NREM Sleep and Antiepileptic Medications Modulate Epileptiform Activity by Altering Cortical Synchrony

2018 ◽  
Vol 49 (6) ◽  
pp. 417-424 ◽  
Author(s):  
Chetan S. Nayak ◽  
N. Mariyappa ◽  
Kaushik K. Majumdar ◽  
G. S. Ravi ◽  
Pradeep D. Prasad ◽  
...  
Keyword(s):  
Phase Synchronization ◽  
Focal Epilepsy ◽  
Sleep Stage ◽  
Epileptiform Activity ◽  
Nrem Sleep ◽  
Sleep Stages ◽  
Epileptiform Discharges ◽  
Drug Naïve ◽  
Antiepileptic Medications

Introduction. The activating role of non–rapid eye movement (NREM) sleep on epileptic cortex and conversely, the seizure remission brought about by antiepileptic medications, has been attributed to their effects on neuronal synchrony. This study aims to understand the role of neural synchrony of NREM sleep in promoting interictal epileptiform discharges (IEDs) in patients with epilepsy (PWE) by assessing the peri-IED phase synchrony during awake and sleep states. It also studies the role played by antiepileptic drugs (AEDs) on EEG desynchronization in the above cohort. Methods. A total of 120 PWE divided into 3 groups (each n = 40; juvenile myoclonic epilepsy [JME], temporal lobe epilepsy [TLE]. and extratemporal lobe epilepsy [Ex-TLE]) were subjected to overnight polysomnography. Each patient group was subdivided into drug-naive and on treatment (Each n = 20). EEG phase synchronization analysis was performed to compare peri-IED phase synchronization indices (SI) during awake and sleep stages and between drug naïve and on treatment groups in 4 frequency bands, namely delta, theta, alpha, and beta. The mean ± SD of peri-IED SI among various subgroups was compared employing a multilevel mixed effects modeling approach. Results. Patients with JME had increased peri-IED cortical synchrony in N3 sleep stage, whereas patients with partial epilepsy had increased IED cortical synchrony in N1 sleep stage. On the other hand, peri-IED synchrony was lower during wake and REM sleep. We also found that peri-IED synchronization in patients with JME was higher in drug-naive patients compared with those on sodium valproate monotherapy in theta, alpha, and beta bands. Conclusion. The findings of this study suggest that sleep stages can alter cortical synchrony in patients with JME and focal epilepsy, with NREM IEDs being more synchronized and wake/REM IEDs being less synchronized. Furthermore, it also suggests that AEDs alleviate seizures in PWE by inhibiting cortical synchrony.

scholarly journals Dream Recall upon Awakening from Non-Rapid Eye Movement Sleep in Older Adults: Electrophysiological Pattern and Qualitative Features

2020 ◽  
Vol 10 (6) ◽  
pp. 343 ◽  
Author(s):  
Serena Scarpelli ◽  
Aurora D’Atri ◽  
Chiara Bartolacci ◽  
Maurizio Gorgoni ◽  
Anastasia Mangiaruga ◽  
...  
Keyword(s):  
Eye Movement ◽  
Sleep Stage ◽  
Nrem Sleep ◽  
Rapid Eye Movement ◽  
Rapid Eye Movement Sleep ◽  
Dream Recall ◽  
Cortical Arousal ◽  
Beta Power ◽  
Dream Report

Several findings support the activation hypothesis, positing that cortical arousal promotes dream recall (DR). However, most studies have been carried out on young participants, while the electrophysiological (EEG) correlates of DR in older people are still mostly unknown. We aimed to test the activation hypothesis on 20 elders, focusing on the Non-Rapid Eye Movement (NREM) sleep stage. All the subjects underwent polysomnography, and a dream report was collected upon their awakening from NREM sleep. Nine subjects were recallers (RECs) and 11 were non-RECs (NRECs). The delta and beta EEG activity of the last 5 min and the total NREM sleep was calculated by Fast Fourier Transform. Statistical comparisons (RECs vs. NRECs) revealed no differences in the last 5 min of sleep. Significant differences were found in the total NREM sleep: the RECs showed lower delta power over the parietal areas than the NRECs. Consistently, statistical comparisons on the activation index (delta/beta power) revealed that RECs showed a higher level of arousal in the fronto-temporal and parieto-occipital regions than NRECs. Both visual vividness and dream length are positively related to the level of activation. Overall, our results are consistent with the view that dreaming and the storage of oneiric contents depend on the level of arousal during sleep, highlighting a crucial role of the temporo-parietal-occipital zone.

