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1.
Methods Mol Biol ; 2130: 249-262, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33284450

RESUMO

The discovery of the suprachiasmatic nucleus (SCN) as the master mammalian pacemaker has since opened up a variety of alternative methods for assessing how external timing cues influence the clock. One powerful approach for understanding how sensory inputs influence the SCN is to monitor acute changes in SCN electrophysiological activity via in vivo extracellular recording. This methodology offers the ability to monitor stimulus-evoked changes in SCN function at very fine timescales and to rapidly test multiple stimuli and/or stimulus repeats within a single animal. In this chapter we describe our methods for acute in vivo multielectrode recording in head-fixed, anesthetized rodents. These allow for monitoring of single-cell/population activity for >12 h; enable the delivery of carefully controlled sensory stimuli; can be used alongside an array of established or novel experimental tools; and are easily adapted to study activity in any other brain region.


Assuntos
Eletroencefalografia/métodos , Núcleo Supraquiasmático/fisiologia , Animais , Eletroencefalografia/instrumentação , Potenciais Evocados Visuais , Camundongos , Microeletrodos , Estimulação Luminosa/métodos
2.
Methods Mol Biol ; 2130: 263-285, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33284451

RESUMO

The ability to record ensemble action potential (AP) discharge frequencies from large populations of neurons over extended periods of time in vitro offers clear advantages in neuroscience and circadian biology research. Here, we provide an overview of a step-by-step method to perform multisite extracellular AP activity recordings in suprachiasmatic and mediobasal hypothalamic nuclei brain slices, using a state-of-the-art perforated multielectrode array system. Further, we describe in detail a setup architecture which systematically delivers stable, high-quality recordings with excellent anatomical accuracy and consistency. We also provide some procedural, technical, and methodological troubleshooting notes and examples of good quality recordings.


Assuntos
Potenciais de Ação , Eletroencefalografia/métodos , Núcleo Supraquiasmático/fisiologia , Amplificadores Eletrônicos , Animais , Ritmo Circadiano , Eletrodos , Eletroencefalografia/instrumentação , Eletroencefalografia/normas
3.
Methods Mol Biol ; 2130: 303-324, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33284454

RESUMO

In mammals, the part of the nervous system responsible for most circadian behavior can be localized to a bilaterally paired structure in the hypothalamus known as the suprachiasmatic nucleus (SCN). Understanding the mammalian circadian system will require a detailed multilevel analysis of neural SCN circuits ex vivo and in vivo. Many of the techniques and approaches that are used for the analysis of the circuitry driving circadian oscillations in the SCN are similar to those employed in other brain regions. There is, however, one fundamental difference that needs to be taken into consideration, that is, the physiological, cell, and molecular properties of SCN neurons vary with the time of day. In this chapter, we will consider the preparations and electrophysiological techniques that we have used to analyze the SCN circuit focusing on the acute brain slice and intact, freely moving animal.


Assuntos
Ritmo Circadiano , Eletroencefalografia/métodos , Técnicas de Patch-Clamp/métodos , Núcleo Supraquiasmático/fisiologia , Animais , Sinalização do Cálcio , Eletroencefalografia/instrumentação , Potenciais Evocados , Camundongos , Microeletrodos , Técnicas de Patch-Clamp/instrumentação , Núcleo Supraquiasmático/metabolismo
4.
Neurodiagn J ; 60(3): 195-207, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-33006508

RESUMO

Since 1995, ASET has periodically published updates to recommendations for best practices in infection prevention for Neurodiagnostic technologists. The latest installment was accepted in December 2019 for publication in Volume 60, Issue 1, before we had much knowledge or understanding about the SARS-CoV-2, the virus that causes COVID-19. This Technical Tips article is presented as an addendum to the 2020 update and includes important information about infection prevention measures specific to procedure protocols when working with patients positive or under investigation for a highly infectious disease, and when working with patients in general during the current pandemic. All Neurodiagnostic technologists who have direct patient care are responsible for ensuring the use of best practices to prevent the spread of infection.


