Jean Delbeke

Ghent University | UGhent · Neurology

Objective: The objective of the study was to record Laryngeal Motor Evoked Potentials (LMEPs) in Vagus Nerve Stimulation (VNS)-implanted patients suffering from Drug-Resistant Epilepsy (DRE). Based on these recordings, LMEPs characteristics were evaluated and compared between responders (R) and non-responders (NR). Finally, possible under- or over...

Aims: The blue light-sensitive chloride-conducting opsin, stGtACR2, provides potent optogenetic silencing of neurons. The present study investigated whether activation of stGtACR2 in granule cells of the dentate gyrus (DG) inhibits epileptic afterdischarges in a rat model. Methods: Rats were bilaterally injected with 0.9 μl of AAV2/7-CaMKIIα-stG...

Background Modulation of the locus coeruleus (LC)-noradrenergic system is a key mechanism of vagus nerve stimulation (VNS). Activation of the LC produces pupil dilation, and the VNS-induced change in pupil diameter was demonstrated in animals as a possible dose-dependent biomarker for treatment titration. Objective This study aimed to characterize...

Infrared Neural Stimulation (INS) is a novel neuromodulation technique involving a rapid temperature increase of the neuron membrane, resulting in action potential triggering. This paper describes an experimental setup developed to measure the spatiotemporal temperature gradients at the surface of an ex vivo sciatic nerve. The setup is also designe...

This work presents an automated analysis algorithm to detect action potentials (APs) in a nerve and quantify its activity. The algorithm is based on template matching. The templates are automatically adapted to individual AP shapes that vary depending on the nerve fibers from which the AP originates, and the recording setup used. The algorithm was...

We report the design, synthesis, and validation of the novel compound photocaged N6-cyclopentyladenosine (cCPA) to achieve precisely localized and timed release of the parent adenosine A1 receptor agonist CPA using 405 nm light. Gi protein-coupled A1 receptors (A1Rs) modulate neurotransmission via pre- and post-synaptic routes. The dynamics of the...

Introduction Repetitive transcranial magnetic stimulation (rTMS) may have anti-epileptic effects, especially in patients with neocortical lesions. Initial clinical trials demonstrated that the duration of the seizure reducing effect is relatively short-lived. In the context of a chronic condition like epilepsy, theta burst stimulation (TBS) may rep...

Objective: The vagus nerve is considered to play a key role in the circadian rhythm. Chronic continuous analysis of the vagus nerve activity could contribute to a better understanding of the role of the vagus nerve in light-dark modulations. This paper presents a continuous analysis of spontaneous vagus nerve activity performed in four rats. Appr...

The measurement of birefringence variations related to nerve activity is a promising label‐free technique for sensing compound neural action potentials (CNAPs). While widely applied in crustaceans, little is known about its efficiency on mammal peripheral nerves. In this work, birefringence recordings to detect CNAPs, and Stokes parameters measurem...

Background: Whiplash injuries typically occur from a motor vehicle collision and lead to chronic whiplash-associated disorders (CWAD) in 20% to 50% of cases. Changes in neurotransmission, metabolism, and networks seem to play a role in the pathogenic mechanism of CWAD. Objectives: To further elucidate the functional brain alterations, a neurophy...

Background Vagus nerve stimulation (VNS) is an adjunctive therapy for drug-resistant epilepsy. Noninvasive evoked potential recordings in laryngeal muscles (LMEPs) innervated by vagal branches may provide a marker to assess effective vagal nerve fiber activation. We investigated VNS-induced LMEPs in patients with epilepsy in acute and chronic setti...

Objective. The blue light-activated inhibitory opsin, stGtACR2, is gaining prominence as a neuromodulatory tool due its ability to shunt-inhibit neurons and is being frequently used in in vivo experimentation. However, experiments involving stGtACR2 use longer durations of blue light pulses, which inadvertently heat up the local brain tissue and co...

Expression of inhibitory designer receptors exclusively activated by designer drugs (DREADDs) on excitatory hippocampal neurons in the hippocampus represents a potential new therapeutic strategy for drug-resistant epilepsy. To overcome the limitations of the commonly used DREADD agonist clozapine, we investigated the efficacy of the novel DREADD li...

Objectives As a potential treatment for epilepsy, transcutaneous auricular vagus nerve stimulation (taVNS) has yielded inconsistent results. Combining transcranial magnetic stimulation with electromyography (TMS-EMG) and electroencephalography (TMS-EEG) can be used to investigate the effect of interventions on cortical excitability by evaluating ch...

