scholarly journals The influence of induction speed on the frontal (processed) EEG

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
D. P. Obert ◽  
P. Sepúlveda ◽  
S. Kratzer ◽  
G. Schneider ◽  
M. Kreuzer
Keyword(s):  
Injection Rate ◽  
Alpha Power ◽  
Verbal Command ◽  
Spectral Edge Frequency ◽  
Induction Group ◽  
Power Spectral ◽  
Beta Power ◽  
Processed Eeg ◽  
Electroencephalogram Eeg ◽  
Slow Injection

Abstract The intravenous injection of the anaesthetic propofol is clinical routine to induce loss of responsiveness (LOR). However, there are only a few studies investigating the influence of the injection rate on the frontal electroencephalogram (EEG) during LOR. Therefore, we focused on changes of the frontal EEG especially during this period. We included 18 patients which were randomly assigned to a slow or fast induction group and recorded the frontal EEG. Based on this data, we calculated the power spectral density, the band powers and band ratios. To analyse the behaviour of processed EEG parameters we calculated the beta ratio, the spectral entropy, and the spectral edge frequency. Due to the prolonged induction period in the slow injection group we were able to distinguish loss of responsiveness to verbal command (LOvR) from loss of responsiveness to painful stimulus (LOpR) whereas in the fast induction group we could not. At LOpR, we observed a higher relative alpha and beta power in the slow induction group while the relative power in the delta range was lower than in the fast induction group. When concentrating on the slow induction group the increase in relative alpha power pre-LOpR and even before LOvR indicated that frontal EEG patterns, which have been suggested as an indicator of unconsciousness, can develop before LOR. Further, LOvR was best reflected by an increase of the alpha to delta ratio, and LOpR was indicated by a decrease of the beta to alpha ratio. These findings highlight the different spectral properties of the EEG at various levels of responsiveness and underline the influence of the propofol injection rate on the frontal EEG during induction of general anesthesia.

Morphine-induced activation of fetal EEG is mediated via central muscarinic pathways

1991 ◽  
Vol 260 (3) ◽  
pp. R509-R517
Author(s):  
H. H. Szeto
Keyword(s):  
Power Distribution ◽  
Low Voltage ◽  
Power Spectral Analysis ◽  
State Transitions ◽  
Spectral Edge Frequency ◽  
Transitional State ◽  
Power Spectral ◽  
The Central Nervous System ◽  
Slow Activity ◽  
Electroencephalogram Eeg

The effect of morphine on fetal electroencephalogram (EEG) was investigated using power spectral analysis. Morphine (0.15-5.0 mg/h) administered directly to the fetal lamb altered fetal EEG in three ways. First, morphine altered the relative incidence of the three preponderant EEG states [high-voltage slow activity (HVSA), transitional, and low-voltage fast activity (LVFA)]. Morphine resulted in a dose-dependent reduction in HVSA, with a reciprocal increase in transitional state at the lower doses and an increase in LVFA at higher doses. Second, morphine resulted in a more fragmented and unstable EEG pattern, with a significant increase in the number of state-to-state transitions. Third, there was a significant increase in the 90% spectral edge frequency as well as relative power distribution in the theta band. Taken together, these data suggest that morphine results in activation of the fetal EEG. This effect was completely abolished by concurrent intracerebroventricular administration of either methyl naloxone or methyl atropine, indicating that it is mediated by specific opioid receptors in the central nervous system and involves activation of central muscarinic pathways.

Polysomnographic Findings in Nights Preceding a Migraine Attack

Cephalalgia ◽  
2001 ◽  
Vol 21 (1) ◽  
pp. 31-37 ◽  
Author(s):  
R Göder ◽  
G Fritzer ◽  
A Kapsokalyvas ◽  
P Kropp ◽  
U Niederberger ◽  
...  
Keyword(s):  
Slow Wave Sleep ◽  
Power Spectra ◽  
Cortical Activation ◽  
Alpha Power ◽  
Sleep Regulation ◽  
Beta Power ◽  
Rem Density ◽  
Sleep Parameters ◽  
Sleep Alterations ◽  
Electroencephalogram Eeg

Sleep recordings were performed in eight patients to analyse sleep alterations preceding migraine attacks. Polysomnographic recordings from nights before an attack were compared with nights without following migraine. We analysed standard sleep parameters and electroencephalogram (EEG) power spectra. The main findings preceding migraine attacks were a significant decrease in the number of arousals, a decrease in rapid eye movement (REM) density, a significant decrease of beta power in the slow wave sleep, and a decrease of alpha power during the first REM period. The results suggest a decrease in cortical activation during sleep preceding migraine attacks. According to the models of sleep regulation, alterations in the function of aminergic or cholinergic brainstem nuclei have to be discussed.