Sleep Stage Deficits in Chronic Schizophrenia

1972 ◽  
Vol 31 (3) ◽  
pp. 815-820 ◽  
Author(s):  
Arthur C. Traub
Keyword(s):  
Sleep Stage ◽  
Chronic Schizophrenia ◽  
Sleep Stages ◽  
Sleep Patterns ◽  
Chronic Schizophrenics ◽  
Delta Sleep

Evidence for the importance of delta sleep is reviewed, and the hypothesis tested that marked deficits in these sleep stages are characteristic of chronic schizophrenics. The sleep patterns of 9 chronic schizophrenics were monitored for 8 consecutive nights by means of continuous all-night EEG, eye and chin-muscle recordings. The main finding was that all Ss showed dramatic and stable deficits in delta sleep stages 3 and 4. The role of factors other than chronic schizophrenia producing this finding is discussed.

Nocturnal Psychophysiological Correlates of Somatic Conditions and Sleep Disorders

1975 ◽  
Vol 6 (1-2) ◽  
pp. 43-62 ◽  
Author(s):  
Joyce D. Kales ◽  
Anthony Kales
Keyword(s):  
Sleep Disorders ◽  
Sleep Stage ◽  
Symptomatic Relief ◽  
Nrem Sleep ◽  
Normal Subjects ◽  
Sleep Stages ◽  
Sleep Laboratory ◽  
Drug Induced ◽  
Night Terrors ◽  
Psychophysiological Correlates

Modern sleep research studies have provided the practicing physician with considerable new information concerning the basic psychophysiology of sleep, the effects of medical conditions on sleep and the role of maturational and emotional factors in producing certain sleep disorders. Medical and psychiatric disorders, sleep disorders and drug-induced sleep stage alterations are studied in the sleep laboratory using the same techniques developed to analyze sleep patterns in normal subjects. After initial sleep laboratory adaptation, a profile of the sleep characteristics of various clinical conditions is obtained. This profile can be compared to sleep profiles of normal subjects as well as to the effects on sleep of subsequent experimental or therapeutic procedures. Various studies have shown that coronary artery, duodenal ulcer and nocturnal headache patients experience angina, increased gastric acid secretion and migraine or cluster headaches, respectively during REM sleep. Adult nocturnal asthmatic episodes occur out of all sleep stages while attacks of dyspnea in asthmatic children occur in all stages except stage 4 sleep. Hypothyroid patients show decreases in stages 3 and 4 sleep, while in hyperthyroid patients the percentage of time spent in stages 3 and 4 sleep is markedly increased. Enuretic episodes occur predominantly in non-rapid eye movement (NREM) sleep. Sleepwalking and night terror episodes occur exclusively out of NREM sleep, particularly from stages 3 and 4 sleep. Most child somnambulists and children with night terrors “outgrow” this disorder, suggesting a delayed maturation of the central nervous system. Stimulant drugs are effective in the treatment of the sleep attacks of narcolepsy and in treating certain cases of hypersomnia, while imipramine is an effective treatment for the auxiliary symptoms of narcolepsy. Psychological disturbances are frequent in adult somnambulism and night terrors as well as in hypersomnia and insomnia. Proper pharmacologic treatment to provide symptomatic relief for insomnia is recommended to enhance the psychotherapeutic process.

scholarly journals Musical components important for the Mozart K448 effect in epilepsy

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Robert J. Quon ◽  
Michael A. Casey ◽  
Edward J. Camp ◽  
Stephen Meisenhelter ◽  
Sarah A. Steimel ◽  
...  
Keyword(s):  
Refractory Epilepsy ◽  
Focal Epilepsy ◽  
Epileptiform Activity ◽  
Brain Regions ◽  
Original Version ◽  
Pharmacological Intervention ◽  
Theta Power ◽  
Epileptiform Discharges ◽  
Interictal Epileptiform Discharges ◽  
Insight Into

