Reduction In Beta Activity Research Articles

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Movement DisordersVolume 38, Issue 4 InfographicFree Access April Infographic First published: 16 April 2023 https://doi.org/10.1002/mds.29091About ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Graphical Abstract April Infographic: Christmas-Related Reduction in Beta Activity in Parkinson's Disease Volume38, Issue4April 2023 RelatedInformation

Christmas-Related Reduction in Beta Activity in Parkinson's Disease.

Subthalamic nucleus (STN) beta (13 - 35 Hz) activity is a biomarker reflecting motor state in Parkinson's disease (PD). Adaptive deep brain stimulation (DBS) aims to use beta activity for therapeutic adjustments, but many aspects of beta activity in real-life situations are unknown. The aim was to investigate Christmas-related influences on beta activity in PD. Differences in Christmas Day to nonfestive daily averages in chronic biomarker recordings in 4 PD patients with a sensing-enabled STN DBS implant were retrospectively analyzed. Sweet-spot and whole-brain network connectomic analyses were performed. Beta activity was significantly reduced on Christmas Eve in all patients (4.00-9.00 p.m.: -12.30 ± 10.78%, P=0.015). A sweet spot in the dorsolateral STN connected recording sites to motor, premotor, and supplementary motor cortices. We demonstrate that festive events can reduce beta biomarker activity. We conclude that circadian and holiday-related changes should be considered when tailoring adaptive DBS algorithms to patient demands. © 2023 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.

Decrease in the activity of irradiated graphite and liquid radioactive waste

Nowadays, the problem of nuclear waste deactivation is very urgent. The method proposed consists of exposing the aqueous solution of radionuclide to powerful nanosecond electromagnetic pulses by placing the treated solution between two electrodes connected to the outlets of the generator. Single-pole current pulses with a length of 1 ns, an amplitude of more than 5 kV, and a repetition frequency of 1 kHz are used. Such pulses can be obtained from the generator units with an amplitude of 5 kV to 15 kV. They have a pulse capacity of 1 to 4 MW, and the mains capacity is below 50 W. The pulse action leads to radiolysis of water and accelerated decay of radionuclides. As a result of radiolysis, hydrated electrons, hydrogen atoms, and various radicals are formed that causes precipitation of radionuclides, such as 137Cs and 90Sr. The description of several experiments and results of experimental investigations of the influence of powerful nanosecond electromagnetic pulses on the properties of water solutions with radioactive nuclides 137Cs and 90Sr and on items of irradiated graphite is presented. Under the influence of pulses on real liquid waste and aqueous solutions, radioactive nuclides in water are reduced by 5 to 50 times during 15 minutes. The effect described is preserved for 20 days. The reduction of beta activity twice during 25 min is observed in big blocks of the irradiated graphite. Flow-through unit for processing of liquid waste is developed, tested, and patented (RU 2726145. MPK G21F 9/28, July 7, 2020). This technology can be used to treat emergency solutions with tritium at Fukushima NPP. of the irradiated graphite.

Is an absolute level of cortical beta suppression required for proper movement? Magnetoencephalographic evidence from healthy aging

Previous research has connected a specific pattern of beta oscillatory activity to proper motor execution, but no study to date has directly examined how resting beta levels affect motor-related beta oscillatory activity in the motor cortex. Understanding this relationship is imperative to determining the basic mechanisms of motor control, as well as the impact of pathological beta oscillations on movement execution. In the current study, we used magnetoencephalography (MEG) and a complex movement paradigm to quantify resting beta activity and movement-related beta oscillations in the context of healthy aging. We chose healthy aging as a model because preliminary evidence suggests that beta activity is elevated in older adults, and thus by examining older and younger adults we were able to naturally vary resting beta levels. To this end, healthy younger and older participants were recorded during motor performance and at rest. Using beamforming, we imaged the peri-movement beta event-related desynchronization (ERD) and extracted virtual sensors from the peak voxels, which enabled absolute and relative beta power to be assessed. Interestingly, absolute beta power during the pre-movement baseline was much stronger in older relative to younger adults, and older adults also exhibited proportionally large beta desynchronization (ERD) responses during motor planning and execution compared to younger adults. Crucially, we found a significant relationship between spontaneous (resting) beta power and beta ERD magnitude in both primary motor cortices, above and beyond the effects of age. A similar link was found between beta ERD magnitude and movement duration. These findings suggest a direct linkage between beta reduction during movement and spontaneous activity in the motor cortex, such that as spontaneous beta power increases, a greater reduction in beta activity is required to execute movement. We propose that, on an individual level, the primary motor cortices have an absolute threshold of beta power that must be reached in order to move, and that an inability to suppress beta power to this threshold results in an increase in movement duration.