Electroencephalogram Bispectral Analysis Predicts the Depth of Midazolam-induced Sedation

1996 ◽  
Vol 84 (1) ◽  
pp. 64-69 ◽  
Author(s):  
Jin Liu ◽  
Harbhej Singh ◽  
Paul F. White
Keyword(s):  
Tactile Stimulation ◽  
Rank Correlation ◽  
Median Frequency ◽  
Verbal Command ◽  
Spectral Edge Frequency ◽  
Spearman’S Rank Correlation ◽  
Spearman's Rho ◽  
Beta Power ◽  
Spearman’S Rho ◽  
A Prospective Study

Background The electroencephalogram (EEG) has been used to study the effects of anesthetic and analgesic drugs on central nervous system function. A prospective study was designed to evaluate the accuracy of various EEG parameters for assessing midazolam-induced sedation during regional anesthesia. Methods Twenty-six consenting adult patients were administered 4.5-20 mg intravenous midazolam (in increments of 0.5-1 mg bolus doses every 6-10 min) until they became unresponsive to tactile stimulation (i.e., mild prodding or shaking). The EEG was continuously recorded from a bifrontal montage (FP1-Cz and FP2-Cz) to obtain the bispectral index (BI), 95% spectral edge frequency (SEF), median frequency (MF), and delta, theta, alpha, and beta power bands. Sedation was assessed clinically at 6-10-min intervals using the Observers' Assessment of Alertness/Sedation (OAA/S) scale, with 1 = no response (unconsciousness) to tactile stimulation to 5 = wide awake. The EEG parameters were correlated with the OAA/S scores using nonparametric Spearman's rank-correlation analysis. Kruskal-Wallis analysis of variance was used to determine significant changes in EEG parameters during the onset of and recovery from midazolam-induced sedation. Results Of the EEG parameters studied, the BI exhibited the best correlation with OAA/S scores during both the onset (Spearman's Rho = 0.815) and recovery (Spearman's Rho = 0.596) phases. With increasing sedation, there was a progressive decrease in the BI (OAA/S score of 5: BI = 95.4 +/- 2.3; 4: 90.3 +/- 4.5; 3:86.6 +/- 4.6; 2:75.6 +/- 9.7; 1:69.2 +/- 13.9). A similar pattern was found for the 95% SEF as the OAA/S score decreased from 4 to 1. Similarly, EEG-BI increased with recovery from the sedative effects of midazolam (OAA/S score = 2:BI = 75.2 +/- 10.2; 3:82.3 +/- 7.3; 4:90.8 +/- 6). However, no consistent changes were found with the other EEG parameters. The mean EEG values between OAA/S scores 3 and 2 and between OAA/S scores 2 and 1 during the onset and recovery phases from midazolam-induced sedation, defined as EEG50 values for response to verbal command (EEG50-VC) and to shaking of the head (EEG50-SH), were 79.3 +/- 8 and 70.8 +/- 14.3, respectively, for EEG-BI. The EEG-BI displayed the smallest coefficients of variation for the EEG50-VC and EEG50-SH values. Conclusions The EEG-BI appears to be a useful parameter for assessing midazolam-induced sedation and can predict the likelihood of a patient responding to verbal commands or to shaking of the head during midazolam-induced sedation.

scholarly journals The Effect of Forest Video Using Virtual Reality on the Stress Reduction of University Students Focused on C University in Korea

2021 ◽  
Vol 18 (23) ◽  
pp. 12805
Author(s):  
Seong-Hee Jo ◽  
Jin-Seok Park ◽  
Poung-Sik Yeon
Keyword(s):  
College Students ◽  
Virtual Reality ◽  
Stress Reduction ◽  
Physiological Stress ◽  
Group Analysis ◽  
Control Group ◽  
Alpha Power ◽  
Beta Power ◽  
Electroencephalogram Eeg ◽  
Positive Effect

The purpose of this study is to study the effect of forest videos using virtual reality (VR) on the stress of college students. The study subjects were 60 college students who watched two-dimensional (2D) and VR videos, and we compared their control heart rate variability (HRV) and electroencephalogram (EEG). As a result, it was found that the VR group had a positive effect on high frequency (HF), standard deviation of all NN intervals (SDNN), and root-mean-square of successive differences (RMSSD) compared with the control group, and the VR group had a positive effect on HF compared with the 2D group. Second, EEG, a physiological indicator, showed statistical differences in Relative Alpha Power (RA), Relative Beta Power (RB), and Ratio of SMR–Mid Beta to Theta (RSMT) in VR groups in intra-group analysis. Among them, it was investigated that watching forest videos on VR became a state of concentration and immersion due to the increase in RSMT. As a result of the above, it was investigated that forest videos using VR had a positive effect on the physiological stress on college students. Therefore, it is expected that a positive effect will occur if VR is used as an alternative to stress management for college students.

