• Konspekt
• Lékařské vědy. Lékařství
• NLK Obory
• neurologie
• fyziologie
• neurovědy

It is well known that in patients with obstructive sleep apnea syndrome (OSAS) the apnea-hypopnea index (AHI) is significantly decreased during slow wave sleep (SWS). It used to be explained by the ability of SWS to stabilize the upper airways against collapse. Another explanation, which is the focus of the current study, is that it is just a result of high instability of SWS to obstructive apnea exposure, i.e. high susceptibility of SWS to transition into lighter sleep stages during exposure to obstructive apneas. A retrospective chart review was performed on 560 males who underwent an overnight polysomnography. Two hundred and eighty-seven patients were eligible for the study. They were divided into 3 groups according to different AHI level. All three groups had a higher SWS occurrence in the lateral position than in the supine position. A special fourth group of patients was created with severe OSAS in the supine position but with very mild OSAS in the lateral position. This group had, in the lateral position, (A) higher AHI in NREM sleep (4.1+/-3.1/h vs. 0.7+/-1.2/h, p<0.001) as well as (B) higher SWS occurrence (27.7+/-15.0 % vs. 21.4+/-16.2 % of NREM sleep, p<0.05), than the group with the lowest AHI in the study, i.e. AHI<5/h in NREM sleep. These data suggest that strong coincidence between SWS and low AHI is the result of the high instability of SWS to obstructive apnea exposure. The data also support the presence of SWS-rebound in OSAS patients in the lateral body position.

• MeSH
• dýchání * MeSH
• lidé MeSH
• mozek patofyziologie   MeSH
• obstrukční spánková apnoe diagnóza   patofyziologie   MeSH
• plíce patofyziologie   MeSH
• polohování pacienta * MeSH
• retrospektivní studie MeSH
• spánek pomalých vln * MeSH
• stupeň závažnosti nemoci MeSH
• supinační poloha * MeSH
• Check Tag
• lidé MeSH
• mužské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• srovnávací studie MeSH

Insomnia is a prevalent and disabling condition whose treatment is not always effective. This pilot study explores the feasibility and effects of closed-loop auditory stimulation (CLAS) as a potential non-invasive intervention to improve sleep, its subjective quality, and memory consolidation in patients with insomnia. A total of 27 patients with chronic insomnia underwent a crossover, sham-controlled study with 2 nights of either CLAS or sham stimulation. Polysomnography was used to record sleep parameters, while questionnaires and a word-pair memory task were administered to assess subjective sleep quality and memory consolidation. The initial analyses included 17 patients who completed the study, met the inclusion criteria, and received CLAS. From those, 10 (58%) received only a small number of stimuli. In the remaining seven (41%) patients with sufficient CLAS, we evaluated the acute and whole-night effect on sleep. CLAS led to a significant immediate increase in slow oscillation (0.5-1 Hz) amplitude and activity, and reduced delta (1-4 Hz) and sigma/sleep spindle (12-15 Hz) activity during slow-wave sleep across the whole night. All these fundamental sleep rhythms are implicated in sleep-dependent memory consolidation. Yet, CLAS did not change sleep-dependent memory consolidation or sleep macrostructure characteristics, number of arousals, or subjective perception of sleep quality. Results showed CLAS to be feasible in patients with insomnia. However, a high variance in the efficacy of our automated stimulation approach suggests that further research is needed to optimise stimulation protocols to better unlock potential CLAS benefits for sleep structure and subjective sleep quality in such clinical settings.

• MeSH
• akustická stimulace * metody   MeSH
• dospělí MeSH
• elektroencefalografie MeSH
• klinické křížové studie * MeSH
• konsolidace paměti fyziologie   MeSH
• kvalita spánku MeSH
• lidé středního věku MeSH
• lidé MeSH
• pilotní projekty MeSH
• polysomnografie * MeSH
• poruchy iniciace a udržování spánku * terapie   patofyziologie   MeSH
• průzkumy a dotazníky MeSH
• spánek pomalých vln * fyziologie   MeSH
• Check Tag
• dospělí MeSH
• lidé středního věku MeSH
• lidé MeSH
• mužské pohlaví MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH

Age-related brain changes affect sleep and are reflected in properties of sleep slow-waves, however, the precise mechanisms behind these changes are still not completely understood. Here, we adapt a previously established whole-brain model relating structural connectivity changes to resting state dynamics, and extend it to a slow-wave sleep brain state. In particular, starting from a representative connectome at the beginning of the aging trajectory, we have gradually reduced the inter-hemispheric connections, and simulated sleep-like slow-wave activity. We show that the main empirically observed trends, namely a decrease in duration and increase in variability of the slow waves are captured by the model. Furthermore, comparing the simulated EEG activity to the source signals, we suggest that the empirically observed decrease in amplitude of the slow waves is caused by the decrease in synchrony between brain regions.

