A Case of Complete Resolution of Repeated Syncope Attacks After a Right-Sided Carotid Endarterectomy.

Syncope is a common clinical entity with variable presentations and often an elusive causal mechanism, even after extensive evaluation. In any case, global cerebral hypoperfusion, resulting from the inability of the circulatory system to maintain blood pressure (BP) at the level necessary to supply blood to the brain efficiently, is the final pathway for syncope. Steno-occlusive carotid artery disease, even if bilateral, does not usually cause syncope. However, the patient presented here had repeated syncope attacks and underwent a thorough examination for suspected cardiac disease, but no abnormality was found. Since there was severe stenosis in the right unilateral internal carotid artery (ICA), but no stenosis in the left ICA or vertebrobasilar artery (VBA), and transient left mild hemiparesis associated with syncope, carotid revascularization surgery for the right ICA was performed, and the repeated syncope attacks completely disappeared after the surgery. The patient's condition improved markedly, and no further episodes of syncope have been reported. We report the relationship between carotid artery stenosis and syncope and discuss its pathomechanism.

Complete autonomic blockade reveals nitric oxide contribution to blood pressure regulation in obese Black women.

PURPOSE: Hypertension is one of the major causes of cardiovascular morbidity and mortality in the USA and disproportionately affects Black women. Endothelial-derived nitric oxide (eNO) substantially regulates blood pressure in humans, and impaired NO-mediated vasodilation has been reported in the Black population. Previous studies using an NO synthase inhibitor, NG-monomethyl-L-arginine (L-NMMA) did not fully determine the NO contribution to blood pressure because of baroreflex buffering. Therefore, in the present study we used trimethaphan, a ganglionic blocker, to inhibit baroreflex buffering and study NO modulation of blood pressure in Black women during L-NMMA infusion. METHODS: L-NMMA at doses of 250 µg/kg per minute was infused in combination with trimethaphan at doses of 4 mg/min to eliminate baroreflex mechanisms. Heart rate (HR) was obtained with continuous electrocardiogram monitoring, and continuous blood pressure was measured with the volume clamp method. The increase in systolic blood pressure (SBP) during both infusions was used to estimate the contribution of NO to blood pressure. RESULTS: Ten Black (age range 30-50 years, body mass index [BMI] 30-45 kg/m2), and nine White women (age range 30-50 years, body mass index 30-45 kg/m2) were enrolled in this study. During autonomic blockade, there was no difference in the decrease in SBP between Black and White women (- 20 ± 16.45 vs. - 24 ± 15.49 mm Hg, respectively; P = 0.659). When autonomic blockade was combined with L-NMMA, Black women had a significant increase in SBP compared to White women (54 ± 13.62 vs. 39 ± 09.64 mm Hg, respectively; P = 0.022, respectively). CONCLUSION: Autonomic blood pressure regulation was similar between Black and White women. However, NO contribution to blood pressure was significantly greater in Black women compared to White women. REGISTRATION: ClinicalTrials.gov: NCT01122407.

Advice to People with Parkinson's in My Clinic: Orthostatic Hypotension.

Orthostatic hypotension (OH) is the most common manifestation of cardiovascular autonomic dysfunction in Parkinson's disease. In this viewpoint, we discuss five practical questions regarding OH in Parkinson's disease: 1) How common is the problem? 2) Why should people with Parkinson's disease and providers care about OH? 3) What are the symptoms of OH? 4) How to confirm a diagnosis of OH? And 5) How to treat OH? OH is an important non-motor symptom of Parkinson's disease for which we have available treatments to significantly mitigate morbidity and possibly positively impact the disease course.

Heart rate variability biofeedback enhances cognitive, motor, psychological, and autonomic functions in post-stroke rehabilitation.