Assuntos
Infecções por Coronavirus/prevenção & controle , Eletroencefalografia/métodos , Controle de Infecções/métodos , Transmissão de Doença Infecciosa do Paciente para o Profissional/prevenção & controle , Pandemias/prevenção & controle , Equipamento de Proteção Individual , Pneumonia Viral/prevenção & controle , Pessoal Técnico de Saúde , Betacoronavirus , Técnicas de Diagnóstico Neurológico/instrumentação , Desinfecção/métodos , Eletroencefalografia/instrumentação , Contaminação de Equipamentos , Humanos , Polissonografia/instrumentação , Polissonografia/métodos
5.
J Vis Exp ; (162)2020 08 20.
Artigo em Inglês | MEDLINE | ID: mdl-32894266

RESUMO

Brainwaves amplitude obtained from electroencephalography (EEG) has been well-recognized as a basis for cognitive capacity, memory, and learning on animals and humans. Adult neurogenesis mechanism is also linked to memory and learning improvement. Traditionally, researchers used to assess learning and memory parameters in rodent models by behavioral tasks. Therefore, the simultaneous monitoring of behavioral changes and EEG is particularly interesting in correlating data between brain activity and task-related behaviors. However, most of the equipment required to perform both studies are either complex, expensive, or uses a wired setup network that hinders the natural animals' movement. In this study, EEG was recorded with a wireless electrophysiology device along with the execution of a novel object recognition task (NORT). The animal's behavior was monitored simultaneously by a video tracking system. Both recordings were analyzed offline by their timestamps which were synched to link EEG signals with the animal's actions. Subjects consist of adult Wistar rats after medium-term environmental enrichment treatment. Six skull screw electrodes were fixed in pairs on both hemispheres over frontal, central, and parietal regions and were referenced to an electrode located posterior of the nasal bone. NORT protocol consists of exposing the animal to two identical objects for 10 min. After 2 h and 24 h, one of the objects was replaced with a novel one. Exploration time for each object was monitored by a behavioral tracking software (BTS) and EEG data recording. The analysis of the EEG synced with behavioral data consists of estimations of alpha and beta relative band power and comparisons between novel object recognition versus familiar object exploration, between three experimental stages. In this manuscript, we have discussed electrodes manufacturing process, epidural electrodes implantation surgery, environmental enrichment protocol, NORT protocol, BTS setup, EEG - BTS coupling for simultaneous monitoring in real-time, and EEG data analysis based on automatic events detection.


Assuntos
Comportamento Animal/fisiologia , Eletroencefalografia/métodos , Hipocampo/fisiologia , Memória/fisiologia , Tecnologia sem Fio , Animais , Ondas Encefálicas/fisiologia , Eletrodos Implantados , Eletroencefalografia/instrumentação , Hipocampo/citologia , Hipocampo/crescimento & desenvolvimento , Masculino , Neurogênese , Ratos , Ratos Wistar
6.
Nat Commun ; 11(1): 4683, 2020 09 17.
Artigo em Inglês | MEDLINE | ID: mdl-32943621

RESUMO

Wearable dry electrodes are needed for long-term biopotential recordings but are limited by their imperfect compliance with the skin, especially during body movements and sweat secretions, resulting in high interfacial impedance and motion artifacts. Herein, we report an intrinsically conductive polymer dry electrode with excellent self-adhesiveness, stretchability, and conductivity. It shows much lower skin-contact impedance and noise in static and dynamic measurement than the current dry electrodes and standard gel electrodes, enabling to acquire high-quality electrocardiogram (ECG), electromyogram (EMG) and electroencephalogram (EEG) signals in various conditions such as dry and wet skin and during body movement. Hence, this dry electrode can be used for long-term healthcare monitoring in complex daily conditions. We further investigated the capabilities of this electrode in a clinical setting and realized its ability to detect the arrhythmia features of atrial fibrillation accurately, and quantify muscle activity during deep tendon reflex testing and contraction against resistance.


Assuntos
Condutividade Elétrica , Epiderme , Monitorização Fisiológica/instrumentação , Movimento (Física) , Pele , Artefatos , Impedância Elétrica , Eletrocardiografia/instrumentação , Eletrocardiografia/métodos , Eletrodos , Eletroencefalografia/instrumentação , Eletroencefalografia/métodos , Eletromiografia/instrumentação , Eletromiografia/métodos , Desenho de Equipamento , Humanos , Monitorização Fisiológica/métodos , Polímeros/química , Sorbitol
8.
Nat Commun ; 11(1): 4550, 2020 09 11.
Artigo em Inglês | MEDLINE | ID: mdl-32917862

RESUMO

Place cells exhibit spatially selective firing fields that collectively map the continuum of positions in environments; how such activity pattern develops with experience is largely unknown. Here, we record putative granule cells (GCs) and mossy cells (MCs) from the dentate gyrus (DG) over 27 days as mice repetitively run through a sequence of objects fixed onto a treadmill belt. We observe a progressive transformation of GC spatial representations, from a sparse encoding of object locations and spatial patterns to increasingly more single, evenly dispersed place fields, while MCs show little transformation and preferentially encode object locations. A competitive learning model of the DG reproduces GC transformations via the progressive integration of landmark-vector cells and spatial inputs and requires MC-mediated feedforward inhibition to evenly distribute GC representations, suggesting that GCs slowly encode conjunctions of objects and spatial information via competitive learning, while MCs help homogenize GC spatial representations.


