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1.
Life Sci Space Res (Amst) ; 40: 19-20, 2024 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-38245344

RESUMEN

Rapid deconditioning and comprehensive deleterious physiological changes that result in bedrest affect every system, function and cell of the body. It was assumed that the inherent inactivity was the cause of the problem, and that exercise would restore good health (Vernikos, 2018). However, numerous studies exploring different types and bouts of exercise once a day during bedrest produced only partial benefits. The usual frequent signal to the vestibular system of the inner ear and the brain, of changing posture, such as standing up regularly during a normal day's activities, goes silent in the microgravity of space, in bedrest or when sitting continuously. Making frequent use of gravity stimulation by standing up often throughout the day accelerates rehabilitation. Though centrifugation has been used in the aerospace field, this is a new approach in clinical practice. Postural change apart, another type of Gravity Therapy is the passive riding of a human centrifuge with or without activity. Accelerated rehabilitation through Gravity Therapy can get patients up and about, back to health sooner, in addition to cutting practical and emotional costs of rehabilitation dramatically. KEY POINT: Other than getting a good night's sleep, spending too much time in bed is bad for your health.


Asunto(s)
Ingravidez , Humanos , Centrifugación , Postura , Reposo en Cama , Ejercicio Físico/fisiología
3.
Front Behav Neurosci ; 17: 1096122, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-36778131

RESUMEN

Introduction: Investigations of biofeedback (BF) and neurofeedback (NF) training for nicotine addiction have been long documented to lead to positive gains in smoking status, behavior and to changes in brain activity. We aimed to: (a) evaluate a multi-visit combined BF/NF intervention as an alternative smoking cessation approach, (b) validate training-induced feedback learning, and (c) document effects on resting-state functional connectivity networks (rsFCN); considering gender and degree of nicotine dependence in a longitudinal design. Methods: We analyzed clinical, behavioral, and electrophysiological data from 17 smokers who completed five BF and 20 NF sessions and three evaluation stages. Possible neuroplastic effects were explored comparing whole-brain rsFCN by phase-lag index (PLI) for different brain rhythms. PLI connections with significant change across time were investigated according to different resting-state networks (RSNs). Results: Improvements in smoking status were observed as exhaled carbon monoxide levels, Total Oxidative Stress, and Fageström scores decreased while Vitamin E levels increased across time. BF/NF promoted gains in anxiety, self-esteem, and several aspects of cognitive performance. BF learning in temperature enhancement was observed within sessions. NF learning in theta/alpha ratio increase was achieved across baselines and within sessions. PLI network connections significantly changed across time mainly between or within visual, default mode and frontoparietal networks in theta and alpha rhythms, while beta band RSNs mostly changed significantly after BF sessions. Discussion: Combined BF/NF training positively affects the clinical and behavioral status of smokers, displays benefit in smoking harm reduction, plays a neuroprotective role, leads to learning effects and to positive reorganization of RSNs across time. Clinical Trial Registration: https://clinicaltrials.gov/ct2/show/NCT02991781.

4.
J Occup Environ Med ; 64(9): e567-e574, 2022 09 01.
Artículo en Inglés | MEDLINE | ID: mdl-35902374

RESUMEN

OBJECTIVE: The aim of this study was to assess the mental health and sleep quality of aviation workers in Greece during the pandemic. METHODS: A cross-sectional study of aviation workers in Greece was conducted. RESULTS: Sleep disturbances were observed in 25.4% of our 548 participants, whereas 8.2% and 5.8% reported at least mild depressive and anxiety symptoms, respectively. The impact of the pandemic on their mental health was their primary concern, which increased for many active pilots according to their workload. Those infected mainly faced daily tiredness and fatigue. Smoking habits and high body mass index were a predisposition for more physical symptoms. Cabin crew and women generally yielded worse scores than the other groups. CONCLUSION: Fear of infection could explain mental health issues, whereas physical symptoms of those infected could be attributed to long-COVID (coronavirus disease) syndrome. Flight attendants' lower ratings may be due to more occupational exposure.