Power Spectral Frequency and Coherence Abnormalities in Patients with Intractable Epilepsy and Their Usefulness in Long-Term Remediation of Seizures Using Neurofeedback

2008 ◽  
Vol 39 (4) ◽  
pp. 203-205 ◽  
Author(s):  
Jonathan E. Walker
Keyword(s):  
Intractable Epilepsy ◽  
Normal Database ◽  
Alpha Power ◽  
Neurofeedback Training ◽  
Intractable Seizures ◽  
Power Spectral ◽  
Beta Power ◽  
Highly Correlated ◽  
Spectral Frequency ◽  
Relative Deficiency

Medically intractable seizures appear to be highly correlated with focal slow activity (delta or theta). They also correlate highly with decreases in the coherence of theta. Normalization of focal slowing and of decreased theta coherence will probably be the neurofeedback approaches most likely to decrease or eliminate seizures in future cases. Neurofeedback has been used for over 35 years to reduce the incidence and severity of seizures. With power training to decrease theta and increase the sensorimotor rhythm (12–15 Hz), an average of 82% of patients experienced a significant reduction in seizure frequency, and occasional remissions were seen. Recent improvements using QEEG to guide neurofeedback training have made it possible to eliminate seizures in most patients, even those with intractable seizures. Following our previous study in 2005, we report an additional 25 patients so treated. We also report an analysis of the frequency of QEEG abnormalities in this patient group. All of the intractable epileptic patients had one or more slow foci (excessive theta or delta compared with the normal database). One third had a relative deficiency of beta power. One fourth had a deficiency of absolute delta. Eighteen percent had excessive absolute alpha power, 18% had deficient absolute alpha power, 18% percent had excessive absolute beta power, and 18% percent had deficient absolute beta power. Hypocoherence of theta was found in 75%, and decreases in alpha coherence were noted in 42%. Hypocoherence of beta was found in 50%, and hypocoherence of delta was found in 25%. Increases in alpha coherence were noted in 33%. Seventeen percent had no coherence abnormalities. When most of the power and coherence abnormalities were normalized with neurofeedback training, all the patients became seizure-free; 76% no longer required an anticonvulsant for seizure control.

scholarly journals Preshooting Electroencephalographic Activity of Professional Shooters in a Competitive State

2021 ◽  
Vol 2021 ◽  
pp. 1-9
Author(s):  
Jie Zhang ◽  
Yunxu Shi ◽  
Chienkai Wang ◽  
Chunmei Cao ◽  
Changshui Zhang ◽  
...  
Keyword(s):  
Alpha Power ◽  
Average Reference ◽  
Significant Linear Correlation ◽  
Beta Power ◽  
Neural Efficiency ◽  
Competitive Shooting ◽  
Electroencephalographic Activity ◽  
Electrocardiogram Ecg ◽  
Electroencephalogram Eeg ◽  
Air Rifle

This study investigated the influence of competitive state on cerebral cortex activity of professional shooters with 10 m air rifle before shooting. Generally, professional athletes have higher neural efficiency compared with ordinary people. We recruited 11 national shooters to complete 60 shots under both noncompetitive and competitive shooting conditions, and simultaneously collected their electroencephalogram (EEG) and electrocardiogram (ECG) information. Theta, alpha, and beta power were computed in the last three seconds preceding each shot from average-reference 29-channel EEG, while EEG characteristics under two conditions were analyzed. The results showed a significant linear correlation between shooting accuracy and EEG power of anterior frontal, central, temporal, and occipital regions in beta and theta bands. In addition, the theta power in occipital regions, alpha power in frontal-central and left occipital regions, and beta power in frontal and mid-occipital regions were higher than those in noncompetitive state. However, heart rate (HR) and shooting accuracy did not change significantly under the two conditions. These findings reveal the changes of cortical activity underlying competition shooting as well as providing further understanding of the neural mechanisms of the shooting process and lay a foundation for the subsequent neuromodulation research.

scholarly journals Exploring Neurofeedback Training for BMI Power Augmentation of Upper Limbs: A Pilot Study

Entropy ◽  
2021 ◽  
Vol 23 (4) ◽  
pp. 443
Author(s):  
Hongbo Liang ◽  
Shota Maedono ◽  
Yingxin Yu ◽  
Chang Liu ◽  
Naoya Ueda ◽  
...  
Keyword(s):  
Training Session ◽  
Training System ◽  
Eeg Signals ◽  
Shoulder Joints ◽  
Power Spectral ◽  
Training Stage ◽  
Beta Power ◽  
Eeg Changes ◽  
Machine Interface ◽  
Flexion And Extension

