Lempel-Ziv complexity
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Major depressive disorder, particularly its treatment-resistant form (TRD), poses significant treatment challenges. Ketamine, an N-methyl-d-aspartate receptor antagonist, has shown promise in rapidly alleviating depressive symptoms by influencing neuroplasticity and glutamatergic modulation, which are thought to influence brain activity complexity. In this placebo-controlled study, we examined the effects of subanesthetic doses of intravenous ketamine on EEG signal complexity in 24 MDD patients, 21 of whom had TRD. Treatment response was defined by a ≥ 33 % reduction in Montgomery-Åsberg Depression Rating Scale (MADRS) after ketamine administration. Patients underwent eyes-closed resting state EEG recording pre-, start-, end- and 24 h post-infusion, analyzed for temporospatial and spatiotemporal Lempel-Ziv complexity (LZCT and LZCS). Results indicated that ketamine significantly increased whole-brain LZCT during infusion compared to placebo (sodium chloride 0.9 %) (16.90 % vs. -4.84 %, 95 % CI 4.29 to 39.18, p = 0.017). Elevated LZCT at end-pre was associated with less short-term symptom improvement the following day. Conversely, lower pretreatment occipital LZCT (0.33 vs. 0.46, 95 % CI 0.007 to 0.26, p = 0.040) predicted a favorable response to ketamine, supported by a logistic regression model with an ROC area of 0.75. No significant changes were observed in LZCS, suggesting limited utility as a biomarker. In conclusion, occipital LZCT could serve as an effective predictive biomarker for ketamine's therapeutic effects in MDD, with implications for patients with TRD. This underscores the potential of EEG complexity measures in stratifying treatment and enhancing our understanding of the neural impacts of ketamine in depressive disorders.
- MeSH
- antagonisté excitačních aminokyselin * aplikace a dávkování farmakologie MeSH
- deprese nereagující na léčbu * farmakoterapie patofyziologie MeSH
- depresivní porucha unipolární * farmakoterapie patofyziologie MeSH
- dospělí MeSH
- dvojitá slepá metoda MeSH
- elektroencefalografie * účinky léků MeSH
- ketamin * aplikace a dávkování farmakologie terapeutické užití MeSH
- lidé středního věku MeSH
- lidé MeSH
- mozek * účinky léků patofyziologie MeSH
- výsledek terapie MeSH
- Check Tag
- dospělí MeSH
- lidé středního věku MeSH
- lidé MeSH
- mužské pohlaví MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
- klinické zkoušky kontrolované MeSH
Measures from the theory of nonlinear dynamics were applied on complex fractionated atrial electrograms (CFAEs) in order to characterize their physiological dynamic behavior. The results were obtained considering 113 short term atrial electrograms (A-EGMs) which were annotated by three experts into four classes of fractionation according to A-EGMs signal regularity. The following measures were applied on A-EGM signals: General Correlation Dimension, Approximate Entropy, Detrended Fluctuation Analysis, Lempel-Ziv Complexity, and Katz-Sevcik, Variance and Box Counting Fractal Dimension. Assessment of disorganization was evaluated by a Kruskal Wallis statistical test. Except Detrended Fluctuation Analysis and Variance Fractal Dimension, the CFAE disorganization was found statistically significant even for low significant level alpha = 0.001. Moreover, the increasing complexity of A-EGM signals was reflected by higher values of General Correlation Dimension of order 1 and Approximate Entropy.
Cardiotocography is the monitoring of fetal heart rate (FHR) and uterine contractions (TOCO), used routinely since the 1960s by obstetricians to detect fetal hypoxia. The evaluation of the FHR in clinical settings is based on an evaluation of macroscopic morphological features and so far has managed to avoid adopting any achievements from the HRV research field. In this work, most of the features utilized for FHR characterization, including FIGO, HRV, nonlinear, wavelet, and time and frequency domain features, are investigated and assessed based on their statistical significance in the task of distinguishing the FHR into three FIGO classes. We assess the features on a large data set (552 records) and unlike in other published papers we use three-class expert evaluation of the records instead of the pH values. We conclude the paper by presenting the best uncorrelated features and their individual rank of importance according to the meta-analysis of three different ranking methods. The number of accelerations and decelerations, interval index, as well as Lempel-Ziv complexity and Higuchi's fractal dimension are among the top five features.
- MeSH
- artefakty MeSH
- automatizace MeSH
- lidé MeSH
- monitorování plodu metody MeSH
- počítačové zpracování signálu MeSH
- srdeční frekvence plodu fyziologie MeSH
- uterus fyziologie MeSH
- Check Tag
- lidé MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
- hodnotící studie MeSH
- práce podpořená grantem MeSH
Cardiotocography (CTG) is the monitoring of fetal heart rate (FHR) and uterine contractions (TOCO) since 1960's used routinely by obstetricians to detect fetal hypoxia. The evaluation of the FHR in clinical settings is based on an evaluation of macroscopic morphological features and so far has managed to avoid adopting any achievements from the HRV research field. In this work, most of the ever-used features utilized for FHR characterization, including FIGO, HRV, nonlinear, wavelet, and time and frequency domain features, are investigated and the features are assessed based on their statistical significance in the task of distinguishing the FHR into three FIGO classes. Annotation derived from the panel of experts instead of the commonly utilized pH values was used for evaluation of the features on a large data set (552 records). We conclude the paper by presenting the best uncorrelated features and their individual rank of importance according to the meta-analysis of three different ranking methods. Number of acceleration and deceleration, interval index, as well as Lempel-Ziv complexity and Higuchi's fractal dimension are among the top five features.
- MeSH
- algoritmy MeSH
- diagnóza počítačová metody MeSH
- kardiotokografie metody MeSH
- lidé MeSH
- odchylka pozorovatele MeSH
- reprodukovatelnost výsledků MeSH
- senzitivita a specificita MeSH
- srdeční frekvence plodu fyziologie MeSH
- znalecký posudek MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- hodnotící studie MeSH
- práce podpořená grantem MeSH
- srovnávací studie MeSH
The use of low sub-perceptual doses of psychedelics ("microdosing") has gained popularity in recent years. Although anecdotal reports claim multiple benefits associated with this practice, the lack of placebo-controlled studies severely limits our knowledge of microdosing and its effects. Moreover, research conducted in standard laboratory settings could fail to capture the motivation of individuals engaged or planning to engage in microdosing protocols, thus underestimating the likelihood of positive effects on creativity and cognitive function. We recruited 34 individuals starting to microdose with psilocybin mushrooms (Psilocybe cubensis), one of the materials most frequently used for this purpose. Following a double-blind placebo-controlled experimental design, we investigated the acute and short-term effects of 0.5 g of dried mushrooms on subjective experience, behavior, creativity (divergent and convergent thinking), perception, cognition, and brain activity. The reported acute effects were significantly more intense for the active dose compared to the placebo, but only for participants who correctly identified their experimental condition. These changes were accompanied by reduced EEG power in the theta band, together with preserved levels of Lempel-Ziv broadband signal complexity. For all other measurements there was no effect of microdosing except for few small changes towards cognitive impairment. According to our findings, low doses of psilocybin mushrooms can result in noticeable subjective effects and altered EEG rhythms, but without evidence to support enhanced well-being, creativity and cognitive function. We conclude that expectation underlies at least some of the anecdotal benefits attributed to microdosing with psilocybin mushrooms.