Asunto(s)
Aviación , COVID-19 , COVID-19/complicaciones , COVID-19/epidemiología , Estudios Transversales , Fatiga/epidemiología , Fatiga/etiología , Femenino , Grecia/epidemiología , Humanos , Salud Mental , Pandemias , Calidad del Sueño , Síndrome Post Agudo de COVID-19
5.
JMIR Res Protoc ; 11(3): e34537, 2022 Mar 10.
Artículo en Inglés | MEDLINE | ID: mdl-35266874

RESUMEN

BACKGROUND: Living labs in the health and well-being domain have become increasingly common over the past decade but vary in available infrastructure, implemented study designs, and outcome measures. The Horizon 2020 Project Virtual Health and Wellbeing Living Lab Infrastructure aims to harmonize living lab procedures and open living lab infrastructures to facilitate and promote research activities in the health and well-being domain in Europe and beyond. This protocol will describe the design of a joint research activity, focusing on the use of innovative technology for both rehabilitation interventions and data collection in a rehabilitation context. OBJECTIVE: With this joint research activity, this study primarily aims to gain insight into each living lab's infrastructure and procedures to harmonize health and well-being living lab procedures and infrastructures in Europe and beyond, particularly in the context of rehabilitation. Secondarily, this study aims to investigate the potential of innovative technologies for rehabilitation through living lab methodologies. METHODS: This study has a mixed methods design comprising multiple phases. There are two main phases of data collection: cocreation (phase 1) and small-scale pilot studies (phase 2), which are preceded by a preliminary harmonization of procedures among the different international living labs. An intermediate phase further allows the implementation of minor adjustments to the intervention or protocol depending on the input that was obtained in the cocreation phase. A total of 6 small-scale pilot studies using innovative technologies for intervention or data collection will be performed across 4 countries. The target study sample comprises patients with stroke and older adults with mild cognitive impairment. The third and final phases involve Delphi procedures to reach a consensus on harmonized procedures and protocols. RESULTS: Phase 1 data collection will begin in March 2022, and phase 2 data collection will begin in June 2022. Results will include the output of the cocreation sessions, small-scale pilot studies, and advice on harmonizing procedures and protocols for health and well-being living labs focusing on rehabilitation. CONCLUSIONS: The knowledge gained by the execution of this research will lead to harmonized procedures and protocols in a rehabilitation context for health and well-being living labs in Europe and beyond. In addition to the harmonized procedures and protocols in rehabilitation, we will also be able to provide new insights for improving the implementation of innovative technologies in rehabilitation. INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID): PRR1-10.2196/34537.

6.
High Blood Press Cardiovasc Prev ; 29(1): 65-74, 2022 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-34773579

RESUMEN

INTRODUCTION: Experiments during spaceflight and simulated microgravity as head-down tilt bedrest, demonstrated the role of arterial stiffness among others, in microgravity induced cardiovascular pathologies and emphasized the need for a robust countermeasure. AIM: The purpose of the present study was to evaluate the use of a new countermeasure, consisting of a high intensity Reactive Sledge (RSL) jumps training protocol, to counteract changes in arterial stiffness during long term head down tilt bedrest (LTBR). METHODS: The participants enrolled in the study were 23 male, healthy volunteers, aged between 20 and 45 years, subjected to LTBR for 60 days and randomly assigned either to a control (11) or to a training sledge (12) group using RSL 3-4 times per week, as a countermeasure. Recorded values were systolic and diastolic blood pressure, heart rate and the user's arterial stiffness index. RESULTS: Compared to baseline measurements, there was a deterioration in the values of arterial stiffness, systolic and diastolic blood pressure and heart rate, in both groups until day 35 of LTBR, interpreted as adaptation to the microgravity environment. From this day until the end of the experiment, arterial stiffness of the control group was constantly fluctuating, while constantly improving for the training group. During the recovery period, arterial stiffness values returned to the pre-experimental levels in both groups. CONCLUSIONS: Overall, arterial stiffness increased the longer the time spent in LTBR and the countermeasure was partially effective in preventing the observed phenomenon. German Clinical Trials Register (DRKS), DRKS00012946, September 18, 2017, retrospectively registered.