Assuntos
Fibras Musgosas Hipocampais/fisiologia , Células de Lugar/fisiologia , Aprendizagem Espacial/fisiologia , Potenciais de Ação/fisiologia , Animais , Eletrodos Implantados , Eletroencefalografia/instrumentação , Masculino , Camundongos , Modelos Animais , Técnicas Estereotáxicas/instrumentação
9.
Medicine (Baltimore) ; 99(30): e21303, 2020 Jul 24.
Artigo em Inglês | MEDLINE | ID: mdl-32791716

RESUMO

The PLEM100 (Inbody Co., Ltd., Seoul, Korea) is a device for measuring phase lag entropy (PLE), a recently developed index for the quantification of consciousness during sedation and general anesthesia. In the present study, we assessed changes in PLE along with the level of consciousness during the induction of general anesthesia using propofol. PLE was compared with the bispectral index (BIS), which is currently the most commonly used index of consciousness.After obtaining Institutional Review Board approval and written informed consent, we enrolled 15 patients (8 men, 7 women; mean age: 37 ±â€Š9 years; mean height: 168 ±â€Š8 cm; mean weight; 68 ±â€Š11 kg) undergoing nasal bone reduction. PLE and BIS sensors were attached simultaneously, and general anesthesia was induced via target-controlled infusion (TCI) of propofol. PLE and BIS scores were recorded when the calculated effect site concentration shown on the TCI pump was equal to the target concentrations of 1.5, 2.0, 2.5, 2.8, 3.0, 3.2, 3.4, and 3.5 µg/mL (and at each 0.1 µg/mL increase, thereafter). Observer's Assessment of Alertness/Sedation (OAA/S) scores were also recorded until unconsciousness was achieved. Throughout the anesthesia period, all pairs of PLE and BIS data were collected using data acquisition software.The partial correlation coefficients between OAA/S scores and PLE, and between OAA/S scores and BIS were 0.778 (P < .001) and 0.846 (P < .001), respectively. Throughout the period of anesthesia, PLE and BIS exhibited a significant positive correlation. The partial correlation coefficient prior to the loss of consciousness was 0.838 (P < .001), and 0.669 (P < .001) following the loss of consciousness. Intra-class correlation between the 2 indices was 0.889 (P < .001) and 0.791 (P < .001) prior and following the loss of consciousness, respectively.PLE exhibited a strong and predictable correlation with both BIS and OAA/S scores. These results suggest that PLE is reliable for assessing the level of consciousness during sedation and general anesthesia.


Assuntos
Anestesia Geral/métodos , Anestésicos Intravenosos/administração & dosagem , Entropia , Propofol/administração & dosagem , Adulto , Estado de Consciência/efeitos dos fármacos , Estado de Consciência/fisiologia , Monitores de Consciência , Eletroencefalografia/instrumentação , Feminino , Humanos , Infusões Intravenosas/métodos , Masculino , Pessoa de Meia-Idade , Osso Nasal/cirurgia , Estudos Prospectivos
10.
Mol Pharmacol ; 98(4): 351-363, 2020 10.
Artigo em Inglês | MEDLINE | ID: mdl-32764093