AbstractThere is growing evidence for the efficacy of music, specifically Mozart’s Sonata for Two Pianos in D Major (K448), at reducing ictal and interictal epileptiform activity. Nonetheless, little is known about the mechanism underlying this beneficial “Mozart K448 effect” for persons with epilepsy. Here, we measured the influence that K448 had on intracranial interictal epileptiform discharges (IEDs) in sixteen subjects undergoing intracranial monitoring for refractory focal epilepsy. We found reduced IEDs during the original version of K448 after at least 30-s of exposure. Nonsignificant IED rate reductions were witnessed in all brain regions apart from the bilateral frontal cortices, where we observed increased frontal theta power during transitions from prolonged musical segments. All other presented musical stimuli were associated with nonsignificant IED alterations. These results suggest that the “Mozart K448 effect” is dependent on the duration of exposure and may preferentially modulate activity in frontal emotional networks, providing insight into the mechanism underlying this response. Our findings encourage the continued evaluation of Mozart’s K448 as a noninvasive, non-pharmacological intervention for refractory epilepsy.

scholarly journals Ketamine and sleep modulate neural complexity dynamics in cats

2021 ◽  
Author(s):  
Claudia Pascovich ◽  
Santiago Castro-Zaballa ◽  
Pedro A.M. Mediano ◽  
Daniel Bor ◽  
Andrés Canales-Johnson ◽  
...  
Keyword(s):  
Response Curve ◽  
Sleep Stage ◽  
Nrem Sleep ◽  
Conscious State ◽  
Sleep Stages ◽  
Highly Sensitive ◽  
Level Of Consciousness ◽  
State Changes ◽  
Intracranial Electrodes ◽  
Different Levels

There is increasing evidence that level of consciousness can be captured by neural informational complexity: for instance, complexity, as measured by the Lempel Ziv (LZ) compression algorithm, decreases during anesthesia and non-rapid eye movement (NREM) sleep in humans and rats, when compared to LZ in awake and REM sleep. In contrast, LZ is higher in humans under the effect of psychedelics, including subanesthetic doses of ketamine. However, it is both unclear how this result would be modulated by varying ketamine doses, and whether it would extend to other species. Here we studied LZ with and without auditory stimulation during wakefulness and different sleep stages in 5 cats implanted with intracranial electrodes, as well as under subanesthetic doses of ketamine (5, 10, and 15 mg/kg i.m.). In line with previous results, LZ was lowest in NREM sleep, but similar in REM and wakefulness. Furthermore, we found an inverted U-shaped curve following different levels of ketamine doses in a subset of electrodes, primarily in prefrontal cortex. However, it is worth noting that the variability in the ketamine dose-response curve across cats and cortices was larger than that in the sleep-stage data, highlighting the differential local dynamics created by two different ways of modulating conscious state. These results replicate previous findings, both in humans and other species, demonstrating that neural complexity is highly sensitive to capture state changes between wake and sleep stages while adding a local cortical description. Finally, this study describes the differential effects of ketamine doses, replicating a rise in complexity for low doses, and further fall as doses approach anesthetic levels in a differential manner depending on the cortex.

scholarly journals Region-specific complexity of the intracranial EEG in the sleeping human brain

2022 ◽  
Vol 12 (1) ◽  
Author(s):  
Elzbieta Olejarczyk ◽  
Jean Gotman ◽  
Birgit Frauscher
Keyword(s):  
Sleep Stage ◽  
Brain Regions ◽  
Sleep Stages ◽  
Precentral Gyrus ◽  
Self Similarity ◽  
Intracranial Eeg ◽  
Brain Signals ◽  
Cortical Regions ◽  
The Brain

