scholarly journals Suppression of epileptic seizures via Anderson localization

2017 ◽  
Vol 14 (127) ◽  
pp. 20160872
Author(s):  
Benjamin J. Zhang ◽  
Maysamreza Chamanzar ◽  
Mohammad-Reza Alam
Keyword(s):  
Inhibitory Neuron ◽  
Epileptic Seizures ◽  
Cortical Model ◽  
Threshold Potential ◽  
Non Invasive ◽  
Neuron Populations ◽  
Random Modulation ◽  
The Mean ◽  
Temporal And Spatial ◽  
The Brain

Here we show that brain seizures can be effectively suppressed through random modulation of the brain medium. We use an established mesoscale cortical model in the form of a system of coupled stochastic partial differential equations. We show that by temporal and spatial randomization of parameters governing the firing rates of the excitatory and inhibitory neuron populations, seizure waves can be significantly suppressed. We find that the attenuation is the most effective when applied to the mean threshold potential. The proposed technique can serve as a non-invasive paradigm to mitigate epileptic seizures without knowing the location of the epileptic foci.

scholarly journals Optogenetics

2015 ◽  
Vol 84 (1) ◽  
pp. 25-27
Author(s):  
Phillip Williams ◽  
Steven Wong
Keyword(s):  
Scientific Method ◽  
Therapeutic Application ◽  
Novel Technology ◽  
Neuron Populations ◽  
Traditional Research ◽  
The World ◽  
Freely Moving ◽  
Temporal And Spatial ◽  
The Brain ◽  
Do So

The nature of the brain presents many challenges to its study, from the intricacy of its structure to the minute timescale at which it functions. Traditional research techniques, such as electrophysiological manipulation and pharmacologic intervention, are limited by their inability to operate with both high temporal and spatial resolution. Optogenetics is a novel technology that provides unparalleled specificity in this regard. It allows for control of neural activity with high temporospatial resolution in a manner that does not disrupt the normal physiology of the system. It is an elegant research tool that uses light to control the electrical activity of genetically defined neuron populations with millisecond precision in systems as complex as freely moving live animals. First demonstrated in 2005, it was identified by Nature as the Scientific Method of the Year in 2010 and is currently used by thousands of labs across the world. It has already yielded new discoveries in a variety of neuroscience subfields and will undoubtedly continue to do so. The technology currently exists in a basic science capacity, but has potential for therapeutic application. It is not without its own limitations, but has advantages over more crude alternatives and has proven to be a powerful tool in the hand of the neuroscientist.

Effective surgical treatment of cerebral cavernous malformations: a multicenter study of 79 pediatric patients

2011 ◽  
Vol 8 (5) ◽  
pp. 522-525 ◽  
Author(s):  
Michael Hugelshofer ◽  
Nicola Acciarri ◽  
Ulrich Sure ◽  
Dimitrios Georgiadis ◽  
Ralf W. Baumgartner ◽  
...  
Keyword(s):  
Pediatric Patients ◽  
Refractory Epilepsy ◽  
Epileptic Seizures ◽  
Neurological Deficits ◽  
Vascular Lesions ◽  
Cerebral Cavernous Malformations ◽  
Cavernous Malformations ◽  
Persistent Symptoms ◽  
The Mean ◽  
The Brain

Object Cerebral cavernous malformations (CCMs) are common vascular lesions in the brain, affecting approximately 0.5% of the population and representing 10%–20% of all cerebral vascular lesions. One-quarter of all CCMs affect pediatric patients, and CCMs are reported as one of the main causes of brain hemorrhage in this age group. Symptoms include epileptic seizures, headache, and focal neurological deficits. Patients with symptomatic CCMs can be treated either conservatively or with resection if lesions cause medically refractory epilepsy or other persistent symptoms. Methods The authors retrospectively analyzed 79 pediatric patients (41 boys and 38 girls) from 3 different centers, who were surgically treated for their symptomatic CCMs between 1974 and 2004. The mean age of the children at first manifestation was 9.7 years, and the mean age at operation was 11.3 years. The main goal was to compare the clinical outcomes with respect to the location of the lesion of children who preoperatively suffered from epileptic seizures. Results Of these patients, 77.3% were seizure free (Engel Class I) after the resection of the CCM. Significant differences in the outcome between children who harbored CCMs at different locations were not found. Conclusions Resection seems to be the favorable treatment of symptomatic CCMs not only in adults but also in children.

scholarly journals Developing A Seizure Prediction Algorithm for A Non-Invasive Neuromodulator

