Background Transient loss of consciousness (TLOC) may be mistaken for other disorders like epilepsy. Our objectives were to identify symptoms that could help differentiate epilepsy from syncope among children with TLOC and to validate previously suggested criteria. Methods We retrospectively reviewed the charts of patients aged 18 years or younger who presented with TLOC attacks from January 2008 to

Background Pure autonomic failure (PAF) and multiple system atrophy (MSA) are rare disorders causing severe autonomic failure. Their initially similar clinical presentation may lead to years of diagnostic difficulties. Improving the differentiation would have an important impact on patients and families in view of better prediction of disease progression. Objective To investigate whether several new

Introduction Patients with postural orthostatic tachycardia syndrome (POTS) have been shown to exhibit comorbid joint hypermobility manifested as Ehlers-Danlos syndrome (EDS) or hypermobility spectrum disorder (HSD). The prevalence of EDS and HSD in POTS has been demonstrated in smaller studies combining adult and pediatric patients. We examined a large series of pediatric patients to determine their

Transient cardiovascular and cerebrovascular responses within the first minute of active standing provide the means to assess autonomic, cardiovascular and cerebrovascular regulation using a real-world everyday stimulus. Traditionally, these responses have been used to detect autonomic dysfunction, and to identify the hemodynamic correlates of patient symptoms and attributable causes of (pre)syncope

Postural Tachycardia Syndrome (PoTS) is a chronic condition often affecting multiple systems with varied presenting symptoms. Diagnosis is made by demonstrating cardiovascular criteria on standing along with clinical assessment. Cardiopulmonary exercise testing has been used to demonstrate and characterise the physiological response to exercise and the severity of the syndrome. Previous studies on

Quercetin-loaded microcapsules (QLM) promote controlled release and higher bioavailability of quercetin, an antioxidant and neuroprotective agent. We evaluated the antioxidant effect of QLM on enteric innervation and in the oxidative status of the ileum of diabetic rats. Wistar adult rats (Rattus norvegicus) were used in six groups containing normoglycemic (N), diabetic (D) and either normoglycemic

This study developed a new method using radiopaque markers under X-ray to measure rat colonic transit by geometric center repeatedly and/or over a time series in the same individually. Additionally, the utility of this method was shown by elucidating the innervation of the autonomic nerve on colonic transit in detail with a pharmacological technique in conscious rats. An in-dwelling silastic cannula

Objective The purpose of this study was to determine the relationship between chronic kidney disease (CKD) and cardiovascular autonomic neuropathy (CAN). Research design and methods From October 2008 to May 2011, we enrolled 218 patients with diabetes and 62 nondiabetic subjects. Heart rate variability was represented as the maximal heart rate minus the minimal heart rate (HRmax-min) during a one-minute

Objectives Modulation of sympathetic activity during acute sleep deprivation can produce various effects on body functions. We studied the effects of acute sleep deprivation before ischemia/reperfusion on myocardial injury in isolated rat hearts, and the role of sympathetic nervous system that may mediate these sleep deprivation induced effects. Methods The animals were randomized into four groups

Short-term sustained hypoxia (SH) elicits active expiration, augmented late-expiratory (late-E) sympathetic activity, increased arterial pressure and ventilation, and amplified sympathetic and abdominal expiratory responses to chemoreflex activation in rats of the Wistar-Ribeirão Preto (WRP) strain. Herein, we investigated whether SH can differentially affect the cardiovascular and respiratory outcomes

The lateral habenula (LHb) is an evolutionarily ancient nucleus that plays an important role in the detection of salient/adverse environmental events. We have previously shown that the LHb is involved in brown adipose tissue (BAT) thermogenesis elicited by stressful situations, and that the medullary raphé, a key lower brainstem sympathetic control centre, mediates BAT thermogenesis elicited by stimulating

The purinergic receptor ligand, ATP, may participate in reflex induced vasoconstriction through sympathetic efferent and sensory afferent mechanisms. However, the role of the purinergic system in contributing to autonomic dysreflexia following spinal cord injury is unclear. The present study investigates the involvement of P2X receptors in contributing to pressor responses during autonomic dysreflexia

