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Letteratura scientifica selezionata sul tema "Direct cortical stimulation"

Autore: Grafiati

Pubblicato: 5 ottobre 2024

Ultima modifica: 11 giugno 2025

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Articoli di riviste sul tema "Direct cortical stimulation"

1

Foster, Brett L., and Josef Parvizi. "Direct cortical stimulation of human posteromedial cortex." Neurology 88, no. 7 (2017): 685–91. http://dx.doi.org/10.1212/wnl.0000000000003607.

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Background:The posteromedial cortex (PMC) is a collective term for an anatomically heterogeneous area of the brain constituting a core node of the human default mode network (DMN), which is engaged during internally focused subjective cognition such as autobiographical memory.Methods:We explored the effects of causal perturbations of PMC with direct electric brain stimulation (EBS) during presurgical epilepsy monitoring with intracranial EEG electrodes.Results:Data were collected from 885 stimulations in 25 patients implanted with intracranial electrodes across the PMC. While EBS of regions immediately dorsal or ventral to the PMC reliably produced somatomotor or visual effects, respectively, we found no observable behavioral or subjectively reported effects when sites within the boundaries of PMC were electrically perturbed. In each patient, null effects of PMC stimulation were observed for sites in which intracranial recordings had clearly demonstrated electrophysiologic responses during autobiographical recall.Conclusions:Direct electric modulation of the human PMC produced null effects when standard functional mapping methods were used. More sophisticated stimulation paradigms (e.g., EBS during experimental cognitive tests) will be required for testing the causal contribution of PMC to human cognition and subjective experience. Nonetheless, our findings suggest that some extant theories of PMC and DMN contribution to human awareness and subjective conscious states require cautious re-examination.

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2

Nitsche, Michael A., Astrid Schauenburg, Nicolas Lang, et al. "Facilitation of Implicit Motor Learning by Weak Transcranial Direct Current Stimulation of the Primary Motor Cortex in the Human." Journal of Cognitive Neuroscience 15, no. 4 (2003): 619–26. http://dx.doi.org/10.1162/089892903321662994.

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Transcranially applied weak direct currents are capable of modulating motor cortical excitability in the human. Anodal stimulation enhances excitability, cathodal stimulation diminishes it. Cortical excitability changes accompany motor learning. Here we show that weak direct currents are capable of improving implicit motor learning in the human. During performance of a serial reaction time task, the primary motor cortex, premotor, or prefrontal cortices were stimulated contralaterally to the performing hand. Anodal stimulation of the primary motor cortex resulted in increased performance, whereas stimulation of the remaining cortices had no effect. We conclude that the primary motor cortex is involved in the acquisition and early consolidation phase of implicit motor learning.

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3

Saleem, Yusra, Komal ., and Stephen Riaz. "Transcranial Direct Current Stimulation (TDCS)." International Journal of Endorsing Health Science Research (IJEHSR) 10, no. 4 (2022): 441–45. http://dx.doi.org/10.29052/ijehsr.v10.i4.2022.441-445.

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Transcranial direct current stimulation (TDCS) is a neuromodulatory device that is used for its ability to enhance cognitive and behavioral performance. Human studies suggest that TDCS modulates cortical excitability during stimulation by nonsynaptic changes of the cells, along with evidence that the after-effects of TDCS are driven by synaptic modification. TDCS represents a potential intervention to enhance cognition across clinical populations, including mild cognitive impairment among psychological and neurological disorders. Studies suggest that TDCS might be helpful in treating depression with appropriate current, size of electrodes, and employment of montages. TDCS opens a new perspective in treating major depressive disorder (MDD) because of its ability to modulate cortical excitability and induce long-lasting effects.

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Schuh, Lori, and Ivo Drury. "Intraoperative electrocorticography and direct cortical electrical stimulation." Seminars in Anesthesia, Perioperative Medicine and Pain 16, no. 1 (1997): 46–55. http://dx.doi.org/10.1016/s0277-0326(97)80007-4.

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5

Oishi, M., K. Suzuki, O. Sasaki, et al. "Crossed aphasia elicited by direct cortical stimulation." Neurology 67, no. 7 (2006): 1306–7. http://dx.doi.org/10.1212/01.wnl.0000238468.84401.d4.

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6

Luders, H. O., I. Derakhshan, M. Oishi, et al. "CROSSED APHASIA ELICITED BY DIRECT CORTICAL STIMULATION." Neurology 68, no. 19 (2007): 1638–40. http://dx.doi.org/10.1212/01.wnl.0000265607.23814.05.

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7

Sehatpour, Pejman, Devin Adair, Stephanie Rohrig, et al. "Cortical Modulation using Transcranial Direct Current Stimulation." Brain Stimulation 7, no. 2 (2014): e4. http://dx.doi.org/10.1016/j.brs.2014.01.017.

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8

Sehatpour, Pejman, Devin Adair, Stephanie Rohrig, Joanna DiCostanzo, and Daniel C. Javitt. "Transcranial Direct Current Stimulation Modulates Cortical Networks." Brain Stimulation 10, no. 1 (2017): e7. http://dx.doi.org/10.1016/j.brs.2016.11.040.

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9

Krings, Timo, Bradley R. Buchbinder, William E. Butler, et al. "Stereotactic Transcranial Magnetic Stimulation: Correlation with Direct Electrical Cortical Stimulation." Neurosurgery 41, no. 6 (1997): 1319–26. http://dx.doi.org/10.1097/00006123-199712000-00016.

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10

Wong, Pei-Ling, Yea-Ru Yang, Shih-Fong Huang, and Ray-Yau Wang. "Effects of Transcranial Direct Current Stimulation Followed by Treadmill Training on Dual-Task Walking and Cortical Activity in Chronic Stroke: A Double-Blinded Randomized Controlled Trial." Journal of Rehabilitation Medicine 55 (March 21, 2023): jrm00379. http://dx.doi.org/10.2340/jrm.v55.5258.

