229 results match your criteria Normal EEG Waveforms


EEG Essentials.

Authors:
William O Tatum

Continuum (Minneap Minn) 2022 04;28(2):261-305

Purpose Of Review: EEG is the best study for evaluating the electrophysiologic function of the brain. The relevance of EEG is based on an accurate interpretation of the recording. Understanding the neuroscientific basis for EEG is essential. Read More

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Characterizing Brain Signals for Epileptic Pre-ictal Signal Classification.

AMIA Annu Symp Proc 2021 21;2021:1215-1224. Epub 2022 Feb 21.

Department of Neurology, University of Texas Health Science Center at Houston, Houston, TX.

Epilepsy is a kind of neurological disorder characterized by recurrent epileptic seizures. While it is crucial to characterize pre-ictal brain electrical activities, the problem to this day still remains computationally challenging. Using brain signal acquisition and advances in deep learning technology, we aim to classify pre-ictal signals and characterize the brain waveforms of patients with epilepsy during the pre-ictal period. Read More

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EEG Evoked Potentials to Repetitive Transcranial Magnetic Stimulation in Normal Volunteers: Inhibitory TMS EEG Evoked Potentials.

Sensors (Basel) 2022 Feb 24;22(5). Epub 2022 Feb 24.

Department of Neurology and Neurological Sciences, Stanford University School of Medicine, Stanford, CA 94304, USA.

The impact of repetitive magnetic stimulation (rTMS) on cortex varies with stimulation parameters, so it would be useful to develop a biomarker to rapidly judge effects on cortical activity, including regions other than motor cortex. This study evaluated rTMS-evoked EEG potentials (TEP) after 1 Hz of motor cortex stimulation. New features are controls for baseline amplitude and comparison to control groups of sham stimulation. Read More

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February 2022

Improving Detection of Hippocampal Epileptiform Activity Using Magnetoencephalography.

J Clin Neurophysiol 2022 Mar;39(3):240-246

Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati, Ohio, U.S.A.

Purpose: Magnetoencephalography (MEG) defines the spike-generating zone and provides targets for invasive monitoring with stereotactic electroencephalography. This retrospective, blinded, cross-sectional study determined whether MEG virtual sensors could identify hippocampal epileptiform activity.

Methods: Using MEG beamformer analysis, virtual sensors were manually placed in bilateral hippocampi and corresponding virtual sensor waveforms were analyzed for the presence of epileptiform activity. Read More

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Shift-invariant waveform learning on epileptic ECoG.

Annu Int Conf IEEE Eng Med Biol Soc 2021 11;2021:1136-1139

Seizure detection algorithms must discriminate abnormal neuronal activity associated with a seizure from normal neural activity in a variety of conditions. Our approach is to seek spatiotemporal waveforms with distinct morphology in electrocorticographic (ECoG) recordings of epileptic patients that are indicative of a subsequent seizure (preictal) versus non-seizure segments (interictal). To find these waveforms we apply a shift-invariant k-means algorithm to segments of spatially filtered signals to learn codebooks of prototypical waveforms. Read More

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November 2021

Optimizing Parameters for Using the Parallel Auditory Brainstem Response to Quickly Estimate Hearing Thresholds.

Ear Hear 2022 Mar/Apr;43(2):646-658

Department of Neuroscience, Del Monte Institute for Neuroscience, University of Rochester, Rochester, New York, USA.

Objectives: Timely assessments are critical to providing early intervention and better hearing and spoken language outcomes for children with hearing loss. To facilitate faster diagnostic hearing assessments in infants, the authors developed the parallel auditory brainstem response (pABR), which presents randomly timed trains of tone pips at five frequencies to each ear simultaneously. The pABR yields high-quality waveforms that are similar to the standard, single-frequency serial ABR but in a fraction of the recording time. Read More

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Spectrum of Electroencephalography Findings in Newly Diagnosed Epilepsy.

