Short-Term Rivastigmine Treatment Reduces EEG Slow-Wave Power in Alzheimer Patients

2001 ◽  
Vol 43 (4) ◽  
pp. 273-276 ◽  
Author(s):  
Georg Adler ◽  
Stefanie Brassen
Keyword(s):  
Slow Wave ◽  
Wave Power ◽  
Short Term

Diagnosis and Assessment of Dementia Using Functional Brain Imaging

1989 ◽  
Vol 1 (1) ◽  
pp. 63-72 ◽  
Author(s):  
Andrew F. Leuchter ◽  
Donald O. Walter
Keyword(s):  
Electrical Activity ◽  
Brain Imaging ◽  
Slow Wave ◽  
Low Frequency ◽  
Functional Brain Imaging ◽  
Wave Power ◽  
Spectral Ratios ◽  
Functional Brain ◽  
Moderate Dementia ◽  
Severity Of Dementia

Functional brain imaging using computer-analyzed electroencephalography was performed in 40 subjects: 15 with mild-to-moderate dementia of the Alzheimer's type (DAT), 13 with mild-to-moderate multi-infarct dementia (MID), and 12 age-matched controls. We examined three different parameters of brain electrical activity in these subjects: absolute slow-wave power, proportional power in all frequency bands, and ratios of high-frequency/low-frequency electrical activity (so-called “spectral ratios”). Spectral ratios were significantly more powerful in discriminating among groups than the other measures. Functional images using spectral ratios revealed that subjects with DAT have a characteristic left temporo-parietal defect which clearly distinguished them from subjects with MID and from control subjects. The severity of dementia was best assessed by examining absolute slow-wave power, which had the strongest linear correlation with mental status testing. Serial images from one subject with DAT over 3 years demonstrate both quantitative and qualitative shifts in slow-wave activity in the course of DAT. The study suggests that functional imaging may be more useful than either simple EEG or computer-analyzed EEG in assessing and diagnosing patients with suspected dementia.

Elevated Plasma Prolactin and EEG Slow Wave Power in Post-Polio Fatigue

1998 ◽  
Vol 4 (2) ◽  
pp. 61-75 ◽  
Author(s):  
Richard L. Bruno ◽  
Susan Creange ◽  
Jerald R. Zimmerman ◽  
Nancy M. Frick
Keyword(s):  
Slow Wave ◽  
Wave Power ◽  
Plasma Prolactin ◽  
Elevated Plasma

Long-Term Wave Power Statistics for Individual Waves

2015 ◽  
Vol 137 (4) ◽  
Author(s):  
Bernt J. Leira ◽  
Dag Myrhaug
Keyword(s):  
Wave Height ◽  
Wave Climate ◽  
Statistical Information ◽  
Power Device ◽  
Wave Power ◽  
Power Devices ◽  
Short Term ◽  
Wave Power Potential ◽  
The Individual

The paper provides long-term bivariate distributions of wave power with wave height, and wave power with wave period. This is relevant for assessments of wave power devices and their potential for converting energy from waves. The results can be applied to compare systematically the wave power potential for individual waves at different locations based on short-term statistical description of the individual waves and the long-term statistical information of the wave climate. Furthermore, it allows for assessment of the efficiency of a given wave power device for each location.

scholarly journals Investigation of Slow-wave Activity Saturation during Surgical Anesthesia Reveals a Signature of Neural Inertia in Humans

2017 ◽  
Vol 127 (4) ◽  
pp. 645-657 ◽  
Author(s):  
Catherine E. Warnaby ◽  
Jamie W. Sleigh ◽  
Darren Hight ◽  
Saad Jbabdi ◽  
Irene Tracey
Keyword(s):  
Slow Wave ◽  
Animal Studies ◽  
Secondary Analysis ◽  
Wave Activity ◽  
Slow Wave Activity ◽  
Data Sets ◽  
Short Term ◽  
Large Variability ◽  
Behavioral Responsiveness ◽  
Dose Responses

Abstract Background Previously, we showed experimentally that saturation of slow-wave activity provides a potentially individualized neurophysiologic endpoint for perception loss during anesthesia. Furthermore, it is clear that induction and emergence from anesthesia are not symmetrically reversible processes. The observed hysteresis is potentially underpinned by a neural inertia mechanism as proposed in animal studies. Methods In an advanced secondary analysis of 393 individual electroencephalographic data sets, we used slow-wave activity dose-response relationships to parameterize slow-wave activity saturation during induction and emergence from surgical anesthesia. We determined whether neural inertia exists in humans by comparing slow-wave activity dose responses on induction and emergence. Results Slow-wave activity saturation occurs for different anesthetics and when opioids and muscle relaxants are used during surgery. There was wide interpatient variability in the hypnotic concentrations required to achieve slow-wave activity saturation. Age negatively correlated with power at slow-wave activity saturation. On emergence, we observed abrupt decreases in slow-wave activity dose responses coincident with recovery of behavioral responsiveness in ~33% individuals. These patients are more likely to have lower power at slow-wave activity saturation, be older, and suffer from short-term confusion on emergence. Conclusions Slow-wave activity saturation during surgical anesthesia implies that large variability in dosing is required to achieve a targeted potential loss of perception in individual patients. A signature for neural inertia in humans is the maintenance of slow-wave activity even in the presence of very-low hypnotic concentrations during emergence from anesthesia.