Asunto(s)
Rigidez Vascular , Ingravidez , Adulto , Reposo en Cama , Presión Sanguínea , Inclinación de Cabeza , Humanos , Masculino , Persona de Mediana Edad , Ingravidez/efectos adversos , Adulto Joven
7.
Front Physiol ; 13: 1024389, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-36741804

RESUMEN

Introduction: The idea behind the presentation of this case relates to utilizing space technology in earth applications with mutual benefit for both patients confined to bed and astronauts. Deconditioning and the progressiveness of skeletal muscle loss in the absence of adequate gravity stimulus have been of physiological concern. A robust countermeasure to muscle disuse is still a challenge for both immobilized patients and astronauts in long duration space missions. Researchers in the space medicine field concluded that artificial gravity (AG) produced by short-radius centrifugation on a passive movement therapy device, combined with exercise, has been a robust multi-system countermeasure as it re-introduces an acceleration field and gravity load. Methods: A short-arm human centrifuge (SAHC) alone or combined with exercise was evaluated as a novel, artificial gravity device for an effective rehabilitation strategy in the case of a stroke patient with disability. The results reveal valuable information on an individualized rehabilitation strategy against physiological deconditioning. A 73-year-old woman was suddenly unable to speak, follow directions or move her left arm and leg. She could not walk, and self-care tasks required maximal assistance. Her condition was getting worse over the years, also she was receiving conventional rehabilitation treatment. Intermittent short-arm human centrifuge individualized protocols were applied for 5 months, three times a week, 60 treatments in total. Results: It resulted in significant improvement in her gait, decreased atrophy with less spasticity on the left body side, and ability to walk at least 100 m with a cane. Balance and muscle strength were improved significantly. Cardiovascular parameters improved responding to adaptations to aerobic exercise. Electroencephalography (EEG) showed brain reorganization/plasticity evidenced through functional connectivity alterations and activation in the cortical regions, especially of the precentral and postcentral gyrus. Stroke immobility-related disability was also improved. Discussion: These alterations were attributed to the short-arm human centrifuge intervention. This case study provides novel evidence supporting the use of the short-arm human centrifuge as a promising therapeutic strategy in patients with restricted mobility, with application to astronauts with long-term muscle disuse in space.

8.
Sleep Med ; 88: 87-89, 2021 12.
Artículo en Inglés | MEDLINE | ID: mdl-34740170

RESUMEN

OBJECTIVE/BACKGROUND: Varenicline (VAR) is used for smoking cessation as it inhibits nicotine for binding on its receptors reducing nicotine dependence. VAR administration has been reported to affect sleep. The aim of this study was to evaluate possible changes in polysomnography (PSG) during VAR treatment (SmokeFreeBrain) in healthy smokers and smokers with obstructive sleep apnea (OSA). PATIENTS/METHODS: Thirty smokers (21 men) with 15.3 ± 10.2 PY, aged 32.8 ± 4.5 years, with BMI 28.6 ± 4 kg/m2, 16 without and 14 with OSA (92% males) were studied with PSG (Embletta MPR-Master) before treatment with VAR while smoking and 20-30 days during VAR administration and smoking cessation for at least 5 days. RESULTS: No significant differences were observed in sleep macro architecture (N1, N2, N3, REM, Sleep Efficiency, Total Sleep Time) during VAR treatment apart from prolongation of sleep latency, N2 and N3 latency in both smokers with and without OSA. Apnea hypopnea index (AHI) was reduced in OSA smokers and especially during REM with a borderline increase of arousal index (ArI) and reduction of sleep efficiency (SE). CONCLUSION: VAR treatment worsened sleep quality as a prolongation of sleep latency, N2 and N3 latency was observed. A marginal reduction of AHI was found in OSA patients, more significantly during REM. Due to the small sample size, further studies are needed to distinguish between the adverse reactions of VAR treatment and smoking cessation effects and to evaluate whether VAR may play a role in OSA treatment.


Asunto(s)
Apnea Obstructiva del Sueño , Cese del Hábito de Fumar , Femenino , Humanos , Masculino , Calidad del Sueño , Sueño REM , Vareniclina
9.
Front Physiol ; 12: 644661, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-34045973