Cureus 2021 Jun 26;13(6):e15938. Epub 2021 Jun 26.

Department of Pediatric Neurology, The Children's Hospital and The Institute Of Child Health, Lahore, PAK.

Background Epilepsy is a neurological disorder that presents with recurrent seizures associated with erratic brain activity which can be measured through EEG in addition to other neurological investigations. However, EEG may show abnormal patterns and waveforms while the patient is having a seizure which is crucial for making an accurate diagnosis. Objective This study aims to evaluate the spectrum of EEG findings in newly diagnosed epileptic patients as part of a neurological investigation. Read More

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Mental workload classification based on ignored auditory probes and spatial covariance.

J Neural Eng 2021 08 13;18(4). Epub 2021 Aug 13.

Center for Cognition and Neuroergonomics, State Key Laboratory of Cognitive Neuroscience and Learning, Beijing Normal University at Zhuhai, Zhuhai, People's Republic of China.

Estimation of mental workload (MWL) levels by electroencephalography (EEG)-based mental state monitoring systems has been widely explored. Using event-related potentials (ERPs), elicited by ignored auditory probes, minimizes intrusiveness and has shown high performance for estimating MWL level when tested in laboratory situations. However, when facing real-world applications, the characteristics of ERP waveforms, like latency and amplitude, are often affected by noise, which leads to a decrease in classification performance. Read More

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The Significance of EEG Alpha Oscillation Spectral Power and Beta Oscillation Phase Synchronization for Diagnosing Probable Alzheimer Disease.

Front Aging Neurosci 2021 7;13:631587. Epub 2021 Jun 7.

Medical School of Chinese People's Liberation Army, Beijing, China.

Alzheimer disease (AD) is the most common cause of dementia in geriatric population. At present, no effective treatments exist to reverse the progress of AD, however, early diagnosis and intervention might delay its progression. The search for biomarkers with good safety, repeatable detection, reliable sensitivity and community application is necessary for AD screening and early diagnosis and timely intervention. Read More

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Microscale Physiological Events on the Human Cortical Surface.

Cereb Cortex 2021 07;31(8):3678-3700

Departments of Neurosciences and Radiology, University of California San Diego, La Jolla, CA 92093, USA.

Despite ongoing advances in our understanding of local single-cellular and network-level activity of neuronal populations in the human brain, extraordinarily little is known about their "intermediate" microscale local circuit dynamics. Here, we utilized ultra-high-density microelectrode arrays and a rare opportunity to perform intracranial recordings across multiple cortical areas in human participants to discover three distinct classes of cortical activity that are not locked to ongoing natural brain rhythmic activity. The first included fast waveforms similar to extracellular single-unit activity. Read More

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Zero-crossing patterns reveal subtle epileptiform discharges in the scalp EEG.

Sci Rep 2021 02 18;11(1):4128. Epub 2021 Feb 18.

Bioelectrics Lab, Institute of Brain and Spine (ICM), (UMRS 1127, CNRS UMR 7225), Pitié-Salpêtriere Hospital, 47 Boulevard de l'Hôpital, 75013, Paris, France.

Clinical diagnosis of epilepsy depends heavily on the detection of interictal epileptiform discharges (IEDs) from scalp electroencephalographic (EEG) signals, which by purely visual means is far from straightforward. Here, we introduce a simple signal analysis procedure based on scalp EEG zero-crossing patterns which can extract the spatiotemporal structure of scalp voltage fluctuations. We analyzed simultaneous scalp and intracranial EEG recordings from patients with pharmacoresistant temporal lobe epilepsy. Read More

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February 2021

Classical and controlled auditory mismatch responses to multiple physical deviances in anaesthetised and conscious mice.

Eur J Neurosci 2021 03 19;53(6):1839-1854. Epub 2020 Dec 19.

Department of Biomedical Engineering, University of Strathclyde, Glasgow, UK.

