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Results for “Spectral Electroencephalography (EEG)”

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At least 19 recordsLinked to original sources
PubMed2025

Personalized Repetitive Transcranial Magnetic Stimulation (PrTMS®) Coupled with Transcranial Photobiomodulation (tPBM) For Co-Occurring Traumatic Brain Injury (TBI) and Post-Traumatic Stress Disorder (PTSD).

This study provides further evidence demonstrating the beneficial effects of PrTMS® treatment in co-occurring disorders. Furthermore, this study illustrates the benefit of augmenting PrTMS® with tPBM for superior outcomes. The positive results of this novel case study can be attributed to brain wave neuromodulation and increased neuronal ATP production, resulting in synergistic enhanced neuroplasticity and brain optimization. Further, large-scale, randomized and blinded studies are recommended to validate our promising preliminary observations utilizing multifaceted interventions for co-occurring disorders.

Co-Occurring Disorders↗
PubMed2025

TMS-EEG in postictal psychosis of epilepsy.

BACKGROUND: Postictal psychosis (PIP) is a poorly understood complication affecting 2 % of individuals with epilepsy. Genomic and neuroimaging studies suggest parallels with schizophrenia. OBJECTIVES: To determine whether Transcranial Magnetic Stimulation coupled with Electroencephalography (TMS-EEG), can reveal schizophrenia-like changes in PIP, especially in Natural Frequency (NF), gamma band Event-Related Spectral Perturbation (ERSP), the N100 peak, and global mean field power (GMFP). METHODS: We applied TMS-EEG targeting the non-dominant hemisphere premotor area in people with focal epilepsy (PWE) with a history of PIP (n = 7) and PWE without any history of psychosis (n = 14). Two-tailed t-tests were applied to TMS-EEG metrics previously studied in schizophrenia to look for differences between the groups, with subgroup analyses excluding participants using benzodiazepines. RESULTS: Demographic and clinical characteristics were similar across the two groups. No significant differences were seen in NF (p = 0.98). We observed a delayed N100 peak latency in the PIP group when excluding those with regular benzodiazepine use (p = 0.05) and increased global mean field power during the 400-600 ms phase of the TEP (p = 0.02). Mean ERSP within the gamma band was lower in the PIP group, though this did not reach statistical significance (p = 0.08). CONCLUSION: This is the first study to apply TMS-EEG in individuals with PIP, demonstrating feasibility and providing methodological insights for future studies. Preliminary findings, including increased GMFP and delayed N100 latency in PIP, suggest possible disruptions in cortical excitability similar to schizophrenia, warranting further investigation.

Humans↗
PubMed1979

Automated detection of EEG artifacts during sleep: preprocessing for all-night spectral analysis.

This paper describes a simple artifact detection algorithm which can be used when large amounts of EEG data are to be automatically processed via spectral analysis techniques in a general purpose digital computer, and visual inspection of each EEG epoch becomes an impossible task. The technique is based on a chi-square (chi(2)) goodness-of-fit test to a Gaussian distribution (CSQ), and it was applied to EEG epochs each 30 sec long. This test proved to be very sensitive to non-stationarities in the EEG amplitude distribution for a particular epoch, and it produced a large value for the chi(2) coefficient when an artifact was present. EEG epochs that gave rise to chi(2) coefficients of value larger than a heuristically determined minimum were discarded from further analysis. The above technique enabled efficient data reduction and reliable automatic off-line processing of 50 nights of sleep EEG via spectral techniques.

Action Potentials↗
PubMedDate not supplied

[Hippocampal EEG in dog, cat and man (author's transl)].

A comparative neurophysiological study of the reactivity of hippocampal EEG in dog, cat and human (an epileptic patient with chronically indwelling electrodes) was carried out. In all 3 species the same type of qualitative changes in hippocampal spectral parameters in the theta frequency band (peak frequency, peak amplitude and rhythmicity) in relation to behavioural tasks was encountered. These results were obtained by means of computing triggered averages of spectral parameters in relation to behavioural events. Both in dog and in cat it was found that transitions in behaviour from a low intensity (e.g. sitting) to a high intensity (e.g. walking) motor activity were accompanied by an increase in the value of the afore mentioned spectral parameters. In man a similar relation between such a transition in gross motor behaviour and hippocampal EEG was, however, not observed. The highest frequencies in the theta band appeared in man to be related to "verbal behaviour and writing". In all 3 species the following generalization appeared to hold; when the same behavioural state occurs at different levels of intensity, a higher intensity of the behaviour--as measured in terms of its motor components--is related to higher values for the spectral parameters of the hippocampal EEG.