EEG Power Spectra Response to a 4-h Phase Advance and Gaboxadol Treatment in 822 Men and Women

To explore the effect of gaboxadol on NREM EEG in transient insomnia using power spectral analysis and evaluate the response between men and women. This was a randomized, double-blind, 3-way, parallel-group transient insomnia study in 22 sleep laboratories. After a baseline night (N1), subjects underwent a 4-h phase-advance of their habitual sleep time the following night (N2). Healthy subjects aged 18-64 y were given single-blind placebo on N1 followed by double-blind treatment on N2 (gaboxadol 10 mg [n = 271], 15 mg [n = 274], or placebo [n = 277]) At baseline, women showed significantly greater values in low frequency activity (< 10 Hz) and in high spindle/low beta frequency activity (14-18 Hz) compared to men. During the phase advance (placebo N2-baseline N1), there was a significant increase in power within the high spindle/low beta frequency range (15-17 Hz) and a significant reduction in beta activity (20-32 Hz), which was greater in women than men. Gaboxadol induced a significant (dose-related) increase in low frequencies (< 8 Hz) and a significant (dose-related) decrease within the alpha/spindle range (11-12 Hz). The effect was dependent upon sex, with a greater magnitude of effect observed in women than men. Gaboxadol shows a characteristic NREM EEG spectral profile in a model of transient insomnia. Men and women show clear differences in NREM EEG activity at baseline, to gaboxadol treatment and to phase-shifts in habitual sleep/wake times. The exact mechanisms underlying the sex differences remain unclear, but sex is an important variable in studies evaluating sleep and gaboxadol. TRIAL REGISTRY INFORMATION: www.clinicaltrials.gov, study identifier: NCT00102167.

Electroencephalographic sleep inertia of the awakening brain

Sleep inertia (SI) denotes a period of hypovigilance, confusion and impaired cognitive and behavioral performance that immediately follows awakening. Based on the observation that the reactivation of some cortical areas is faster than other upon awakening, here we examined regional differences between presleep and postsleep waking period. Moreover, we also compared rapid eye movements (REM) and stage 2 non-rapid eye movements (NREM) awakenings in a within-subject design. Presleep and postsleep waking electroencephalogram (EEG; 5 min with eyes-closed and 5 min with eyes-open) of 18 healthy subjects (12 males, mean age=23.8±2.3 years) were recorded from 19 derivations. Participants slept for two consecutive nights in the laboratory. In one night they were awakened from stage 2 NREM, while in the other from REM sleep. EEG power spectra were calculated across the following bands: delta (1–4 Hz), theta (5–7 Hz), alpha (8–12 Hz), beta-1 (13–16 Hz) and beta-2 (17–24 Hz). Moreover, a detailed hertz-by-hertz analysis has been repeated in the 2–4 Hz frequency range. Postsleep wakefulness, compared to presleep, is characterized by a generalized decrease of higher beta-1 and beta-2 EEG power over almost all scalp locations. A detailed analysis of topographical modifications in the low-frequency range showed that postsleep wakefulness is characterized by an increased delta activity in the posterior scalp locations, and by a concomitant frontal decrease compared to presleep. Moreover, it was found a prevalence of EEG power in the high frequency ranges (beta-1 and beta-2) upon awakening from stage 2 compared to REM awakenings over the left anterior derivations. Altogether these findings support the hypothesis that a generalized reduction in beta activity and increased delta activity in more posterior areas upon awakening may represent the EEG substratum of the sleep inertia phenomenon.