Human mismatch negativity (MMN) is modelled in rodents and other non-human species to examine its underlying neurological mechanisms, primarily described in terms of deviance-detection and adaptation. Using the mouse model, we aim to elucidate subtle dependencies between the mismatch response (MMR) and different physical properties of sound. Epidural field potentials were recorded from urethane-anaesthetised and conscious mice during oddball and many-standards control paradigms with stimuli varying in duration, frequency, intensity and inter-stimulus interval. Read More

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Electrophysiological Dynamics of Visual-Tactile Temporal Order Perception in Early Deaf Adults.

Front Neurosci 2020 23;14:544472. Epub 2020 Sep 23.

Department of Psychology, University of Nevada, Reno, Reno, NV, United States.

Studies of compensatory plasticity in early deaf (ED) individuals have mainly focused on unisensory processing, and on spatial rather than temporal coding. However, precise discrimination of the temporal relationship between stimuli is imperative for successful perception of and interaction with the complex, multimodal environment. Although the properties of cross-modal temporal processing have been extensively studied in neurotypical populations, remarkably little is known about how the loss of one sense impacts the integrity of temporal interactions among the remaining senses. Read More

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September 2020

Distinguishing Epileptiform Discharges From Normal Electroencephalograms Using Adaptive Fractal and Network Analysis: A Clinical Perspective.

Front Physiol 2020 5;11:828. Epub 2020 Aug 5.

Institute of Automation, Chinese Academy of Sciences, Beijing, China.

Epilepsy is one of the most common disorders of the brain. Clinically, to corroborate an epileptic seizure-like symptom and to find the seizure localization, electroencephalogram (EEG) data are often visually examined by a clinical doctor to detect the presence of epileptiform discharges. Epileptiform discharges are transient waveforms lasting for several tens to hundreds of milliseconds and are mainly divided into seven types. Read More

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Control analysis of electrical stimulation for epilepsy waveforms in a thalamocortical network.

J Theor Biol 2020 11 5;504:110391. Epub 2020 Jul 5.

School of Mathematics and Statistics, Northwestern Polytechnical University, Xi'an, Shaanxi 710072, China.

Physiological experiments and computational models both show that the thalamic reticular nucleus (RE) participates in inducing various firing patterns of cortex. Absence seizure, featured by 2-4 Hz spike-wave discharges (SWD) oscillation, is a high incidence of disease in children. Lots of electrophysiological experiments have verified the correlation between absence seizures and RE, however, the dynamical mechanisms are not well understood. Read More

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November 2020

Hypnagogic Frontal EEG Bursts in Children: Epileptic or Not?

Authors:
Anita N Datta

J Clin Neurophysiol 2021 Nov;38(6):536-541

Division of Neurology, Department of Pediatrics, BC Children's Hospital, Faculty of Medicine, University of British Columbia, Vancouver, BC, Canada; and.

Purpose: Various EEG patterns emerge in drowsiness. Intermittent bilateral midfrontal slowing (BFS) and hypnogogic frontal predominant sharply contoured waveforms (HFSC), maximal at (Fz, F3-4, and Fp1-2), are often encountered. These do not meet the criteria for epileptiform discharges. Read More

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November 2021

Neurocognitive Inhibitory Control Ability Performance and Correlations with Biochemical Markers in Obese Women.

Int J Environ Res Public Health 2020 04 15;17(8). Epub 2020 Apr 15.

Institution of Physical Education, Health and Leisure Studies, National Cheng Kung University, Tainan 701401, Taiwan.

Inhibitory control, the ability to suppress prepotent responses and resist irrelevant stimuli, is thought to play a critical role in the maintenance of obesity. However, electrophysiological performance related to different inhibitory control processes and their relationship with motor response inhibition and cognitive interference and potential biochemical mechanisms in middle-aged, obese women are as yet unclear. This work thus compared different neurocognitive Go/Nogo and Stroop task performance in healthy sedentary normal-weight and obese women, as well as their correlation with biochemical markers. Read More

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[Pitfalls in Reading EEG for Temporal Lobe Epilepsy: The "Southern-hemisphere" Spike and Normal Variants].