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Objective: To explore the effects of transcranial direct current stimulation followed by treadmill training on dual-task gait performance and contralesional cortical activity in chronic stroke patients.Methods: Forty-five chronic stroke participants were randomized into 3 groups: a bilateral transcranial direct current stimulation and treadmill training group; a cathodal transcranial direct current stimulation and treadmill training group; and a sham transcranial direct current stimulation and treadmill training group for 50 min per session (20 min transcranial direct current stimulation followed by 30 min treadmill training), 3 sessions per week for 4 weeks. Outcome measures included cognitive dual-task walking, motor dual-task walking, walking performance, contralesional cortical activity, and lower-extremity motor control.Results: The cathodal transcranial direct current stimulation + treadmill training group showed significantly greater improvements in cognitive dual-task walking speed than the other groups (p cathodal vs sham = 0.006, p cathodal vs bilateral = 0.016). In the cathodal transcranial direct current stimulation + treadmill training group the silent period duration increased significantly more than in the other groups (p < 0.05). Changes in motor evoked potentials in the cathodal transcranial direct current stimulation + treadmill training group were greater than those in the sham transcranial direct current stimulation + treadmill training group (p < 0.05). No significant changes were observed in the bilateral transcranial direct current stimulation + treadmill training group.Conclusion: Cathodal transcranial direct current stimulation followed by treadmill training is an effective intervention for improving cognitive dual-task walking and modulating contralesional cortical activity in chronic stroke. No beneficial effects were observed after bilateral transcranial direct current stimulation and treadmill training.LAY ABSTRACTDual-task walking is essential for daily functioning, both at home and socially. This study explored the effects of transcranial direct current stimulation followed by treadmill training on dual-task gait performance and contralesional cortical activity in chronic stroke patients. A total of 45 chronic stroke patients were randomized to 1 of 3 groups: a bilateral transcranial direct current stimulation and treadmill training group, a cathodal transcranial direct current stimulation and treadmill training group, or a sham transcranial direct current stimulation and treadmill training group for 50 min per session, 3 sessions per week for 4 weeks. Cognitive dual-task walking, motor dual-task walking, walking performance, contralesional cortical activity, and lower-extremity motor control of the affected side were measured before and after the intervention. The results show that cathodal transcranial direct current stimulation followed by treadmill training is an effective intervention for improving cognitive dual-task walking and modulating contralesional cortical activityin individuals with chronic stroke.

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Tesi sul tema "Direct cortical stimulation"

1

Lacuey, Lecumberri Nuria. "Human autonomic and respiratory responses to direct cortical electrical stimulation." Doctoral thesis, Universitat Autònoma de Barcelona, 2018. http://hdl.handle.net/10803/666840.

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Los pacientes con epilepsia son bien conocidos por tener un mayor riesgo de muerte súbita inesperada. El riesgo de muerte súbita inesperada en pacientes con epilepsia (SUDEP) varía de 0,35 a 2,3 por cada 1000 personas por año en las poblaciones de base comunitaria, a 6,3 a 9,3 en los candidatos a cirugía para la epilepsia. Los mecanismos agónicos precisos que desencadenan SUDEP son desconocidos, aunque la evidencia reciente del estudio de unidades de monitoreo de Epilepsia (MORTEMUS) apunta al colapso combinado respiratorio y cardiovascular que conduce al fatal evento. Los signos adversos del sistema nervioso autónomo son prominentes durante las convulsiones. Arritmias cardíacas (bradicardia, asistolia, taquiarritmias) en aproximadamente el 72% de los pacientes con epilepsia, hipotensión post ictal, sensibilidad barorrefleja alterada (que puede comprometer el flujo sanguíneo cerebral), incremento del tono simpático, expresado como aumento de la sudoración y disminución de la variabilidad inter-ictal del ritmo cardíaco nocturno (HRV) son comunes. La alteración severa de la respiración se ve típicamente en las convulsiones clónicas tónicas generalizadas (GTCS). Las características del electroencefalograma (EEG), incluida la supresión generalizada post-ictal en el EEG (PGES), sugieren un alto riesgo de SUDEP, se correlacionan fuertemente con un aumento de la sudoración y una disminución de la HRV y pueden ir acompañadas de hipotensión profunda. Los mecanismos neuronales subyacentes a estos patrones necesitan ser definidos. La epilepsia es un trastorno cortical prototípico, donde la mayoría de los síntomas se producen por la activación o inhibición de regiones específicas en la corteza. Las descargas epileptiformes que involucran un área específica en el cerebro pueden inducir síntomas relacionados con la funcionalidad de ese área. De manera similar, la estimulación eléctrica del cerebro se puede usar para mapear funciones cerebrales. Aunque varios estudios que usan estimulación eléctrica cerebral han sugerido el posible papel de estructuras corticales en la respiración y el control autonómico, los informes de algunos investigadores han indicado hallazgos mixtos, de tal manera que no hay consenso sobre las áreas precisas de la corteza involucrada. Nuestro objetivo fue identificar los sitios corticales con funciones en el control respiratorio y/o autonómico y correlacionar la activación inducida por las crisis epilepticas o la inhibición de estas estructuras, con particulares patrones autonómicos y respiratorios peri-ictales reconocidos como posibles índices de riesgo de muerte. Este estudio describe el papel de varias estructuras límbicas/paralímbicas en la respiración y el control de la presión arterial humana, y los mecanismos patogénicos de la respiración y las respuestas autonómicas durante las crisis epilépticas, proporcionando información sobre los mecanismos que pueden desencadenan la muerte súbita inesperada en los pacientes con epilepsia (SUDEP).<br>Patients with epilepsy are well known to be at increased risk of sudden unexpected death. The risk of Sudden Unexpected Death in Epilepsy Patients (SUDEP) ranges from 0.35 to 2.3 per 1000 people per year in community-based populations, to 6.3 to 9.3 in epilepsy surgery candidates. SUDEP’s precise agonal mechanisms are unknown, although recent evidence from the Mortality in Epilepsy Monitoring Units Study (MORTEMUS) points to combined respiratory and cardiovascular collapse driving the fatal event. Adverse autonomic nervous system signs are prominent during seizures. Cardiac arrhythmias (bradycardia, asystole, tachyarrhythmias) in approximately 72% of epilepsy patients, post-ictal hypotension, impaired baroreflex sensitivity (potentially compromising cerebral blood flow), enhanced sympathetic outflow, expressed as increased sweating and decreased inter-ictal nocturnal heart rate variability (HRV) are common. Severe alteration of breathing is typically seen in generalized tonic clonic seizures (GTCS). Electroencephalogram (EEG) characteristics, including post-ictal generalized EEG suppression (PGES), are suggestive of high SUDEP-risk, strongly correlate with increased sweating and decreased HRV, and may be accompanied by profound hypotension. Neural mechanisms underlying these patterns need to be defined. Epilepsy is a prototypic cortical disorder, where most of the symptoms are produced by the activation or inhibition of specific regions in the cortex. Epileptiform discharges involving a specific area in the brain may induce symptoms related with that area’s functionality. In a similar manner, electrical brain stimulation can be used to map brain functions. Although several studies using brain electrical stimulation have suggested the possible role of cortical structures in respiration and autonomic control, reports from some investigators have indicated mixed findings, such that there is no consensus on the precise areas of cortex concerned. We aimed to identify cortical sites with roles in respiratory and/or autonomic control and to correlate seizure induced activation or inhibition of these structures to particular peri-ictal autonomic and breathing patterns recognized as potential indices of risk for death. This study describes the role of several limbic/paralimbic structures in respiration and human blood pressure control, and pathomechanisms of breathing and autonomic responses during epileptic seizures, providing insights into mechanisms of failure in SUDEP.