2020 ◽  
Vol 5 (6) ◽  
pp. 715-724
Author(s):  
Mahnaz Asgharpour ◽  
Mehdi Sedighi ◽  
Mohammad Reza Jahed Motlagh
Keyword(s):  
Small World ◽  
Epileptic Seizures ◽  
Prediction Algorithm ◽  
Epileptogenic Zone ◽  
Small World Network ◽  
Seizure Prediction ◽  
Non Invasive ◽  
The Mean ◽  
Induced Currents ◽  
Precise Time

In this study, a novel real-time seizure prediction algorithm is introduced to predict epileptic seizures. The proposed algorithm is expected to be applicable in a noninvasive neuromodulator. As a model of the epileptogenic zone, a small-world network of Huber-Braun neurons was built up. To assess the effects of noninvasive stimulation techniques, such as transcranial magnetic stimulation, this network was modified, and the magneto-motive forces and the electromagnetically induced currents were further applied on the network. Comprehensive investigations of the electroencephalograms of epilepsy patients have suggested that some chaotic mechanisms generate the seizures. Hence, chaos and bifurcation theory was applied, and the induced current was considered as the bifurcation parameter. The bifurcation diagram of the 'inter-spike' intervals of the mean voltage of the small world network was obtained. The precise time at which the bifurcation took place was subsequently considered as the time of the seizure onset. Comparisons of the bifurcation diagrams obtained from the patients’ electroencephalographs showed that the proposed network model could reasonably represent the actual neuronal networks of the epileptogenic zone. A dataset of the electroencephalographs of epilepsy patients and normal volunteers from an epilepsy center in Germany was used to validate the prediction algorithm. The simulation results show that the proposed algorithm has a significant capability to predict the precise occurrence of seizures and the achieved sensitivity, accuracy, and specificity of this approach were remarkably higher than those reported in previous studies.

scholarly journals Assessing white matter pathway reproducibility from human whole-brain tractography clustering

2019 ◽  
Author(s):  
Jason Kai ◽  
Ali R. Khan
Keyword(s):  
Spectral Clustering ◽  
Short Range ◽  
Non Invasive ◽  
Human Connectome Project ◽  
Intraclass Correlations ◽  
Structural Connections ◽  
Euclidean Distances ◽  
The Mean ◽  
The Brain ◽  
Identification Tool

AbstractDiffusion MRI, together with tractography techniques, is a non-invasive tool to investigate the brain’s structural pathways (tracts). These tracts join together different regions of the brain and tract identification often involves the use of manual ROIs or automated techniques such as clustering. By studying these connections, current understanding of the connectome can be improved and changes due to disease in patient populations may be identified. We developed a tool to automatically identify all pathways in the human brain, including the short-range, U-shaped tracts, and map quantitative scalar metrics along the pathway trajectory for subsequent analysis. Pathways are identified via a spectral clustering technique on two datasets: Human Connectome Project (intersubject) and MyConnectome Project (intrasubject) and the reliability of the extracted tract and scalar values are evaluated. Average Euclidean distances and volumetric overlap were computed and indicated good spatial reliability. Intraclass correlations of the fractional anisotropy value mapped along the tract was calculated and exhibited good reproducibility within each dataset. Additionally, these evaluation metrics, together with the coefficient of variation of the mean streamline count is used to determine reliably identified U-shaped tracts across the datasets. The developed tract identification tool is an additional resource to studying the human connectome with increased confidence in the results. The identified reliable U-shaped tracts contributes to the identification of common structural connections across individuals and aids in advancing our understanding of the brain’s short-range pathways.

Complexity Measures of Brain Electrophysiological Activity

2010 ◽  
Vol 24 (2) ◽  
pp. 131-135 ◽  
Author(s):  
Włodzimierz Klonowski ◽  
Pawel Stepien ◽  
Robert Stepien
Keyword(s):  
Brain Activity ◽  
Deterministic Chaos ◽  
Epileptic Seizures ◽  
Eeg Signal ◽  
Eeg Signals ◽  
Complexity Measures ◽  
Electrophysiological Activity ◽  
Signal Complexity ◽  
Physiological Sleep ◽  
The Brain

Over 20 years ago, Watt and Hameroff (1987 ) suggested that consciousness may be described as a manifestation of deterministic chaos in the brain/mind. To analyze EEG-signal complexity, we used Higuchi’s fractal dimension in time domain and symbolic analysis methods. Our results of analysis of EEG-signals under anesthesia, during physiological sleep, and during epileptic seizures lead to a conclusion similar to that of Watt and Hameroff: Brain activity, measured by complexity of the EEG-signal, diminishes (becomes less chaotic) when consciousness is being “switched off”. So, consciousness may be described as a manifestation of deterministic chaos in the brain/mind.

