A Pilot Randomized Trial of Combined Cognitive-Behavioral Therapy and Exercise Training Versus Exercise Training Alone for the Management of Chronic Insomnia in Obstructive Sleep Apnea.

Insomnia treatment among individuals with comorbid insomnia and obstructive sleep apnea is suboptimal. In a pilot randomized controlled trial, 19 individuals with comorbid insomnia and obstructive sleep apnea were allocated to one of two arms: EX + EX, consisting of two 8-week phases of exercise training (EX), or RE + CBTiEX, encompassing 8 weeks of relaxation training (RE) followed by 8 weeks of combined cognitive-behavioral therapy and exercise (CBTiEX). Outcomes included Insomnia Severity Index (ISI), polysomnography, and cardiorespiratory fitness measures. A mixed-model analysis of variance revealed a Group × Time interaction on peak oxygen consumption change, F(1, 14) = 10.1, p = .007, and EX increased peak oxygen consumption (p = .03, g' = -0.41) and reduced ISI (p = .001, g' = 0.82) compared with RE (p = .49, g = 0.16) post-8 weeks. Post-16 weeks, there was a significant Group × Time interaction (p = .014) driven by RE + CBTiEX yielding a larger improvement in ISI (p = .023, g' = 1.48) than EX + EX (p = .88, g' < 0.1). Objective sleep was unchanged. This study showed promising effects of regular EX alone and combined with cognitive-behavioral therapy for insomnia on ISI in comorbid insomnia and obstructive sleep apnea.

Impaired post-sleep apnea autonomic arousals in patients with drug-resistant epilepsy.

OBJECTIVE: Sudden and unexpected deaths in epilepsy (SUDEP) pathophysiology may involve an interaction between respiratory dysfunction and sleep/wake state regulation. We investigated whether patients with epilepsy exhibit impaired sleep apnea-related arousals. METHODS: Patients with drug-resistant (N = 20) or drug-sensitive (N = 20) epilepsy and obstructive sleep apnea, as well as patients with sleep apnea but without epilepsy (controls, N = 20) were included. We explored (1) the respiratory arousal threshold based on nadir oxygen saturation, apnea-hypopnea index, and fraction of hypopnea among respiratory events; (2) the cardiac autonomic response to apnea/hypopnea quantified as percentages of changes from the baseline in RR intervals (RRI), high (HF) and low (LF) frequency powers, and LF/HF. RESULTS: The respiratory arousal threshold did not differ between groups. At arousal onset, RRI decreased (-9.42%) and LF power (179%) and LF/HF ratio (190%) increased. This was followed by an increase in HF power (118%), p < 0.05. The RRI decrease was lower in drug-resistant (-7.40%) than in drug-sensitive patients (-9.94%) and controls (-10.91%), p < 0.05. LF and HF power increases were higher in drug-resistant (188%/126%) than in drug-sensitive patients (172%/126%) and controls (177%/115%), p < 0.05. CONCLUSIONS: Cardiac reactivity following sleep apnea is impaired in drug-resistant epilepsy. SIGNIFICANCE: This autonomic dysfunction might contribute to SUDEP pathophysiology.

The effects of acute exercise and a nap on heart rate variability and memory in young sedentary adults.