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Austin, Vivienne Catherine Marie. "fMRI investigation of a model of direct cortical stimulation in rodent brain." Thesis, University of Oxford, 2003. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.275373.

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Usami, Kiyohide. "Sleep modulates cortical connectivity and excitability in humans: direct evidence from neural activity induced by single-pulse electrical stimulation." Kyoto University, 2015. http://hdl.handle.net/2433/202800.

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Kobayashi, Katsuya. "Different Mode of Afferents Determines the Frequency Range of High Frequency Activities in the Human Brain: Direct Electrocorticographic Comparison between Peripheral Nerve and Direct Cortical Stimulation." Kyoto University, 2015. http://hdl.handle.net/2433/202676.

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Floyd, John Tyler. "Lower Extremity Transcranial Direct Current Stimulation (TDCS)| The Effect of Montage and Medium on Cortical Excitability." Thesis, University of Central Arkansas, 2018. http://pqdtopen.proquest.com/#viewpdf?dispub=10686422.

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<p> The dissertation consists of three parts. The first part is a systematic review of the literature regarding transcranial direct current stimulation (tDCS) and its effects on lower extremity motor behaviors and corticospinal excitability of the lower extremity representation of the motor cortex in healthy subjects. The second part investigates how different electrode montages and electrode conductance mediums affect corticospinal excitability of the tibialis anterior (TA) representation of the motor cortex in healthy subjects. The third part studies how different electrode montage and electrode conductance medium combinations affect ankle tracking accuracy in healthy subjects regarding the dominant lower extremity.</p><p>

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Amadi, Ugwechi. "Transcranial stimulation to enhance cortical plasticity in the healthy and stroke-affected motor system." Thesis, University of Oxford, 2012. http://ora.ox.ac.uk/objects/uuid:bb27ac6f-a79d-459a-b5a0-e9a209ac7132.

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This thesis investigated transcranial direct current stimulation (tDCS) as applied to the motor system, and its ability to modulate underlying cortical processes and resultant motor behaviours. Functional magnetic resonance imaging (fMRI) and transcranial magnetic stimulation (TMS) were employed to assess the extent to which tDCS induces quantifiable changes in neural structure and function in controls and stroke patients. Modifications in the connectivity of intrinsic functional networks following tDCS application were examined using resting state fMRI. Polarity-specific changes were found: cathodal (inhibitory) tDCS increased the strength of the default mode network and increased functional coupling between major nodes within the motor network. No significant effects were found following anodal (excitatory) tDCS. Although anodal tDCS elicited only subtle changes in resting activity, it is known to produce robust modifications of behaviour. Single and paired-pulse TMS were used to investigate the neurophysiological underpinnings of these changes. Consistent with the theory of homeostatic plasticity, anodal tDCS applied prior to task performance increased GABAA-mediated cortical inhibition and worsened behaviour. The specificity of these changes suggests a central role for the mechanism of surround inhibition. A longitudinal clinical trial in chronic stroke patients was conducted to determine the utility of tDCS as an adjunct in motor rehabilitation. Serial MRI scans revealed that, when combined with motor training, anodal tDCS increased functional activity and grey matter in primarily ipsilesional motor areas. These brain changes were correlated with behavioural improvements in the stroke-affected upper limb. The laterality of connectivity at baseline, as measured by resting state activity and corticospinal tract integrity, was predictive of response to the rehabilitation program, particularly in those stroke patients who received tDCS. Asymmetry favouring the contralesional hemisphere predicted greater behavioural gains. Such results underscore the importance of re-normalisation of structure and functional activity toward the lesioned hemisphere in stroke rehabilitation.

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Huang, Austin. "Cortical Stimulation Mapping of Heschl’s Gyrus in the Auditory Cortex for Tinnitus Treatment." Scholarship @ Claremont, 2019. https://scholarship.claremont.edu/cmc_theses/2073.

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Tinnitus is the perception of sound in the absence of an actual sound stimulus. Recent developments have shifted the focus to the central nervous system and the neural correlate of tinnitus. Broadly, tinnitus involves cortical map rearrangement, pathological neural synchrony, and increased spontaneous firing rates. Various cortical regions, such as Heschl’s gyrus in the auditory cortex, have been found to be associated with different aspects of tinnitus, such as perception and loudness. I propose a cortical stimulation mapping study of Heschl’s gyrus using a depth and subdural electrode montage to conduct electrocorticography. This study would provide high-resolution data on abnormal frequency band oscillations characteristic of tinnitus and pinpoint regions where they occur. The validity of the neural synchrony model would also be tested in this study.

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Qin, Jing. "The effects of transcranial direct current stimulation (tDCS) on balance control in Parkinson's disease (PD)." Thesis, Queensland University of Technology, 2021. https://eprints.qut.edu.au/211438/1/Jing_Qi_Thesis.pdf.