Brain Nerve 2020 Apr;72(4):425-436

Division of Neurology, Kobe University Graduate School of Medicine.

Electroencephalogram (EEG) reading in clinical settings commonly uses three montage types: referential montage, bipolar montage, and average montage. Since each montage type has its advantages and disadvantages, there is no single best montage. To correctly read EEG, it is essential 1) to use the montage appropriate for the focus and distribution of epileptic activity and 2) to correctly recognize EEG waveforms that are often misdiagnosed as epileptic activity. Read More

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Interictal Epileptiform Discharges and the Quality of Human Intracranial Neurophysiology Data.

Front Hum Neurosci 2020 3;14:44. Epub 2020 Mar 3.

Department of Neurological Surgery, University of California, San Francisco, San Francisco, CA, United States.

Intracranial electroencephalography (IEEG) involves recording from electrodes placed directly onto the cortical surface or deep brain locations. It is performed on patients with medically refractory epilepsy, undergoing pre-surgical seizure localization. IEEG recordings, combined with advancements in computational capacity and analysis tools, have accelerated cognitive neuroscience. Read More

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The Shape of Water Stream Induces Differences in P300 and Alpha Oscillation.

Front Hum Neurosci 2019 20;13:460. Epub 2020 Jan 20.

Center for Brain, Mind and KANSEI Sciences Research, Hiroshima University, Hiroshima, Japan.

Touching is a fundamental human behavior used to evaluate objects in the external world. Many previous studies have used tactile stimulation to conduct psychological and psychophysiological experiments. However, most of these studies used solid material, not water stream, as an experimental stimulus. Read More

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January 2020

Transcranial alternating current stimulation in the theta band but not in the delta band modulates the comprehension of naturalistic speech in noise.

Neuroimage 2020 04 20;210:116557. Epub 2020 Jan 20.

Department of Bioengineering and Centre for Neurotechnology, Imperial College London, South Kensington Campus, SW7 2AZ, London, UK. Electronic address:

Auditory cortical activity entrains to speech rhythms and has been proposed as a mechanism for online speech processing. In particular, neural activity in the theta frequency band (4-8 ​Hz) tracks the onset of syllables which may aid the parsing of a speech stream. Similarly, cortical activity in the delta band (1-4 ​Hz) entrains to the onset of words in natural speech and has been found to encode both syntactic as well as semantic information. Read More

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Bottom-up and top-down neural signatures of disordered multi-talker speech perception in adults with normal hearing.

Elife 2020 01 21;9. Epub 2020 Jan 21.

Eaton-Peabody Laboratories, Massachusetts Eye and Ear Infirmary, Boston, United States.

In social settings, speech waveforms from nearby speakers mix together in our ear canals. Normally, the brain unmixes the attended speech stream from the chorus of background speakers using a combination of fast temporal processing and cognitive active listening mechanisms. Of >100,000 patient records,~10% of adults visited our clinic because of reduced hearing, only to learn that their hearing was clinically normal and should not cause communication difficulties. Read More

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January 2020

[Fecal microbiota transplantation regulates the cholinergic anti-inflammatory pathway in cerebral cortex of septic rats through intestinal microbiota].

Zhonghua Wei Zhong Bing Ji Jiu Yi Xue 2019 Sep;31(9):1102-1107

Department of General Medicine, Hebei General Hospital, Shijiazhuang 050051, Hebei, China.

Objective: To investigate the effects of fecal microbiota transplantation on septic gut flora and the cortex cholinergic anti-inflammatory pathway in rats.

Methods: Sixty clean grade male Sprague-Dawley (SD) rats were divided into normal saline (NS) control group, sepsis model group and fecal microbiota transplantation group by random number table, with 20 rats in each group. The rat model of sepsis was reproduced by injection of 10 mg/kg lipopolysaccharide (LPS) via tail vein, the rats in the NS control group was given the same amount of NS. Read More

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September 2019

The Parallel Auditory Brainstem Response.