Recent evidence suggests that the autonomic nervous system can contribute to memory consolidation during sleep. Whether fluctuations in cardiac autonomic activity during sleep following physical exercise contribute to the process of memory consolidation has not been studied. We assessed the effects of a non-rapid eye movement (NREM) nap following acute exercise on cardiac autonomic regulation assessed with heart rate variability (HRV) to examine if HRV influences memory processes. Fifty-six (59% female) healthy young adults (23.14 ± 3.74 years) were randomly allocated to either the exercise plus nap (ExNap, n = 27) or nap alone (NoExNap, n = 29) groups. The ExNap group performed a 40-minute moderate-intensity cycling, while the NoExNap group was sedentary prior to learning 45 neutral pictures for a later test. Subsequently, participants underwent a 60-minute NREM nap while measuring EKG, followed by a visual recognition test. Our results indicated that heart rate did not significantly differ between the groups (p = .243), whereas vagally mediated HRV indices were lower in the ExNap group compared to the NoExNap group (p < .05). There were no significant differences in sleep variables between the groups (p > .05). Recognition accuracy was significantly higher in the ExNap group than in the NoExNap group (p = .027). In addition, the recognition accuracy of the ExNap group was negatively associated with vagally mediated HRV (p < .05). Pre-nap acute exercise appears to attenuate parasympathetic activity and to alter the relationship between memory and cardiac autonomic activity.

Central control of cardiac activity as assessed by intra-cerebral recordings and stimulations.

Some of the most important integrative control centers for the autonomic nervous system are located in the brainstem and the hypothalamus. However, growing recent neuroimaging evidence support that a set of cortical regions, named the central autonomic network (CAN), is involved in autonomic control and seems to play a major role in continuous autonomic cardiac adjustments to high-level emotional, cognitive or sensorimotor cortical activities. Intracranial explorations during stereo-electroencephalography (SEEG) offer a unique opportunity to address the question of the brain regions involved in heart-brain interaction, by studying: (i) direct cardiac effects produced by the electrical stimulation of specific brain areas; (ii) epileptic seizures inducing cardiac modifications; (iii) cortical regions involved in cardiac interoception and source of cardiac evoked potentials. In this review, we detail the available data assessing cardiac central autonomic regulation using SEEG, address the strengths and also the limitations of this technique in this context, and discuss perspectives. The main cortical regions that emerge from SEEG studies as being involved in cardiac autonomic control are the insula and regions belonging to the limbic system: the amygdala, the hippocampus, and the anterior and mid-cingulate. Although many questions remain, SEEG studies have already demonstrated afferent and efferent interactions between the CAN and the heart. Future studies in SEEG should integrate these afferent and efferent dimensions as well as their interaction with other cortical networks to better understand the functional heart-brain interaction.

CVRanalysis: a free software for analyzing cardiac, vascular and respiratory interactions.

Introduction: Simultaneous beat-to-beat R-R intervals, blood pressure and respiration signals are routinely analyzed for the evaluation of autonomic cardiovascular and cardiorespiratory regulations for research or clinical purposes. The more recognized analyses are i) heart rate variability and cardiac coherence, which provides an evaluation of autonomic nervous system activity and more particularly parasympathetic and sympathetic autonomic arms; ii) blood pressure variability which is mainly linked to sympathetic modulation and myogenic vascular function; iii) baroreflex sensitivity; iv) time-frequency analyses to identify fast modifications of autonomic activity; and more recently, v) time and frequency domain Granger causality analyses were introduced for assessing bidirectional causal links between each considered signal, thus allowing the scrutiny of many physiological regulatory mechanisms. Methods: These analyses are commonly applied in various populations and conditions, including mortality and morbidity predictions, cardiac and respiratory rehabilitation, training and overtraining, diabetes, autonomic status of newborns, anesthesia, or neurophysiological studies. Results: We developed CVRanalysis, a free software to analyze cardiac, vascular and respiratory interactions, with a friendly graphical interface designed to meet laboratory requirements. The main strength of CVRanalysis resides in its wide scope of applications: recordings can arise from beat-to-beat preprocessed data (R-R, systolic, diastolic and mean blood pressure, respiration) or raw data (ECG, continuous blood pressure and respiratory waveforms). It has several tools for beat detection and correction, as well as setting of specific areas or events. In addition to the wide possibility of analyses cited above, the interface is also designed for easy study of large cohorts, including batch mode signal processing to avoid running repetitive operations. Results are displayed as figures or saved in text files that are easily employable in statistical softwares. Conclusion: CVRanalysis is freely available at this website: anslabtools.univ-st-etienne.fr. It has been developed using MATLAB® and works on Windows 64-bit operating systems. The software is a standalone application avoiding to have programming skills and to install MATLAB. The aims of this paper area are to describe the physiological, research and clinical contexts of CVRanalysis, to introduce the methodological approach of the different techniques used, and to show an overview of the software with the aid of screenshots.

