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Electrocorticography

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https://www.readbyqxmd.com/read/29923502/quantitative-simulation-of-extracellular-single-unit-recording-from-the-surface-of-cortex
#1
Mackenna Hill, Estefania Rios, Shyam Kumar Sudhakar, Douglas Roossien, Ciara Maria Caldwell, Dawen Cai, Omar Ahmed, Scott Lempka, Cynthia A Chestek
OBJECTIVE: Neural recording is important for a wide variety of clinical applications. Until recently, recording from the surface of the brain, even when using micro-electrocorticography (µECoG) arrays, was not thought to enable recording from individual neurons. Recent results suggest that when the surface electrode contact size is sufficiently small, it may be possible to record single neurons from the brain's surface. In this study, we use computational techniques to investigate the ability of surface electrodes to record the activity of single neurons...
June 20, 2018: Journal of Neural Engineering
https://www.readbyqxmd.com/read/29920373/gridloc-an-automatic-and-unsupervised-localization-method-for-high-density-ecog-grids
#2
Mariana P Branco, Michael Leibbrand, Mariska J Vansteensel, Zachary V Freudenburg, Nick F Ramsey
Precise localization of electrodes is essential in the field of high-density (HD) electrocorticography (ECoG) brain signal analysis in order to accurately interpret the recorded activity in relation to functional anatomy. Current localization methods for subchronically implanted HD electrode grids involve post-operative imaging. However, for situations where post-operative imaging is not available, such as during acute measurements in awake surgery, electrode localization is complicated. Intra-operative photographs may be informative, but not for electrode grids positioned partially or fully under the skull...
June 16, 2018: NeuroImage
https://www.readbyqxmd.com/read/29916770/investigation-of-subdural-electrode-displacement-in-invasive-epilepsy-surgery-workup-using-neuronavigation-and-intraoperative-mri
#3
Bjoern Sommer, Stefan Rampp, Arnd Doerfler, Hermann Stefan, Hajo M Hamer, Michael Buchfelder, Karl Roessler
OBJECTIVES: One of the main obstacles of electrode implantation in epilepsy surgery is the electrode shift between implantation and the day of explantation. We evaluated this possible electrode displacement using intraoperative MRI (iopMRI) data and CT/MRI reconstruction. METHODS: Thirteen patients (nine female, four male, median age 26 ± 9.4 years) suffering from drug-resistant epilepsy were examined. After implantation, the position of subdural electrodes was evaluated by 3...
June 19, 2018: Neurological Research
https://www.readbyqxmd.com/read/29915532/engineering-artificial-somatosensation-through-cortical-stimulation-in-humans
#4
Brian Lee, Daniel Kramer, Michelle Armenta Salas, Spencer Kellis, David Brown, Tatyana Dobreva, Christian Klaes, Christi Heck, Charles Liu, Richard A Andersen
Sensory feedback is a critical aspect of motor control rehabilitation following paralysis or amputation. Current human studies have demonstrated the ability to deliver some of this sensory information via brain-machine interfaces, although further testing is needed to understand the stimulation parameters effect on sensation. Here, we report a systematic evaluation of somatosensory restoration in humans, using cortical stimulation with subdural mini-electrocorticography (mini-ECoG) grids. Nine epilepsy patients undergoing implantation of cortical electrodes for seizure localization were also implanted with a subdural 64-channel mini-ECoG grid over the hand area of the primary somatosensory cortex (S1)...
2018: Frontiers in Systems Neuroscience
https://www.readbyqxmd.com/read/29891885/real-life-speech-production-and-perception-have-a-shared-premotor-cortical-substrate
#5
Olga Glanz Iljina, Johanna Derix, Rajbir Kaur, Andreas Schulze-Bonhage, Peter Auer, Ad Aertsen, Tonio Ball
Motor-cognitive accounts assume that the articulatory cortex is involved in language comprehension, but previous studies may have observed such an involvement as an artefact of experimental procedures. Here, we employed electrocorticography (ECoG) during natural, non-experimental behavior combined with electrocortical stimulation mapping to study the neural basis of real-life human verbal communication. We took advantage of ECoG's ability to capture high-gamma activity (70-350 Hz) as a spatially and temporally precise index of cortical activation during unconstrained, naturalistic speech production and perception conditions...