Sympathetic emissions directed towards the skeletal muscle circulation — muscle sympathetic nerve activity (MSNA) — represent a key mechanism for maintaining homeostasis and supporting human survival during physiological stress. Pulse-rhythmic bursts formed by the synchronous discharge of differently-sized sympathetic action potentials (APs) represent the primary characteristic of MSNA. Of the APs

This study attempts to clarify the neural control of cerebral blood flow (CBF) during head-down postural rotation, which induces a cephalad fluid shift in urethane-anesthetized rats. The animals were placed on a table, tilted to a 45° head-down position over 5 s and maintained in that position. Head-down rotation (HDR) induced a transient decrease (8 ± 3 mm Hg; mean ± SE) in mean arterial blood pressure

The exercise pressor reflex is exaggerated in type 2 diabetes mellitus (T2DM). Hyperglycemia, a main characteristic of T2DM, likely contributes to this exaggerated response. However, the isolated effect of acute hyperglycemia, independent of T2DM, on the exercise pressor reflex is not known. Therefore, the purpose of this study was to determine the effect of acute, local exposure to hyperglycemia on

Background According to expert opinion, orthostatic hypotension (OH) associated to a change in heart rate (ΔHR) less than 15 bpm suggests neurogenic OH (NOH). Recently, the ratio between HR and systolic blood pressure changes at 3 min of tilt test (ΔHR/ΔSBP) has been proposed as a better index than the ΔHR cut-off of 17 bpm. Our aim was to validate these indexes based on HR in an independent cohort

The impact of oxygen on the cerebral response to the cold pressor test (CPT) remains unknown. In 13 participants, blood pressure, middle and posterior cerebral artery blood velocity (MCAv and PCAv, respectively) were measured during an isocapnic normoxic and hypoxic (SpO2 = 85%) CPT. The main findings were: 1) the MCAv response to the CPT was greater compared to the PCAv in both normoxic and hypoxic

Adenosine and nitric oxide act on the fine-tuning regulation of neural cardiovascular control in the nucleus tractus solitarius (NTS). Although the interaction between adenosine and NO is well known in the periphery, the mechanisms by which adenosine interferes in the dynamics of nitrergic neurotransmission, related to neural control of circulation, are not completely understood and might be relevant

Sex differences in the regulation of autonomic and cerebrovascular responses to orthostatic stress remain unclear. The objectives of this study were to concurrently investigate autonomic control and cerebrovascular resistance indices, including critical closing pressure (CrCP) and resistance area product (RAP), during upright tilt in men and women. In 13 women and 14 men (18–29 years), ECG, non-invasive

Orthostatic hypotension (OH), a debilitating disorder characterized by a drop in blood pressure when in the upright position, may be treated through several pharmacologic and lifestyle modifications. The treatment is aimed at decreasing the symptoms, mainly the falls, increase the standing time, and improve the activities of daily life. A recent expert consensus outlined the management of orthostatic

The vascular beds of various cranial tissues receive common carotid flow, which contributes to blood flow redistribution associated with animal behaviors such as grooming, but the medullary autonomic regulation of carotid flow resistance (CAR) is poorly understood. This study is the first to examine the response sites of CAR in the rat rostral ventrolateral medulla (RVLM) presympathetic area to chemical

Diabetic autonomic neuropathy affects the entire autonomic nervous system and can lead to dysfunction of the cardiovascular, gastrointestinal, and genitourinary organ systems. Genitourinary dysfunction associated with diabetic autonomic neuropathy includes diabetic bladder dysfunction, sexual dysfunction, and recurrent urinary tract infections. Urological complications in diabetes mellitus are very

Oxytocin (OT) from the hypothalamus is increased in several cardiorespiratory nuclei and systemically in response to a variety of stimuli and stressors, including hypoxia. Within the nucleus tractus solitarii (nTS), the first integration site for cardiorespiratory reflexes, OT enhances synaptic transmission, action potential (AP) discharge, and cardiac baroreflex gain. The hypoxic stressor obstructive