AbstractAs the brain is a complex system with occurrence of self-similarity at different levels, a dedicated analysis of the complexity of brain signals is of interest to elucidate the functional role of various brain regions across the various stages of vigilance. We exploited intracranial electroencephalogram data from 38 cortical regions using the Higuchi fractal dimension (HFD) as measure to assess brain complexity, on a dataset of 1772 electrode locations. HFD values depended on sleep stage and topography. HFD increased with higher levels of vigilance, being highest during wakefulness in the frontal lobe. HFD did not change from wake to stage N2 in temporo-occipital regions. The transverse temporal gyrus was the only area in which the HFD did not differ between any two vigilance stages. Interestingly, HFD of wakefulness and stage R were different mainly in the precentral gyrus, possibly reflecting motor inhibition in stage R. The fusiform and parahippocampal gyri were the only areas showing no difference between wakefulness and N2. Stages R and N2 were similar only for the postcentral gyrus. Topographical analysis of brain complexity revealed that sleep stages are clearly differentiated in fronto-central brain regions, but that temporo-occipital regions sleep differently.

Increased Chin Muscle Tone during All Sleep Stages in Children Taking SSRI Antidepressants and in Children with Narcolepsy Type 1

SLEEP ◽  
2021 ◽  
Author(s):  
Raffaele Ferri ◽  
Maria P Mogavero ◽  
Oliviero Bruni ◽  
Giuseppe Plazzi ◽  
Carlos H Schenck ◽  
...  
Keyword(s):  
Rem Sleep ◽  
Serotonin Reuptake ◽  
Treatment Duration ◽  
Muscle Tone ◽  
Sleep Stage ◽  
Nrem Sleep ◽  
Sleep Stages ◽  
Pharmacological Properties ◽  
Age And Sex

Abstract Study Objectives To assess if selective serotonin reuptake inhibitor (SSRI) antidepressants are able to modify the chin EMG tone during sleep also in children. Methods Twenty-three children and adolescents (12 girls, mean age 14.1 years, SD 2.94) under therapy with antidepressant for their mood disorder were consecutively recruited and had a PSG recording. Twenty-one were taking were taking SSRI and treatment duration was 2-12 months. An age- and sex matched group of 33 control children (17 girls, mean age 14.2 years, SD 2.83) and 24 children with narcolepsy type 1 (12 girls, mean age 13.7 years, SD 2.80) were also included. The Atonia Index was then computed for each NREM sleep stage and for REM sleep, also all EMG activations were counted. Results Atonia Index in all sleep stages was found to be significantly reduced in children with narcolepsy followed by the group taking SSRI antidepressants and the number of EMG activations was also increased in both groups. Fluoxetine, in particular, was found to be significantly associated with reduced Atonia index during NREM sleep stages N1, N2, and N3, and with increased number of EMG activations/hour during sleep stage N3. Conclusions Similarly to adults, SSRI antidepressants are able to modify the chin EMG tone also in children during REM sleep, as well as during NREM sleep stages. Different pharmacological properties of the different SSRI might explain the differential effect on chin tone during sleep found in this study.

scholarly journals SCALP HIGH FREQUENCY OSCILLATION RATE DEPENDS ON SLEEP STAGE AND DECREASES WITH TIME SPENT IN SLEEP

2021 ◽  
Author(s):  
Dorottya Cserpan ◽  
Richard Rosch ◽  
Santo Pietro Lo Biundo ◽  
Johannes Sarnthein ◽  
Georgia Ramantani
Keyword(s):  
High Frequency ◽  
Time Window ◽  
Sleep Stage ◽  
Nrem Sleep ◽  
Interval Length ◽  
High Frequency Oscillation ◽  
Sleep Cycle ◽  
Sleep Stages ◽  
Pediatric Epilepsy ◽  
Scalp Eeg