RESUMEN

PURPOSE: Increasing the level of gravity passively on a centrifuge, should be equal to or even more beneficial not only to astronauts living in a microgravity environment but also to patients confined to bed. Gravity therapy (GT) may have beneficial effects on numerous conditions, such as immobility due to neuromuscular disorders, balance disorders, stroke, sports injuries. However, the appropriate configuration for administering the Gz load remains to be determined. METHODS: To address these issues, we studied graded G-loads from 0.5 to 2.0g in 24 young healthy, male and female participants, trained on a short arm human centrifuge (SAHC) combined with mild activity exercise within 40-59% MHR, provided by an onboard bicycle ergometer. Hemodynamic parameters, as cardiac output (CO), stroke volume (SV), mean arterial pressure (MAP), systolic blood pressure (SBP), diastolic blood pressure (DBP), and heart rate (HR) were analyzed, as well as blood gas analysis. A one-way repeated measures ANOVA and pairwise comparisons were conducted with a level of significance p < 0.05. RESULTS: Significant changes in heart rate variability (HRV) and its spectral components (Class, Fmax, and VHF) were found in all g loads when compared to standing (p < 0.001), except in 1.7 and 2.0g. There were significant changes in CO, cardiac index (CI), and cardiac power (CP) (p < 0.001), and in MAP (p = 0.003) at different artificial gravity (AG) levels. Dose-response curves were determined based on statistically significant changes in cardiovascular parameters, as well as in identifying the optimal G level for training, as well as the optimal G level for training. There were statistically significant gender differences in Cardiac Output/CO (p = 0.002) and Cardiac Power/CP (p = 0.016) during the AG training as compared to standing. More specifically, these cardiovascular parameters were significantly higher for male than female participants. Also, there was a statistically significant (p = 0.022) gender by experimental condition interaction, since the high-frequency parameter of the heart rate variability was attenuated during AG training as compared to standing but only for the female participants (p = 0.004). CONCLUSION: The comprehensive cardiovascular evaluation of the response to a range of graded AG loads, as compared to standing, in male and female subjects provides the dose-response framework that enables us to explore and validate the usefulness of the centrifuge as a medical device. It further allows its use in precisely selecting personalized gravity therapy (GT) as needed for treatment or rehabilitation of individuals confined to bed.

10.
J Sleep Res ; 30(5): e13323, 2021 10.
Artículo en Inglés | MEDLINE | ID: mdl-33829595

RESUMEN

We investigated the alterations of sleep regulation and promotion biomarkers as adenosine through its enzymes total adenosine deaminase (tADA)/adenosine deaminase (ADA2) in a microgravity analogue environment of head-down-tilt bed rest and their association with brain connectivity networks during non-rapid eye movement sleep stage 3 (NREM3), as well as the effectiveness of the reactive sledge (RSL) jump countermeasure to promote sleep. A total of 23 healthy male volunteers were maintained in 6° head-down-tilt position for 30 days and assigned either to a control or to a RSL group. Blood collection and polysomnographic recordings were performed on data acquisition day 1, 14, 30 and -14, 21, respectively. Immunochemical techniques and network-based statistics were employed for adenosine enzymes and cortical connectivity estimation. Our findings indicate that human blood adenosine biomarkers as well as NREM3 cortical functional connectivity are impaired in simulated microgravity. RSL physical activity intervened in sleep quality via tADA/ADA2 fluctuations lack, minor cortical connectivity increases, and limited degree of node and resting-state networks. Statistically significant decreases in adenosine biomarkers and NREM3 functional connectivity involving regions (left superior temporal gyrus, right postcentral gyrus, precuneus, left middle frontal gyrus, left postcentral gyrus, left angular gyrus and precuneus) of the auditory, sensorimotor default-mode and executive networks highlight the sleep disturbances due to simulated microgravity and the sleep-promoting role of RSL countermeasure. The head-down-tilt environment led to sleep deterioration projected through NREM3 cortical brain connectivity or/and adenosine biomarkers shift. This decline was more pronounced in the absence of the RSL countermeasure, thereby highlighting its likely exploitation during space missions.


Asunto(s)
Adenosina , Reposo en Cama , Biomarcadores , Inclinación de Cabeza , Humanos , Imagen por Resonancia Magnética , Masculino , Descanso , Fases del Sueño
11.
Sleep Med Rev ; 55: 101377, 2021 02.
Artículo en Inglés | MEDLINE | ID: mdl-33017770

RESUMEN

Sleep staging is a vital process conducted in order to analyze polysomnographic data. To facilitate prompt interpretation of these recordings, many automatic sleep staging methods have been proposed. These methods rely on bio-signal recordings, which include electroencephalography, electrocardiography, electromyography, electrooculography, respiratory, pulse oximetry and others. However, advanced, uncomplicated and swift sleep-staging-evaluation is still needed in order to improve the existing polysomnographic data interpretation. The present review focuses on automatic sleep staging methods through bio-signal recording including current and future challenges.