The Efficient Antiviral Response of A549 Cells Is Enhanced When Mitochondrial Respiration Is Promoted.

When exposed to a viral infection, the attacked cells promptly set up defense mechanisms. As part of the antiviral responses, the innate immune interferon pathway and associated interferon-stimulated genes notably allow the production of proteins bearing antiviral activity. Numerous viruses are able to evade the interferon response, highlighting the importance of controlling this pathway to ensure their efficient replication. Several viruses are also known to manipulate the metabolism of infected cells to optimize the availability of amino acids, nucleotides, and lipids. They then benefit from a reprogramming of the metabolism that favors glycolysis instead of mitochondrial respiration. Given the increasingly discussed crosstalk between metabolism and innate immunity, we wondered whether this switch from glycolysis to mitochondrial respiration would be beneficial or deleterious for an efficient antiviral response. We used a cell-based model of metabolic reprogramming. Interestingly, we showed that increased mitochondrial respiration was associated with an enhanced interferon response following polyriboinosinic:polyribocytidylic acid (poly:IC) stimulation. This suggests that during viral infection, the metabolic reprogramming towards glycolysis is also part of the virus' strategies to inhibit the antiviral response.

Effect of Cognitive-Behavioral Therapy on Nocturnal Autonomic Activity in Patients with Fibromyalgia: A Preliminary Study.

Objective: fibromyalgia is a complex chronic pain syndrome characterized by widespread musculoskeletal pain, insomnia and autonomic alterations. Cognitive-behavioral therapy (CBT) is regarded as a promising treatment in fibromyalgia, but its impact on autonomic function remains uncertain. In this research, we studied the effect of CBT on autonomic functions in fibromyalgia. Methods: Twenty-five participants underwent overnight polysomnographic recordings before and after CBT programs focused on pain (CBT-P) or a hybrid modality focused on pain and insomnia (CBT-C). Sleep quality, daily pain, depression and anxiety were assessed by self-reported questionnaires. We analyzed heart rate variability (HRV) using high-frequency power (HF) as a marker for parasympathetic activity, and low-frequency power (LF) and the LF/HF ratio as relative sympathetic markers during wakefulness and at each sleep stage. Results: After treatment, 14 patients (/25, 58.0%) reported improvement in their sleep: 6 in the CBT-P condition (/12, 50%), and 8 in the CBT-C condition (/13, 61.5%). We found that, regardless of the type of CBT, patients who reported improvement in sleep quality (n = 14, 58%) had an increase in HF during stages N2 (p < 0.05) and N3 (p < 0.05). These changes were related to improvement in sleep quality (N2, r = −0.43, p = 0.033) but not to pain, depression or anxiety. Conclusions: This study showed an improvement in parasympathetic cardiac control during non-rapid-eye-movement sleep following CBT in fibromyalgia participants who reported better sleep after this therapy. CBT may have a cardio-protective effect and HRV could be used as a sleep monitoring tool in fibromyalgia.

Insomnia Symptoms, Sleep Hygiene, Mental Health, and Academic Performance in Spanish University Students: A Cross-Sectional Study.