Although there is considerably more data showing an association between type 2 diabetes mellitus (T2DM) and autonomic neuropathy, accumulating evidence indicates that cardiovascular autonomic neuropathy (CAN) is common in persons with impaired glucose tolerance (IGT). Furthermore, CAN may occur early after a metabolic insult and obesity, especially among mean, and seems to play an important role in

Background and aims Recently, it was demonstrated that optogenetics could be used to stimulate enteric calretinin neurons, leading to increased colonic transit in vitro and in vivo. The aim of the current study was to determine if similar approaches could be used to stimulate the isolated mouse small intestine, with the aim of potentially also improving transit in the small bowel. Methods Cre-Lox recombination

Neurogenic orthostatic hypotension (OH) is a disabling disorder caused by impairment of the normal autonomic compensatory mechanisms that maintain upright blood pressure. Nonpharmacologic treatment is always the first step in the management of this condition, but a considerable number of patients will require pharmacologic therapies. Denervation hypersensitivity and impairment of baroreflex buffering

We describe clinical and laboratory findings in 35 patients tested positive for SARS-CoV-2 by reverse transcriptase-polymerase chain reaction on nasopharyngeal swab experiencing one or multiple syncope at disease onset. Clinical neurologic and cardiologic examination, and electrocardiographic findings were normal. Chest computed tomography showed findings consistent with interstitial pneumonia. Arterial

Delayed orthostatic hypotension is a fall in blood pressure beyond 3 min of standing or upright tilt table testing. The prevalence, clinical features and pathophysiology are reviewed. To date, there is little data to support a standardized or recommended treatment. However, the 10-year mortality rates of individuals with delayed orthostatic hypotension are approximately 50%. Despite the fact that delayed

Objective Long QT-Syndrome (LQTS) patients are at risk of arrhythmias and seizures. We investigated whether autonomic and cardiac repolarization measures differed based on LQTS genotypes, and in LQTS patients with vs. without arrhythmias and seizures. Methods We used 24-h ECGs from LQTS1 (n = 87), LQTS2 (n = 50), and LQTS genotype negative patients (LQTS(−), n = 16). Patients were stratified by LQTS

Gastrointestinal autonomic neuropathy represents an important and diverse, but poorly appreciated, manifestation of diabetic autonomic neuropathy that impacts negatively on quality of life. There is no test to assess gastrointestinal autonomic nerve damage directly in humans; cardiovascular autonomic reflex tests are often used as a surrogate, but are suboptimal. Gastrointestinal symptoms are common

This review summarizes the current literature on the epidemiology of orthostatic hypotension (OH) in the elderly and in patients with autonomic impairment also known as neurogenic OH (nOH); these two conditions have distinct pathophysiologies and affect different patient populations. The prevalence of OH in the elderly varies depending on the study population. In community dwellers, OH prevalence is

Objective The urodynamics underlying lower urinary tract (LUT) dysfunction in frontotemporal lobar degeneration (FTLD) has not been reported. Herein, we investigated LUT function in FTLD patients by performing a urodynamics analysis. Patients and methods We recruited five FTLD patients with LUT symptoms: three men, two women; mean age, 70.4 years; mean disease duration, 3.8 years; mean Hoehn-Yahr grade

Autonomic alterations at the onset of exercise are critical to redistribute cardiac output towards the contracting muscles while preventing a fall in arterial pressure due to excessive vasodilation within the contracting muscles. Neural mechanisms responsible for these adjustments include central command, the exercise pressor reflex, and arterial and cardiopulmonary baroreflexes. The exercise pressor

Objective To investigate circadian rhythms of blood pressure (BP) and rate pressure product (RPP) in children with postural tachycardia syndrome (POTS) by performing 24-hour ambulatory blood pressure monitoring (24-h ABPM). Methods 103 POTS children and 84 age- and gender-matched healthy children were enrolled and they got 24-h ABPM under usual routine of diurnal activity and nocturnal sleep. Results

A parasympathetic reactivation is an underlying mechanism mediating the rapid fall in heart rate (HR) at the onset of post-exercise ischemia (PEI) in humans. Herein, we tested the hypothesis that, compared to men, women present a slower HR recovery at the cessation of isometric handgrip exercise (i.e., onset of PEI) due to an attenuated cardiac vagal reactivation. Forty-seven (23 women) young and healthy