Asunto(s)
Electroencefalografía , Fases del Sueño , Electromiografía , Electrooculografía , Humanos , Polisomnografía
12.
Front Neurol ; 12: 746832, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-35058870

RESUMEN

Short-arm human centrifugation (SAHC) is proposed as a robust countermeasure to treat deconditioning and prevent progressive disability in a case of secondary progressive multiple sclerosis. Based on long-term physiological knowledge derived from space medicine and missions, artificial gravity training seems to be a promising physical rehabilitation approach toward the prevention of musculoskeletal decrement due to confinement and inactivity. So, the present study proposes a novel infrastructure based on SAHC to investigate the hypothesis that artificial gravity ameliorates the degree of disability. The patient was submitted to a 4-week training programme including three weekly sessions of 30 min of intermittent centrifugation at 1.5-2 g. During sessions, cardiovascular, muscle oxygen saturation (SmO2) and electroencephalographic (EEG) responses were monitored, whereas neurological and physical performance tests were carried out before and after the intervention. Cardiovascular parameters improved in a way reminiscent of adaptations to aerobic exercise. SmO2 decreased during sessions concomitant with increased g load, and, as training progressed, SmO2 of the suffering limb dropped, both effects suggesting increased oxygen use, similar to that seen during hard exercise. EEG showed increased slow and decreased fast brain waves, with brain reorganization/plasticity evidenced through functional connectivity alterations. Multiple-sclerosis-related disability and balance capacity also improved. Overall, this study provides novel evidence supporting SAHC as a promising therapeutic strategy in multiple sclerosis, based on mechanical loading, thereby setting the basis for future randomized controlled trials.

13.
IEEE Trans Neural Netw Learn Syst ; 31(1): 113-123, 2020 01.
Artículo en Inglés | MEDLINE | ID: mdl-30892246

RESUMEN

Understanding of the neuroscientific sleep mechanisms is associated with mental/cognitive and physical well-being and pathological conditions. A prerequisite for further analysis is the identification of the sleep macroarchitecture through manual sleep staging. Several computer-based approaches have been proposed to extract time and/or frequency-domain features with accuracy ranging from 80% to 95% compared with the golden standard of manual staging. However, their acceptability by the medical community is still suboptimal. Recently, utilizing deep learning methodologies increased the research interest in computer-assisted recognition of sleep stages. Aiming to enhance the arsenal of automatic sleep staging, we propose a novel classification framework based on convolutional neural networks. These receive as input synchronizations features derived from cortical interactions within various electroencephalographic rhythms (delta, theta, alpha, and beta) for specific cortical regions which are critical for the sleep deepening. These functional connectivity metrics are then processed as multidimensional images. We also propose to augment the small portion of sleep onset (N1 stage) through the Synthetic Minority Oversampling Technique in order to deal with the great difference in its duration when compared with the remaining sleep stages. Our results (99.85%) indicate the flexibility of deep learning techniques to learn sleep-related neurophysiological patterns.


Asunto(s)
Corteza Cerebral/diagnóstico por imagen , Corteza Cerebral/fisiología , Redes Neurales de la Computación , Fases del Sueño/fisiología , Adulto , Algoritmos , Automatización , Aprendizaje Profundo , Electroencefalografía/estadística & datos numéricos , Sincronización de Fase en Electroencefalografía , Humanos , Masculino , Persona de Mediana Edad , Reproducibilidad de los Resultados , Procesamiento de Señales Asistido por Computador , Análisis de Ondículas , Adulto Joven
14.
Neurol India ; 67(Supplement): S182-S187, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-31134908

RESUMEN

This review addresses central nervous system (CNS) physiological changes during inter-planetary missions, specifically sensorimotor processing and sleep disorders. Isolation, confinement and induced stress factors also have a detrimental effect on cognitive and mental well-being, which could jeopardize mission accomplishment. Although countermeasures have been proposed, they mostly focus on cardiovascular and/or musculoskeletal systems. Long-term space flights require optimal cognitive performance of crew members during weightlessness for longer time periods independent of ground support. The present study describes various countermeasures trends in neuroscientific data acquisition and future perspectives of advanced analysis through functional connectivity and graph theory. These could be used to identify early deterioration patterns and evaluate the robustness of countermeasures employed.