Electroencephalography neurofeedback (EEG-NFB) training can induce changes in the power of targeted EEG bands. The objective of this study is to enhance and evaluate the specific changes of EEG power spectral density that the brain-machine interface (BMI) users can reliably generate for power augmentation through EEG-NFB training. First, we constructed an EEG-NFB training system for power augmentation. Then, three subjects were assigned to three NFB training stages, based on a 6-day consecutive training session as one stage. The subjects received real-time feedback from their EEG signals by a robotic arm while conducting flexion and extension movement with their elbow and shoulder joints, respectively. EEG signals were compared with each NFB training stage. The training results showed that EEG beta (12–40 Hz) power increased after the NFB training for both the elbow and the shoulder joints’ movements. EEG beta power showed sustained improvements during the 3-stage training, which revealed that even the short-term training could improve EEG signals significantly. Moreover, the training effect of the shoulder joints was more obvious than that of the elbow joints. These results suggest that NFB training can improve EEG signals and clarify the specific EEG changes during the movement. Our results may even provide insights into how the neural effects of NFB can be better applied to the BMI power augmentation system and improve the performance of healthy individuals.

scholarly journals Neurophysiological and behavioural effects of conventional and high definition tDCS

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Fabio Masina ◽  
Giorgio Arcara ◽  
Eleonora Galletti ◽  
Isabella Cinque ◽  
Luciano Gamberini ◽  
...  
Keyword(s):  
Response Times ◽  
Power Reduction ◽  
Alpha Power ◽  
High Definition ◽  
Mixed Effect ◽  
State Dependency ◽  
Mixed Effect Models ◽  
Beta Power ◽  
Neurophysiological Data ◽  
Spectrum Density

AbstractHigh-definition transcranial direct current stimulation (HD-tDCS) seems to overcome a drawback of traditional bipolar tDCS: the wide-spread diffusion of the electric field. Nevertheless, most of the differences that characterise the two techniques are based on mathematical simulations and not on real, behavioural and neurophysiological, data. The study aims to compare a widespread tDCS montage (i.e., a Conventional bipolar montage with extracephalic return electrode) and HD-tDCS, investigating differences both at a behavioural level, in terms of dexterity performance, and a neurophysiological level, as modifications of alpha and beta power as measured with EEG. Thirty participants took part in three sessions, one for each montage: Conventional tDCS, HD-tDCS, and sham. In all the conditions, the anode was placed over C4, while the cathode/s placed according to the montage. At baseline, during, and after each stimulation condition, dexterity was assessed with a Finger Tapping Task. In addition, resting-state EEG was recorded at baseline and after the stimulation. Power spectrum density was calculated, selecting two frequency bands: alpha (8–12 Hz) and beta (18–22 Hz). Linear mixed effect models (LMMs) were used to analyse the modulation induced by tDCS. To evaluate differences among the montages and consider state-dependency phenomenon, the post-stimulation measurements were covariate-adjusted for baseline levels. We observed that HD-tDCS induced an alpha power reduction in participants with lower alpha at baseline. Conversely, Conventional tDCS induced a beta power reduction in participants with higher beta at baseline. Furthermore, data showed a trend towards a behavioural effect of HD-tDCS in participants with lower beta at baseline showing faster response times. Conventional and HD-tDCS distinctively modulated cortical activity. The study highlights the importance of considering state-dependency to determine the effects of tDCS on individuals.

scholarly journals Age-dependent electroencephalogram (EEG) patterns during sevoflurane general anesthesia in infants

eLife ◽  
2015 ◽  
Vol 4 ◽  
Author(s):  
Laura Cornelissen ◽  
Seong-Eun Kim ◽  
Patrick L Purdon ◽  
Emery N Brown ◽  
Charles B Berde
Keyword(s):  
General Anesthesia ◽  
Temporal Dynamics ◽  
Brain Activity ◽  
Body Movement ◽  
Video Recording ◽  
Brain State ◽  
Alpha Power ◽  
State Monitoring ◽  
Spatio Temporal ◽  
Electroencephalogram Eeg

Electroencephalogram (EEG) approaches may provide important information about developmental changes in brain-state dynamics during general anesthesia. We used multi-electrode EEG, analyzed with multitaper spectral methods and video recording of body movement to characterize the spatio-temporal dynamics of brain activity in 36 infants 0–6 months old when awake, and during maintenance of and emergence from sevoflurane general anesthesia. During maintenance: (1) slow-delta oscillations were present in all ages; (2) theta and alpha oscillations emerged around 4 months; (3) unlike adults, all infants lacked frontal alpha predominance and coherence. Alpha power was greatest during maintenance, compared to awake and emergence in infants at 4–6 months. During emergence, theta and alpha power decreased with decreasing sevoflurane concentration in infants at 4–6 months. These EEG dynamic differences are likely due to developmental factors including regional differences in synaptogenesis, glucose metabolism, and myelination across the cortex. We demonstrate the need to apply age-adjusted analytic approaches to develop neurophysiologic-based strategies for pediatric anesthetic state monitoring.

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