Search Results (1,166)

Periodic limb movements in sleep (PLMS) are a prevalent disorder characterized by rhythmic, involuntary movements of the lower limbs, such as dorsiflexion of the ankle and extension of the big toe, occurring in periodic intervals during sleep. These movements are often linked to disrupted autonomic nervous system (ANS) activity and altered interoception. Interoception involves perceiving internal bodily states, like heartbeat, breathing, hunger, and temperature, and plays a crucial role in maintaining homeostasis and the mind–body connection. This review explores the complex relationships between PLMS, heart rate variability (HRV), ANS dysregulation, and their impact on psychiatric disorders. By synthesizing the existing literature, it provides insights into how ANS dysregulation and altered interoceptive processes, alongside PLMS, contribute to psychiatric conditions. The review highlights the potential for integrated diagnostic and therapeutic approaches and presents a cause-and-effect model illustrating the mutual influence of psychiatric disorders, ANS dysregulation, PLMS, and interoception. Full article

(1) Background: Our previous studies indicated that low-intensity extremely low-frequency electric field (ELF-EF) treatment alters autonomic activities, as revealed through heart rate variability (HRV) analysis. However, the high-frequency (HF) component of HRV that reflects parasympathetic activity showed no changes either during or after the end of the treatment, suggesting the involvement of sympathetic nerves. (2) Methods: To examine this issue in the present study, the effect of ELF-EF on skin conductance (SC), which is controlled solely by sympathetic nerves, was analyzed. Twelve healthy subjects underwent a 20 min ELF-EF treatment (applied voltage: 9 kV, induced current density: below 6 mA/m²) and a sham treatment in a random order with an interval of more than 2 weeks. SC and HRV were recorded under the eyes-open condition during a 2 min period both before and after the treatment. (3) Results: The number of spontaneous fluctuations in skin conductance (SC-SFs) significantly decreased after the ELF-EF treatment, suggesting psychological changes, including relaxation. The skin conductance level, heart rate, and HRV indices did not change after the ELF-EF treatment. (4) Conclusion: The results support the idea that low-intensity ELF-EF affects autonomic nerves by reducing sympathetic activity, as reflected by SC-SFs. Full article

Introduction: Severe acute respiratory infection (SARI) is mainly caused by viral pathogens, with a high prevalence in high-risk populations such as infants and older adults. Coinfections by different viruses are frequent and, in some cases, associated with severe disease outcomes. Purpose: The main purpose of this study was to identify respiratory viruses circulating in Barranquilla during the peaks of the COVID-19 pandemic and estimate the prevalence of viral coinfections in samples from individuals with different degrees of respiratory infection. Methods: We received 5083 samples between epidemiological weeks 33–42 of 2021 submitted by the District Health Laboratory of Barranquilla and four local healthcare institutions during COVID-19 surveillance. Among them, we analyzed 101 samples from individuals presenting with influenza-like illness (ILI). Eighteen respiratory viruses, including SARS-CoV-2, were evaluated via qRT-PCR using nasal swabs or nasopharyngeal aspirate samples. Results: Of the 101 study individuals, 56 were male and 45 were female (55.5% and 44.5%, respectively); 25.7% of individuals were infected with at least one of the evaluated viruses. Respiratory syncytial virus (RSV) and human rhinovirus (HRV) were the two most frequently detected viruses (30.7% and 15.4% of total positives, respectively). Coinfections with two or more respiratory viruses accounted for 42% of the total positive cases. Discussion: Our findings indicate the presence of different respiratory viruses in swab or nasopharyngeal aspirate samples from individuals with ILI, including coinfections. These results reveal the circulation of several respiratory viruses in the city of Barranquilla, confirming their importance as potential causes of SARI in Colombia and the need for their active surveillance. Full article

This exploratory study investigates changes in the autonomic cardiac system of young analog astronauts in a hostile, confined, and isolated environment. It uses linear and nonlinear indices of heart rate variability (HRV) during a Mars analog mission to assess how HRV varies under day and night stressors. This study is guided by the hypothesis that significant HRV changes occur based on adaptation days, aiming to offer insights into autonomic nervous system (ANS) adaptation to environmental stressors. Over five days in August 2022, five analog astronauts faced adverse conditions in the Mojave Desert, simulating Martian conditions. Electrocardiograms were recorded daily for five minutes during morning and evening sessions to extract short-term RR time series. HRV parameters were analyzed using both time- and frequency-domain indices and nonlinear measures. Significant differences in HRV parameters across days highlight the mission environment’s impact on autonomic cardiac function. Morning measurements showed significant changes in average RR intervals and heart rate, indicating ANS adaptation. Nonlinear indices such as detrended fluctuation analysis and approximate entropy also showed significant differences, reflecting shifts in autonomic function. The Borg scale indicated reduced perceived exertion over time, aligning with HRV changes. Increased vagal activity during Mars analog adaptation under confinement/isolation may be crucial for cardiovascular adaptation and survival in future space flights. Full article