Introduction: Electrophysiological and neuroimaging studies have demonstrated that large-scale brain networks are affected during the development of epilepsy. These networks can be investigated using diffusion magnetic resonance imaging (dMRI). The most commonly used model to analyze dMRI is diffusion tensor imaging (DTI). However, DTI metrics are...

On-demand stimulation improves the efficacy of vagus nerve stimulation (VNS) in refractory epilepsy. The vagus nerve is the main peripheral parasympathetic connection and seizures are known to exhibit autonomic symptoms. Therefore, we hypothesized that seizure detection is possible through vagus nerve electroneurogram (VENG) recording. We developed...

Objective: To design and implement a setup for ex-vivo optical stimulation for exploring the effect of several key parameters (optical power and pulse duration), activation features (threshold, spatial selectivity) and recovery characteristics (repeated stimuli) in peripheral nerves. Approach: A nerve chamber allowing ex-vivo electrical and opti...

Aim GtACR2, a light-activated chloride channel, is an attractive tool for neural inhibition as it can shunt membrane depolarizations. In this study, we assessed the effect of activating GtACR2 on in vivo hippocampal CA1 activity evoked by Schaffer collateral (SC) stimulation. Methods Adult male Wistar rats were unilaterally injected with 0.5 μL of...

The pace of research and development in neuroscience, neurotechnology, and neurorehabilitation is rapidly accelerating, with the number of publications doubling every 4.2 years. Maintaining this progress requires technological standards and scientific reporting guidelines to provide frameworks for communication and interoperability. The present lac...

Objective: Finite element modelling has been widely used to understand the effect of stimulation on the nerve fibres. Yet the literature on analysis of spontaneous nerve activity is much scarcer. In this study, we introduce a method based on a finite element model, to analyse spontaneous nerve activity with a typical bipolar electrode recording se...

Objective: One third of epilepsy patients do not become seizure-free using conventional medication. Therefore, there is a need for alternative treatments. Preclinical research using designer receptors exclusively activated by designer drugs (DREADDs) has demonstrated initial success in suppressing epileptic activity. Here, we evaluated whether lon...

The pace of research and development in neuroscience, neurotechnology, and neurorehabilitation is rapidly accelerating, with the number of publications doubling every 4.2 years. Maintaining this progress requires technological standards and scientific reporting guidelines to provide frameworks for communication and interoperability. The present lac...

An amendment to this paper has been published and can be accessed via the original article.

Background Vagus nerve stimulation is a treatment for refractory epilepsy. The vagus nerve carries parasympathetic information and innervates multiple organs. As seizures are commonly associated with autonomic manifestations, we believe that biomarkers for diseases affecting autonomic functions such as epilepsy can be found in vagus nerve signals....

Implanted neural interfaces represent a rapidly growing field, which includes deep brain, peroneal, phrenic, and vagus nerve stimulators, while substantial research efforts have been invested in the development of experimental applications, such as cortical prostheses, retinal prostheses, spinal cord stimulators, etc. The aim of the present chapter...

BACKGROUND Recent experiments in rats have demonstrated significant effects of VNS on hippocampal excitability but were partially attributed to hypothermia, induced by the applied VNS parameters. OBJECTIVE To allow meaningful preclinical research on the mechanisms of VNS and translation of rodent results to clinical VNS trials, we aimed to identif...

Objective Deep brain stimulation (DBS) is an increasingly applied treatment for various neuropsychiatric disorders including drug‐resistant epilepsy, and it may be optimized by rationalizing the stimulation protocol based on increased knowledge of its mechanism of action. We evaluated the effects of minutes to hours of hippocampal DBS on hippocampa...

Objective: More than one-third of patients with temporal lobe epilepsy (TLE) continue to have seizures despite treatment with antiepileptic drugs, and many experience severe drug-related side effects, illustrating the need for novel therapies. Selective expression of inhibitory Designer Receptors Exclusively Activated by Designer Drugs (DREADDs) a...

Vagus nerve stimulation (VNS) therapy is associated with laryngeal muscle activation and induces voice modifications, well-known side effects of the therapy resulting from co-activation of the recurrent laryngeal nerve. In this study, we describe the non-invasive transcutaneous recording of laryngeal motor evoked potentials (LMEPs), which could ser...

AIM. Vagus nerve stimulation (VNS) modulates hippocampal dentate gyrus (DG) electrophysiology and induces hypothermia in freely moving rats. This study evaluated whether hippocampal (CA1) electrophysiology is similarly modulated and to what extent this is associated with VNS-induced hypothermia. METHODS. Six freely moving rats received a first 4[Fo...