BACKGROUND: Insomnia has been associated with decreased academic performance and unhealthy behaviors in university students. Although many studies have analyzed sleep phenomenology among this population, only few have focused on insomnia and its related variables. In addition, such studies do not always include a clinical interview or a specific and validated instrument for measuring insomnia. This study aimed to explore the prevalence of insomnia symptoms and the relationship between insomnia and health habits, mental health, and academic performance in a large university student sample. METHODS: Five hundred and eighty-two students were recruited from the University of Granada, Spain. Data were collected through an online survey with questions on sociodemographic and academic data and health habits as well as the Pittsburgh Sleep Quality Index, Insomnia Severity Index, Sleep Hygiene Index, and Sleepiness, Depression, Anxiety, and Stress Scales. A multiple regression analysis explored the relationship between academic performance, health habits, mood state, and insomnia symptoms. RESULTS: The prevalence of students with symptoms of insomnia was high (39.7%). A multiple logistic regression analysis revealed that depression, sleep hygiene, stress and anxiety were significant predictors of insomnia symptoms. Multivariate analyses revealed that subjective insomnia symptoms, sleep efficiency, and depression were significantly correlated with academic performance in a dependent way. CONCLUSIONS: In university students, anxiety, stress, and poor sleep hygiene are risk factors for insomnia, which plays an important role in academic performance. Promoting sleep and mental health could be a potentially effective way to improve their academic performance.

Elevated Heart Rate and Pain During a Cold Pressor Test Correlates to Pain Catastrophizing.

To understand the variable response to pain, researchers have examined the change in cardiovascular measures to a uniform painful stimulation. Pain catastrophizing is the tendency to magnify or exaggerate pain sensations, and it affects the outcome of rehabilitation in a clinical setting. Its effect on cardiovascular changes during a painful stimulus is unclear. Twenty-four healthy human participants completed the study. All participants completed a cold pressor test while subjective pain intensity was measured with a numeric pain scale from 0-10. Continuous cardiac output measurements were obtained with finger-pulse plethysmograph waveform analysis. The measurements included systolic and diastolic blood pressure, heart rate averaged over 30 s intervals. Pain catastrophizing and anxiety were assessed using the pain catastrophizing scale (PCS), and Spielberger's State-Trait Anxiety Inventories, respectively. Peak pain was correlated to pain catastrophizing (r = 0.628, p < 0.01). There was a strong correlation between change in heart rate (HR) and subjective peak pain (r = 0.805, p < 0.01), total PCS (r = 0.474, p < 0.05), and the helplessness subscale of the PCS (r = 0.457, p < 0.05). Peak pain and catastrophizing explained a significant amount of the variance for the change in HR during the cold pressor test (R2 of 0.649 and 0.224 respectively, p = 0.019). These novel findings demonstrate a psycho-physiological relationship between cardiovascular changes and pain catastrophizing. Further research should include participants with subacute or persistent pain.

Heart rate variability biofeedback in chronic disease management: A systematic review.

BACKGROUND: Heart rate variability biofeedback (HRVB) is a non-pharmacological intervention used in the management of chronic diseases. METHOD: A systematic search was performed according to eligibility criteria including adult chronic patients, HRVB as main treatment with or without control conditions, and psychophysiological outcomes as dependent variables. RESULTS: In total, 29 articles were included. Reported results showed the feasibility of HRVB in chronic patients without adverse effects. Significant positive effects were found in various patient profiles on hypertension and cardiovascular prognosis, inflammatory state, asthma disorders, depression and anxiety, sleep disturbances, cognitive performance and pain, which could be associated with improved quality of life. Improvements in clinical outcomes co-occurred with improvements in heart rate variability, suggesting possible regulatory effect of HRVB on autonomic function. CONCLUSIONS: HRVB could be effective in managing patients with chronic diseases. Further investigations are required to confirm these results and recommend the most effective method.

EEG changes reflecting pain: is alpha suppression better than gamma enhancement?