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Gordon, Pedro Caldana. "Excitabilidade cortical motora como preditora de resposta na esquizofrenia." Universidade de São Paulo, 2018. http://www.teses.usp.br/teses/disponiveis/5/5169/tde-14022019-084004/.

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O desenvolvimento da estimulação magnética transcraniana (EMT) permitiu o estudo de potenciais evocados motores eliciados pela estimulação direta do córtex cerebral de forma não-invasiva. Foi observado que diferentes paradigmas de estimulação cortical por EMT apresentam diferentes padrões de resposta, que posteriormente foram associados ao funcionamento de circuitos corticais GABAérgicos e glutamatérgicos do córtex motor, compondo assim índices de excitabilidade cortical motora (ECM). Ademais, desvios da normalidade de tais índices foram encontrados em diversas condições clínicas, incluindo transtornos mentais como a esquizofrenia. O uso dessas medidas também auxiliou o desenvolvimento da estimulação transcraniana por corrente contínua (ETCC), técnica que se mostrou capaz de produzir efeitos neuromodulatórios no sistema nervoso central de forma segura e com mínimos efeitos adversos. Tal técnica vem apresentando possibilidades terapêuticas promissoras, como por exemplo, tendo sido observado sua eficácia no alívio de alucinações auditivas de indivíduos com esquizofrenia. O uso de ETCC para tratamento de sintomas negativos da esquizofrenia também pode vir a se mostrar uma abordagem eficaz, e a análise da ECM pode auxiliar no entendimento dos seus mecanismos de ação e atuar como possível preditor de resposta terapêutica. O objetivo do presente estudo é avaliar o perfil de ECM em um grupo de indivíduos com esquizofrenia, e as possíveis influências de um protocolo terapêutico utilizando ETCC sobre essas medidas. Com esse objetivo, foi selecionada uma coorte de sujeitos com esquizofrenia que participou em ensaio clínico randomizado e controlado com placebo (estimulação sham), tendo a ETCC como intervenção ativa alvo. A ECM foi mensurada na avaliação inicial dos sujeitos, assim como após a primeira sessão de ETCC, e quando da avaliação de desfecho primário. O protocolo terapêutico de ETCC envolveu a colocação de 2 eletrodos de área 5x7 cm, pólo anódico aplicado sobre região correspondente ao córtex pré-frontal dorsolateral esquerdo e pólo catódico aplicado sobre córtex de transição temporoparietal esquerdo; com intensidade de corrente de 2 mA, aplicada por 20 minutos. Cada sujeito foi submetido a 10 sessões no total. Encontramos que idade se correlacionou com diminuição da inibição intracortical, reproduzindo resultado previamente encontrado em indivíduos saudáveis. Acerca da modulação da ECM após sessão de ETCC, observamos que sujeitos submetidos à intervenção ativa apresentaram aumento da inibição intracortical no hemisfério estimulado, em oposição à ausência de mudança significativa da ECM nos sujeitos que receberam estimulação placebo. Os resultados sugerem que sessão de ETCC, utilizando os parâmetros aplicados neste estudo, levou ao aumento da inibição intracortical. Devido a evidências prévias de déficit de inibição intracortical em pessoas com esquizofrenia, é possível que o fenômeno observado represente mecanismo terapêutico da ETCC. É necessário verificar se tal efeito sobre a ECM acompanha medidas objetivas de resposta clinica. Caso isto se comprove, a ECM pode se tornar um valioso marcador de resposta terapêutica e evolução clinica em pacientes com esquizofrenia<br>The development of transcranial magnetic stimulation allowed the study of motor evoked potentials by applying direct stimuli to the brain cortex in a non-invasive fashion. Different stimulation protocols were observed to yield different response patterns, which were later associated with the functioning of cortical GABAergic and glutamatergic circuits, assembled as motor cortex excitability indices. Also, deviations from normality of such indices were observed in several clinical conditions, including mental disorders such as schizophrenia. The use of these measurements also helped the development of transcranial direct current stimulation (tDCS), a technique which was shown to promote neuromodulatory effects in central nervous system, with potential treatment applications. This technique has been used with success in the treatment of auditory hallucinations in patients with schizophrenia. The use of tDCS might also be effective in the treatment of negative symptoms of schizophrenia, and motor cortex excitability analysis might be used to clarify its physiological effects and act as a possible treatment response predictor. The aim of the present study is to evaluate the motor cortical excitability profile of individuals with schizophrenia, as well as possible influences of tDCS over these measurements. With this aim, we selected a cohort of subjects with schizophrenia who participated in a randomized placebo controlled clinical trial using transcranial direct current stimulation (and sham stimulation for placebo), and measuring motor cortical excitability during baseline evaluation, after the first stimulation session, and at the time of the primary outcome evaluation. The transcranial direct current stimulation protocol used in the present study involved the use of 2 electrodes of area 5x7 cm, anode placed over the region corresponding to the left dorsolateral prefrontal cortex, and cathode over the left cortical temporoparietal juntion. A current of 2 mA intensity was applied for 20 minutes. Each subject underwent a total of 10 sessions. We found that age was correlated to reduced intracortical inhibition, as has been previously found in healthy subjects. Regarding changes of motor cortical excitability following a transcranial direct current stimulation session, we observed that subjects that received the active stimulation displayed an increase in intracortical inhibition, as opposed to those who received sham stimulation, which did not present with any significant change. Results suggest that transcranial direct current stimulation session, using the parameters described in this study, led to an increase in intracortical inhibition. Given previous evidence of intracortical inhibition deficit in individuals with schizophrenia, it is possible that the observed phenomenon corresponds to a treatment mechanism of the electrical stimulation in this population. This need to be confirmed by comparing such changes in cortical excitability to objective measurements of clinical improvement. In case that is confirmed, measurement of motor cortical excitability may have a valuable application as a marker of treatment response and clinical outcome for patients with schizophrenia

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Kan, Benjamin. "Effect of transcranial direct current stimulation (tDCS) on maximal voluntary isometric strength and endurance of the elbow flexors." Thesis, Edith Cowan University, Research Online, Perth, Western Australia, 2011. https://ro.ecu.edu.au/theses/375.