High frequency oscillations (HFO) in scalp EEG are a new and promising epilepsy biomarker. HFO analysis is typically restricted to random and relatively brief sleep segments. However, considerable fluctuations of HFO rates have been observed over the recording nights, particularly in relation to sleep stages and cycles. Here, we identify the timing within the sleep period and the minimal data interval length that allow for sensitive and reproducible detection of scalp HFO. We selected 16 seizure-free whole-night scalp EEG recordings of children and adolescents with focal lesional epilepsy (median age 7.6 y, range 2.2-17.4 y). We used an automated and clinically validated HFO detector to determine HFO rates (80-250 Hz) in bipolar channels. To identify significant variability over different NREM sleep stages and over time spent in sleep, we modelled HFO rate as a Poisson process. We analysed the test-retest reliability to evaluate the reproducibility of HFO detection across recording intervals. Scalp HFO rates were higher in N3 than in N2 sleep and highest in the first sleep cycle, decreasing with time spent in sleep. In N3 sleep, the median reliability of HFO detection increased from 67% to 79% to 100% for 5-, 10-, and 15-min data intervals, improving significantly (p=0.004) from 5 to 10 min but not from 10 to 15 min. In this analysis of whole-night scalp EEG, we identified the first N3 sleep stage as the most sensitive time window for HFO rate detection. N3 data intervals of 10 min duration are required and sufficient for reliable measurements of HFO rates. Our study provides a robust and reliable framework for implementing scalp HFO as an EEG biomarker in pediatric epilepsy.

scholarly journals Interictal epileptiform activity in sleep and wakefulness in patients with temporal lobe epilepsy

2019 ◽  
pp. 21-26
Author(s):  
A.G. Broutian ◽  
A.I. Belyakova-Bodina ◽  
S.M. Dolgova ◽  
T.N. Pushkar ◽  
A.A. Abramova
Keyword(s):  
Cortical Neurons ◽  
Epileptiform Activity ◽  
Nrem Sleep ◽  
Epileptiform Discharge ◽  
Sleep Stages ◽  
Recording Time ◽  
Temporal Epilepsy ◽  
Major Mechanism ◽  
Eeg Recordings ◽  
Sleep Recording

Sleep is an important activator of epileptiform activity, with epileptiform discharge (ED) probability varying among sleep stages. The aim of our study was to analyze the association between epileptiform activity and sleep stages or wakefulness in adults with temporal discharges. We analyzed 32 long-term overnight EEG recordings. All focal discharges were marked, and the entire sleep was staged. Absolute general epileptiform discharge index (EDI), defined as a ratio of total ED number to the full recording time in hours, as well as absolute EDIs for REM, N1, N2 and N3 stages were calculated. The majority of patients (28) had the highest EDI in N3. EDI increased significantly while sleep progressed to deeper stages, reaching its peak in N3. In REM sleep, EDI sharply declined (p < 0.01) reaching the levels of wakefulness. Increasing synchronization of cortical neurons is thought to be the major mechanism of EDI rise in NREM sleep. Hence, N3 seems to be the most sensitive stage to capture EDs, which highlights the importance of deep sleep recording in patients with temporal epilepsy.

scholarly journals Correlation of sleep macrostructure parameters and idiopathic epilepsies

2002 ◽  
Vol 60 (2B) ◽  
pp. 353-357 ◽  
Author(s):  
José Roberto Santiago Barreto ◽  
Regina Maria França Fernandes ◽  
Américo Ceiki Sakamoto
Keyword(s):  
Focal Epilepsy ◽  
Total Sleep Time ◽  
Nrem Sleep ◽  
Sleep Time ◽  
Control Group ◽  
Idiopathic Generalized Epilepsy ◽  
Recording Time ◽  
Antiepileptic Medications ◽  
Generalized Epilepsy ◽  
Idiopathic Epilepsies

Sleep and epilepsy share some common mechanisms. The objective of the present investigation was to study the macrostructure of sleep in patients with idiopathic epilepsies, focal and generalized, comparing these two groups to each other and to a control group of 12 individuals without epilepsy. A total of 35 polysomnographies were performed, 12 of them in the control group, 10 in patients with idiopathic generalized epilepsies, and 13 in patients with idiopathic focal epilepsies. Antiepileptic medications were maintained for ethical reasons. The group with idiopathic focal epilepsy showed an increase in the total recording time (p = 0.04) and the group with idiopathic generalized epilepsy had a reduction of phase 4 NREM sleep. The efficiency of total sleep period and of total sleep time was also lower in the group with idiopathic generalized epilepsy (p = 0.03 in both cases). We concluded that the group with idiopathic generalized epilepsy presents sleep of poorer quality, whereas the group with idiopathic focal epilepsy presents a tendency toward an excessive somnolence.

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