This study evaluated the influence of acute fatigue on heart rate variability (HRV) and muscle oxygen saturation (SmO₂) at rest, as well as the reliability of SmO₂ data measured using near-infrared spectroscopy (NIRS) during a vascular occlusion test (VOT). Twelve physically active subjects participated. Measurements included perceived muscle soreness using the visual analog scale (VAS pain), HRV parameters, variables of resting SmO₂ (desaturation and resaturation), and reoxygenation kinetics (mean response time, MRT) through a VOT-NIRS located in the vastus lateralis (VL). Measurements were taken at three points: 24 h before, before exhaustive exercise, and 30 min after exhaustive exercise. The results indicated that acute fatigue increased resting muscle oxygen consumption in desaturation (+22 SmO₂) and resaturation (+18 SmO₂), improved MRT (−15 s), and elevated sympathetic nervous system (SNS) activity, as observed in the R-R interval (−262 ms) and SNS index (+0.5). HRV significantly influenced desaturation (r² = 0.69), resaturation (r² = 0.60), and MRT (r² = 0.54). Reliability was established with an ICC of 0.49 and 0.63 for desaturation and resaturation, respectively. Real changes in desaturation and resaturation should be considered ≥ 7% SmO₂ at rest and ≥ 11% SmO₂ to avoid daily fatigue interference. In conclusion, acute fatigue increases resting SmO₂ consumption and is associated with higher SNS activity and increased VAS pain. Full article

This study investigated the long-term cardiovascular effects of coronavirus disease (COVID-19) in elite male athletes by comparing the heart rate variability (HRV), arterial stiffness, and other cardiovascular parameters between those with and without prior COVID-19 infection. Methods: This cross-sectional study evaluated 120 elite male athletes (60 post COVID-19, 60 controls) using anthropometric measurements, body composition analysis, pulmonary function tests, HRV analysis, arterial stiffness assessments, hemodynamic monitoring, and microcirculatory function tests. Results: Athletes post COVID-19 showed significantly higher lean mass (p = 0.007), forced vital capacity (p = 0.001), and forced expiratory volume in 1 s (p = 0.007) than controls. HRV parameters did not significantly differ between the groups. Post-COVID-19 athletes exhibited peripheral vascular resistance (p = 0.048) and reflection index (p = 0.038). No significant differences were observed in the blood pressure, cardiac output, oxygen saturation, or microcirculatory oxygen absorption. Conclusions: Elite male athletes showed notable cardiovascular resilience after COVID-19, with only minor differences in vascular function. The maintained cardiac autonomic function and improved lung parameters in post-COVID-19 athletes suggests an adaptive response. These findings support the cardiovascular health of elite athletes following COVID-19 but emphasize the importance of continued monitoring. Full article

Detecting stress is important for improving human health and potential, because moderate levels of stress may motivate people towards better performance at cognitive tasks, while chronic stress exposure causes impaired performance and health risks. We propose a Brain–Computer Interface (BCI) system to detect stress in the context of high-pressure work environments. The BCI system includes an electroencephalogram (EEG) headband with dry electrodes and an electrocardiogram (ECG) chest belt. We collected EEG and ECG data from 40 participants during two stressful cognitive tasks: the Cognitive Vigilance Task (CVT), and the Multi-Modal Integration Task (MMIT) we designed. We also recorded self-reported stress levels using the Dundee Stress State Questionnaire (DSSQ). The DSSQ results indicated that performing the MMIT led to significant increases in stress, while performing the CVT did not. Subsequently, we trained two different models to classify stress from non-stress states, one using EEG features, and the other using heart rate variability (HRV) features extracted from the ECG. Our EEG-based model achieved an overall accuracy of 81.0% for MMIT and 77.2% for CVT. However, our HRV-based model only achieved 62.1% accuracy for CVT and 56.0% for MMIT. We conclude that EEG is an effective predictor of stress in the context of stressful cognitive tasks. Our proposed BCI system shows promise in evaluating mental stress in high-pressure work environments, particularly when utilizing an EEG-based BCI. Full article