Post-stroke patients often experience psychological distress and autonomic nervous system (ANS) dysregulation, impacting their well-being. This study evaluated the effectiveness of heart rate variability (HRV) biofeedback on cognitive, motor, psychological, and ANS functions in sixty-two ischemic stroke patients (43 males, mean age = 60.1) at a Medical Center in southern Taiwan. To prevent interaction, we allocated patients to the HRV biofeedback or control (usual care) group based on their assigned rehabilitation days, with 31 patients in each group. Assessments conducted at baseline, three, and six months included the Montreal Cognitive Assessment (MoCA), Fugl-Meyer Assessment for Upper Extremities (FMA-UE), Perceived Stress Scale, Hospital Anxiety and Depression Scales (HADS), and HRV indices. Mixed-effect models were used to analyze Group by Time interactions. The results revealed significant interactions across all functions. At 3 months, significant improvements in the HRV biofeedback group were observed only in MoCA, FMA-UE, and HADS-depression scores compared to the control group. By 6 months, all measured outcomes demonstrated significant improvements in the biofeedback group relative to the control group. These results suggest that HRV biofeedback may be an effective complementary intervention in post-stroke rehabilitation, warranting further validation.

Heart Rate Variability in a Vocal Stress Test with Special Consideration of the Objective Voice Function.

OBJECTIVE: Many employees, especially in voice-intensive professions, are under psychological stress at work, which is very difficult to objectify. The aim of the study was to analyze correlations between heart rate variability (HRV) parameters and objective voice function using weighted voice parameters (Dysphonia Severity Index [DSI]) in order to determine whether subjects with impaired vocal function show a predominance of sympathetic control during a vocal stress test. STUDY DESIGN: Prospective. METHODS: Fifty-three people of working age were examined. After asking for sociodemographic, occupational, and voice-related data, the objective voice function was determined using the DiVAS voice diagnostics system, and a 20-minute vocal stress test was performed. The electrocardiogram was recorded using medilog AR12plus during the vocal stress test and in a 5-minute rest phase before and a 5-minute recovery phase after the test. HRV was analyzed using the Kubios HRV Premium software. RESULTS: HRV was reduced during the vocal stress test compared to the resting and recovery phase. A Spearman correlation analysis showed significant correlations, particularly between the frequency-related HRV parameters and the DSI. The DSI correlated positively with the high frequency (HF) band (the relative power and the normalized unit). The DSI correlated negatively with the quotient between low frequency and HF and the low frequency normalized unit. CONCLUSION: During a vocal stress test, adults in working age show a correlation between parameters of objective vocal function and parameters of HRV. The more impaired the objective vocal function, the higher the predominance of sympathetic activation under vocal stress. The voice can therefore be seen as a "warning signal" for the processes in the autonomic nervous system. The use of preventive strategies for stress management and for voice health appears to be particularly beneficial in vocally stressful occupations in order to achieve a positive effect on parasympathetic activity.

Autonomic assessment at the intersection of psychosocial and gastrointestinal health.

BACKGROUND: Wearable technology is increasingly used in clinical practice and research to monitor functional gastrointestinal symptoms and mental health. AIMS: This article explores the potential of wearable sensors to enhance the understanding of the autonomic nervous system (ANS), particularly its role in linking psychological and gastrointestinal function. The ANS, facilitates brain-gut communication and is responsive to psychosocial conditions. It is implicated in disorders related to psychological stress and gut-brain interaction. Wearable technology enables tracking of the ANS in daily life, offering complementary and alternative methods from traditional lab-based measures. This review places focus on autonomic metrics such as respiratory sinus arrhythmia, vagal efficiency, and electrodermal activity as well as self-reports of autonomic symptoms. DISCUSSION: Potential applications include use of wearable sensors for tracking autonomic activity in disorder of gut-brain interaction such as cyclic vomiting syndrome, in which ANS dysregulation may be triggered by psychosocial factors. Considerations for data interpretation and contextualization are addressed, acknowledging challenges such as situational confounders of ANS activity and accuracy of wearable devices.

Acute Sympathetic Blockade Improves Insulin-Mediated Microvascular Blood Flow in the Forearm of Adult Human Subjects With Obesity.