Orthostatic hypotension (OH) is a common clinical manifestation characterized by a significant fall in blood pressure with postural change and is frequently accompanied by debilitating symptoms of orthostatic intolerance. The reported prevalence of OH ranges between 5 and 10% in middle-aged adults with a burden that increases concomitantly with age; in those over 60 years of age, the prevalence is

Periaqueductal gray (PAG) is a midbrain region that projects to areas controlling behavioral and autonomic outputs and is involved in the behavioral and physiological components of defense reactions. Since Raphe Pallidus (RPa) is a medial medullary region comprising sympathetic premotor neurons governing heart function, it is worth considering the PAG-RPa path. We assessed: i) whether PAG projects

Background Epicardial ganglionated plexuses (GP) have an important role in the pathogenesis of atrial fibrillation (AF). The relationship between anatomical, histological and functional effects of GP is not well known. We previously described atrioventricular (AV) dissociating GP (AVD-GP) locations. In this study, we hypothesised that ectopy triggering GP (ET-GP) are upstream triggers of atrial ectopy/AF

Orexin (OX), which regulates sleep and wakefulness and feeding behaviors has 2 isoforms, orexin-A and -B (OXA and OXB). In this study, the distribution of OXA and OXB was examined in the rat superior salivatory nucleus (SSN) using retrograde tracing and immunohistochemical and methods. OXA- and OXB-immunoreactive (-ir) nerve fibers were seen throughout the SSN. These nerve fibers surrounded SSN neurons

The bladder is innervated by axons of sympathetic and parasympathetic efferent nerves, and by spinal afferent neurons. The objective was to characterise anatomically and immunohistochemically the terminal endings of sensory and autonomic motor nerve endings in wholemount preparations of the mouse bladder. We used both anterograde labelling of pelvic and hypogastric nerves ex vivo and anterograde labelling

Background Patients with a systemic right ventricle are prone to develop heart failure. Abnormal heart rate variability (HRV), a measure of autonomic dysfunction, is associated with morbidity and mortality in patients with left ventricular failure. The association between HRV and supraventricular arrhythmias (SVTs), which are associated with adverse events in this population, was assessed. Methods

Purpose POTS patients undergo labial salivary gland biopsies (LSGB) for histologic confirmation of Sjogren's syndrome (SS). Predictive features of positive results are unknown. Methods 161 POTS patients underwent LSGB. Their charts were reviewed for antibody and diagnostic testing results. Results Only 11% (17/161) of POTS patients were SS positive. There were more positive ANA antibodies in those

While acetylcholine is regarded to be the main directly contractile transmitter substance in the urinary bladder, interactions with other transmitters likely occur. Presently, the interplay between purinergic and cholinergic signalling was investigated to unravel the involvement of the urothelium and efferent neurons in the functionally important purinergically evoked release of acetylcholine in vitro

Postural tachycardia syndrome (POTS) is a chronic form of orthostatic intolerance associated with cognitive dysfunction. We hypothesized executive function and attention is impaired in POTS during active standing. Eighty-seven POTS participants and 39 healthy controls of similar age, sex, and education level completed executive function (Stroop word-color) and attention (CogState Identification) tests

Neurogenic orthostatic hypotension (nOH) is a common comorbidity in patients with neurodegenerative diseases. It is associated with an increased risk of falls, incident cardiovascular disease, and all-cause mortality. There are over 5 million individuals in the U.S. with heart failure (HF) with an associated 50% mortality rate at 5 years. The prevalence of nOH and HF increase with age and, as the population

Psychological symptoms are frequently reported in patients with Postural Orthostatic Tachycardia Syndrome (POTS); however, the nature of these symptoms is not well understood. The current study described baseline psychological symptoms in patients with POTS, and examined associations between psychological and self-report autonomic symptoms. Participants reported mild anxiety symptoms, moderate depressive

The central adrenergic and noradrenergic neurotransmitter systems diffusively affect the operation of the spinal neural network and dynamically gauge central sympathetic outflow. Using in vitro splanchnic nerve–thoracic spinal cord preparations as an experimental model, this study examined the intraspinal α1-adrenoceptor-meidated modulation of sympathetic firing behaviors. Several sympathetic single-fiber