Asunto(s)
Encéfalo/fisiología , Neurología/tendencias , Vuelo Espacial/tendencias , Astronautas , Medio Ambiente Extraterrestre , Humanos , Desempeño Psicomotor , Simulación del Espacio
15.
Neurol India ; 67(Supplement): S221-S226, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-31134913

RESUMEN

Microgravity (MG) is one of the main problems that astronauts have to cope with during space missions. Long-duration space travel can have detrimental effects on human neurophysiology. Despite scientific efforts, these effects are still insufficiently investigated. Animal earth-based analogs are used to investigate potential nervous system associated perturbations that might occur during prolonged space missions. Hindlimb unloading, Tail suspension and Pelvic suspension models are currently used in MG studies. Loss of homeostasis of certain biological pathways in the nervous system can lead to the functioning and expression of receptors/genes, and the release and functioning of neurotransmitters and neuronal membrane ion channels into specific brain regions. The potential impact of MG on molecular mechanisms linked to neurophysiology through animal earth-based analogs is reviewed. The effect of molecular signalling pathways on the decline of neuronal connectivity and cognitive and neuroplasticity function under MG simulated conditions will be studied. The role of biomarkers including neurotransmitters, genes or receptors will be highlighted in the healthy and MG-affected brain. MG-mediated neurodegenerative mechanisms linked to learning and memory impairment will be highlighted. This review depicts the current rodent models applied to simulate MG ground based approaches and investigates the MG induced changes in the nervous system. The neuropathological profile of the above animal MG ground-based models can be comparable to the effects of ageing, anxiety and other neurological disorders. The advantages and limitations of the existing approaches are discussed. MG induced neurophysiology outcomes can be extrapolated to study other clinical applications.


Asunto(s)
Encéfalo/fisiología , Modelos Animales , Ingravidez/efectos adversos , Animales , Biomarcadores , Suspensión Trasera/métodos , Homeostasis , Humanos , Vuelo Espacial , Simulación del Espacio
16.
Annu Int Conf IEEE Eng Med Biol Soc ; 2019: 1395-1398, 2019 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-31946153

RESUMEN

In this paper we present the first steps in developing SmartHypnos, an easy to use and user friendly graphical user interface, which aims to provide polysomngographic data visualization and the detection and classification of sleep related events. Currently SmartHypnos supports the visualization of EEG, ECG, EOG and EMG signals, and respiratory signals such as nasal pressure, thermistor, oxygen saturation, thoracic and abdominal belt recordings. All these are incorporated into an interface that provides quick and effortless access to the signals mentioned above. The interface displays automatic sleep staging capabilities as well as the detection of apnea events with accuracy rates surpassing 80%. It is expected that SmartHypnos will reduce the time required to analyze sleep data and also reduce possible human errors.


Asunto(s)
Visualización de Datos , Humanos , Polisomnografía , Sueño , Síndromes de la Apnea del Sueño
17.
Annu Int Conf IEEE Eng Med Biol Soc ; 2019: 4046-4067, 2019 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-31946760

RESUMEN

In this paper we propose a novel methodology for investigating pathological sleep patterns through network neuroscience approaches. It consists of initial identification of statistically significant alterations in cortical functional connectivity patterns. The resulting sub-network is then analyzed by employing graph theory for estimating both global performance metrics (integration and specialization) as well as the significance of specific network nodes and their hierarchical organization. So, nodes with important role in network structure are recognized and their functionality is correlated with adenosine biomarker which is important in sleep regulation and promotion. The aforementioned pipeline is applied in a dataset of sleep data gathered during a microgravity simulation experiment. The analysis was performed on cortical resting-state networks involved in sleep physiology. It demonstrated the detrimental effects of microgravity which were more prominent for the group which did not perform reactive sledge jumps as a countermeasure.


Asunto(s)
Mapeo Encefálico , Encéfalo/fisiología , Ambientes Extremos , Sueño , Simulación de Ingravidez , Adenosina/análisis , Adulto , Biomarcadores/análisis , Humanos , Imagen por Resonancia Magnética , Masculino , Neurobiología , Adulto Joven
18.
Behav Neurol ; 2018: 4876287, 2018.
Artículo en Inglés | MEDLINE | ID: mdl-30151058