• MeSH
• dospělí MeSH
• elektroencefalografie * MeSH
• konektom * MeSH
• lidé středního věku MeSH
• lidé MeSH
• modely neurologické * MeSH
• mozek * fyziologie   MeSH
• počítačová simulace MeSH
• senioři MeSH
• spánek pomalých vln * fyziologie   MeSH
• stárnutí * fyziologie   MeSH
• Check Tag
• dospělí MeSH
• lidé středního věku MeSH
• lidé MeSH
• mužské pohlaví MeSH
• senioři MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH

• MeSH
• deprese patofyziologie   MeSH
• pohyby očí MeSH
• spánek REM MeSH
• stadia spánku MeSH

Slow-wave synchronous acoustic stimulation is a promising research and therapeutic tool. It is essential to clearly understand the principles of the synchronization methods, to know their performances and limitations, and, most importantly, to have a clear picture of the effect of stimulation on slow-wave activity (SWA). This paper covers the mentioned and currently missing parts of knowledge that are essential for the appropriate development of the method itself and future applications. Artificially streamed real sleep EEG data were used to quantitatively compare the two currently used real-time methods: the phase-locking loop (PLL) and the fixed-step stimulus in our own implementation. The fixed-step stimulation method was concluded to be more reliable and practically applicable compared to the PLL method. The sleep experiment with chronic insomnia patients in our sleep laboratory was analyzed in order to precisely characterize the effect of sound stimulation during deep sleep. We found that there is a significant phase synchronization of delta waves, which were shown to be the most sensitive metric of the effect of acoustic stimulation compared to commonly used averaged signal and power analyses. This finding may change the understanding of the effect and function of the SWA stimulation described in the literature.

• MeSH
• akustická stimulace MeSH
• elektroencefalografie MeSH
• lidé MeSH
• spánek pomalých vln * MeSH
• spánek MeSH
• techniky fyzikální terapie MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH

The dialogue between cortex and hippocampus is known to be crucial for sleep-dependent memory consolidation. During slow wave sleep, memory replay depends on slow oscillation (SO) and spindles in the (neo)cortex and sharp wave-ripples (SWRs) in the hippocampus. The mechanisms underlying interaction of these rhythms are poorly understood. We examined the interaction between cortical SO and hippocampal SWRs in a model of the hippocampo-cortico-thalamic network and compared the results with human intracranial recordings during sleep. We observed that ripple occurrence peaked following the onset of an Up-state of SO and that cortical input to hippocampus was crucial to maintain this relationship. A small fraction of ripples occurred during the Down-state and controlled initiation of the next Up-state. We observed that the effect of ripple depends on its precise timing, which supports the idea that ripples occurring at different phases of SO might serve different functions, particularly in the context of encoding the new and reactivation of the old memories during memory consolidation. The study revealed complex bidirectional interaction of SWRs and SO in which early hippocampal ripples influence transitions to Up-state, while cortical Up-states control occurrence of the later ripples, which in turn influence transition to Down-state.

• MeSH
• elektroencefalografie metody   MeSH
• hipokampus fyziologie   MeSH
• konsolidace paměti fyziologie   MeSH
• lidé MeSH
• neokortex fyziologie   MeSH
• spánek pomalých vln fyziologie   MeSH
• spánek fyziologie   MeSH
• thalamus fyziologie   MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Research Support, N.I.H., Extramural MeSH
• Research Support, U.S. Gov't, Non-P.H.S. MeSH

• MeSH
• adjuvancia imunologická MeSH
• glykopeptidy MeSH
• spánek účinky léků   MeSH