Mechanical stretch of the urothelium induces the release of ATP that activates bladder afferent nerves. In the rat urinary bladder, ATP is also a contractile co-transmitter in the parasympathetic innervation. In isolated preparations, ATP evokes a urothelial release of acetylcholine that substantially contributes to ATP-evoked contractile responses. Currently we aimed to further examine the interactions

Scorpion envenomation is a public health problem in tropical and subtropical areas. In Brazil, Tityus serrulatus is the biggest cause of accidents with venomous animals. Tityus serrulatus venom causes symptoms related to a great activation of the autonomic system attributed to a massive release of sympathetic and parasympathetic mediators. This effect is attributed to the presence of toxins acting

Background Cardiac sympathetic blockade is a therapeutic approach for arrhythmias and heart failure and may be a beneficial effect of high thoracic epidural anesthesia. These treatments require detailed knowledge of the spatial location and distribution of cardiac autonomic nerves, however, there are controversies on this subject in humans. Objective To provide a systematic overview of current knowledge

The relation between vascular sympathetic tone and the amplitude of arterial pressure (AP) Mayer waves was examined by analyzing 60-min recordings of AP and renal sympathetic nerve activity (RSNA) obtained in conscious rats before and after lipopolysaccharide administration, which results in strong sympathoexcitation. Mayer waves completely disappeared together with accompanying oscillations of RSNA

Saphenous (SAFN) nerve stimulation was recently shown in anesthetized rats to elicit bladder-inhibitory responses in a frequency-dependent manner; however, the mechanism of action is unknown. The goal of this study was to investigate the potential role of the hypogastric nerve (HGN) in this inhibitory pathway by examining stimulation-evoked changes in bladder function under four different experimental

Nesfatin-1 is a multifunctional neuropeptide having crucial autonomic roles. It is well known that nesfatin-1 collaborates with other central neuromodulatory systems, such as central corticotropin-releasing hormone, melanocortin, oxytocin, and cholinergic systems to show its autonomic effects. Central arachidonic acid cascade plays an important role to provide the homeostasis by exhibiting similar

BACKGROUND Renal denervation is effective for modulating augmented sympathetic nerve activity (SNA) in heart failure with reduced ejection fraction (HFrEF). We have demonstrated that renal iodine123-metaiodobenzylguanidine (123I-MIBG) scintigraphy is associated with muscle sympathetic nerve activity (MSNA) in patients with hypertension. However, it is unclear whether renal 123I-MIBG scintigraphy is

Inspiratory muscle exercise (IME) can be an alternative to conventional exercise. We aimed to evaluate the effect of IME on glucose, glucose variability, and autonomic cardiovascular control in type 2 diabetes. Fourteen diabetic subjects were randomly assigned to IME with 2% maximal inspiratory pressure (PImax) or 60% PImax wearing a continuous glucose monitoring system for three days. Glucose variability

BACKGROUND Treatment induced neuropathy of diabetes (TIND) is an iatrogenic painful sensory and autonomic neuropathy. Although the prevalence is not known, it is seen in up to 10% of tertiary cases referred for evaluation of diabetic neuropathy. EVIDENCE TIND is associated with a decrease in the glycosylated hemoglobin A1C in individuals with longstanding hyperglycemia. TIND is more common in individuals

Spinal cord injury (SCI) leads to autonomic nervous system damage, resulting in loss of sympathetic control to the vasculature and the heart proportional to injury level. Given maintained cardiac parasympathetic control, we hypothesized that SCI demonstrates a compensatory, higher baroreflex gain compared to able-bodied that relates to injury level (neurological and/or sensory). We compared baroreflex

OBJECTIVE To study the frequency of latent and overt involuntary emotional expression disorder (IEED) in postural tachycardia syndrome (PoTS). METHODS We compared 51 PoTS patients with 15 neurally mediated hypotension (NMH) patients and 12 control subjects using the Center for Neurologic Study-Lability Scale (CNS-LS) for latent IEED and the PHQ-9 questionnaire for depression screening before head-up