OBJECTIVE: Suppression of alpha and enhancement of gamma electroencephalographic (EEG) power have both been suggested as objective indicators of cortical pain processing. While gamma activity has been emphasized as the best potential marker, its spectral overlap with pain-related muscular responses is a potential drawback. Since muscle contractions are almost universal concomitants of physical pain, here we investigated alpha and gamma scalp-recorded activities during either tonic pain or voluntary facial grimaces mimicking those triggered by pain. METHODS: High-density EEG (128 electrodes) was recorded while 14 healthy participants either underwent a cold pressor test (painful hand immersion in 10 °C water) or produced stereotyped facial/nuchal contractions (grimaces) mimicking those evoked by pain. The scalp distribution of spectral EEG changes was quantified via vector-transformation of maps and compared between the pain and grimacing conditions by calculating the cosine of the angle between the two corresponding topographies. RESULTS: Painful stimuli significantly enhanced gamma power bilaterally in fronto-temporal regions and decreased alpha power in the contralateral central scalp. Sustained cervico-facial contractions (grimaces) gave also rise to significant gamma power increase in fronto-temporal regions but did not decrease central scalp alpha. While changes in alpha topography significantly differed between the pain and grimace situations, the scalp topography of gamma power was statistically indistinguishable from that occurring during grimaces. CONCLUSION: Gamma power induced by painful stimuli or voluntary facial-cervical muscle contractions had overlapping topography. Pain-related alpha decrease in contralateral central scalp was less disturbed by muscle activity and may therefore prove more discriminant as an ancillary pain biomarker.

Psychometric properties of the Spanish version of the Sleep Hygiene Index.

The Sleep Hygiene Index (SHI) has shown adequate psychometric properties in samples from several countries but has not been validated in Spanish. The aims of the study were to translate the original (i.e., English) version of the SHI into Spanish and to evaluate the psychometric properties of this instrument (i.e., factor structure, internal consistency reliability, and concurrent, predictive, and discriminant validity) in Spanish adults. The overall sample, comprising 548 university students, was divided into two groups based on their self-reported insomnia symptoms (Insomnia Severity Index) because sleep hygiene has been shown to be closely related to insomnia. The Pittsburgh Sleep Quality Index and the Stanford Sleepiness Scale were used for testing concurrent validity. The Depression, Anxiety, and Stress Scale was used for testing predictive validity. Three items were dropped from the original SHI scale due to their low factor loadings. The principal component analysis revealed a four-factor solution for the SHI, accounting for 65.58% of the total variance in the overall sample, for 65.34% in the noninsomnia group, and for 63.50% in the insomnia group. Factor 1 comprised items regarding sleep-disrupting behaviors; Factor 2 comprised items regarding cognitive activation; Factor 3 comprised items about bedroom comfort; and Factor 4 comprised items on sleep/wake time. Omega coefficient indices for the SHI ranged from 0.751 to 0.878 in the overall sample, from 0.734 to 0.822 in the noninsomnia group, and from 0.724 to 0.835 in the insomnia group. The Spanish version of the SHI can be regarded as a reliable tool with adequate concurrent and predictive validity for assessing sleep hygiene in Spanish people with or without insomnia symptoms.

The importance of sleep and physical activity on well-being during COVID-19 lockdown: reunion island as a case study.

BACKGROUND: Lockdown has been one of the major worldwide strategies to control the spread of coronavirus disease 2019 (COVID-19). Its consequences on the well-being of individuals needs to be better understood. The objective of this work was to evaluate the impact of lockdown on the well-being of a general population and the factors associated with this potential impairment of well-being in a population that has been only lightly affected by COVID-19 such as in Reunion island, an overseas French department. METHODS: An online survey was proposed to the population of Reunion Island between the 35th and 54th days of lockdown relative to pre- and per-lockdown periods. Well-being was measured by the 5-item World Health Organization Well-Being Index, with some questions about sleep habits (Pittsburgh questionnaire), weekly physical activity (IPAQ), health, and lifestyle. RESULTS: Four hundred volunteers answered the survey. They reported a 15.7% decrease in well-being (p < 0.001), accompanied by increased anxiety (p < 0.001), decreased weekly physical activity (p < 0.001), delayed and poorer quality sleep (p < 0.001). Multivariate logistical analysis showed that impairment in well-being during lockdown was independently associated with an increase in anxiety (odds ratio (OR): 4.77 (3.26-6.98), p < 0.001), decrease in weekly physical activity (OR: 0.58 (0.43-0.79), p < 0.001), and poor-quality sleep (OR: 0.29 (0.19-0.43), p < 0.001). CONCLUSIONS: This study suggested an impairment in well-being during lockdown, associated with anxiety, lack of physical activity and sleep disruptions. Public policies must consider these factors as levers for improving the well-being of the population in order to effectively combat the spread of COVID-19.