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The present study investigated the effects of transcranial direct current stimulation (tDCS) on maximal voluntary contraction strength (MVC) and the time to failure (TTF) of an isometric muscle endurance test of the elbow flexors. Prior to the main study, the test-retest reliability of MVC and TTF measures was investigated using 10 men (33.2 ± 9.4 y) for the measurements separated by 60 min (within-day) and one week (between-day). Coefficient of variation (CV), Intraclass correlation (ICC, R), a paired t-test and the Bland-Altman plots revealed that TTF at 30% MVC task was reliable, and was able to detect a possible effect of tDCS on TTF, if the magnitude of effect was greater than 11%. Based on the reliability study results, it was hypothesised that tDCS would increase TTF from the first test to the second test separated by 60 min, when a tDCS treatment was administered immediately before the second test. Fifteen men (27.7 ± 8.4 y) were tested for MVC and TTF at 30%-MVC before and immediately after tDCS or sham intervention (10 min) in three separate sessions. In two sessions direct current (2 mA) was delivered through saline-soaked sponge electrodes, with the anode placed on the scalp overlying the right motor cortical representation of the left arm and the cathode secured over the right shoulder. One session was a sham intervention (current delivery for the first 30s). The order of the intervention sessions was randomised and counterbalanced amongst the subjects and subjects who were blinded to intervention type. Changes in MVC strength and TTF from pre to post intervention were compared between the interventions by a two-way repeated measures ANOVA. No significant differences were evident for the two tDCS sessions. MVC strength (baseline: 66.0 ± 11.4 Nm) decreased by 5.9 ± 4.2 % (P

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Libri sul tema "Direct cortical stimulation"

1

Nitsche, Michael A., Andrea Antal, David Liebetanz, Nicolas Lang, Frithjof Tergau, and Walter Paulus. Neuroplasticity induced by transcranial direct current stimulation. Edited by Charles M. Epstein, Eric M. Wassermann, and Ulf Ziemann. Oxford University Press, 2012. http://dx.doi.org/10.1093/oxfordhb/9780198568926.013.0017.

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This article explores the use of brain stimulation as a tool of neuroplasticity. Recent studies have shown that brain stimulation with weak direct currents is a technique used to generate prolonged modifications of cortical excitability and activity. Transcranial direct current stimulation (tDCS) generates modulations of excitability. The efficacy of electric brain stimulation is defined by the combination of strength of current, size of stimulated area, and stimulation duration. The two main fields of clinical application on tDCS are: the exploration of pathological alterations of neuroplasticity in neurological and psychiatric diseases, and the evaluation of a possible clinical benefit of tDCS in these diseases. Further studies are needed to explore this area if prolonged, repetitive, or stronger stimulation protocols, for which safety has to be assured, could evolve into clinically more relevant improvement. This article reinforces the fact that brain stimulation with weak direct currents could evolve as a promising tool in neuroplasticity research.

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Rotenberg, Alexander, Alvaro Pascual-Leone, and Alan D. Legatt. Transcranial Electrical and Magnetic Stimulation. Edited by Donald L. Schomer and Fernando H. Lopes da Silva. Oxford University Press, 2017. http://dx.doi.org/10.1093/med/9780190228484.003.0028.

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Noninvasive magnetic and electrical stimulation of cerebral cortex is an evolving field. The most widely used variant, transcranial electrical stimulation (TES), is routinely used for intraoperative monitoring. Transcranial magnetic stimulation (TMS) and transcranial direct current stimulation (tDCS) are emerging as clinical and experimental tools. TMS has gained wide acceptance in extraoperative functional cortical mapping. TES and TMS rely on pulsatile stimulation with electrical current intensities sufficient to trigger action potentials within the stimulated cortical volume. tDCS, in contrast, is based on neuromodulatory effects of very-low-amplitude direct current conducted through the scalp. tDCS and TMS, particularly when applied in repetitive trains, can modulate cortical excitability for prolonged periods and thus are either in active clinical use or in advanced stages of clinical trials for common neurological and psychiatric disorders such as major depression and epilepsy. This chapter summarizes physiologic principles of transcranial stimulation and clinical applications of these techniques.

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Nuwer, Marc R., and Stephan Schuele. Electrocorticography. Edited by Donald L. Schomer and Fernando H. Lopes da Silva. Oxford University Press, 2017. http://dx.doi.org/10.1093/med/9780190228484.003.0030.

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Electrocorticography (ECoG) is the method of recording electroencephalographic signals directly from surgically exposed cerebral cortex. It detects intraoperatively the cortical regions with substantial epileptiform interictal discharges. Direct cortical stimulation during ECoG provides a method of identifying language, motor, and sensory regions during a craniotomy. Both techniques—the identification of cortex with epileptic activity and cortex with important eloquent functional activity—help determine limits for surgical cortical resection. These are used most commonly during epilepsy and tumor surgery. Anesthetic agents can adversely affect the recording, and ECoG restricts the types of anesthesia that can be used. The amount of spiking from diffuse or remote cortical regions on ECoG can predict the success of postoperative seizure control.

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Gad, Heba, Daniel Bateman, and Paul E. Holtzheimer. Neurostimulation Therapies, Side Effects, Risks, and Benefits. Oxford University Press, 2017. http://dx.doi.org/10.1093/med/9780199374656.003.0016.

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Neurostimulation therapies are an alternative for non-responders to pharmacological or psychotherapy management, as well as when first-line treatments are contraindicated for treatment of neuropsychiatric disorders in the elderly. Brain stimulation treatments for neuropsychiatric disorders include the following FDA approved treatments for major depressive disorder: electroconvulsive therapy (ECT), which remains one of the most effective therapies for several neuropsychiatric disorders; repetitive transcranial magnetic stimulation (rTMS); and vagus nerve stimulation (VNS). Deep brain stimulation (DBS);magnetic seizure therapy (MST); transcranial direct-current stimulation (tDCS); and direct cortical stimulation (DCS) are not currently FDA approved. These techniques are reviewed in this chapter with special attention to their application in older adults. Medicolegal issues of informed consent and substituted decisions for procedures are also discussed.

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Mason, Peggy. Basal Ganglia. Oxford University Press, 2017. http://dx.doi.org/10.1093/med/9780190237493.003.0025.