BACKGROUND: Obesity is associated with resistance to the metabolic (glucose uptake) and vascular (nitric-oxide mediated dilation and microvascular recruitment) actions of insulin. These vascular effects contribute to insulin sensitivity by increasing tissue delivery of glucose. Studies by us and others suggest that sympathetic activation contributes to insulin resistance to glucose uptake. Here we tested the hypothesis that sympathetic activation contributes to impaired insulin-mediated vasodilation in adult subjects with obesity. METHODS AND RESULTS: In a randomized crossover study, we used a euglycemic hyperinsulinemic clamp in 12 subjects with obesity to induce forearm arterial vasodilation (forearm blood flow) and microvascular recruitment (contrast-enhanced ultrasonography) during an intrabrachial infusion of saline (control) or phentolamine (sympathetic blockade). Insulin increased forearm blood flow on both study days (from 2.21±1.22 to 4.89±4.21 mL/100 mL per min, P=0.003 and from 2.42±0.89 to 7.19±3.35 mL/100 mL per min, P=0.002 for the intact and blocked day, respectively). Sympathetic blockade with phentolamine resulted in a significantly greater increase in microvascular flow velocity (∆microvascular flow velocity: 0.23±0.65 versus 2.51±3.01 arbitrary intensity units (AIU/s) for saline and phentolamine respectively, P=0.005), microvascular blood volume (∆microvascular blood volume: 1.69±2.45 versus 3.76±2.93 AIU, respectively, P=0.05), and microvascular blood flow (∆microvascular blood flow: 0.28±0.653 versus 2.51±3.01 AIU2/s, respectively, P=0.0161). To evaluate if this effect was not due to nonspecific vasodilation, we replicated the study in 6 subjects with obesity comparing intrabrachial infusion of phentolamine to sodium nitroprusside. At doses that produced similar increases in forearm blood flow, insulin-induced changes in microvascular flow velocity were greater during phentolamine than sodium nitroprusside (%microvascular flow velocity=58% versus 29%, respectively, P=0.031). CONCLUSIONS: We conclude that sympathetic activation impairs insulin-mediated microvascular recruitment in adult subjects with obesity.

Cardiovascular autonomic neuropathy in diabetes: an update with a focus on management.

Cardiovascular autonomic neuropathy (CAN) is an under-recognised yet highly prevalent microvascular complication of diabetes. CAN affects approximately 20% of people with diabetes, with recent studies highlighting the presence of CAN in prediabetes (impaired glucose tolerance and/or impaired fasting glucose), indicating early involvement of the autonomic nervous system. Understanding of the pathophysiology of CAN continues to evolve, with emerging evidence supporting a potential link between lipid metabolites, mitochondrial dysfunction and genetics. Recent advancements, such as streamlining CAN detection through wearable devices and monitoring of heart rate variability, present simplified and cost-effective approaches for early CAN detection. Further research on the optimal use of the extensive data provided by such devices is required. Despite the lack of specific pharmacological interventions targeting the underlying pathophysiology of autonomic neuropathy, several studies have suggested a favourable impact of newer glucose-lowering agents, such as sodium-glucose cotransporter 2 inhibitors and glucagon-like peptide-1 receptor agonists, where there is a wealth of clinical trial data on the prevention of cardiovascular events. This review delves into recent developments in the area of CAN, with emphasis on practical guidance to recognise and manage this underdiagnosed condition, which significantly increases the risk of cardiovascular events and mortality in diabetes.

Assessing Children's Autonomic Nervous System Activity During Structured Tasks: A Feasibility and Reliability Study in Ghana.