Changes in electroencephalographic activities following pressure stimulation in humans

We investigated brain activity in response to orofacial pain in 20 healthy subjects in order to characterize the relationship between pain and changes in brain function. First, the pressure pain threshold (PPT) at the styloid process of the temporal bone (Libman's point) of 20 subjects was measured by a pressure algometer. Second, electroencephalographic (EEG) changes of 20 subjects before and after 10 s of constant pressure stimulation at Libman's point were measured. These 20 subjects were divided into two groups: 10 subjects with higher PPT (high group) and 10 subjects with lower PPT (low group). EEG change in beta activity after stimulation was greater in the low group than the high group, and there was a significant negative correlation between this change and PPT, with even minor constant stimulation inducing larger EEG change in individuals highly receptive to pain. The present study demonstrated that a relative reduction in beta activity after pain stimulation was more remarkable in subjects with lower PPT than in subjects with higher PPT, and that this change was closely related to a hemispheric balance, with even minor constant stimulation inducing changes in brain waves in individuals highly sensitive to pain.

Quantitative electroencephalogram of posterior cortical areas of fluent and stuttering participants during reading with normal and altered auditory feedback.

In the left and right hemisphere, posterior quantitative electroencephalogram Beta band activity (13.5-25.5 Hz) of seven adult participants who stutter and seven age-matched normal controls was obtained while subjects read text under three experimental conditions of normal auditory feedback, delayed auditory feedback, and frequency-altered feedback. Data were obtained from surface electrodes affixed to the scalp using a commercial electrode cap. Electroencephalogram activity was amplified, band-pass analog-filtered, and then digitized. During nonaltered auditory feedback, stuttering participants displayed Beta band hyperreactivity, with the right temporal-parietal lobe region showing the greatest activity. Under conditions of delayed auditory feedback and frequency-altered auditory feedback, the stuttering participants displayed a decrease in stuttering behavior accompanied by a strong reduction in Beta activity for the posterior-temporal-parietal electrode sites, and the left hemisphere posterior sites evidenced a larger area of reactivity. Such findings suggest than an alteration in the electrical fields of the cortex occurred in the stuttering participants under both conditions, possibly reflecting changes in neurogenerator status or current dipole activity. Further, one could propose that stuttering reflects an anomaly of the sensory-linguistic motor integration wherein each hemisphere generates competing linguistic messages at hyperreactive amplitudes.

Quantitative Electroencephalographic Correlates of Cognitive Decline in Normal Elderly Subjects

We obtained a topographic computer analysis of the electroencephalogram in 53 normal elderly subjects. Normal aging was not associated with an increase in slow (delta) activity. However, cognitive performance correlated positively with fast (beta) activity particularly in frontal leads, even after controlling for age, education, occupation, and medication. Five subjects who showed early signs of cognitive decline, had all a marked reduction in beta activity suggesting that this may be an early indication of intellectual loss.

Topographic Mapping of Quantitative EEG Variables in Chronic Heavy Marihuana Users: Empirical Findings with Psychiatric Patients

EEG studies of marihuana use dating back to 1945 were reviewed. The earlier studies depended upon visual analysis of the tracing, and while some minor frequency and amplitude variations occurred in some subjects, there was no consistent THC induced change noticeable across subjects. Quantitative EEG studies of acute exposure to THC came later and produced reliable findings of a placebo controlled dose dependent THC induced increase in relative power of alpha, combined with decreased alpha frequency and a reduction of beta activity. These findings were reported for data collected from central-occipital derivations only. In our present investigation, we report that chronic heavy THC users have EEGs characterized by (1) increased absolute power of all frequencies over all cortical areas (2) hyperfrontality of elevated relative and absolute power and coherence values of alpha activity, and (3) a decrease in relative power of all non-alpha frequencies. Methodological issues were discussed and some suggestions were made for continuing research in this area.