Emotion regulation of others' positive and negative emotions is related to distinct patterns of heart rate variability and situational empathy.

Although emotion regulation has been proposed to be crucial for empathy, investigations on emotion regulation have been primarily limited to intrapersonal processes, leaving the interpersonal processes of self-regulation rather unexplored. Moreover, studies showed that emotion regulation and empathy are related with increased autonomic activation. How emotion regulation and empathy are related at the autonomic level, and more specifically during differently valenced social situations remains an open question. Healthy adults viewed a series of short videos illustrating a target who was expressing positive, negative, or no emotions during a social situation (Positive, Negative, or Neutral Social Scenes). Prior to each video, participants were instructed to reappraise their own emotions (Up-regulation, Down-regulation, or No-regulation). To assess autonomic activation, RR intervals (RRI), high frequency (HF) components of heart rate variability (HRV), and electrodermal activity phasic responses (EDRs) were calculated. Situational empathy was measured through a visual analogue scale. Participants rated how empathic they felt for a specific target. Up- and Down-regulation were related to an increase and a decrease in situational empathy and an increase in RRI and HF, respectively, compared to the control condition (No-regulation). This suggests increased activity of the parasympathetic branch during emotion regulation of situational empathic responses. Positive compared to Negative Social Scenes were associated with decreased situational empathy, in addition to a slightly but non-significantly increased HF. Altogether, this study demonstrates that emotion regulation may be associated with changes in situational empathy and autonomic responses, preferentially dominated by the parasympathetic branch and possibly reflecting an increase of regulatory processes. Furthermore, the current study provides evidence that empathy for different emotional valences is associated with distinct changes in situational empathy and autonomic responses.

Causal analyses to study autonomic regulation during acute head-out water immersion, head-down tilt and supine position.

NEW FINDINGS: What is the central question of this study? Can Granger causality analysis of R-R intervals, systolic blood pressure and respiration provide evidence for the different physiological mechanisms induced during thermoneutral water immersion, 6 deg head-down tilt and supine position tests that are not accessible using traditional heart rate variability and baroreflex methods? What is the main finding and its importance? The Granger analysis demonstrated a significant difference in the causal link from R-R intervals to respiration between water immersion and head-down tilt. The underlying physiological mechanism explaining this difference could be the variation in peripheral resistances. ABSTRACT: Thermoneutral head-out water immersion (WI) and 6 deg head-down tilt (HDT) are used to simulate SCUBA diving, swimming and microgravity, because these models induce an increase in central blood volume. Standard methods to analyse autonomic regulation have demonstrated an increase in parasympathetic activity and baroreflex sensitivity during these experimental conditions. However, such methods are not adapted to quantify all closed-loop interactions involved in respiratory and cardiovascular regulation. To overcome this limitation, we used Granger causality analysis between R-R intervals (RR), systolic blood pressure (SBP) and respiration (RE) in eight young, healthy subjects, recorded during 30 min periods in the supine position, WI and HDT. For all experimental conditions, we found a bidirectional causal relationship between RE and RR and between RR and SBP, with a dominant direction from RR to SBP, and a unidirectional causality from RE to SBP. These causal relationships remained unchanged for the three experimental tests. Interestingly, there was a lower causal relationship from RR to RE during WI compared with HDT. This causal link from RR to RE could be modulated by peripheral resistances. These results highlight differences in cardiovascular regulation during WI and HDT and confirm that Granger causality might reveal physiological mechanisms not accessible with standard methods.