scholarly journals Visual imagery and visual perception induce similar changes in occipital slow waves of sleep

2019 ◽  
Vol 121 (6) ◽  
pp. 2140-2152 ◽  
Author(s):  
Giulio Bernardi ◽  
Monica Betta ◽  
Jacinthe Cataldi ◽  
Andrea Leo ◽  
José Haba-Rubio ◽  
...  
Keyword(s):  
Visual Perception ◽  
Eye Movement ◽  
Slow Wave ◽  
Visual Imagery ◽  
Nrem Sleep ◽  
Wave Activity ◽  
Slow Waves ◽  
Slow Wave Activity ◽  
Short Term ◽  
Visual Areas

Previous studies have shown that regional slow-wave activity (SWA) during non-rapid eye movement (NREM) sleep is modulated by prior experience and learning. Although this effect has been convincingly demonstrated for the sensorimotor domain, attempts to extend these findings to the visual system have provided mixed results. In this study we asked whether depriving subjects of external visual stimuli during daytime would lead to regional changes in slow waves during sleep and whether the degree of “internal visual stimulation” (spontaneous imagery) would influence such changes. In two 8-h sessions spaced 1 wk apart, 12 healthy volunteers either were blindfolded while listening to audiobooks or watched movies (control condition), after which their sleep was recorded with high-density EEG. We found that during NREM sleep, the number of small, local slow waves in the occipital cortex decreased after listening with blindfolding relative to movie watching in a way that depended on the degree of visual imagery subjects reported during blindfolding: subjects with low visual imagery showed a significant reduction of occipital sleep slow waves, whereas those who reported a high degree of visual imagery did not. We also found a positive relationship between the reliance on visual imagery during blindfolding and audiobook listening and the degree of correlation in sleep SWA between visual areas and language-related areas. These preliminary results demonstrate that short-term alterations in visual experience may trigger slow-wave changes in cortical visual areas. Furthermore, they suggest that plasticity-related EEG changes during sleep may reflect externally induced (“bottom up”) visual experiences, as well as internally generated (“top down”) processes.NEW & NOTEWORTHY Previous work has shown that slow-wave activity, a marker of sleep depth, is linked to neural plasticity in the sensorimotor cortex. We show that after short-term visual deprivation, subjects who reported little visual imagery had a reduced incidence of occipital slow waves. This effect was absent in subjects who reported strong spontaneous visual imagery. These findings suggest that visual imagery may “substitute” for visual perception and induce similar changes in non-rapid eye movement slow waves.

scholarly journals Resting-state slow wave power, healthy aging and cognitive performance

2014 ◽  
Vol 4 (1) ◽  
Author(s):  
Eleni L. Vlahou ◽  
Franka Thurm ◽  
Iris-Tatjana Kolassa ◽  
Winfried Schlee
Keyword(s):  
Cognitive Performance ◽  
Slow Wave ◽  
Resting State ◽  
Healthy Aging ◽  
Wave Power

scholarly journals Abnormally abrupt transitions from sleep-to-wake in Huntington’s disease sheep (Ovis aries) are revealed by automated analysis of sleep/wake transition dynamics

PLoS ONE ◽  
2021 ◽  
Vol 16 (5) ◽  
pp. e0251767
Author(s):  
William T. Schneider ◽  
Szilvia Vas ◽  
Alister U. Nicol ◽  
A. Jennifer Morton
Keyword(s):  
Huntington's Disease ◽  
Huntington’S Disease ◽  
Slow Wave ◽  
Early Stage ◽  
Automated Analysis ◽  
Ovis Aries ◽  
Wave Power ◽  
Sheep Model ◽  
Transition Dynamics ◽  
Sleep Abnormalities

Sleep disturbance is a common and disruptive symptom of neurodegenerative diseases such as Alzheimer’s and Huntington’s disease (HD). In HD patients, sleep fragmentation appears at an early stage of disease, although features of the earliest sleep abnormalities in presymptomatic HD are not fully established. Here we used novel automated analysis of quantitative electroencephalography to study transitions between wake and non-rapid eye movement sleep in a sheep model of presymptomatic HD. We found that while the number of transitions between sleep and wake were similar in normal and HD sheep, the dynamics of transitions from sleep-to-wake differed markedly between genotypes. Rather than the gradual changes in EEG power that occurs during transitioning from sleep-to-wake in normal sheep, transition into wake was abrupt in HD sheep. Furthermore, transitions to wake in normal sheep were preceded by a significant reduction in slow wave power, whereas in HD sheep this prior reduction in slow wave power was far less pronounced. This suggests an impaired ability to prepare for waking in HD sheep. The abruptness of awakenings may also have potential to disrupt sleep-dependent processes if they are interrupted in an untimely and disjointed manner. We propose that not only could these abnormal dynamics of sleep transitions be useful as an early biomarker of HD, but also that our novel methodology would be useful for studying transition dynamics in other sleep disorders.

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