The significance of physiological regulation in relation to behavioral and emotional regulation is well documented, but primarily in economically advantaged contexts. Few studies have been conducted in low- and middle-income countries. We investigated the feasibility and reliability of measuring autonomic nervous system (ANS) activity and behavior during challenge tasks in 30 children aged 8-10 years in Ghana during two visits, 1 week apart. Completeness of ANS data ranged from 80% to 100% across all tasks. There was low-to-moderate test-retest reliability of video mood induction (VMI) emotion ratings and balloon analog risk task (BART) pumps (r = 0.34-0.52). VMI elicited higher targeted emotion ratings in Visit 2 than Visit 1. Respiratory sinus arrhythmia (RSA) was higher, and pre-ejection period (PEP) was longer at Visit 2 than Visit 1 for baseline and both tasks. RSA was higher at baseline than during the VMI anger scene at Visit 1, whereas PEP was shorter at baseline than during all VMI emotion scenes at Visit 2. RSA was higher at baseline than during BART at both visits. In conclusion, ANS data collection within evocative and arousing challenge tasks was feasible in Ghana, and the tasks were generally reliable and effective in eliciting target emotions and risk-taking behavior in this sample.

Sympathetic response following unannounced loss of balance during walking in young adults - laboratory study.

BACKGROUND: An unannounced balance loss during walking, i.e., balance perturbation, is a stressful event that changes the activity of the Sympathetic Nervous System (SNS). We examined SNS response to unannounced balance perturbation during walking, simulating real-life conditions of balance loss. RESEARCH QUESTION: Do laboratory-induced unannounced balance losses during walking cause a sympathetic response, and if so - does it habituate after a series of perturbations? METHODS: 34 young adults underwent a series of six successive unannounced balance perturbations while walking on a treadmill. Sympathetic activity was monitored continuously using Electrodermal Activity and compared before and immediately after each unannounced perturbation. RESULTS: All perturbations elicited a significant increase in Electrodermal Activity (p<0.001), indicating a phasic increase in the sympathetic drive. The relative phasic increase of Electrodermal Activity caused by the first perturbation was significantly higher than the last perturbation (p<0.05). Three types of Electrodermal Activity behavior were observed: Steady level tonic SNS activity, increased SNS activity, and decreased SNS activity. SIGNIFICANCE: Balance loss during walking triggers phasic SNS response, this response habituates after a series of unannounced balance perturbations. In addition, three distinct patterns of tonic sympathetic activity may imply variations in the ability of the SNS response to habituate across individuals.

Psychophysiological and interpersonal effects of parallel group crafting: a multimodal study using EEG and ECG.

In occupational therapy, crafts and groups are used as therapeutic tools, but their electrophysiological effects have not been well described. This study aimed to investigate the effects of group crafting on the physiological synchrony (PS) of dyadic heartbeats and on the autonomic activity and electroencephalogram (EEG) of individuals. In this cross-sectional study, individuals' EEG and dyadic electrocardiogram (ECG) were measured during the task in a variety of conditions. The three conditions were alone, parallel, nonparallel. Autonomic activity from the subjects' ECG, PS from the dyadic ECG, and current source density from exact Low Resolution Brain Electromagnetic Tomography (eLORETA) from subjects' EEG were analyzed. Measurements from 30 healthy young adults showed that the parallel condition significantly increased subjects' parasympathetic activity and dyadic PS. Parallel condition and frontal midline theta influenced parasympathetic activity, whereas parasympathetic activity was not associated with PS. Dyadic lag value were correlated with frontal delta, beta, and gamma activity. The results suggest that crafting in parallel groups increases parasympathetic activity and PS through different mechanisms, despite the absence of direct interaction. They also explain the electrophysiological evidence for the use of crafts and groups in psychiatric occupational therapy, such as increased relaxation and PS.

Suspected Diphtheria Toxoid and Tetanus Toxoid (dTdap) Booster Vaccine-Induced Postural Orthostatic Tachycardia Syndrome (POTS).

We describe a case of a 40-year-old South Asian woman who presented with symptoms suggestive of postural orthostatic tachycardia syndrome (POTS) following a diphtheria toxoid and tetanus toxoid (dTdap) booster vaccination administered one week prior. The patient's POTS responded favorably to treatment with low-dose fludrocortisone and ivabradine. Clinicians should maintain a high index of suspicion for POTS as a possible vaccine adverse event (VAE) post-dTdap booster inoculation and be aware of appropriate management strategies.

