ms, after stimulus, peak at 0.6–1.5 ms, and subsequent decay at 1–2 ms. Images were obtained following electrical stimulation of the tibial or peroneal branches distally. Spatially distinguishable activity with centre-to-centre separation distance of 0.57 ± 0.04 mm (mean ± S.E.) was obtained in N = 24 experiments in n = 3 rats. EIT were much superior to those collected by Inverse Source Analysis (ISA) performed on CAPs recorded simultaneously to the EIT. Images were cross-validated with co-registered histological images. Comparison showed the position mismatch was 0.1 mm ± 0.03 mm between EIT and histology, and 0.14 mm ± 0.06 mm between EIT and inverse source imaging. Nerve fascicular traffic can be successfully imaged using EIT. This offers a potential means to identify the function of fascicles in autonomic nerve in vivo and so avoid off-target effect by selective stimulation. This could yield significant benefits in vagal nerve stimulation in epilepsy, where hoarseness is a limiting factor, and in the new field of Electroceutical treatment of disease by electrical stimulation of autonomic nerve.

Effects of adjunctive trigeminal nerve stimulation in major depressive disorder in a dose-ranging trial

BACKGROUND: • Neuromodulation via Cranial Nerve Pathways: • Vagus Nerve Stimulation (VNS) initially demonstrated the potential for clinical neuromodulation of key CNS structures via stimulation of cranial nerves. • Cranial nerve stimulation may alter the activity of deeper structures via pathways that traverse multiple synapses. • Fibers of the trigeminal nerve (Fig 1) innervate the face and project to the nucleus tractus solitarius (NTS), locus coeruleus, reticular formation, raphe nuclei, and thalamic structures, and from there to sensory, limbic, and other cortical and subcortical structures [1,2]. • Neuroimaging MOA Data (Fig 2) from 15O PET imaging indicated rapid and robust acute increases in rCBF from stimulation in anterior cingulate (BA 24, 32), inferior frontal gyrus (BA 44,6,22), and medial and middle frontal gyri incl DLPFC (BA 6,8,45,46) [2]. • Trigeminal Nerve Stimulation in Epilepsy: In Phase I and Phase II trials in drug-resistant epilepsy (DRE), significant reduction in seizure frequency was shown without serious adverse events [cf 1,3], using at-home neuromodulation with external Trigeminal Nerve Stimulation (eTNS), primarily while asleep. • TNS in Major Depressive Disorder: Subjects in the epilepsy trials reported significant improvement in mood symptoms [3], independent of seizure improvement, prompting an open adjunctive trial in unipolar MDD. • In an 8-week open trial in a treatment-resistant sample (average ATHF 5.2), significant improvements in mood were detected, with 55% achieving response and 36% achieving remission at the end of the 8-week trial [4]. • Independent open replication confirmed the observation of therapeutic benefit of eTNS in MDD [5]. METHODS: • Subjects: 43 adults (age 23-65, avg 43.0 (11.5 sd)) with evaluable data were enrolled with: nonpsychotic unipolar MDD; current MDD episode >4 months; nonresponse with >6 week use of at least one antidepressant in current episode (ATHF 1-10); ongoing treatment with at least one antidepressant medication, with dose held constant during trial participation. • Trial Design: Under double-blind conditions, the dose ranging period lasted 6 weeks to the primary endpoint, with randomized assignment to an active stimulation regimen (2Hz N=9; 20Hz N=12; 120Hz N=14) vs a sham regimen (0Hz N=8); subjects were then crossed over to active stimulation (120Hz) for an additional 6 weeks. • Assessments made every 2 weeks included the Beck Depression Inventory (BDI), Inventory of Depressive Symptomology (IDS-SR) and Hamilton Depression Rating Scale (HDRS17). • TNS Intervention: Subjects placed stimulating electrodes over supraorbital branches of the trigeminal nerve nightly for ~8 hr, primarily while asleep (Figs 1 & 3). All subjects continued on their medications without change in dose during the trial. • Statistical Analyses: performed with SPSS using ttest, ANOVA, chi square RESULTS:

Lead revision surgery for vagus nerve stimulation in epilepsy: Outcomes and efficacy

We present, to our knowledge, the first published analysis of vagus nerve stimulation (VNS) lead revisions to incorporate quality of life, clinical response, and antiepileptic drug (AED) burden in postrevision clinical outcomes. Ten patients were followed and had no postoperative complications. Seven patients had improvement in quality of life, and three experienced no change. Eight patients noted a restoration of clinical response comparable with initial VNS implantation. Seven patients reported 30–60% improvement in seizure reduction, two experienced >60%, and one noted <30%. Six patients had no change in AED burden. Vagus nerve stimulation lead revision should be considered a safe option for patients with VNS lead failure and medically intractable epilepsy.

Vagus nerve stimulation for epilepsy: a meta-analysis of efficacy and predictors of response

Vagus nerve stimulation for epilepsy: a meta-analysis of efficacy and predictors of response

Therapeutic effects of vagus nerve stimulation in epilepsy and implications for sudden unexpected death in epilepsy

Vagus nerve stimulation (VNS) is a non-pharmacological therapy approved by the FDA for treatment of patients with partial-onset epilepsy. The most frequently encountered adverse effects typically occur during stimulation, are usually mild to moderate in severity, and resolve with reduction in current intensity or spontaneously over time. There are no apparent effects of VNS on vagally mediated visceral function. Though the precise mechanism of action of VNS remains unknown, available evidence suggests that central autonomic nervous system pathways are involved, which have also been implicated in sudden unexpected death in epilepsy (SUDEP). Studies to date of VNS and SUDEP are limited and do not conclusively show an association between VNS and SUDEP rates independent of other epilepsy-specific variables.

Cardiac vagal tests and vagus nerve stimulation in epilepsy

Cardiac vagal tests and vagus nerve stimulation in epilepsy

Evaluation of Refractory Epilepsy Treated with Vagus Nerve Stimulation for up to 5 Years; Ventricular Asystole During Vagal Nerve Stimulation for Epilepsy in Humans; Acute Blood Flow Changes and Efficacy of Vagus Nerve Stimulation in Partial Epilepsy; Unexpected Places: How Did Vagal Nerve Stimulation Become a Treatment for Epilepsy?

Evaluation of Refractory Epilepsy Treated with Vagus Nerve Stimulation for up to 5 Years; Ventricular Asystole During Vagal Nerve Stimulation for Epilepsy in Humans; Acute Blood Flow Changes and Efficacy of Vagus Nerve Stimulation in Partial Epilepsy; Unexpected Places: How Did Vagal Nerve Stimulation Become a Treatment for Epilepsy?

A SENSORY CORTICAL REPRESENTATION OF THE VAGUS NERVE: WITH A NOTE ON THE EFFECTS OF LOW BLOOD PRESSURE ON THE CORTICAL ELECTROGRAM

A SENSORY CORTICAL REPRESENTATION OF THE VAGUS NERVE: WITH A NOTE ON THE EFFECTS OF LOW BLOOD PRESSURE ON THE CORTICAL ELECTROGRAM