RESUMO

Ryanodine receptor (RYR) mutations confer stress-triggered malignant hyperthermia (MH) susceptibility. Dietary caffeine (CAF) is the most commonly consumed psychoactive compound by humans. CAF-triggered Ca2+ release and its influences on skeletal muscle contractility are widely used as experimental tools to study RYR function/dysfunction and diagnose MH susceptibility. We hypothesize that dietary CAF achieving blood levels measured in human plasma exacerbates the penetrance of RYR1 MH susceptibility mutations triggered by gaseous anesthetic, affecting both central and peripheral adverse responses. Heterozygous R163C-RYR1 (HET) MH susceptible mice are used to investigate the influences of dietary CAF on both peripheral and central responses before and after induction of halothane (HAL) maintenance anesthesia under experimental conditions that maintain normal core body temperature. HET mice receiving CAF (plasma CAF 893 ng/ml) have significantly shorter times to respiratory arrest compared with wild type, without altering blood chemistry or displaying hyperthermia or muscle rigor. Intraperitoneal bolus dantrolene before HAL prolongs time to respiratory arrest. A pilot electrographic study using subcutaneous electrodes reveals that dietary CAF does not alter baseline electroencephalogram (EEG) total power, but significantly shortens delay to isoelectric EEG, which precedes respiratory and cardiac arrest. CAF ± HAL are studied on RYR1 single-channel currents and HET myotubes to define molecular mechanisms of gene-by-environment synergism. Strong pharmacological synergism between CAF and HAL is demonstrated in both single-channel and myotube preparations. Central and peripheral nervous systems mediate adverse responses to HAL in a HET model of MH susceptibility exposed to dietary CAF, a modifiable lifestyle factor that may mitigate risks of acute and chronic diseases associated with RYR1 mutations. SIGNIFICANCE STATEMENT: Dietary caffeine at a human-relevant dose synergizes adverse peripheral and central responses to anesthesia in malignant hyperthermia susceptible mice. Synergism of these drugs can be attributed to their actions at ryanodine receptors.


Assuntos
Cafeína/efeitos adversos , Dantroleno/efeitos adversos , Halotano/efeitos adversos , Hipertermia Maligna/fisiopatologia , Fibras Musculares Esqueléticas/fisiologia , Mutação , Canal de Liberação de Cálcio do Receptor de Rianodina/genética , Animais , Cafeína/farmacologia , Dantroleno/administração & dosagem , Modelos Animais de Doenças , Sinergismo Farmacológico , Eletroencefalografia/instrumentação , Feminino , Halotano/administração & dosagem , Heterozigoto , Humanos , Injeções Intraperitoneais , Masculino , Hipertermia Maligna/genética , Camundongos , Canal de Liberação de Cálcio do Receptor de Rianodina/metabolismo
11.
PLoS One ; 15(8): e0236982, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32745099

RESUMO

BACKGROUND: Continuous intrapartum fetal monitoring is challenging and its clinical benefits are debated. The project evaluated whether short-term-variation (STV) and other computerised fetal heart rate (FHR) parameters (baseline FHR, long-term-variation, accelerations and decelerations) predicted acidaemia at birth. The aims of the study were to assess the changes in FHR pattern during labour and determine the feasibility of undertaking a definitive trial by reporting the practicalities of using the monitoring device, participant recruitment, data collection and staff training. METHODS: 200 high-risk women carrying a term singleton, non-anomalous fetus, requiring continuous FHR monitoring in labour were consented to participate from the Jessop Wing maternity unit, Sheffield, UK. The trans-abdominal fetal ECG monitor was placed as per clinical protocol. During the monitoring session, clinicians were blinded to the computerised FHR parameters. We analysed the last hour of the FHR and its ability to predict umbilical arterial blood pH <7.20 using receiver operator characteristics (ROC) curves. RESULTS: Of 200 women, 137 cases were excluded as either the monitor did not work from the onset of labour (n = 30), clinical staff did not return or used the monitor on another patient (n = 37), umbilical cord blood not obtained (n = 25), FHR data not recorded within an hour of birth (n = 34) and other reasons (n = 11). In 63 cases included in the final analysis, the computer-derived FHR parameters did not show significant correlation with umbilical artery cord pH <7.20. Labour was associated with a significant increase in short and long term variation of FHR and number of deceleration (P<0.001). However, baseline FHR decreased significantly before delivery (P<0.001). CONCLUSIONS: The project encountered a number of challenges, with learning points crucial to informing the design of a large study to evaluate the potential place of intrapartum computerised FHR parameters, using abdominal fetal ECG monitor before its clinical utility and more widespread adoption can be ascertained.