Trends Hear 2019 Jan-Dec;23:2331216519871395

Department of Biomedical Engineering, University of Rochester, NY, USA.

The frequency-specific tone-evoked auditory brainstem response (ABR) is an indispensable tool in both the audiology clinic and research laboratory. Most frequently, the toneburst ABR is used to estimate hearing thresholds in infants, toddlers, and other patients for whom behavioral testing is not feasible. Therefore, results of the ABR exam form the basis for decisions regarding interventions and hearing habilitation with implications extending far into the child's future. Read More

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Somatosensory Cross-Modal Reorganization in Children With Cochlear Implants.

Front Neurosci 2019 26;13:469. Epub 2019 Jun 26.

Department of Speech, Language, and Hearing Sciences, University of Colorado Boulder, Boulder, CO, United States.

Deprived of sensory input, as in deafness, the brain tends to reorganize. Cross-modal reorganization occurs when cortices associated with deficient sensory modalities are recruited by other, intact senses for processing of the latter's sensory input. Studies have shown that this type of reorganization may affect outcomes when sensory stimulation is later introduced via intervention devices. Read More

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Adult EEG.

Handb Clin Neurol 2019 ;160:103-124

Department of Neurology, Mayo Clinic College of Medicine and Health Sciences, Jacksonville, FL, United States.

After more than 85 years of development and use in clinical practice, the electroencephalogram (EEG) remains a dependable, inexpensive, and useful diagnostic tool for the investigation of the electrophysiologic activity of the brain. The advent of digital technology has led to greater sophistication and multiple software applications to extend the utility of EEG beyond the confines of the laboratory. Despite the discovery of new waveforms, basic neurophysiologic principles remain essential to the clinical care of patients. Read More

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December 2019

Can the Lateralized Readiness Potential Detect Suppressed Manual Responses to Pure Tones?

J Am Acad Audiol 2020 01 24;31(1):61-68. Epub 2019 Jun 24.

Ordre des orthophonistes et audiologistes du Québec, Polyclinique de l'Oreille - Audiosanté, Montréal, Canada.

Background: Willfully not responding to auditory stimuli hampers accurate behavioral measurements. An objective measure of covert manual suppression recorded during response tasks may be useful to assess the veracity of responses to stimuli.

Purpose: To investigate whether the lateralized readiness potential (LRP), an electrophysiological measure of corticomotor response and suppression, may be of use in determining when participants hear but do not respond to pure tones. Read More

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January 2020

Cortical Auditory Evoked Potentials in Response to Frequency Changes with Varied Magnitude, Rate, and Direction.

J Assoc Res Otolaryngol 2019 10 5;20(5):489-498. Epub 2019 Jun 5.

Department of Otorhinolaryngology and Head & Neck Surgery, University Medical Center Utrecht, Room G.02.531, P.O. Box 85500, 3508 GA, Utrecht, The Netherlands.

Recent literature on cortical auditory evoked potentials has focused on correlations with hearing performance with the aim to develop an objective clinical tool. However, cortical responses depend on the type of stimulus and choice of stimulus parameters. This study investigates cortical auditory evoked potentials to sound changes, so-called acoustic change complexes (ACC), and the effects of varying three stimulus parameters. Read More

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October 2019

Abnormal neural responses to harmonic syntactic structures in congenital amusia.

Psychophysiology 2019 09 21;56(9):e13394. Epub 2019 May 21.

Music College, Shanghai Normal University, Shanghai, China.

In music, harmonic syntactic structures are organized hierarchically through local and long-distance dependencies. This study investigated whether congenital amusia, a neurodevelopmental disorder of pitch perception, is associated with impaired processing of harmonic syntactic structures. For stimuli, we used harmonic sequences containing two phrases, where the first phrase ended with a half cadence and the second with an authentic cadence. Read More

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September 2019