Background: Many COVID-19 survivors still experience long-term effects of an acute infection, most often characterised by neurological, cognitive and psychiatric sequelae. The treatment of this condition is challenging, and many hypotheses have been proposed. Non-invasive vagus nerve stimulation using slow-paced breathing (SPB) could stimulate both central nervous system areas and parasympathetic autonomic pathways, leading to neuromodulation and a reduction in inflammation. The aim of the present study was to evaluate physical, cognitive, emotional symptoms, executive functions and autonomic cardiac modulation after one month of at-home slow breathing intervention. Methods: 6655 healthcare workers (HCWs) were contacted via a company email in November 2022, of which N = 58 HCWs were enrolled as long COVID (cases) and N = 53 HCWs as controls. A baseline comparison of the two groups was performed. Subsequently each case was instructed on how to perform a resonant SPB using visual heart rate variability (HRV) biofeedback. They were then given a mobile video tutorial breathing protocol and asked to perform it three times a day (morning, early afternoon and before sleep). N = 33 cases completed the FU. At T0 and T1, each subject underwent COVID-related, psychosomatic and dysfunctional breathing questionnaires coupled with heart rate variability and manual dexterity assessments. Results: After one month of home intervention, an overall improvement in long-COVID symptoms was observed: confusion/cognitive impairment, chest pain, asthenia, headache and dizziness decreased significantly, while only a small increase in manual dexterity was found, and no relevant changes in cardiac parasympathetic modulation were observed. Full article

Background: Prolonged sitting is a risk factor for cardiovascular disease (CVD). We examined whether moderate aerobic exercise prior to prolonged sitting (EX + SIT) has protective effects on peripheral and central cardiovascular and autonomic measures. Methods: Young women (n = 26; 23.4 ± 4.3 years old; BMI = 23.1 ± 4.3) completed two sessions in random order: (1) EX + SIT, which consisted of 25 min of moderate aerobic exercise followed by a 3 h prolonged sitting bout, and (2) a 3 h prolonged sitting bout only (SIT-only). Seated peripheral and central blood pressure (BP), pulse wave velocity (PWV), and heart rate variability (HRV) were measured at baseline and after 1 h, 2 h, and 3 h of sitting. Generalized linear mixed models with random effects examined the effects of conditions (i.e., EX + SIT vs. SIT) on BP, PWV, and HRV while adjusting for baseline values. Results: Only peripheral and central diastolic BP (β = 2.18; p = 0.016 and β = 1.99; p = 0.034, respectively) were significantly lower in the EX + SIT condition compared to the SIT-only condition. No differences were detected in other BP, PWV, or HRV variables between the two conditions (p > 0.05 for all). Conclusions: Performing moderate aerobic exercise in the morning before engaging in prolonged sitting bouts may reduce some of the prolonged-sitting-induced cardiovascular impairments in young women. Further research is needed to confirm these findings in males and middle-aged/older adults. Full article

Background: Heart rate variability (HRV) is the change in time intervals between heart beats, reflecting the autonomic nervous system’s ability to adapt to psychological and physiological demands. Slow breathing enhances parasympathetic activity, increasing HRV. Pranayama, a yoga breathing technique, affords the conscious regulation of respiration frequency. This study aimed to characterize HRV, blood pressure and peripheral oxygen saturation of basic yoga breathing slow techniques with regular yoga practitioners. Methods: In total, 45 yoga practitioners were included in the study (including 7 males, mean age of 54.04 ± 11.97 years) with varying levels of yoga experience (minimum 3 months, maximum 37 years). Participants performed three breathing conditions: baseline (control) and two yoga techniques (abdominal (adham) and complete (mahat)) breathing, each for 10 min in the supine position (i.e., savasana). For each condition, respiratory frequency, heart rate (HR), blood pressure and peripheral oxygen levels were collected. Results: The findings revealed that both abdominal and complete yoga breathing techniques promoted a decrease in respiratory frequency (p < 0.001, r = 0.61; p < 0.001, r = 0.61, respectively), and an increase in peripheral oxygen saturation (p < 0.001, r = 0.50; p < 0.001, r = 0.46, respectively), along with blood pressure decreases in all mean values, and a significant decrease in systolic pressure, considering all conditions (p = 0.034, W = 0.08). There were significant increases in standard deviation of HR during abdominal and complete yoga breathing techniques compared with the baseline (p = 0.003, r = 0.31; p < 0.001, r = 0.47, respectively), indicating enhanced parasympathetic activity. Moreover, the complete breathing technique exhibited the greatest variability in HRV measures, with several significant differences compared with abdominal breathing (standard deviation of HR, p < 0.001, r = 0.42; SD2, standard deviation of points perpendicular to the Poincaré parallel line, p < 0.003, r = 0.31; SD1/SD2, p < 0.003, r = 0.31), suggesting a more profound impact on autonomic modulation. Conclusions: simple, inexpensive and non-intrusive abdominal and complete yoga breathing techniques can effectively and momentarily enhance HRV and oxygen saturation in adults, mature adults and the elderly. Full article