Animals↗
PubMed1976

Visible and non-visible EEG changes demonstrated by spectral parameter analysis.

A change of the heart rate in patients with complete AV-block and externally controllable cardiac pace-makers was earlier shown to influence cerebral function, as measured by psychological tests. To determine whether this influence manifests itself in the EEG, 9 patients aged 43-83 years were examined, all having complete AV-block and externally controllable pace-makers. Their EEGs were recorded at different heart rates between 40 and 100/min at rest and during a mental arithmatic test. The EEG record was evaluated visually and analysed by means of Spectral Parameter Analysis (SPA), introduced by Zetterberg (1969). The changes in the spectral parameters in relation to the heart rates were analysed statistically, In several cases significant changes appeared but the interindividual variations were large. Certain typical patterns could, however, be observed and their importance as a measure of cerebral function due to changes in the cerebral blood flow are discussed. These EEG changes revealed through SPA did not correspond to any visually observable changes in the EEG records. Differences in the spectral parameters between rest and test situations were analysed. Some of the differences found could easily be observed by visual inspection of the EEG. The advantage with SPA was that the changes could be described both qualitatively and quantitavely because SPA separates the spectral properties of the signals into components corresponding to well-known components of the EEG signal.

Adult↗
PubMed1977

EEG operant conditioning in a monkey model: II. EEG spectral analysis.

EEG power spectral analysis was studied from 14 (alumina-gel) chronically epileptic, undrugged monkeys during an EEG operant conditioning experiment. The composite profile of the average epileptic monkey shows the majority of power to be below 10 Hz. Because of the large variance in the data, no significant changes in the EEG power spectra could be detected as a function of conditioning. The possible reasons for this large variance are discussed. Hypothesis from previous human "biofeedback" studies would allow the prediction that those frequencies corresponding to the mu and sensory-motor-rhythm should negatively covary with seizure frequency. Data from this study did not support such assertions. The method of using spectral analysis for quantifying changes in the EEG which covary with operant conditioning is evaluated.

Animals↗
PubMed1979

Intra- and interhemispheric EEG differences quantified by spectral analysis. Comparative study of two groups of schizophrenics and a control group.

In this work we have studied comparatively the relationships between alpha intensity, alpha frequency, root-mean-square amplitude and their standard deviations, versus the location of the four recorded EEG channels: left and right rolando-parietal, left and right parieto-occipital. Twenty-four spectral parameters were computed for each 5-min EEG recording, in the eyes closed situation. The hebephrenic group (36 EEGs from six patients) presented higher values of alpha intensity and RMS amplitudes with low coefficient of variation when compared with the other groups. The left/right rolando-parietal amplitude ratio was 0.73 versus 1.52 for the parieto-occipital ratio. An amplitude hypovariability in the central regions, probably associated with hyperarousal, especially in the left hemisphere, can then be observed in hebephrenics, together with high alpha intensity on the left parieto-occipital area. The two groups of schizophrenics differ from the control group (27 EEGs from 12 subjects) in terms of spectral parameters, the hebephrenic group presenting a possible interhemispheric dysfunction.

Adult↗
PubMed2026

Disentangling oscillatory and aperiodic neural activity in autism: A spectral parameterization analysis of neurofeedback intervention.

BACKGROUND: Autism Spectrum Disorder (ASD) is characterized by atypical neural oscillations and heterogeneous alterations in excitation/inhibition (E/I) balance, the directionality of which varies across individuals, neural circuits, and developmental stages. While Alpha-band neurofeedback (NFB) is a promising intervention, its underlying neurophysiological mechanisms remain unclear, partly due to the conflation of periodic and aperiodic signals in traditional EEG analysis. METHODS: This randomized controlled trial recruited 40 children with ASD, assigned to either an experimental group (Alpha-training NFB) or a no-feedback group. Resting-state EEG and behavioral assessments (SRS, ABC) were collected pre- and post-intervention. We employed spectral parameterization to decompose neural activity into aperiodic (1/f slope, offset) and periodic (periodic alpha power, center frequency) components. RESULTS: NFB training yielded significant behavioral improvements in social cognition and relating skills. Physiologically, the experimental group exhibited a significant steepening of the aperiodic slope (increased exponent), reflecting a reduction in neural noise and potential optimization of inhibitory modulation. Furthermore, we observed enhanced periodic alpha power and an acceleration of the alpha center frequency (ACF), indicative of improved neural efficiency and maturation. These physiological shifts in frontal and occipital regions were significantly correlated with improvements in behavioral scores. CONCLUSION: Alpha-training NFB was associated with improvements in caregiver-rated behavioral scores and modulated spectral features of resting-state EEG in children with ASD. These findings validate the utility of spectral parameterization markers in evaluating neuromodulatory interventions.