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The core function of the basal ganglia is action selection, the process of choosing between mutually exclusive actions. Under baseline or default conditions, the basal ganglia suppress movement and prevent more than one movement from occurring simultaneously. The importance of chunking and operational learning is explored through exemplary typing tasks. Pathways through the basal ganglia employ the same input and output ports. Inputs far outnumber outputs from the basal ganglia. Subcortical loops through the basal ganglia are more effective than are cortical loops. The functions of the hyperdirect, direct and indirect pathways to motor control in the skeletomotor loop are detailed. Hemiballismus, Parkinson’s disease, and Huntington’s disease are key basal ganglia disorders. The use of deep brain stimulation (DBS) of the subthalamic nucleus as a treatment for Parkinson’s disease is discussed. Finally, additional basal ganglia loops such as the oculomotor loop are introduced.

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Ilmoniemi, Risto J., and Jari Karhu. TMS and electroencephalography: methods and current advances. Edited by Charles M. Epstein, Eric M. Wassermann, and Ulf Ziemann. Oxford University Press, 2012. http://dx.doi.org/10.1093/oxfordhb/9780198568926.013.0037.

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Electroencephalography (EEG) combined with transcranial magnetic stimulation (TMS) provides detailed real-time information about the state of the cortex. EEG requires only two to four electrodes and can be a part of most TMS studies. When used with magnetic resonance imaging (MRI) based targeting and conductor modelling, the TMS-EEG combination is a sophisticated brain-mapping tool. This article explains the mechanisms of TMS-evoked EEG. It describes the technique of recording TMS evoked EEG and the possible challenges for the same. Furthermore, it describes possible solutions to these challenges. By varying the TMS intensities, interstimulus intervals, induced current direction, and cortical targets, a rich spectrum of functional information can be obtained. Cortical excitability and connectivity can be studied directly by combining TMS with EEG or other brain-imaging methods, not only in motor, but also nonmotor, areas.

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OʼShea, Jacinta, and Matthew F. S. Rushworth. Higher visual cognition: search, neglect, attention, and eye movements. Edited by Charles M. Epstein, Eric M. Wassermann, and Ulf Ziemann. Oxford University Press, 2012. http://dx.doi.org/10.1093/oxfordhb/9780198568926.013.0028.

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This article reviews the contribution of transcranial magnetic stimulation (TMS) research to the understanding of attention, eye movements, visual search, and neglect. It considers how TMS studies have confirmed, refined, or challenged prevailing ideas about the neural basis of higher visual cognition. It shows that TMS has enhanced the understanding of the location, timing, and functional roles of visual cognitive processes in the human brain. The main focus is on studies of posterior parietal cortex (PPC), with reference to recent work on the frontal eye fields (FEFs). TMS offers many advantages to complement neuropsychological patient studies to enhance the understanding of how the fronto-parietal cortical nerves function. The visuo-spatial neglect- and extinction-like deficits incurred by parietal damage have been modelled successfully using TMS. Future work might be directed at teasing apart the distinct functional roles of nodes within this frontoparietal network in different sensorimotor contexts.

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Capitoli di libri sul tema "Direct cortical stimulation"

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Mehdorn, H. Maximillian, Simone Goebel, and Arya Nabavi. "Direct Cortical Stimulation and fMRI." In fMRI. Springer Berlin Heidelberg, 2013. http://dx.doi.org/10.1007/978-3-642-34342-1_13.

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Mehdorn, Maximillian H., Simone Goebel, and Arya Nabavi. "Direct Cortical Stimulation and fMRI." In fMRI. Springer Berlin Heidelberg, 2010. http://dx.doi.org/10.1007/978-3-540-68132-8_12.

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Mehdorn, H. Maximilian, Simone Goebel, and Arya Nabavi. "Direct Cortical Stimulation and fMRI." In fMRI. Springer International Publishing, 2020. http://dx.doi.org/10.1007/978-3-030-41874-8_21.

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Polanía, Rafael, Michael A. Nitsche, and Walter Paulus. "Modulation of Functional Connectivity with Transcranial Direct Current Stimulation." In Cortical Connectivity. Springer Berlin Heidelberg, 2012. http://dx.doi.org/10.1007/978-3-662-45797-9_7.

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Radhu, Natasha, Daniel M. Blumberger, and Zafiris J. Daskalakis. "Cortical Inhibition and Excitation in Neuropsychiatric Disorders Using Transcranial Magnetic Stimulation." In Transcranial Direct Current Stimulation in Neuropsychiatric Disorders. Springer International Publishing, 2016. http://dx.doi.org/10.1007/978-3-319-33967-2_6.

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Ries, Stephanie K., Kesshi Jordan, Robert T. Knight, and Mitchel Berger. "Lesion-Behavior Awake Mapping with Direct Cortical and Subcortical Stimulation." In Lesion-to-Symptom Mapping. Springer US, 2022. http://dx.doi.org/10.1007/978-1-0716-2225-4_14.

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Rego, Gabriel, Lucas Murrins Marques, Marília Lira da Silveira Coêlho, and Paulo Sérgio Boggio. "Modulating the Social and Affective Brain with Transcranial Stimulation Techniques." In Social and Affective Neuroscience of Everyday Human Interaction. Springer International Publishing, 2022. http://dx.doi.org/10.1007/978-3-031-08651-9_15.

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AbstractTranscranial brain stimulation (TBS) is a term that denotes different noninvasive techniques which aim to modulate brain cortical activity through an external source, usually an electric or magnetic one. Currently, there are several techniques categorized as TBS. However, two are more used for scientific research, the transcranial magnetic stimulation (TMS) and the transcranial direct current stimulation (tDCS), which stimulate brain areas with a high-intensity magnetic field or a weak electric current on the scalp, respectively. They represent an enormous contribution to behavioral, cognitive, and social neuroscience since they reveal how delimited brain cortical areas contribute to some behavior or cognition. They have also been proposed as a feasible tool in the clinical setting since they can modulate abnormal cognition or behavior due to brain activity modulation. This chapter will present the standard methods of transcranial stimulation, their contributions to social and affective neuroscience through a few main topics, and the studies that adopted those techniques, also summing their findings.