The effect of exercise training on heart rate variability in patients with hypertension: A systematic review and meta-analysis.

We aimed to assess the effect of exercise training on heart rate variability (HRV) in hypertensive patients and to provide practical recommendations. We systematically searched seven databases for randomized controlled trials (RCTs) comparing the efficacy of exercise interventions vs. non-exercise control for HRV in adults with hypertension. HRV parameters, blood pressure (BP), and heart rate (HR) from the experimental and control groups were extracted to carry out meta-analysis. To explore the heterogeneity, we performed sensitivity analysis, sub-analysis, and meta-regression. Twelve RCTs were included, and the main results demonstrated exercise produced improvement in root mean square of successive RR-intervals differences (RMSSD) and high frequency (HF), and reductions in LF/HF, resting systolic blood pressure (SBP), and HR. The sub-analysis and meta-regression showed that AE improved more HRV indices and was effective in reducing BP compared with RE. Follow-up duration was also an important factor. Data suggests exercise training has ameliorating effects on HRV parameters, resting SBP, and HR in hypertensive patients, showing enhanced autonomic nervous system function and vagal activity. This effect may be better realized with exercise interventions of 4 weeks or more. Considering our results and the hypertension practice guidelines, we tend to recommend patients choose supervised AE.

Integrative Effects of Transcutaneous Electrical Acustimulation and Autonomic-Endocrine Mechanisms on Postprocedural Recovery in Patients With Endoscopic Retrograde Cholangio-Pancreatography.

OBJECTIVES: This study aimed to investigate the integrative effects and mechanisms of transcutaneous electrical acustimulation (TEA) on postprocedural recovery from endoscopic retrograde cholangio-pancreatography (ERCP). MATERIALS AND METHODS: A total of 86 patients for elective ERCP were randomly ordered to receive TEA (n = 43) at acupoints PC6 and ST36 or Sham-TEA (n = 43) at sham points from 24 hours before ERCP (pre-ERCP) to 24 hours after ERCP (PE24). Scores of gastrointestinal (GI) motility-related symptoms and abdominal pain, gastric slow waves, and autonomic functions were recorded through the spectral analysis of heart rate variability; meanwhile, circulatory levels of inflammation cytokines of tumor necrosis factor-α (TNF-α) and interleukin (IL)-10 and GI hormones of motilin, ghrelin, cholecystokinin (CCK), and vasoactive intestinal peptide (VIP) were assessed by enzyme-linked immunosorbent assay. RESULTS: 1) TEA, but not Sham-TEA, decreased the post-ERCP GI motility-related symptom score (2.4 ± 2.6 vs 7.9 ± 4.6, p < 0.001) and abdominal pain score (0.5 ± 0.7 vs 4.1 ± 2.7, p < 0.001) at PE24, and decreased the post-ERCP hospital day by 20.0% (p ＜0.05 vs Sham-TEA); 2) TEA improved the average gastric percentage of normal slow waves and dominant frequency by 34.6% and 33.3% at PE24, respectively (both p < 0.001 vs Sham-TEA); 3) TEA, but not Sham-TEA, reversed the ERCP-induced increase of TNF-α but not IL-10 at PE24, reflected as a significantly lower level of TNF-α in the TEA group than in the Sham-TEA group (1.6 ± 0.5 pg/mL vs 2.1 ± 0.9 pg/mL, p ＜ 0.01); 4) compared with Sham-TEA, TEA increased vagal activity by 37.5% (p ＜ 0.001); and 5) TEA caused a significantly higher plasma level of ghrelin (1.5 ± 0.8 ng/ml vs 1.1 ± 0.7 ng/ml, p ＜ 0.05) but not motilin, VIP, or CCK than did Sham-TEA at PE24. CONCLUSION: TEA at PC6 and ST36 accelerates the post-ERCP recovery, reflected as the improvement in GI motility and amelioration of abdominal pain, and suppression of the inflammatory cytokine TNF-α may mediate through both autonomic and ghrelin-related mechanisms.