June 11, 2018: Scientific Reports
https://www.readbyqxmd.com/read/29890343/using-electrocorticogram-baseline-seizure-frequency-to-assess-the-efficacy-of-responsive-neurostimulation
#6
Michael G Young, Sumeet Vadera, Jack J Lin, Lilit Mnatsakanyan
BACKGROUND: The effect of direct brain responsive neurostimulation on the frequency of electrographic seizures in patients with medically refractory focal epilepsy has not been evaluated by chronic ambulatory electrocorticographic monitoring. METHODS: This was a retrospective study of 9 patients who underwent implantation of the responsive neurostimulator (RNS) system from 2015 to 2017 at the University of California, Irvine. Leads were placed at the ictal onset zone as determined by intracranial electroencephalography (EEG)...
June 8, 2018: Epilepsy & Behavior: E&B
https://www.readbyqxmd.com/read/29888819/electrocorticography-reveals-continuous-auditory-and-visual-speech-tracking-in-temporal-and-occipital-cortex
#7
C Micheli, I M Schepers, M Ozker, D Yoshor, M S Beauchamp, J W Rieger
During natural speech perception, humans must parse temporally continuous auditory and visual speech signals into sequences of words. However, most studies of speech perception present only single words or syllables. We used electrocorticography (subdural electrodes implanted on the brains of epileptic patients) to investigate the neural mechanisms for processing continuous audiovisual speech signals consisting of individual sentences. Using partial correlation analysis, we found that posterior superior temporal gyrus (pSTG) and medial occipital cortex tracked both the auditory and visual speech envelopes...
June 11, 2018: European Journal of Neuroscience
https://www.readbyqxmd.com/read/29886144/source-reconstruction-of-the-sensorimotor-network-from-resting-state-macaque-electrocorticography
#8
R Hindriks, C Micheli, C A Bosman, R Oostenveld, C Lewis, D Mantini, P Fries, G Deco
The discovery of hemodynamic (BOLD-fMRI) resting-state networks (RSNs) has brought about a fundamental shift in our thinking about the role of intrinsic brain activity. The electrophysiological underpinnings of RSNs remain largely elusive and it has been shown only recently that electric cortical rhythms are organized into the same RSNs as hemodynamic signals. Most electrophysiological studies into RSNs use magnetoencephalography (MEG) or scalp electroencephalography (EEG), which limits the spatial resolution with which electrophysiological RSNs can be observed...
June 7, 2018: NeuroImage
https://www.readbyqxmd.com/read/29877818/a-16-channel-cmos-chopper-stabilized-analog-front-end-ecog-acquisition-circuit-for-a-closed-loop-epileptic-seizure-control-system
#9
Chung-Yu Wu, Cheng-Hsiang Cheng, Zhi-Xin Chen
In this paper, a 16-channel analog front-end (AFE) electrocorticography signal acquisition circuit for a closed-loop seizure control system is presented. It is composed of 16 input protection circuits, 16 auto-reset chopper-stabilized capacitive-coupled instrumentation amplifiers (AR-CSCCIA) with bandpass filters, 16 programmable transconductance gain amplifiers, a multiplexer, a transimpedance amplifier, and a 128-kS/s 10-bit delta-modulated successive-approximation-register analog-to-digital converter (SAR ADC)...
June 2018: IEEE Transactions on Biomedical Circuits and Systems
https://www.readbyqxmd.com/read/29860298/a-lexical-semantic-hub-for-heteromodal-naming-in-middle-fusiform-gyrus
#10
Kiefer James Forseth, Cihan Mehmet Kadipasaoglu, Christopher Richard Conner, Gregory Hickok, Robert Thomas Knight, Nitin Tandon
Semantic memory underpins our understanding of objects, people, places, and ideas. Anomia, a disruption of semantic memory access, is the most common residual language disturbance and is seen in dementia and following injury to temporal cortex. While such anomia has been well characterized by lesion symptom mapping studies, its pathophysiology is not well understood. We hypothesize that inputs to the semantic memory system engage a specific heteromodal network hub that integrates lexical retrieval with the appropriate semantic content...