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Callejón-Leblic, M. A., and Pedro C. Miranda. "A Computational Parcellated Brain Model for Electric Field Analysis in Transcranial Direct Current Stimulation." In Brain and Human Body Modeling 2020. Springer International Publishing, 2020. http://dx.doi.org/10.1007/978-3-030-45623-8_5.

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AbstractRecent years have seen the use of increasingly realistic electric field (EF) models to further our knowledge of the bioelectric basis of noninvasive brain techniques such as transcranial direct current stimulation (tDCS). Such models predict a poor spatial resolution of tDCS, showing a non-focal EF distribution with similar or even higher magnitude values far from the presumed targeted regions, thus bringing into doubt the classical criteria for electrode positioning. In addition to magnitude, the orientation of the EF over selected neural targets is thought to play a key role in the neuromodulation response. This chapter offers a summary of recent works which have studied the effect of simulated EF magnitude and orientation in tDCS, as well as providing new results derived from an anatomically representative parcellated brain model based on finite element method (FEM). The results include estimates of mean and peak tangential and normal EF values over different cortical regions and for various electrode montages typically used in clinical applications.

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Lei, Tingju, Ding Ma, and Feng Jiang. "Mapping the Cortical Activation Changes Induced by Transcranial Direct Current Stimulation: A fNIRS-tDCS Study." In Proceedings of the 6th International Asia Conference on Industrial Engineering and Management Innovation. Atlantis Press, 2015. http://dx.doi.org/10.2991/978-94-6239-145-1_34.

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Tatemoto, Tsuyoshi, Tomofumi Yamaguchi, Yohei Otaka, Kunitsugu Kondo, and Satoshi Tanaka. "Anodal Transcranial Direct Current Stimulation over the Lower Limb Motor Cortex Increases the Cortical Excitability with Extracephalic Reference Electrodes." In Converging Clinical and Engineering Research on Neurorehabilitation. Springer Berlin Heidelberg, 2013. http://dx.doi.org/10.1007/978-3-642-34546-3_135.

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Atti di convegni sul tema "Direct cortical stimulation"

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Hong, Yirye, June Sic Kim, and Chun Kee Chung. "Direct Cortical Stimulation for inducing Artificial Speech Perception: A Preliminary Study." In 2023 11th International Winter Conference on Brain-Computer Interface (BCI). IEEE, 2023. http://dx.doi.org/10.1109/bci57258.2023.10078541.

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Sellers, Kristin K., William L. Schuerman, Heather E. Dawes, Edward F. Chang, and Matthew K. Leonard. "Comparison of Common Artifact Rejection Methods applied to Direct Cortical and Peripheral Stimulation in Human ECoG." In 2019 9th International IEEE/EMBS Conference on Neural Engineering (NER). IEEE, 2019. http://dx.doi.org/10.1109/ner.2019.8716980.

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Thomas, Chris, Abhishek Datta, and Adam Woods. "Effect of Aging on Cortical Current Flow Due to Transcranial Direct Current Stimulation: Considerations for Safety." In 2018 40th Annual International Conference of the IEEE Engineering in Medicine and Biology Society (EMBC). IEEE, 2018. http://dx.doi.org/10.1109/embc.2018.8513014.

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Khan, Bilal, Nathan Hervey, Ann Stowe, Timea Hodics, and George Alexandrakis. "Use of functional near-infrared spectroscopy to monitor cortical plasticity induced by transcranial direct current stimulation." In SPIE BiOS, edited by Nikiforos Kollias, Bernard Choi, Haishan Zeng, et al. SPIE, 2013. http://dx.doi.org/10.1117/12.2003446.

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Dutta, Anirban, Rahima S. Boulenouar, David Guiraud, and Michael A. Nitsche. "Delineating the effects of anodal transcranial direct current stimulation on myoelectric control based on slow cortical potentials." In 2014 36th Annual International Conference of the IEEE Engineering in Medicine and Biology Society (EMBC). IEEE, 2014. http://dx.doi.org/10.1109/embc.2014.6944277.

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Cao, Pengjia, Kaijie Wu, Mingjie Sun, Xinyu Chai, and Qiushi Ren. "Evoked Cortical Potential and Optic Nerve Response after Direct Electrical Stimulation of the Optic Nerve in Rabbits." In 2007 IEEE/ICME International Conference on Complex Medical Engineering. IEEE, 2007. http://dx.doi.org/10.1109/iccme.2007.4381951.

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Leote, J., R. Loucao, M. Lauterbach, et al. "Understanding network reorganization after glioma regrowth: comparing connectivity measures from functional magnetic resonance imaging to direct cortical stimulation." In 2019 IEEE 6th Portuguese Meeting on Bioengineering (ENBENG). IEEE, 2019. http://dx.doi.org/10.1109/enbeng.2019.8692523.

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Lellis, Caio de Almeida, Marco Alejandro Menacho Herbas, Glaucia Borges Dantas, and Leonardo Rizier Galvão. "Transcranial Direct Current Stimulation in the Management of Refractory Symptoms of Parkinson’s Disease: A Systematic Review." In XIII Congresso Paulista de Neurologia. Zeppelini Editorial e Comunicação, 2021. http://dx.doi.org/10.5327/1516-3180.221.

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Introduction: Transcranial direct current stimulation (tDCS) is a non-invasive brain stimulation technique increasingly used in neurology. Objectives: To evaluate the safety and efficacy of tDCS in refractory symptoms of Parkinson’s disease (PD). Design and setting: A systematic review of the literature conducted at the Pontifical Catholic University of Goiás. Methods: A systematic review of the literature was conducted in the MedLine and Lilacs databases, with the following search strategy: “(Parkinson Disease) AND (Transcranial Direct Current Stimulation OR TDCS)”. Randomized clinical trials (10 years) were included. Results: One of the studies concluded that simultaneous tDCS of the primary motor cortex (M1) and dorsolateral prefrontal cortex (DLPC) Also, two other articles evaluated the motor response after stimulation of the left DLPC for 20 minutes, with the first realizing improved fine motor performance and attenuation of common oscillatory cortical activity in PD patients, while the second finding an improvement in balance and functional mobility when compared to placebo. Regarding cognitive and mood changes, one of the studies pointed out that a single session of tDCS on the left DLPC is insufficient to improve working memory and inhibition control. Conclusion: tDCS was shown to be a safe and effective therapeutic option in reducing gait freezing and mood disorders, as well as improving fine motor performance and cognition. It is emphasized that further studies on the subject with a larger sample are needed.