V průběhu spánku se může objevit celá řada záchvatových motorických projevů s různou etiologií. Při jejich hodnocení je klíčové zejména odlišení epileptických záchvatů od jiných poruch spánku. Epileptické záchvaty ve spánku jsou relativně časté a v přibližně 12 % jsou téměř výhradně vázány na spánek. Nejčastějším typem epileptických záchvatů ve spánku jsou fokální hyperkinetické záchvaty v rámci tzv. na spánek vázané hypermotorické epilepsie (sleep-related hypermotor epilepsy - SHE), dříve známé pod názvem noční frontální epilepsie, přičemž po stránce etiologie a lokalizace epileptického ložiska se jedná o heterogenní skupinu. Odlišení SHE může být obtížné zejména od NREM parasomnií vzhledem k některým společným patofyziologickým mechanismům a časté koincidenci obou poruch. Další typy záchvatových projevů ve spánku představuje porucha chování v REM spánku, poruchy pohybu souvisejících se spánkem, jakými jsou rytmické pohyby vázané na spánek, hypnagogické záškuby, periodické pohyby dolními končetinami a různé formy myoklonu. V neposlední řadě se během noci můžeme setkat s panickými atakami a psychogenními neepileptickými záchvaty.

There is a wide range of different paroxysmal motor events with various aetiology during sleep. The most important issue in their evaluation is to distinguish epileptic seizures from other sleep disorders. Sleep-related epileptic seizures are relatively frequent and they may occur predominantly or exclusively during sleep in approximately 12 %. The most frequent seizure type during sleep is a focal hyperkinetic seizure in the frame of the sleep-related hypermotor epilepsy (SHE), previously known as nocturnal frontal lobe epilepsy, which is a heterogeneous group in terms of aetiology and localization of epileptic focus. The differentiation of SHE from NREM parasomnia may sometimes be difficult, because of relatively frequent cooccurrence of both disorders and because of some shared pathophysiological mechanisms. Other possibilities of paroxysmal motor events during sleep represent REM sleep behaviour disorder, sleep-related movement disorders including sleep-related rhythmic movement disorder, sleep startle, periodic leg movement and various forms of myoclonus. Last but not least the psychogenic non-epileptic seizures or panic attacks may occur during the night.

• Klíčová slova
• záchvatové stavy ve spánku,
• MeSH
• epilepsie diagnóza   terapie   MeSH
• lidé MeSH
• parasomnie spojené s REM spánkem diagnóza   terapie   MeSH
• porucha chování v REM spánku * diagnóza   terapie   MeSH
• poruchy spánku a bdění * diagnóza   terapie   MeSH
• spánek pomalých vln MeSH
• záchvaty * diagnóza   terapie   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• přehledy MeSH

The duration of slow-wave sleep (SWS) is related to the reported sleep quality and to the important variables of mental and physical health. The internal cues to end an episode of SWS are poorly understood. One such internal cue is the initiation of a body movement, which is detectable as electromyographic (EMG) activity in sleep-electroencephalography (EEG). In the present study, we characterized the termination of SWS episodes by movement to explore its potential as a biomarker. To this end, we characterized the relation between the occurrence of SWS termination by movement and individual characteristics (age, sex), SWS duration and spectral content, chronotype, depression, medication, overnight memory performance, and, as a potential neurological application, epilepsy. We analyzed 94 full-night EEG-EMG recordings (75/94 had confirmed epilepsy) in the video-EEG monitoring unit of the EpiCARE Centre Salzburg, Austria. Segments of SWS were counted and rated for their termination by movement or not through the visual inspection of continuous EEG and EMG recordings. Multiple linear regression was used to predict the number of SWS episodes that ended with movement by depression, chronotype, type of epilepsy (focal, generalized, no epilepsy, unclear), medication, gender, total duration of SWS, occurrence of seizures during the night, occurrence of tonic-clonic seizures during the night, and SWS frequency spectra. Furthermore, we assessed whether SWS movement termination was related to overnight memory retention. According to multiple linear regression, patients with overall longer SWS experienced more SWS episodes that ended with movement (t = 5.64; p = 0.001). No other variable was related to the proportion of SWS that ended with movement, including no epilepsy-related variable. A small sample (n = 4) of patients taking Sertraline experienced no SWS that ended with movement, which was significant compared to all other patients (t = 8.00; p < 0.001) and to n = 35 patients who did not take any medication (t = 4.22; p < 0.001). While this result was based on a small subsample and must be interpreted with caution, it warrants replication in a larger sample with and without seizures to further elucidate the role of the movement termination of SWS and its potential to serve as a biomarker for sleep continuity and for medication effects on sleep.

• Publikační typ
• časopisecké články MeSH