May 30, 2018: Brain: a Journal of Neurology
https://www.readbyqxmd.com/read/29848632/a-theta-rhythm-in-macaque-visual-cortex-and-its-attentional-modulation
#11
Georgios Spyropoulos, Conrado Arturo Bosman, Pascal Fries
Theta rhythms govern rodent sniffing and whisking, and human language processing. Human psychophysics suggests a role for theta also in visual attention. However, little is known about theta in visual areas and its attentional modulation. We used electrocorticography (ECoG) to record local field potentials (LFPs) simultaneously from areas V1, V2, V4, and TEO of two macaque monkeys performing a selective visual attention task. We found a ≈4-Hz theta rhythm within both the V1-V2 and the V4-TEO region, and theta synchronization between them, with a predominantly feedforward directed influence...
May 30, 2018: Proceedings of the National Academy of Sciences of the United States of America
https://www.readbyqxmd.com/read/29845008/locally-stable-brain-states-predict-suppression-of-epileptic-activity-by-enhanced-cognitive-effort
#12
Sarah F Muldoon, Julia Costantini, W R S Webber, Ronald Lesser, Danielle S Bassett
Cognitive effort is known to play a role in healthy brain state organization, but little is known about its effects on pathological brain dynamics. When cortical stimulation is used to map functional brain areas prior to surgery, a common unwanted side effect is the appearance of afterdischarges (ADs), epileptiform and potentially epileptogenic discharges that can progress to a clinical seizure. It is therefore desirable to suppress this activity. Here, we analyze electrocorticography recordings from 15 patients with epilepsy...
2018: NeuroImage: Clinical
https://www.readbyqxmd.com/read/29803145/language-mapping-using-electrocorticography-versus-stereoelectroencephalography-a-case-series
#13
James J Young, Kelly Coulehan, Madeline C Fields, Ji Yeoun Yoo, Lara V Marcuse, Nathalie Jette, Fedor Panov, Saadi Ghatan, Heidi A Bender
Direct electrical stimulation (DES) is sometimes used in epilepsy surgery to identify areas that may result in language deficits if resected. Extraoperative language mapping is usually performed using electrocorticography (ECOG) - grids and strip electrodes; however, given the better safety profile of stereoelectroencephalogaphy (SEEG), it would be desirable to determine if mapping using SEEG is also effective. We report a case series of fifteen patients that underwent language mapping with either ECOG (5), SEEG (9), or both (1)...
May 23, 2018: Epilepsy & Behavior: E&B
https://www.readbyqxmd.com/read/29799344/spreading-depolarization-in-acute-brain-injury-inhibited-by-ketamine-a-prospective-randomized-multiple-crossover-trial
#14
Andrew P Carlson, Mohammad Abbas, Robert L Alunday, Fares Qeadan, C William Shuttleworth
OBJECTIVE Retrospective clinical data and case studies support a therapeutic effect of ketamine in suppression of spreading depolarization (SD) following brain injury. Preclinical data strongly support efficacy in terms of frequency of SD as well as recovery from electrocorticography (ECoG) depression. The authors present the results of the first prospective controlled clinical trial testing the role of ketamine used for clinical sedation on occurrence of SD. METHODS Ten patients with severe traumatic brain injury (TBI) or aneurysmal subarachnoid hemorrhage (SAH) were recruited for this pilot trial...
May 25, 2018: Journal of Neurosurgery
https://www.readbyqxmd.com/read/29769525/asynchronous-suppression-of-visual-cortex-during-absence-seizures-in-stargazer-mice
#15
Jochen Meyer, Atul Maheshwari, Jeffrey Noebels, Stelios Smirnakis
Absence epilepsy is a common childhood disorder featuring frequent cortical spike-wave seizures with a loss of awareness and behavior. Using the calcium indicator GCaMP6 with in vivo 2-photon cellular microscopy and simultaneous electrocorticography, we examined the collective activity profiles of individual neurons and surrounding neuropil across all layers in V1 during spike-wave seizure activity over prolonged periods in stargazer mice. We show that most (~80%) neurons in all cortical layers reduce their activity during seizures, whereas a smaller pool activates or remains neutral...