Background Electrical stimulation of peripheral nerves is used in a variety of applications such as restoring motor function in paralyzed limbs, and more recently, as means to provide intuitive sensory feedback in limb prostheses. However, literature on the safety requirements for stimulation is scarce, particularly for chronic applications. Some a...

Deep Brain Stimulation (DBS) has evolved into a well-accepted add-on treatment for patients with severe Parkinsons disease as well as for other chronic neurological conditions. The focal action of electrical stimulation can yield better responses and it exposes the patient to fewer side effects compared to pharmaceuticals distributed throughout the...

Vagus nerve stimulation (VNS) is a widely used neuromodulation technique that is currently used or being investigated as therapy for a wide array of human diseases such as epilepsy, depression, Alzheimer's disease, tinnitus, inflammatory diseases, pain, heart failure and many others. Here, we report a pronounced decrease in brain and core temperatu...

Photonic stimulation is a new modality of nerve stimulation, which could overcome some of the electrical stimulation limitations. In this paper, we present the results of photonic stimulation of rodent sciatic nerve with a 1470 nm laser. Muscle activation was observed with radiant exposure of 0.084 J/cm².

There is a continuous drive to find new, improved therapies that have a different mechanism of action in order to help diminish the sizable percentage of persons with pharmacoresistant epilepsy. Uric acid is increasingly recognized as contributing to the pathophysiology of multiple disorders, and there are indications that uric acid might play a ro...

Although vagus nerve stimulation (VNS) is widely used, therapeutic mechanisms and optimal stimulation parameters remain elusive. In the present study, we investigated the effect of VNS on hippocampal field activity and compared the efficiency of different VNS paradigms. Hippocampal electroencephalography (EEG) and perforant path dentate field-evoke...

Neural prostheses have already a long history and yet the cochlear implant remains the only success story about a longterm sensory function restoration. On the other hand, neural implants for deep brain stimulation are gaining acceptance for variety of disorders including Parkinson’s disease and obsessive-compulsive disorder. It is anticipated that...

Implantation of neuroprosthetic electrodes induces a stereotypical state of neuroinflammation, which is thought to be detrimental for the neurons surrounding the electrode. Mechanisms of this type of neuroinflammation are still not understood well. Recent experimental and theoretical results point out possible role of the diffusion species in this...

Animal models reproducing the characteristics of human epilepsy are essential for the elucidation of the pathophysiological mechanisms. In epilepsy research there is ongoing debate on whether the epileptogenic process is a continuous process rather than a step function. The aim of this study was to assess progression of epileptogenesis over the lon...

Vagus nerve stimulation (VNS) is a treatment for refractory epilepsy and depression. Previous studies using invasive recording electrodes showed that VNS induces laryngeal motor-evoked potentials (LMEPs) through the co-activation of the recurrent laryngeal nerve and subsequent contractions of the laryngeal muscles. The present study investigates th...

Background: Vagus Nerve Stimulation (VNS) has seizure-suppressing effects but the underlying mechanism is not fully understood. To further elucidate the mechanisms underlying VNS-induced seizure suppression at a neurophysiological level, the present study examined effects of VNS on hippocampal excitability using dentate gyrus evoked potentials (EP...

It has been shown that vagus nerve stimulation (VNS) has an antidepressant-like effect in the forced swim test. The mechanism of action underlying this effect is incompletely understood, but there is evidence suggesting that the locus coeruleus (LC) may play an important role. In this study, noradrenergic LC neurons were selectively lesioned to tes...

Background: In many temporal lobe epilepsy (TLE) patients both hippocampi are seizure onset zones. These patients are unsuitable candidates for epilepsy surgery but may be amenable to hippocampal deep brain stimulation (DBS). The optimal DBS parameters for these patients are unknown. Recent observations suggest that even in patients with a unilate...

Background Depression is the most common psychiatric comorbidity in epilepsy patients. The lack of success with current pharmacological interventions for this patient population, highlights the importance of optimizing non-pharmacological neuromodulatory treatments such as vagus nerve stimulation (VNS). Studies on the antidepressant effect of VNS i...

Neurostimulation is a promising treatment for refractory epilepsy. We studied the effect of cortical stimulation with different parameters in the rat motor cortex stimulation model. High intensity simulation (threshold for motor response - 100 μA), high frequency (130 Hz) stimulation during 1 h decreased cortical excitability, irrespective of the i...