Renal autonomic dynamics in hypertension: how can we evaluate sympathetic activity for renal denervation?

This review explores the various pathophysiological factors influencing antihypertensive effects, involving the regulation of vascular resistance, plasma volume, cardiac function, and the autonomic nervous system, emphasizing the interconnected processes regulating blood pressure (BP). The kidney's pivotal role in BP control and its potential contribution to hypertension is complicated but important to understand the effective mechanisms of renal denervation (RDN), which may be a promising treatment for resistant hypertension. Excessive stimulation of the sympathetic nervous system or the renin-angiotensin-aldosterone system (RAAS) can elevate BP through various physiological changes, contributing to chronic hypertension. Renal sympathetic efferent nerve activation leads to elevated norepinephrine levels and subsequent cascading effects on vasoconstriction, renin release, and sodium reabsorption. RDN reduces BP in resistant hypertension by potentially disrupting sensory afferent nerves, decreasing feedback activation to the central nervous system, and reducing efferent sympathetic nerve activity in the heart and other structures. RDN may also modulate central sympathetic outflow and inhibit renal renin-angiotensin system overactivation. While evidence for RDN efficacy in hypertension is increasing, accurate patient selection becomes crucial, considering complex interactions that vary among patients. This review also discusses methods to evaluate autonomic nerve activity from the golden standard to new potential examination for finding out optimization in stimulation parameters or rigorous patient selection based on appropriate biomarkers.

Agreement of ultra-short-term heart rate variability measure after different repeated bouts of sprint ability tests.

This study aims to explore: (1) the validity of post-exercise ultra-short-term heart rate variability (HRVust) after two different bouts of repeated sprint ability test (RSA), and (2) the relationship between HRVust measure and RSA performance. Twenty adolescent male futsal players voluntarily participated in this study (age: 17.65 ± 1.81 years, body height: 170.88 ± 4.98 cm, body weight: 61.78 ± 4.67 kg). The participants performed a standard RSA test (RSAstandard) and an RSA test with a 10% decrement of the best sprint time test (RSA10%decrement) on two separate occasions within a week. On both occasions, a 5-min resting electrocardiography was administered pre- and post-RSA exercise protocols. The first 30-s (HRVust30s), 60-s (HRVust60s), and 60-120-s (HRVust1-2min) were extracted and used to compare with the standard of 5-min HRV recording (HRVcriterion). The natural logarithm (ln) of the standard deviation of normal-to-normal intervals (SDNN) and root mean square of successive normal-to-normal interval differences (RMSSD) HRV indices were utilised to establish intraclass correlation coefficient (ICC2,1), coefficient of variation (%CV), and Pearson product-moment correlation (r). Results revealed the ICC values of HRVust lnSDNN (RSAstandard = 0.77-0.88; RSA10%decrement = 0.41-0.71) and lnRMSSD (RSAstandard = 0.81-0.86; RSA10%decrement = 0.57-0.82). Furthermore, significantly positive correlations between best sprint time and post-exercise HRVust indices were found in lnSDNN (r = 0.47-0.62; p < 0.05) and lnRMSSD (r = 0.45; p < 0.05). Additionally, a large CV of lnSDNN (RSAstandard = 32%-45%; RSA10%decrement = 29%-39%), lnRMSSD (RSAstandard = 50%-66%; RSA10%decrement = 48%-52%), and ratio (RSAstandard = 45%-126%; RSA10%decrement = 27%-45%) was found after the RSA protocols. In conclusion, the number of bouts of RSA exercise potentially influences the agreement of post-exercise time-domain HRVust indices to standard HRV measure.

Intraoperative pelvic neuromonitoring based on bioimpedance signals: a new method analyzed on 30 patients.