RESUMEN

Smoking and stress cooccur in different stages of a nicotine addiction cycle, affecting brain function and showing additive impact on different physiological responses. Resting-state functional connectivity has shown potential in identifying these alterations. Nicotine addiction has been associated with detrimental effects on functional integrity of the central nervous system, including the organization of resting-state networks. Prolonged stress may result in enhanced activation of the default mode network (DMN). Considering that biofeedback has shown promise in alleviating physiological manifestations of stress, we aimed to explore the possible neuroplastic effects of biofeedback training on smokers. Clinical, behavioral, and neurophysiological (resting-state EEG) data were collected from twenty-seven subjects before and after five sessions of skin temperature training. DMN functional cortical connectivity was investigated. While clinical status remained unaltered, the degree of nicotine dependence and psychiatric symptoms were significantly improved. Significant changes in DMN organization and network properties were not observed, except for a significant increase of information flow from the right ventrolateral prefrontal cortex and right temporal pole cortex towards other DMN components. Biofeedback aiming at stress alleviation in smokers could play a protective role against maladaptive plasticity of connectivity. Multiple sessions, individualized interventions and more suitable methods to promote brain plasticity, such as neurofeedback training, should be considered.


Asunto(s)
Biorretroalimentación Psicológica/fisiología , Plasticidad Neuronal/fisiología , Cese del Hábito de Fumar/psicología , Adulto , Anciano , Biorretroalimentación Psicológica/métodos , Encéfalo/fisiopatología , Mapeo Encefálico/métodos , Femenino , Humanos , Masculino , Persona de Mediana Edad , Red Nerviosa/fisiopatología , Vías Nerviosas/fisiopatología , Corteza Prefrontal/fisiopatología , Fumadores , Fumar/psicología , Estrés Fisiológico/fisiología , Tabaquismo/fisiopatología
19.
Front Hum Neurosci ; 12: 110, 2018.
Artículo en Inglés | MEDLINE | ID: mdl-29628883

RESUMEN

Sleep staging, the process of assigning labels to epochs of sleep, depending on the stage of sleep they belong, is an arduous, time consuming and error prone process as the initial recordings are quite often polluted by noise from different sources. To properly analyze such data and extract clinical knowledge, noise components must be removed or alleviated. In this paper a pre-processing and subsequent sleep staging pipeline for the sleep analysis of electroencephalographic signals is described. Two novel methods of functional connectivity estimation (Synchronization Likelihood/SL and Relative Wavelet Entropy/RWE) are comparatively investigated for automatic sleep staging through manually pre-processed electroencephalographic recordings. A multi-step process that renders signals suitable for further analysis is initially described. Then, two methods that rely on extracting synchronization features from electroencephalographic recordings to achieve computerized sleep staging are proposed, based on bivariate features which provide a functional overview of the brain network, contrary to most proposed methods that rely on extracting univariate time and frequency features. Annotation of sleep epochs is achieved through the presented feature extraction methods by training classifiers, which are in turn able to accurately classify new epochs. Analysis of data from sleep experiments on a randomized, controlled bed-rest study, which was organized by the European Space Agency and was conducted in the "ENVIHAB" facility of the Institute of Aerospace Medicine at the German Aerospace Center (DLR) in Cologne, Germany attains high accuracy rates, over 90% based on ground truth that resulted from manual sleep staging by two experienced sleep experts. Therefore, it can be concluded that the above feature extraction methods are suitable for semi-automatic sleep staging.

20.
Stud Health Technol Inform ; 150: 485-9, 2009.
Artículo en Inglés | MEDLINE | ID: mdl-19745359

RESUMEN

Driver sleepiness due to sleep deprivation is a causative factor of many road accidents. Reducing the extent of the sleepy driving problem by developing a countermeasure device that will monitor the sleepiness level of the driver is crucial to improve the safety of the roads. Among numerous physiological measurements, the electroencephalographic (EEG) signal seems to be the most sensitive to detect sleepiness. Previous studies in the field have found consistent alterations of EEG signal during sleepy driving, though they face methodological limitations. We present here preliminary results from a real-driving experiment in which a more complete experimental setup was followed. The subjects were exposed to driving conditions twice: once after they had a normal sleep during the previous night, and once after they remained awake for at least 24 hours prior to the experiment. Significant alterations were observed in the alpha and beta EEG frequencies bands between the two sessions. Electroopthalmographic (EOG) measurements revealed an increased number of eye blinking during the sleep-deprived session in comparison to the control condition. Both measurements can be used for the successful design of a sleepiness detection countermeasure device.


Asunto(s)
Accidentes de Tránsito/prevención & control , Conducción de Automóvil , Monitoreo Ambulatorio/métodos , Fases del Sueño , Adulto , Humanos , Masculino
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