Background/Objectives: Psychological distress is a significant concern among cancer patients, negatively affecting their quality of life and adherence to treatment. The Cancer Patient Empowerment Program (CancerPEP) was developed as a comprehensive, home-based intervention aimed at reducing psychological distress by incorporating physical activity, dietary guidance, and social support. This study aimed to evaluate the feasibility, accrual and attrition rates, safety, and effectiveness of the CancerPEP intervention, with and without the biofeedback device, on psychological distress from baseline to 6 months, specifically focusing on the effects of group randomization and the difference between pre- and post-intervention results. Methods: This single-site, crossover randomized clinical trial included 104 cancer patients who were randomized to receive the CancerPEP intervention, with or without a Heart Rate Variability (HRV) biofeedback monitor. At 6 months, participants who did not receive the device were allowed to use one until the end of the year, while those who did receive the device were followed up to 12 months. Randomization was stratified by the presence or absence of clinically significant psychological distress and metastatic status. Psychological distress was assessed using the Kessler Psychological Distress Scale (K10) at baseline, 6 months, and 12 months. The primary endpoint was the presence of nonspecific psychological distress, as measured by the K10 scale at 6 months from the trial start, based on group randomization. A secondary exploratory analysis assessed psychological distress at baseline, 6 months, and 12 months for both groups, while controlling for group randomization and prognostic covariates. Prognostic covariates included age; comorbidities; time between diagnosis and randomization; treatment modality; relationship status; and use of prescribed medications for anxiety, depression, or both. An exploratory sub-analysis was conducted for the breast cancer subgroup, based on the sample size available after recruitment. The trial is registered at ClinicalTrials.gov (NCT05508412). Results: The provision of the HRV biofeedback monitor in conjunction with the CancerPEP intervention did not significantly affect the primary outcome in either the full sample or the breast cancer subgroup, indicating that the HRV biofeedback provision was not beneficial in this trial. No self-reported or otherwise discovered adverse events at the 6-month mark were observed. About 10% of participants were lost to follow-up in both the early and late HRV monitor provision groups. Participation in the CancerPEP program led to a significant reduction in psychological distress over time. The odds of psychological distress were significantly higher at the start of the trial than at the end of the intervention (aOR = 2.64, 95% CI: 1.53–4.56) or 6 months after the intervention (aOR = 2.94, 95% CI: 1.62–5.30). Similarly, in the breast cancer subgroup, distress was higher at the trial’s start than at 6 months, i.e., after the intervention (aOR = 2.25, 95% CI: 1.24–4.08), or at the end of the trial at 12 months (aOR = 2.73, 95% CI: 1.35–5.52). Conclusions: CancerPEP significantly reduces psychological distress in cancer patients, with consistent improvements noted across various cancer types and stages, including benefits specifically for breast cancer patients. These findings build upon the success of the Prostate Cancer Patient Empowerment Program (PC-PEP), indicating that a similar comprehensive intervention can be advantageous for all cancer patients and may be further tailored to address specific needs. With its holistic approach—encompassing physical, dietary, and psychosocial support—CancerPEP shows promise as a vital component of survivorship care. Ongoing 24-month evaluations will yield critical data on its long-term benefits. Additionally, a randomized trial with a control group (usual care without intervention) for breast cancer patients is currently under way and could potentially guide the integration of CancerPEP into standard oncology care to enhance patient outcomes and quality of life. Full article