Comparison of Fluorine(18)-fluorodeoxyglucose and Gallium(68)-citrate PET/CT in patients with tuberculosis

2019 ◽  
Vol 58 (05) ◽  
pp. 371-378
Author(s):  
Alfred O. Ankrah ◽  
Ismaheel O. Lawal ◽  
Tebatso M.G. Boshomane ◽  
Hans C. Klein ◽  
Thomas Ebenhan ◽  
...  
Keyword(s):  
Tracer Uptake ◽  
Pet Ct ◽  
The Mean ◽  
18F Fdg ◽  
Definition Of ◽  
Gallium 68 ◽  
Attending Physician ◽  
Pet Scans ◽  
The Brain

Abstract 18F-FDG and 68Ga-citrate PET/CT have both been shown to be useful in the management of tuberculosis (TB). We compared the abnormal PET findings of 18F-FDG- and 68Ga-citrate-PET/CT in patients with TB. Methods Patients with TB on anti-TB therapy were included. Patients had a set of PET scans consisting of both 18F-FDG and 68Ga-citrate. Abnormal lesions were identified, and the two sets of scans were compared. The scan findings were correlated to the clinical data as provided by the attending physician. Results 46 PET/CT scans were performed in 18 patients, 11 (61 %) were female, and the mean age was 35.7 ± 13.5 years. Five patients also had both studies for follow-up reasons during the use of anti-TB therapy. Thirteen patients were co-infected with HIV. 18F-FDG detected more lesions than 68Ga-citrate (261 vs. 166, p < 0.0001). 68Ga-citrate showed a better definition of intracerebral lesions due to the absence of tracer uptake in the brain. The mean SUVmax was higher for 18F-FDG compared to 68Ga-citrate (5.73 vs. 3.01, p < 0.0001). We found a significant correlation between the SUVmax of lesions that were determined by both tracers (r = 0.4968, p < 0.0001). Conclusion Preliminary data shows 18F-FDG-PET detects more abnormal lesions in TB compared to 68Ga-citrate. However, 68Ga-citrate has better lesion definition in the brain and is therefore especially useful when intracranial TB is suspected.

NON-INVASIVE BCI METHOD: EEG - ELECTROENCEPHALOGRAPHY

2019 ◽  
pp. 139-145
Author(s):  
Selma Büyükgöze
Keyword(s):  
Brain Computer Interface ◽  
Computer Interface ◽  
Electrode Placement ◽  
Eeg Signals ◽  
Non Invasive ◽  
Brain Signals ◽  
Brain States ◽  
The Brain

Brain Computer Interface consists of hardware and software that convert brain signals into action. It changes the nerves, muscles, and movements they produce with electro-physiological signs. The BCI cannot read the brain and decipher the thought in general. The BCI can only identify and classify specific patterns of activity in ongoing brain signals associated with specific tasks or events. EEG is the most commonly used non-invasive BCI method as it can be obtained easily compared to other methods. In this study; It will be given how EEG signals are obtained from the scalp, with which waves these frequencies are named and in which brain states these waves occur. 10-20 electrode placement plan for EEG to be placed on the scalp will be shown.

Automated System for Epileptic Seizures Prediction based on Multi-Channel Recordings of Electrical Brain Activity

2018 ◽  
pp. 115-122 ◽  
Author(s):  
V. A. Maksimenko ◽  
A. A. Harchenko ◽  
A. Lüttjohann
Keyword(s):  
Epileptic Seizure ◽  
Brain Activity ◽  
Epileptic Seizures ◽  
Automated System ◽  
Brain Computer Interfaces ◽  
Electrical Brain Activity ◽  
Computer Interfaces ◽  
Prediction And Prevention ◽  
The Brain

Introduction: Now the great interest in studying the brain activity based on detection of oscillatory patterns on the recorded data of electrical neuronal activity (electroencephalograms) is associated with the possibility of developing brain-computer interfaces. Braincomputer interfaces are based on the real-time detection of characteristic patterns on electroencephalograms and their transformation  into commands for controlling external devices. One of the important areas of the brain-computer interfaces application is the control of the pathological activity of the brain. This is in demand for epilepsy patients, who do not respond to drug treatment.Purpose: A technique for detecting the characteristic patterns of neural activity preceding the occurrence of epileptic seizures.Results:Using multi-channel electroencephalograms, we consider the dynamics of thalamo-cortical brain network, preceded the occurrence of an epileptic seizure. We have developed technique which allows to predict the occurrence of an epileptic seizure. The technique has been implemented in a brain-computer interface, which has been tested in-vivo on the animal model of absence epilepsy.Practical relevance:The results of our study demonstrate the possibility of epileptic seizures prediction based on multichannel electroencephalograms. The obtained results can be used in the development of neurointerfaces for the prediction and prevention of seizures of various types of epilepsy in humans. 