PURPOSE: Increasing importance has been attributed in recent years to the preservation of the pelvic autonomic nerves during rectal resection to achieve better functional results. In addition to improved surgical techniques, intraoperative neuromonitoring may be useful. METHODS: This single-arm prospective study included 30 patients who underwent rectal resection performed with intraoperative neuromonitoring by recording the change in the tissue impedance of the urinary bladder and rectum after stimulation of the pelvic autonomic nerves. The International Prostate Symptom Score, the post-void residual urine volume and the Low Anterior Resection Syndrome Score (LARS score) were assessed during the 12-month follow-up period. RESULTS: A stimulation-induced change in tissue impedance was observed in 28/30 patients (93.3%). In the presence of risk factors such as low anastomosis, neoadjuvant radiotherapy and a deviation stoma, an average increase of the LARS score by 9 points was observed 12 months after surgery (p = 0,04). The function of the urinary bladder remained unaffected in the first week (p = 0,7) as well as 12 months after the procedure (p = 0,93). CONCLUSION: The clinical feasibility of the new method for pelvic intraoperative neuromonitoring could be verified. The benefits of intraoperative pelvic neuromonitoring were particularly evident in difficult intraoperative situations with challenging visualization of the pelvic nerves.

Frequency and severity of autonomic dysfunction assessed by objective hemodynamic responses and patient-reported symptoms in individuals with myasthenia gravis.

Introduction: Myasthenia gravis (MG), a rare autoimmune disorder, poses diagnostic and management challenges, with increasing incidence in Europe and significant impact on patient quality of life. Despite prevalent autonomic symptoms, comprehensive assessments integrating subjective and objective measures are lacking. We aimed to investigate the prevalence and severity of autonomic dysfunction in patients with MG and healthy controls (HCs). Materials and methods: We used beat-to-beat hemodynamic responses during standardized autonomic function tests (AFTs) and the Composite Autonomic Symptom Score 31 (COMPASS-31) questionnaire. Study participants including, 53 patients with MG and 30 age- and sex matched HCs underwent standardized cardiovascular AFTs and completed the COMPASS-31 questionnaire. Patients were categorized into Non-CAN and CAN groups based on their Cardiovascular Autonomic Neuropathy (CAN) status, as evaluated using the Composite Autonomic Scoring Scale (CASS). During the AFTs, cardiovascular parameters including heart rate, systolic blood pressure (BP), diastolic BP, mean BP, stroke volume (SV), cardiac output (CO), and total peripheral resistance (TPR) were measured. Results: Twenty patients with MG (38%) exhibited mild CAN (CASS ≥2) with a median total CASS score of 1.00 and CASS 0.00 in HCs. Adrenergic impairment was observed in 27 patients (52%), with 13 patients (24.5%) exhibiting longer pressure recovery time after Valsalva maneuver (VM). Cardiovagal impairment was evident in 71% of patients, with abnormal results observed in 39.6% for the deep breathing test and 56.6% for the VM. CAN MG showed worse scores than HCs for the total COMPASS-31 (p < 0.001), orthostatic (OI) (p < 0.001), secretomotor (p = 0.004), and pupillomotor domains (p = 0.004). Total COMPASS-31 and OI scores were correlated with worse disease outcomes (disease duration, severity), hemodynamic parameter changes (SV, CO, TPR) during phase II late of VM, and with changes (Δtilt-supine) in Δsystolic BP, Δdiastolic BP, Δmean BP, ΔTPR during head-up-tilt test, but not with CASS score. Conclusion: Our findings demonstrate mild cardiovascular autonomic impairment in adrenergic and cardiovagal domains in patients with MG. Additionally, patient-reported autonomic symptoms correlated with hemodynamic changes during AFTs and worse disease outcomes and not with the grade of autonomic abnormalities. Incorporating beat-to-beat hemodynamics during AFTs may offer further insights for characterizing orthostatic intolerance symptoms in MG group.