Autonomic Cardiac Reactivity to Painful Procedures Under Hypnosis in Pediatric Emergencies: A Feasibility Study.

Pain sensation is characterized by abrupt changes in central nervous system activity producing autonomic reactivity. While clinical hypnosis has demonstrated its benefits for children in pain management, it is not clear whether hypnosis modulated autonomic pain response in children in clinical conditions. Here, we studied autonomic responses under hypnosis to sutures in pediatric emergencies. For that, 42 children (mean age: 6.5 years, range 1.5 to 13) were divided into two groups consecutively (hypnosis and control groups), according to their choice. Time-frequency analysis was applied on RR intervals (heart rate interbeat intervals, or RRI) to estimate parasympathetic reactivity based on high frequency power (HF) and the Analgesia Nociception Index (ANI®) and on sympathetic reactivity (low frequency power [LF]) and LF/HF ratio). We observed that RRI and LF/HF ratio varied according to suture and hypnosis (p < 0.05): RRI was higher and LF/HF ratio was lower during sutures in the hypnosis group in comparison to the control group whereas HF and ANI® increased only during hypnosis. To conclude, hypnosis in pediatric emergencies reduces sympathetic cardiac pain reactivity and could be a marker of pain relief under hypnosis, while parasympathetic activity seems to be a better marker of hypnosis.

Autonomic cardiovascular adaptations to acute head-out water immersion, head-down tilt and supine position.

PURPOSE: Thermoneutral head-out water immersion (WI) and 6° head-down tilt (HDT) have been considered as suitable models to increase central blood volume and simulate autonomic cardiovascular adaptations to microgravity, swimming or scuba diving. However, any differences in autonomic cardiovascular adaptations are still unclear. In this study, we hypothesized that WI induces a higher activation of arterial baroreceptors and the parasympathetic system. METHODS: Ten healthy men underwent 30 min of WI, HDT, and a supine position (SP). RR intervals (RRI) and blood pressure (BP) were continuously monitored. High frequency power (HF), low frequency power (LF) and LF/HF ratio were calculated to study sympathetic and parasympathetic activities, and a spontaneous baroreflex method was used to study arterial baroreflex sensitivity (aBRS). Lung transfer of nitric oxide and carbon monoxide (TLNO/TLCO), vital capacity and alveolar volume (Vc/VA) were measured to study central blood redistribution. RESULTS: We observed (1) a similar increase in RRI and decrease in BP; (2) a similar increase in HF power during all experimental conditions, whereas LF increased after; (3) a similar rise in aBRS; (4) a similar increase in Vc/VA and decrease in TLNO/TLCO in all experimental conditions. CONCLUSIONS: These results showed a cardiac parasympathetic dominance to the same extent, underpinned by a similar arterial baroreflex activation during WI and HDT as well as control SP. Future studies may address their association with cold or hyperoxia to assess their ability to replicate autonomic cardiovascular adaptations to microgravity, swimming or scuba diving.

Association between insomnia disorder and cognitive function in middle-aged and older adults: a cross-sectional analysis of the Canadian Longitudinal Study on Aging.