Assuntos
Eletroencefalografia/instrumentação , Monitorização Fetal/métodos , Frequência Cardíaca Fetal/fisiologia , Acidose/fisiopatologia , Adulto , Cardiotocografia , Eletrocardiografia , Estudos de Viabilidade , Feminino , Sangue Fetal , Doenças Fetais/fisiopatologia , Feto/fisiopatologia , Humanos , Concentração de Íons de Hidrogênio , Trabalho de Parto , Gravidez
12.
Neural Netw ; 129: 55-74, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32502798

RESUMO

Convolutional neural networks (CNNs) are emerging as powerful tools for EEG decoding: these techniques, by automatically learning relevant features for class discrimination, improve EEG decoding performances without relying on handcrafted features. Nevertheless, the learned features are difficult to interpret and most of the existing CNNs introduce many trainable parameters. Here, we propose a lightweight and interpretable shallow CNN (Sinc-ShallowNet), by stacking a temporal sinc-convolutional layer (designed to learn band-pass filters, each having only the two cut-off frequencies as trainable parameters), a spatial depthwise convolutional layer (reducing channel connectivity and learning spatial filters tied to each band-pass filter), and a fully-connected layer finalizing the classification. This convolutional module limits the number of trainable parameters and allows direct interpretation of the learned spectral-spatial​ features via simple kernel visualizations. Furthermore, we designed a post-hoc gradient-based technique to enhance interpretation by identifying the more relevant and more class-specific features. Sinc-ShallowNet was evaluated on benchmark motor-execution and motor-imagery datasets and against different design choices and training strategies. Results show that (i) Sinc-ShallowNet outperformed a traditional machine learning algorithm and other CNNs for EEG decoding; (ii) The learned spectral-spatial features matched well-known EEG motor-related activity; (iii) The proposed architecture performed better with a larger number of temporal kernels still maintaining a good compromise between accuracy and parsimony, and with a trialwise rather than a cropped training strategy. In perspective, the proposed approach, with its interpretative capacity, can be exploited to investigate cognitive/motor aspects whose EEG correlates are yet scarcely known, potentially characterizing their relevant features.


Assuntos
Interfaces Cérebro-Computador , Eletroencefalografia/métodos , Aprendizado de Máquina , Movimento , Eletroencefalografia/instrumentação , Humanos , Imaginação
13.
Neurology ; 94(24): e2608-e2614, 2020 06 16.
Artigo em Inglês | MEDLINE | ID: mdl-32385187

RESUMO

OBJECTIVE: To outline changes made to a neurology residency program in response to coronavirus disease 2019 (COVID-19). METHODS: In early March 2020, the first cases of COVID-19 were announced in the United States. New York City quickly became the epicenter of a global pandemic, and our training program needed to rapidly adapt to the increasing number of inpatient cases while being mindful of protecting providers and continuing education. Many of these changes unfolded over days, including removing residents from outpatient services, minimizing the number of residents on inpatient services, deploying residents to medicine services and medical intensive care units, converting continuity clinic patient visits to virtual options, transforming didactics to online platforms only, and maintaining connectedness in an era of social distancing. We have been able to accomplish this through daily virtual meetings among leadership, faculty, and residents. RESULTS: Over time, our program has successfully rolled out initiatives to service the growing number of COVID-related inpatients while maintaining neurologic care for those in need and continuing our neurologic education curriculum. CONCLUSION: It has been necessary and feasible for our residency training program to undergo rapid structural changes to adapt to a medical crisis. The key ingredients in doing this successfully have been flexibility and teamwork. We suspect that many of the implemented changes will persist long after the COVID-19 crisis has passed and will change the approach to neurologic and medical training.


Assuntos
Infecções por Coronavirus , Educação de Pós-Graduação em Medicina/organização & administração , Neurologia/educação , Pandemias , Pneumonia Viral , Centros Médicos Acadêmicos , Assistência Ambulatorial , Betacoronavirus , Congressos como Assunto , Educação a Distância , Eletroencefalografia/instrumentação , Eletroencefalografia/métodos , Serviço Hospitalar de Emergência , Recursos em Saúde , Humanos , Unidades de Terapia Intensiva , Cidade de Nova Iorque , Equipamento de Proteção Individual , Encaminhamento e Consulta , Telemedicina , Comunicação por Videoconferência
14.
Clin Neurophysiol ; 131(8): 2023-2031, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32405259