scholarly journals CT perfusion in peripheral arterial disease—hemodynamic differences before and after revascularisation

2021 ◽  
Author(s):  
Patrick Veit-Haibach ◽  
Martin W. Huellner ◽  
Martin Banyai ◽  
Sebastian Mafeld ◽  
Johannes Heverhagen ◽  
...  
Keyword(s):  
Peripheral Arterial Disease ◽  
Ct Perfusion ◽  
Arterial Disease ◽  
Lower Leg ◽  
Therapy Control ◽  
Non Invasive ◽  
Before And After ◽  
Invasive Method ◽  
The Mean ◽  
Peripheral Arterial

Abstract Objectives The purpose of this study was the assessment of volumetric CT perfusion (CTP) of the lower leg musculature in patients with symptomatic peripheral arterial disease (PAD) before and after interventional revascularisation. Methods Twenty-nine consecutive patients with symptomatic PAD of the lower extremities requiring interventional revascularisation were assessed prospectively. All patients underwent a CTP scan of the lower leg, and hemodynamic and angiographic assessment, before and after intervention. Ankle-brachial pressure index (ABI) was determined. CTP parameters were calculated with a perfusion software, acting on a no outflow assumption. A sequential two-compartment model was used. Differences in CTP parameters were assessed with non-parametric tests. Results The cohort consisted of 24 subjects with an occlusion, and five with a high-grade stenosis. The mean blood flow before/after (BFpre and BFpost, respectively) was 7.42 ± 2.66 and 10.95 ± 6.64 ml/100 ml*min−1. The mean blood volume before/after (BVpre and BVpost, respectively) was 0.71 ± 0.35 and 1.25 ± 1.07 ml/100 ml. BFpost and BVpost were significantly higher than BFpre and BVpre in the treated limb (p = 0.003 and 0.02, respectively), but not in the untreated limb (p = 0.641 and 0.719, respectively). Conclusions CTP seems feasible for assessing hemodynamic differences in calf muscles before and after revascularisation in patients with symptomatic PAD. We could show that CTP parameters BF and BV are significantly increased after revascularisation of the symptomatic limb. In the future, this quantitative method might serve as a non-invasive method for surveillance and therapy control of patients with peripheral arterial disease. Key Points • CTP imaging of the lower limb in patients with symptomatic PAD seems feasible for assessing hemodynamic differences before and after revascularisation in PAD patients. • This quantitative method might serve as a non-invasive method, for surveillance and therapy control of patients with PAD.

scholarly journals Non-Invasive Molecular Survey of Sarcoptic Mange in Wildlife: Diagnostic Performance in Wolf Faecal Samples Evaluated by Multi-Event Capture–Recapture Models

Pathogens ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 243
Author(s):  
Julieta Rousseau ◽  
Mónia Nakamura ◽  
Helena Rio-Maior ◽  
Francisco Álvares ◽  
Rémi Choquet ◽  
...  
Keyword(s):  
Molecular Detection ◽  
High Specificity ◽  
Sarcoptes Scabiei ◽  
Sarcoptic Mange ◽  
Diagnostic Specificity ◽  
Non Invasive ◽  
Faecal Samples ◽  
Capture Recapture ◽  
The Mean ◽  
Event Capture

Sarcoptic mange is globally enzootic, and non-invasive methods with high diagnostic specificity for its surveillance in wildlife are lacking. We describe the molecular detection of Sarcoptes scabiei in non-invasively collected faecal samples, targeting the 16S rDNA gene. We applied this method to 843 Iberian wolf Canis lupus signatus faecal samples collected in north-western Portugal (2006–2018). We further integrated this with serological data (61 samples from wolf and 20 from red fox Vulpes vulpes, 1997–2019) in multi-event capture–recapture models. The mean predicted prevalence by the molecular analysis of wolf faecal samples from 2006–2018 was 7.2% (CI95 5.0–9.4%; range: 2.6–11.7%), highest in 2009. The mean predicted seroprevalence in wolves was 24.5% (CI95 18.5–30.6%; range: 13.0–55.0%), peaking in 2006–2009. Multi-event capture–recapture models estimated 100% diagnostic specificity and moderate diagnostic sensitivity (30.0%, CI95 14.0–53.0%) for the molecular method. Mange-infected individually identified wolves showed a tendency for higher mortality versus uninfected wolves (ΔMortality 0.150, CI95 −0.165–0.458). Long-term serology data highlights the endemicity of sarcoptic mange in wild canids but uncovers multi-year epidemics. This study developed and evaluated a novel method for surveying sarcoptic mange in wildlife populations by the molecular detection of S. scabiei in faecal samples, which stands out for its high specificity and non-invasive character.

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