The mechanism of action of vagus nerve stimulation (VNS) for pharmacoresistant epilepsy is unknown and the therapeutic outcome is highly variable. We investigated stimulation-induced vagus nerve electrophysiological responses in rats using various stimulation parameters. Conduction velocity, I 50, rheobase and chronaxie were calculated. We identifi...

Objectives: Vagus nerve stimulation (VNS) is an effective treatment for refractory epilepsy. It remains unknown whether VNS efficacy is dependent on output current intensity. The present study investigated the effect of various VNS output current intensities on cortical excitability in the motor cortex stimulation rat model. The hypothesis was tha...

BACKGROUND: Cuff electrodes have been widely used chronically in different clinical applications. This neural interface has been dominantly used for nerve stimulation while interfering noise is the major issue when employed for recording purposes. Advancements have been made in rejecting extra-neural interference by using continuous ring contacts i...

According to a first aspect, the invention relates to a device (10) for electrochemically releasing a composition and comprising: one working electrode (30) comprising an electroactive conjugated polymer (40) containing or doped with said composition, a counter electrode (50), and a reference electrode (60). The device (10) is characterized in that...

The control of robotic prostheses based on pattern recognition algorithms is a widely studied subject that has shown promising results in acute experiments. The long-term implementation of this technology, however, has not yet been achieved due to practical issues that can be mainly attributed to the use of surface electrodes and their highly envir...

This paper proposes a method for the automatic classification of heartbeats in an ECG signal. Since this task has specific characteristics such as time dependences between observations and a strong class unbalance, a specific classifier is proposed and evaluated on real ECG signals from the MIT arrhythmia database. This classifier is a weighted var...

Visual pathways are often schematized as a parallel afferent transmission of pixel image matrices. Suggested interfaces would thus have numerous contacts in close proximity to the target elements. However, well organised tissue reactions would actively keep electrodes away from the neural units. Alternatively, self sizing spiral cuffs were wrapped...

Vagus nerve stimulation (VNS) is an adjunctive treatment for patients with refractory epilepsy. In more than 30% of the patients VNS has no therapeutic effect. The goal of this study was to find an objective parameter that can be used as an indicator of effective stimulation of the vagus nerve. The electrophysiological response to VNS was recorded...

The diagnosis of cardiac dysfunctions requires the analysis of long-term ECG signal recordings, often containing hundreds to thousands of heart beats. In this work, automatic inter-patient classification of heart beats follow-ing AAMI guidelines is investigated. The prior of the normal class is by far larger than the other classes, and the classifi...

While the effects of early visual deprivation on auditory and tactile functions have been widely studied, little is known about olfactory function in early blind subjects. The present study investigated the potential effect of early blindness on the electrophysiological correlates of passive odour perception. Event-related potentials (ERPs) were re...

Vagus nerve stimulation (VNS) is an established treatment for refractory epilepsy. The ADNS-300 is a new system for VNS that includes a rechargeable stimulus generator and an electrode for combined stimulation and recording. In this feasibility study, three patients were implanted with ADNS-300 for therapeutic VNS. In addition, compound action pote...

To examine the visual evoked potentials (VEP) and electroretinograms (ERG) generated during electrical stimulation of the human optic nerve using the optic nerve visual prosthesis. Two volunteers blind from retinitis pigmentosa (RP) and with no light perception each received a chronically implanted optic nerve visual prosthesis. Cortical evoked pot...

Visual prostheses are the focus of intensive research efforts to restore some measure of useful vision to blind or near-blind patients. The development of such technology is being guided to an extent by tools that simulate prosthesis behavior for healthy sighted subjects in order to assess system requirements and configurations. These simulators, h...

Long-term ECG recordings are often required for the monitoring of the cardiac function in clinical applications. Due to the high number of beats to evaluate, inter-patient computer-aided heart beat classification is of great importance for physicians. The main difficulty is the extraction of discriminative features from the heart beat time series....

Vagus nerve stimulation has become a recognized form of treatment for several conditions such as refractory epilepsy and depression. Vagus nerve signals have recently been recorded in rats in order to gain a better understanding of its exact mechanism of interference with these pathologies. For this purpose, nerve cuff electrodes offer many advanta...

A reliable diagnosis of cardiac diseases can sometimes only be obtained by observing the heart of a patient for a long time period where every single heart beat is of importance. Computer-aided classification of heart beats is therefore of great help. The classification of the complete heart beat has many advantages compared to a classification of...

Implanted neurostimulators are commonly used to activate peripheral nerves or brain cells through one or more electrodes. Because of the variable conditions, the stimulation parameters required to obtain the seeked effect vary from subject to subject and from time to time in the same subject. Sensing the evoked compound action potential is therefor...