RESUMO

There are questions and challenges regarding neurologic complications in COVID-19 patients. EEG is a safe and efficient tool for the evaluation of brain function, even in the context of COVID-19. However, EEG technologists should not be put in danger if obtaining an EEG does not significantly advance diagnosis or change management in the patient. Not every neurologic problem stems from a primary brain injury: confusion, impaired consciousness that evolves to stupor and coma, and headaches are frequent in hypercapnic/hypoxic encephalopathies. In patients with chronic pulmonary disorders, acute symptomatic seizures have been reported in acute respiratory failure in 6%. The clinician should be aware of the various EEG patterns in hypercapnic/hypoxic and anoxic (post-cardiac arrest syndrome) encephalopathies as well as encephalitides. In this emerging pandemic of infectious disease, reduced EEG montages using single-use subdermal EEG needle electrodes may be used in comatose patients. A full 10-20 EEG complement of electrodes with an ECG derivation remains the standard. Under COVID-19 conditions, an expedited study that adequately screens for generalized status epilepticus, most types of regional status epilepticus, encephalopathy or sleep may serve for most clinical questions, using simplified montages may limit the risk of infection to EEG technologists. We recommend noting whether the patient is undergoing or has been placed prone, as well as noting the body and head position during the EEG recording (supine versus prone) to avoid overinterpretation of respiratory, head movement, electrode, muscle or other artifacts. There is slight elevation of intracranial pressure in the prone position. In non-comatose patients, the hyperventilation procedure should be avoided. At present, non-specific EEG findings and abnormalities should not be considered as being specific for COVID-19 related encephalopathy.


Assuntos
Encefalopatias/fisiopatologia , Infecções por Coronavirus/complicações , Eletroencefalografia/métodos , Pneumonia Viral/complicações , Guias de Prática Clínica como Assunto , Encefalopatias/diagnóstico , Encefalopatias/etiologia , Infecções por Coronavirus/diagnóstico , Infecções por Coronavirus/terapia , Cuidados Críticos/métodos , Cuidados Críticos/normas , Eletroencefalografia/instrumentação , Eletroencefalografia/normas , Humanos , Pandemias , Posicionamento do Paciente/métodos , Pneumonia Viral/diagnóstico , Pneumonia Viral/terapia
15.
Brain Stimul ; 13(3): 815-818, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32289712

RESUMO

BACKGROUND: Recording electroencephalography (EEG) from the targeted cortex immediately before and after focal transcranial electrical stimulation (TES) remains a challenge. METHODS: We introduce a hybrid stimulation-recording approach where a single EEG electrode is inserted into the inner electrode of a double-ring montage for focal TES. The new combined electrode was placed at the C3 position of the EEG 10-20 system. Neuronal activity was recorded in two volunteers before and after 20 Hz alternating-current TES at peak-to-peak intensities of 1 and 2 mA. TES-induced electric field distributions were simulated with SIMNIBS software. RESULTS: Using the hybrid stimulation-recording set-up, EEG activity was successfully recorded directly before and after TES. Simulations revealed comparable electrical fields in the stimulated cortex for the pseudomonopolar montage with and without embedded EEG electrode. CONCLUSION: The hybrid TES-EEG approach can be used to probe after-effects of focal TES on neuronal activity in the targeted cortex.


Assuntos
Córtex Cerebral/fisiologia , Eletroencefalografia/métodos , Estimulação Transcraniana por Corrente Contínua/métodos , Eletrodos , Eletroencefalografia/instrumentação , Humanos , Neurônios/fisiologia , Software , Estimulação Transcraniana por Corrente Contínua/instrumentação
16.
J Neuroeng Rehabil ; 17(1): 50, 2020 04 16.
Artigo em Inglês | MEDLINE | ID: mdl-32299460

RESUMO

BACKGROUND: Prediction of Gait intention from pre-movement Electroencephalography (EEG) signals is a vital step in developing a real-time Brain-computer Interface (BCI) for a proper neuro-rehabilitation system. In that respect, this paper investigates the feasibility of a fully predictive methodology to detect the intention to start and stop a gait cycle by utilizing EEG signals obtained before the event occurrence. METHODS: An eight-channel, custom-made, EEG system with electrodes placed around the sensorimotor cortex was used to acquire EEG data from six healthy subjects and two amputees. A discrete wavelet transform-based method was employed to capture event related information in alpha and beta bands in the time-frequency domain. The Hjorth parameters, namely activity, mobility, and complexity, were extracted as features while a two-sample unpaired Wilcoxon test was used to get rid of redundant features for better classification accuracy. The feature set thus obtained was then used to classify between 'walk vs. stop' and 'rest vs. start' classes using support vector machine (SVM) classifier with RBF kernel in a ten-fold cross-validation scheme. RESULTS: Using a fully predictive intention detection system, 76.41±4.47% accuracy, 72.85±7.48% sensitivity, and 79.93±5.50% specificity were achieved for 'rest vs. start' classification. While for 'walk vs. stop' classification, the obtained mean accuracy, sensitivity, and specificity were 74.12±4.12%, 70.24±6.45%, and 77.78±7.01% respectively. Overall average True Positive Rate achieved by this methodology was 72.06±8.27% with 1.45 False Positives/min. CONCLUSION: Extensive simulations and resulting classification results show that it is possible to achieve statistically similar intention detection accuracy using either only pre-movement EEG features or trans-movement EEG features. The classifier performance shows the potential of the proposed methodology to predict human movement intention exclusively from the pre-movement EEG signal to be applied in real-life prosthetic and neuro-rehabilitation systems.