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Venkatakrishnan, A., J. L. Contreras-Vidal, M. Sandrini, and L. G. Cohen. "Independent component analysis of resting brain activity reveals transient modulation of local cortical processing by transcranial direct current stimulation." In 2011 33rd Annual International Conference of the IEEE Engineering in Medicine and Biology Society. IEEE, 2011. http://dx.doi.org/10.1109/iembs.2011.6091998.

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Bernardo, Juliana Matos Ferreira, Artur Bruno Silva Gomes, Felipe Jatobá Leite Nonato de Sá, Júlia Gonçalves Ferreira, and Maria Rosa da Silva. "Phantom pain: pathophysiology and therapeutic approaches." In XIII Congresso Paulista de Neurologia. Zeppelini Editorial e Comunicação, 2021. http://dx.doi.org/10.5327/1516-3180.496.

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Background: Phantom pain is a mentally debilitating neuropathy that affects post-amputees. It interferes with the independence and performance of activities, therefore affecting the quality of life. Its pathophysiology ranges from lesions in peripheral innervations, to spinal functional changes, modulation of cortical circuits and psychological factors Objectives : Demonstrate new therapeutic approaches and establish a relation with the pathophysiological mechanisms. Methods: Integrative review applying the descriptors: “phantom pain”, “physiopathology”, “post amputation pain”, “treatment”, and the Boolean operator AND. The searches were carried out at PUBMED with 142 results, at BVS with 113, and at Scielo ,showing no results. At the end, 9 papers were selected. No linguistic filters were used and articles published between 2016 and May 2020 were incorporated. Results: (1) Motor images, mental and visual representation of the limb and its function; (2) peripheral interfaces enables prosthetic control; both techniques active cortical reorganization by promoting sensory feedback to motor stimuli. (3) repetitive transcranial magnetic stimulation and (4) direct current, a non-invasive approach, for maladaptive cortical neuromodulation, in addition to stimulate peripheral innervation. In surgical interventions, (5) targeted muscle reinnervation is used in the residual nerves on amputation process to reinnervate the motor terminal of the remaining muscles, promoting nerve growth and organization. Conclusions Physiological investigation applied to treatments enables effective therapeutics, anticipating rehabilitation. The representation of images, peripheral interfaces, brain stimulation and less invasive surgical techniques.

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Rapporti di organizzazioni sul tema "Direct cortical stimulation"

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Koven, William, Gordon Grau, Benny Ron, and Tetsuya Hirano. Improving fry quality, survival and growth in commercially farmed fish by dietary stimulation of thyroid hormone production in premetamorphosing larvae. United States Department of Agriculture, 2004. http://dx.doi.org/10.32747/2004.7695856.bard.

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There is a direct correlation between successful metamorphosis from larvae to post-larvae and the quality of the resultant juveniles or fry. Juvenile quality, in turn, is a major factor influencing fish production level and market price. However, following the profound morphological and physiological changes occurring during metamorphosis, the emerging juveniles in some species characteristically demonstrate heterotrophic growth, poor pigmentation, cannibalism and generally poor survival. The white grouper (Epinephelus aeneus) in Israel and the Pacific threadfin (Polydactylussexfilis) in Hawaii are two promising candidates for mariculture that have high market value but a natural fishery that has sharply declined in recent years. Unfortunately, their potential for culture is severely hampered by variable metamorphic success limiting their production. The main objective was to compare the efficacy and economic viability of dietary or environmental iodine on metamorphic success and juvenile quality in the white grouper and the pink snapper which would lead to improved commercial rearing protocols and increased production of these species both in Israel and the US. The Hawaii Institute of Marine Biology encountered problems with the availability of pink snapper brood stock and larvae and changed to Pacific threadfin or moi which is rapidly becoming a premier aquaculture species in Hawaii and throughout the Indo-Pacific. The white grouper brood stock at the National Center for Mariculture was lost as a result of a viral outbreak following the sudden breakdown of the ozone purification system. In addition, the NCM suffered a devastating fire in the fall of 2007 that completely destroyed the hatchery and laboratory facilities although the BARD project samples were saved. Nevertheless, by studying alternate species a number of valuable findings and conclusions that can contribute to improved metamorphosis in commercially valuable marine species resulted from this collaborative effort. The Israeli group found that exposing white grouper larvae to external TH levels synchronized and increased the rate of metamorphosis. This suggested that sub-optimal synthesis of TH may be a major factor causing size heterogeneity in the larval population and high mortality through cannibalism by their larger more metamorphosed cohorts. Two protocols were developed to enrich the larvae with higher levels of the TH precursor, iodine; feeding iodine enriched Artemia or increasing the level of seawater iodine the larvae are exposed to. Results of accumulated iodine in gilthead seabream larvae indicated that the absorption of iodine from the water is markedly more efficient than feeding iodine enriched Artemia nauplii. Samples for TH, which will be analyzed shortly, will be able to determine if another dietary factor is lacking to effectively utilize surplus tissue iodine for TH synthesis. Moreover, these samples will also clarify which approach to enriching larvae with iodine, through the live food or exposure to iodine enriched seawater is the most efficient and cost effective. The American group found that moi larvae reared in ocean water, which possessed substantially higher iodine levels than those found in seawater well water, grew significantly larger, and showed increased survival compared with well water reared larvae. Larvae reared in ocean water also progressed more rapidly through developmental stages than those in low-iodine well seawater. In collaboration with Israeli counterparts, a highly specific and precise radioimmunoassay procedure for thyroid hormones and cortisol was developed. Taken altogether, the combined Hawaiian and Israeli collaborative research suggests that for teleost species of commercial value, adequate levels of environmental iodine are more determinate in metamorphosis than iodine levels in the live zooplankton food provided to the larvae. Insuring sufficiently high enough iodine in the ambient seawater offers a much more economical solution to improved metamorphosis than enriching the live food with costly liposomes incorporating iodine rich oils.

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