Humans↗
PubMed1977

Automatic noctural sleep sampling: a useful method in clinical electroencephalography.

The clinical usefulness of obtaining a sleep record in epileptic patients is well established. However, in many clinical EEG laboratories, it is difficult to obtain records at night during the patient's natural sleep. Thus, most sleep EEGs are recorded in the EEG laboratory during daytime and are induced by drugs. A 16 channel cable-telemetry system is described which automatically samples throughout the night the EEG of patients while sleeping in their room or ward without the aid of any medication. The electrodes and the cable-telemetry unit are applied to the patient in the afternoon and the system is checked. The patient is then instructed to plug the system into a wall box upon retiring and to disconnect it when he wakes up in the morning. The EEG samples are automatically written out during the night on one of the EEG machines located in the EEG laboratory to which the system is connected via spectral intra-hospital wiring. The duration of the samples and of the intervals separating them can be varied according to the circumstances. We have found this method to be very helpful in the investigation of epileptic patients, especially those considered for surgical treatment.

Electroencephalography↗
PubMed1978

EEG signs of cerebrovascular disorder, using physical exercise as a provocative method.

A group of patients suffering from cerebrovascular insufficiency was submitted to a pilot EEG investigation using physical exercise as a provocative method. Two control groups, one of young (20--30 years) and another of older (more than 50 years) subjects, were also investigated. Quantitative EEG spectral data, determined at rest and during a period after physical exercise, showed that deviations of the frequency distribution of the alpha band were related to cerebrovascular insufficiency.

Adult↗
PubMed1977

Sequential frequency analysis: a method to quantify event related EEG changes.

A hybrid method of frequency analysis is described by means of which EEG changes related to stimulus-response tasks have been studied. Frequency analysis was carried out using a bank of 20 analog filters by means of which quantitative spectral data were obtained as a function of time. Storing, averaging and statistical analysis of these time-varying spectral data were performed, using a general purpose computer (PDP 11-20). The method proved to be useful for analysis of the non-stationary properties of EEG changes related to certain behavioural events.

Analog-Digital Conversion↗
PubMed1979

Hippocampal EEG and behaviour in dog. I. Hippocampal EEG correlates of gross motor behaviour.

It was shown that rewarding spectral shifts (i.e. increase in amplitude or peak frequency of the hippocampal EEG) causes a solitary dog to show increased motor behaviour. Rewarded spectral shifts concurred with a variety of behavioural transitions. It was found that statistically significant modulations occur in the spectral properties of the hippocampal EEG correlated with: (1) the transition from walking to standing; (2) the transition from standing while eating to walking away from the food dish; (3) the increase in speed of a walking dog, caused by rewarding the animal; and with (4) each head movement in a learned series of head movements. Thus behavioural transitions to a more active state are accompanied by an increase of amplitude, frequency and rhythmicity in the theta band of the hippocampal EEG; behavioural transitions to a less active state show the inverse relationship with the hippocampal EEG. A close relationship between modulations of the dog's hippocampal EEG activity and elementary motor acts is stressed. The hypothesis is put forward that the spectral properties of the hippocampal EEG reflect the degree to which a number of motor and sensory structures in the limbic midbrain and brain stem are active.

Animals↗
PubMed1979

EEG effects of physostigmine and choline chloride in humans.

Seventeen normal volunteers received either 0.5 mg, 1.5 mg, or 2.5 mg physostigmine i.v. in a placebo-drug-placebo single-blind design. EEG was recorded simultaneously and analyzed by computerized spectral analysis. Eleven healthy elderly volunteers (mean age = 69.1 years) with mild memory impairment were treated with placebo, followed by oral choline chloride (either 8 g/day for 3 weeks, or 16 g/day for 1 week), and then, again, placebo. Recordings of spontaneous EEG and EEG event-related potentials (contingent negative variation) were obtained during both placebo and choline treatments. The larger doses of physostigmine produced an increase in low frequency activity and a slowing of the peak alpha frequency. Oral choline chloride had no effect on the EEG as measured by spectral analysis, but appears to have differential effects on contingent negative variation (CNV) amplitude and reaction time, depending upon the initial CNV amplitude.

Adult↗