Assuntos
Interfaces Cérebro-Computador , Eletroencefalografia/métodos , Intenção , Movimento/fisiologia , Processamento de Sinais Assistido por Computador , Córtex Somatossensorial/fisiologia , Adulto , Amputados/reabilitação , Eletroencefalografia/instrumentação , Estudos de Viabilidade , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Máquina de Vetores de Suporte , Adulto Jovem
17.
Epilepsia ; 61(5): 841-855, 2020 05.
Artigo em Inglês | MEDLINE | ID: mdl-32227349

RESUMO

This article emphasizes the role of the technological progress in changing the landscape of epilepsy surgery and provides a critical appraisal of robotic applications, laser interstitial thermal therapy, intraoperative imaging, wireless recording, new neuromodulation techniques, and high-intensity focused ultrasound. Specifically, (a) it relativizes the current hype in using robots for stereo-electroencephalography (SEEG) to increase the accuracy of depth electrode placement and save operating time; (b) discusses the drawback of laser interstitial thermal therapy (LITT) when it comes to the need for adequate histopathologic specimen and the fact that the concept of stereotactic disconnection is not new; (c) addresses the ratio between the benefits and expenditure of using intraoperative magnetic resonance imaging (MRI), that is, the high technical and personnel expertise needed that might restrict its use to centers with a high case load, including those unrelated to epilepsy; (d) soberly reviews the advantages, disadvantages, and future potentials of neuromodulation techniques with special emphasis on the differences between closed and open-loop systems; and (e) provides a critical outlook on the clinical implications of focused ultrasound, wireless recording, and multipurpose electrodes that are already on the horizon. This outlook shows that although current ultrasonic systems do have some limitations in delivering the acoustic energy, further advance of this technique may lead to novel treatment paradigms. Furthermore, it highlights that new data streams from multipurpose electrodes and wireless transmission of intracranial recordings will become available soon once some critical developments will be achieved such as electrode fidelity, data processing and storage, heat conduction as well as rechargeable technology. A better understanding of modern epilepsy surgery will help to demystify epilepsy surgery for the patients and the treating physicians and thereby reduce the surgical treatment gap.


Assuntos
Epilepsia/cirurgia , Procedimentos Cirúrgicos Robóticos/instrumentação , Encéfalo/fisiopatologia , Encéfalo/cirurgia , Eletroencefalografia/instrumentação , Eletroencefalografia/métodos , Ablação por Ultrassom Focalizado de Alta Intensidade/instrumentação , Ablação por Ultrassom Focalizado de Alta Intensidade/métodos , Humanos , Fotocoagulação a Laser/instrumentação , Fotocoagulação a Laser/métodos , Terapia a Laser/instrumentação , Terapia a Laser/métodos , Imagem por Ressonância Magnética Intervencionista/instrumentação , Imagem por Ressonância Magnética Intervencionista/métodos , Neuronavegação/instrumentação , Neuronavegação/métodos , Procedimentos Cirúrgicos Robóticos/métodos , Robótica
18.
Sci Rep ; 10(1): 5218, 2020 03 23.
Artigo em Inglês | MEDLINE | ID: mdl-32251333