Basal parasympathetic deficits in C9orf72 hexanucleotide repeat expansion carriers relate to smaller frontoinsula and thalamus volume and lower empathy.

Diminished basal parasympathetic nervous system activity is a feature of frontotemporal dementia that relates to left frontoinsula dysfunction and empathy impairment. Individuals with a pathogenic expansion of the hexanucleotide repeat in chromosome 9 open reading frame 72 (C9orf72), the most common genetic cause of frontotemporal dementia and amyotrophic lateral sclerosis, provide a unique opportunity to examine whether parasympathetic activity is disrupted in genetic forms of frontotemporal dementia and to investigate when parasympathetic deficits manifest in the pathophysiological cascade. We measured baseline respiratory sinus arrhythmia, a parasympathetic measure of heart rate variability, over two minutes in a sample of 102 participants that included 19 asymptomatic expansion carriers (C9+ asymp), 14 expansion carriers with mild cognitive impairment (C9+ MCI), 16 symptomatic expansion carriers with frontotemporal dementia (C9+ FTD), and 53 expansion-negative healthy controls (C9- HC) who also underwent structural magnetic resonance imaging. In follow-up analyses, we compared baseline respiratory sinus arrhythmia in the C9+ FTD group with an independent age-, sex-, and clinical severity-matched group of 26 people with sporadic behavioral variant frontotemporal dementia. The Frontotemporal Lobar Degeneration-modified Clinical Dementia Rating-Sum of Boxes score was used to quantify behavioral symptom severity, and informant ratings on the Interpersonal Reactivity Index provided measures of participants' current emotional (empathic concern) and cognitive (perspective-taking) empathy. Results indicated that the C9+ FTD group had lower baseline respiratory sinus arrhythmia than the C9+ MCI, C9+ asymp, and C9- HC groups, a deficit that was comparable to that of sporadic behavioral variant frontotemporal dementia. Linear regression analyses indicated that lower baseline respiratory sinus arrhythmia was associated with worse behavioral symptom severity and lower empathic concern and perspective-taking across the C9orf72 expansion carrier clinical spectrum. Whole-brain voxel-based morphometry analyses in participants with C9orf72 pathogenic expansions found that lower baseline respiratory sinus arrhythmia correlated with smaller gray matter volume in the left frontoinsula and bilateral thalamus, key structures that support parasympathetic function, and in the bilateral parietal lobes, occipital lobes, and cerebellum, regions that are also vulnerable in individuals with C9orf72 expansions. This study provides novel evidence that basal parasympathetic functioning is diminished in FTD due to C9orf72 expansions and suggests that baseline respiratory sinus arrhythmia may be a potential non-invasive biomarker that is sensitive to behavioral symptoms in the early stages of disease.

Effects of repeated cryostimulation exposures on sleep and wellness in healthy young adults.

The aim of this study was to evaluate the effects of daily whole-body cryostimulation (WBC) sessions during 5 consecutive days on wellness and sleep parameters in healthy young men and women. Twenty healthy subjects (9 women; 11 men) aged 23.1 ± 2.6 years old participated in this randomized protocol, with 5 consecutive days with (CRYO) or without WBC (CONT) exposure. Sleep was analyzed over the 5 nights in each condition. Sleep quality and quantity were assessed via actimetry, cerebral activity and questionnaires. Nocturnal heart rate variability (HRV) was also recorded and questionnaires were given to assess wellness and mood. Repeated WBC exposures had a beneficial impact on mood and anxiety. It also improved subjective sleep quality (scored from 3.6 ± 0.5 pre to 3.9 ± 0.3), especially in women. Also, repeated WBC sessions modulated sleep architecture by increasing slow wave sleep duration (+7.3 ± 16.8 min) during the nights without impacting other sleep parameters, nor nocturnal HRV. In conclusion, repeated WBC seems to be an effective strategy to improve slow wave sleep duration in healthy young subjects. The reported psychological improvements may better benefit women than men.