May 16, 2018: Nature Communications
https://www.readbyqxmd.com/read/29752244/spatial-temporal-dynamics-of-the-sensorimotor-cortex-sustained-and-transient-activity
#16
E Salari, Z V Freudenburg, M J Vansteensel, N F Ramsey
How the sensorimotor cortex is organized with respect to controlling different features of movement is unclear. One unresolved question concerns the relation between the duration of an action and the duration of the associated neuronal activity change in the sensorimotor cortex. Using subdural electrocorticography electrodes, we investigated in five subjects, whether high frequency band (HFB; 75-135 Hz) power changes have a transient or sustained relation to speech duration, during pronunciation of the Dutch /i/ vowel with different durations...
May 2018: IEEE Transactions on Neural Systems and Rehabilitation Engineering
https://www.readbyqxmd.com/read/29749917/a-novel-neural-prosthesis-providing-long-term-electrocorticography-recording-and-cortical-stimulation-for-epilepsy-and-brain-computer-interface
#17
Pantaleo Romanelli, Marco Piangerelli, David Ratel, Christophe Gaude, Thomas Costecalde, Cosimo Puttilli, Mauro Picciafuoco, Alim Benabid, Napoleon Torres
OBJECTIVE Wireless technology is a novel tool for the transmission of cortical signals. Wireless electrocorticography (ECoG) aims to improve the safety and diagnostic gain of procedures requiring invasive localization of seizure foci and also to provide long-term recording of brain activity for brain-computer interfaces (BCIs). However, no wireless devices aimed at these clinical applications are currently available. The authors present the application of a fully implantable and externally rechargeable neural prosthesis providing wireless ECoG recording and direct cortical stimulation (DCS)...
May 11, 2018: Journal of Neurosurgery
https://www.readbyqxmd.com/read/29740294/converging-evidence-from-electrocorticography-and-bold-fmri-for-a-sharp-functional-boundary-in-superior-temporal-gyrus-related-to-multisensory-speech-processing
#18
Muge Ozker, Daniel Yoshor, Michael S Beauchamp
Although humans can understand speech using the auditory modality alone, in noisy environments visual speech information from the talker's mouth can rescue otherwise unintelligible auditory speech. To investigate the neural substrates of multisensory speech perception, we compared neural activity from the human superior temporal gyrus (STG) in two datasets. One dataset consisted of direct neural recordings (electrocorticography, ECoG) from surface electrodes implanted in epilepsy patients (this dataset has been previously published)...
2018: Frontiers in Human Neuroscience
https://www.readbyqxmd.com/read/29678760/sub-millimeter-ecog-pitch-in-human-enables-higher-fidelity-cognitive-neural-state-estimation
#19
John Hermiz, Nicholas Rogers, Erik Kaestner, Mehran Ganji, Daniel R Cleary, Bob S Carter, David Barba, Shadi A Dayeh, Eric Halgren, Vikash Gilja
Electrocorticography (ECoG), electrophysiological recording from the pial surface of the brain, is a critical measurement technique for clinical neurophysiology, basic neurophysiology studies, and demonstrates great promise for the development of neural prosthetic devices for assistive applications and the treatment of neurological disorders. Recent advances in device engineering are poised to enable orders of magnitude increase in the resolution of ECoG without comprised measurement quality. This enhancement in cortical sensing enables the observation of neural dynamics from the cortical surface at the micrometer scale...
August 1, 2018: NeuroImage
https://www.readbyqxmd.com/read/29676287/electrophysiological-correlates-of-neurodegeneration-in-motor-and-non-motor-brain-regions-in-amyotrophic-lateral-sclerosis-implications-for-brain-computer-interfacing
#20
Philipp Kellmeyer, Moritz Grosse-Wentrup, Andreas Schulze-Bonhage, Ulf Ziemann, Tonio Ball
OBJECTIVE: For patients with amyotrophic lateral sclerosis (ALS) who are suffering from severe communication or motor problems, brain-computer interfaces (BCIs) can improve the quality of life and patient autonomy. However, current BCI systems are not as widely used as their potential and patient demand would let assume. This underutilization is a result of technological as well as user-based limitations but also of the comparatively poor performance of currently existing BCIs in patients with late-stage ALS, particularly in the locked-in state...
April 20, 2018: Journal of Neural Engineering
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