Myxomatous mitral valve disease (MMVD) is the most prevalent cardiac disease in dogs. This study aimed to compare the arrhythmogenic profile and heart rate variability (HRV) of dogs with MMVD in stages B1 and B2. Electrocardiographic exams and the medical records of 60 dogs were analyzed, and HRV, P wave dispersion, QT interval dispersion, and QT interval instability parameters were determined. The results showed significantly increased values in stage B2 compared with stage B1 (p < 0.05) regarding P wave maximum and minimum duration (Pmax and Pmin) and short-term instability (STI). In contrast, no statistically significant differences were observed regarding HRV parameters, P wave dispersion, or QT interval dispersion. Our findings showed that cardiac remodeling in stage B2 could not significantly alter the sympathovagal balance and showed little interference with the predisposition of arrhythmias in dogs with MMVD. Full article

Cerebral palsy (CP) is a group of movement disorders that impair posture and mobility, often leading to spasticity and joint contractures. Interventions like serial casting are commonly used to improve joint mobility and manage spasticity in children with CP. However, its effects on the autonomic nervous system (ANS) remain unclear. This study aimed to evaluate the effects of serial casting and ankle–foot orthoses (AFOs) on ANS responses during a virtual reality (VR) standing task, comparing these interventions with a barefoot condition. Thirty children with CP were randomized into three groups (n = 10 per group): serial casting, AFOs, and barefoot. Heart rate variability (HRV) was used to assess ANS responses across three phases: seated rest, VR task, and recovery. The results showed that the serial casting group exhibited higher sympathetic activity during rest compared to the other groups, but had a reduced sympathetic response during the VR task. Additionally, the serial casting group displayed a more pronounced parasympathetic rebound during recovery, similar to the orthoses and barefoot groups. While serial casting provides essential joint stability, it alters ANS response patterns, leading to heightened sympathetic activation at rest, without providing significant improvements in ANS behavior during physical activity. Full article

Some respiratory viruses, such as Human Rhinovirus, SARS-CoV-2, and Enterovirus D-68 (EV-D68), share the feature of hijacking host lipids in order to generate specialised replication organelles (ROs) with unique lipid compositions to enable viral replication. We have recently uncovered a novel non-canonical function of the stimulator of interferon genes (STING) pathway, as a critical factor in the formation of ROs in response to HRV infection. The STING pathway is the main DNA virus sensing system of the innate immune system controlling the type I IFN machinery. Although it is well-characterised as part of the DNA sensor machinery, the STING function in RNA viral infections is largely unexplored. In the current study, we investigated whether other RO-forming RNA viruses, such as EV-D68 and SARS-CoV-2, can also utilise STING for their replication. Using genetic and pharmacological inhibition, we demonstrate that STING is hijacked by these viruses and is utilised as part of the viral replication machinery. STING also co-localises with glycolytic enzymes needed to fuel the energy for replication. The inhibition of STING leads to the modulation of glucose metabolism in EV-D68-infected cells, suggesting that it might also manipulate immunometabolism. Therefore, for RO-generating RNA viruses, STING seems to have non-canonical functions in membrane lipid re-modelling, and the formation of replication vesicles, as well as immunometabolism. Full article

This paper introduces a novel method for emotion classification within virtual reality (VR) environments, which integrates biosignal processing with advanced machine learning techniques. It focuses on the processing and analysis of electrocardiography (ECG) and galvanic skin response (GSR) signals, which are established indicators of emotional states. To develop a predictive model for emotion classification, we extracted key features, i.e., heart rate variability (HRV), morphological characteristics, and Hjorth parameters. We refined the dataset using a feature selection process based on statistical techniques to optimize it for machine learning applications. The model achieved an accuracy of 97.78% in classifying emotional states, demonstrating that by accurately identifying and responding to user emotions in real time, VR systems can become more immersive, personalized, and emotionally resonant. Ultimately, the potential applications of this method are extensive, spanning various fields. Emotion recognition in education would allow further implementation of adapted learning environments through responding to the current emotional states of students, thereby fostering improved engagement and learning outcomes. The capability for emotion recognition could be used by virtual systems in psychotherapy to provide more personalized and effective therapy through dynamic adjustments of the therapeutic content. Similarly, in the entertainment domain, this approach could be extended to provide the user with a choice regarding emotional preferences for experiences. These applications highlight the revolutionary potential of emotion recognition technology in improving the human-centric nature of digital experiences. Full article