OBJECTIVES: This study examined the differences in cognitive function between middle-aged and older adults with insomnia disorder, insomnia symptoms only (ISO) or no insomnia symptoms (NIS), in the context of other health and lifestyle factors. METHODS: Twenty-eight thousand four hundred eighty-five participants >45 years completed questionnaires, physical examinations, and neuropsychological testing across domains of processing speed, memory, and executive functions. An eight-question instrument assessed participants' sleep, defining subjects with insomnia symptoms, probable insomnia disorder (PID), or NIS. The associations between these three groups and cognitive performance were examined with linear regression models adjusted for lifestyle and clinical factors. RESULTS: PID was identified in 1,068 participants (3.7% of the sample) while 7,813 (27.5%) experienced ISO. Participants with PID exhibited greater proportions of adverse medical and lifestyle features such as anxiety, depression, and diabetes than both other groups. Analyses adjusting for age, sex, education, as well as medical and lifestyle factors demonstrated that adults with PID exhibited declarative memory deficits (Rey Auditory Verbal Learning Test) compared with ISO or NIS. Adults with insomnia symptoms exhibited better performance on a task of mental flexibility than both other groups. CONCLUSIONS: These findings suggest that insomnia disorder in middle-aged and older adults is associated with poorer health outcomes and worse memory performance than adults with insomnia symptoms alone or without any sleep complaints, even after adjustment for comorbidities. The assessment of longitudinal data within this cohort will be critical to understand if insomnia disorder may increase the risk of further cognitive decline.

How the insula speaks to the heart: Cardiac responses to insular stimulation in humans.

Despite numerous studies suggesting the role of insular cortex in the control of autonomic activity, the exact location of cardiac motor regions remains controversial. We provide here a functional mapping of autonomic cardiac responses to intracortical stimulations of the human insula. The cardiac effects of 100 insular electrical stimulations into 47 epileptic patients were divided into tachycardia, bradycardia, and no cardiac response according to the magnitude of RR interval (RRI) reactivity. Sympathetic (low frequency, LF, and low to high frequency powers ratio, LF/HF ratio) and parasympathetic (high frequency power, HF) reactivity were studied using RRI analysis. Bradycardia was induced by 26 stimulations (26%) and tachycardia by 21 stimulations (21%). Right and left insular stimulations induced as often a bradycardia as a tachycardia. Tachycardia was accompanied by an increase in LF/HF ratio, suggesting an increase in sympathetic tone; while bradycardia seemed accompanied by an increase of parasympathetic tone reflected by an increase in HF. There was some left/right asymmetry in insular subregions where increased or decreased heart rates were produced after stimulation. However, spatial distribution of tachycardia responses predominated in the posterior insula, whereas bradycardia sites were more anterior in the median part of the insula. These findings seemed to indicate a posterior predominance of sympathetic control in the insula, whichever the side; whereas the parasympathetic control seemed more anterior. Dysfunction of these regions should be considered when modifications of cardiac activity occur during epileptic seizures and in cardiovascular diseases.

Parasomnia versus epilepsy: An affair of the heart?

OBJECTIVE: Differential diagnosis between sleep-related epileptic seizures and NREM parasomnia remains challenging. Pathophysiological markers to differentiate both conditions are needed. Activation of autonomic system is present in arousal reactions and epileptic seizures. Our study investigated whether cardiac reactivity differed between arousal disorders and sleep-related seizures. METHODS: Nocturnal recordings of 50 patients (10 in each group: frontal lobe epilepsy [FLE], temporal lobe epilepsy [TLE], nocturnal terror [NT], confusional arousal [CA], normal arousals [NA]) were retrospectively selected. Timing of the first motor sign and description of behaviours were assessed. Beat-to-beat RR intervals (RRI) as well as heart rate variability were analysed over a period of 60 heartbeats before and after first motor manifestation. The slope and area under the curve (AUC) of RRI were calculated. RESULTS: A significant decrease in RRI was observed at the onset of all events. Statistical analysis revealed: lower RRI in TLE than in other groups; higher slope of RRI in FLE than in NA and TLE, and higher AUC in NT and FLE than in TLE, and in NT than in NA. Sleep stage, episode duration, vocalization characteristics, lateralized or abnormal posture, exploratory behaviour differed between epileptic and parasomnia groups. DISCUSSION: Analysis of cardiac reactivity seems to be a useful objective tool, together with clinical features, for diagnosing abnormal behaviour during sleep. Cardiac reactivity in TLE could reflect epileptic discharge propagation to brain areas involved in autonomic control, while FLE and NT might involve a strong non-specific activation of the sympathetic system.