RESUMO

Dry electrode electroencephalogram (EEG) recording combined with wireless data transmission offers an alternative tool to conventional wet electrode EEG systems. However, the question remains whether the signal quality of dry electrode recordings is comparable to wet electrode recordings in the clinical context. We recorded the resting state EEG (rsEEG), the visual evoked potentials (VEP) and the visual P300 (P3) from 16 healthy subjects (age range: 26-79 years) and 16 neurological patients who reported subjective memory impairment (age range: 50-83 years). Each subject took part in two recordings on different days, one with 19 dry electrodes and another with 19 wet electrodes. They reported their preferred EEG system. Comparisons of the rsEEG recordings were conducted qualitatively by independent visual evaluation by two neurologists blinded to the EEG system used and quantitatively by spectral analysis of the rsEEG. The P100 visual evoked potential (VEP) and P3 event-related potential (ERP) were compared in terms of latency, amplitude and pre-stimulus noise. The majority of subjects preferred the dry electrode headset. Both neurologists reported that all rsEEG traces were comparable between the wet and dry electrode headsets. Absolute Alpha and Beta power during rest did not statistically differ between the two EEG systems (p > 0.05 in all cases). However, Theta and Delta power was slightly higher with the dry electrodes (p = 0.0004 for Theta and p < 0.0001 for Delta). For ERPs, the mean latencies and amplitudes of the P100 VEP and P3 ERP showed comparable values (p > 0.10 in all cases) with a similar spatial distribution for both wet and dry electrode systems. These results suggest that the signal quality, ease of set-up and portability of the dry electrode EEG headset used in our study comply with the needs of clinical applications.


Assuntos
Eletrodos , Eletroencefalografia/instrumentação
19.
Epilepsia ; 61(4): 766-775, 2020 04.
Artigo em Inglês | MEDLINE | ID: mdl-32160324

RESUMO

OBJECTIVE: Seizure diaries kept by patients are unreliable. Automated electroencephalography (EEG)-based seizure detection systems are a useful support tool to objectively detect and register seizures during long-term video-EEG recording. However, this standard full scalp-EEG recording setup is of limited use outside the hospital, and a discreet, wearable device is needed for capturing seizures in the home setting. We are developing a wearable device that records EEG with behind-the-ear electrodes. In this study, we determined whether the recognition of ictal patterns using only behind-the-ear EEG channels is possible. Second, an automated seizure detection algorithm was developed using only those behind-the-ear EEG channels. METHODS: Fifty-four patients with a total of 182 seizures, mostly temporal lobe epilepsy (TLE), and 5284 hours of data, were recorded with a standard video-EEG at University Hospital Leuven. In addition, extra behind-the-ear EEG channels were recorded. First, a neurologist was asked to annotate behind-the-ear EEG segments containing selected seizure and nonseizure fragments. Second, a data-driven algorithm was developed using only behind-the-ear EEG. This algorithm was trained using data from other patients (patient-independent model) or from the same patient (patient-specific model). RESULTS: The visual recognition study resulted in 65.7% sensitivity and 94.4% specificity. By using those seizure annotations, the automated algorithm obtained 64.1% sensitivity and 2.8 false-positive detections (FPs)/24 hours with the patient-independent model. The patient-specific model achieved 69.1% sensitivity and 0.49 FPs/24 hours. SIGNIFICANCE: Visual recognition of ictal EEG patterns using only behind-the-ear EEG is possible in a significant number of patients with TLE. A patient-specific seizure detection algorithm using only behind-the-ear EEG was able to detect more seizures automatically than what patients typically report, with 0.49 FPs/24 hours. We conclude that a large number of refractory TLE patients can benefit from using this device.


Assuntos
Algoritmos , Eletroencefalografia/instrumentação , Epilepsia do Lobo Temporal/diagnóstico , Convulsões/diagnóstico , Processamento de Sinais Assistido por Computador , Eletrodos , Eletroencefalografia/métodos , Epilepsia do Lobo Temporal/complicações , Feminino , Humanos , Masculino , Convulsões/etiologia , Sensibilidade e Especificidade , Dispositivos Eletrônicos Vestíveis
20.
BMJ Case Rep ; 13(2)2020 Feb 11.
Artigo em Inglês | MEDLINE | ID: mdl-32051155

RESUMO

A 9-year-old female with Trisomy 21 with complex craniovertebral instability causing severe cervicomedullary compression underwent occipitocervical fusion. This paper will discuss the anaesthetic management and highlight the use of the Narcotrend monitor not only as a depth of consciousness monitor but more importantly as a tool to detect surgery-induced cerebral hypoperfusion by monitoring the right and left cerebral hemispheres independently and simultaneously.


Assuntos
Anestesia Geral , Vértebras Cervicais/cirurgia , Eletroencefalografia/instrumentação , Instabilidade Articular/cirurgia , Monitorização Intraoperatória/instrumentação , Fusão Vertebral , Criança , Síndrome de Down/complicações , Feminino , Humanos , Instabilidade Articular/etiologia
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