Search results for "Autonomic system"
showing 10 items of 247 documents
Dynamic cerebrovascular autoregulation in patients prone to postural syncope: Comparison of techniques assessing the autoregulation index from sponta…
2021
Abstract Three approaches to the assessment of cerebrovascular autoregulation (CA) via the computation of the autoregulation index (ARI) from spontaneous variability of mean arterial pressure (MAP) and mean cerebral blood flow velocity (MCBFV) were applied: 1) a time domain method (TDM); 2) a nonparametric method (nonPM); 3) a parametric method (PM). Performances were tested over matched and surrogate unmatched pairs. Data were analyzed at supine resting (REST) and during the early phase of 60° head-up tilt (TILT) in 13 subjects with previous history of postural syncope (SYNC, age: 28 ± 9 yrs.; 5 males) and 13 control individuals (noSYNC, age: 27 ± 8 yrs.; 5 males). Analysis was completed b…
Autonomic dysfunction in patients with achalasia.
1995
It has been previously shown that patients with achalasia may have motor abnormalities of the stomach, small bowel and biliary system. This study investigates whether a disturbance of extraintestinal autonomic function occurs. Autonomic function studies were performed in 15 patients with achalasia and 15 age- and sex-matched healthy controls. Pupillo-grams were obtained during darkness, light exposure and after pilocarpine administration. Cardiovascular function studies included determinations of heart rate variation during deep breathing and orthostasis. In addition, we determined blood pressure changes in response to sustained handgrip, cold exposure and orthostasis. Neurohormonal functio…
Oesophageal motility disorders in type 1 diabetes mellitus and their relation to cardiovascular autonomic neuropathy.
2006
The relationship between cardiovascular autonomic neuropathy (CVAN) and oesophageal dysfunction in diabetes mellitus has not been well established because reports are contradictory. The aim of this study was to assess oesophageal function and its correlation with CVAN in type 1 diabetic patients without oesophageal symptoms. Forty-six type 1 diabetic patients without oesophageal symptoms (DG) and 34 healthy volunteers (CG) were studied. Both groups underwent CVAN tests and oesophageal manometry and pH-metry. Differences between groups regarding results of cardiovascular autonomic tests and oesophageal studies were statistically analysed. Compared with the CG, the DG group showed insufficien…
Ventilatory responses to imagined exercise.
1996
We studied whether the ventilatory responses to imagined exercise are influenced by automatic processes. Twenty-nine athletes produced mental images of a sport event with successive focus on the environment, the preparation, and the exercise. Mean breathing frequency increased from 15 to 22 breaths/min. Five participants reported having voluntarily controlled breathing, two of them during preparation. Twenty participants reported that their breathing pattern changed during the experiment: 11 participants were unable to correctly report on the direction of changes in frequency, and 13 incorrectly reported changes in amplitude. This finding suggests that these changes were not voluntary in mo…
Measuring postural-related changes of spontaneous baroreflex sensitivity after repeated long-duration diving: Frequency domain approaches
2012
Sustained water immersion is thought to modulate orthostatic tolerance to an extent dependent on the duration and repetition over consecutive days of the diving sessions. We tested this hypothesis investigating in ten healthy subjects the potential changes in the cardiovascular response to head-up tilt induced by single and multiple resting air dives. Parametric cross-spectral analysis of spontaneous RR interval and systolic arterial pressure variability was performed in three experimental sessions: before diving (BD), after single 6-hour dive (ASD), and after multiple 6-hour dives (AMD, 5 consecutive days with 18-hour surface interval). From this analysis, baroreflex sensitivity (BRS) was …
Effect of Cabergoline on Metabolism in Prolactinomas.
2013
<b><i>Introduction:</i></b> Hyperprolactinemia has been implicated in the pathogenesis of obesity and glucose intolerance and is reportedly associated with an impaired metabolic profile. The current study aimed at investigating the effects of 12- and 60-month treatment with cabergoline (CAB) on metabolic syndrome (MetS) in patients with prolactinomas. <b><i>Patients and Methods:</i></b> 61 patients with prolactinomas (13 men, 48 women, 41 with microadenoma, 20 with macroadenoma), aged 34.4 ± 10.3 years, entered the study. In all patients, prolactin (PRL) and metabolic parameters were assessed at diagnosis and after 12 and 60 months of continuo…
Diurnal coupling between testosterone and cortisol from adolescence to older adulthood
2016
The hypothalamic-pituitary-adrenal (HPA) and hypothalamic-pituitary-gonadal (HPG) axes are typically conceptualized as mutually inhibitory systems; however, previous studies have found evidence for positive within-person associations (i.e., coupling) between cortisol and testosterone. One developmental hypothesis is that positive testosterone-cortisol coupling is unique to the adolescent period and that coupling becomes attenuated, or even switches direction, in adulthood. This study used a lifespan sample (N = 292, ages 11 to 88) to test for age-related differences in coupling between cortisol and testosterone in daily life. Participants provided salivary hormone samples at waking, 30 minu…
Behavioral and event-related potential distraction effects with regularly occurring auditory deviants
2007
When auditory stimulation contains infrequent task-irrelevant changes (deviants), behavioral responses to task-relevant aspects of the stimulation are prolonged. Event-related brain potentials (ERPs) show that deviants elicit mismatch negativity (MMN), P3a, and reorienting negativity (RON). Here, we examine whether distraction effects can also be elicited within fixed auditory sequences with deviant probabilities of 0.25, 0.33, and 0.5. Deviants varied either in pitch, loudness, or sound source location. In all conditions MMN and P3a were elicited, suggesting that an automatic detection of and an attentional allocation to the change occurred. With relative frequencies of 25% and 33%, devian…
Orexin and sleep quality in anorexia nervosa: Clinical relevance and influence on treatment outcome
2015
Background and aims Orexins/hypocretins are orexigenic peptides implicated in the regulation of feeding behavior and the sleep/wake cycle. Little is known about the functioning of these peptides in anorexia nervosa (AN). The aims of the current study were to evaluate the extent to which orexin-A might be linked to sleep and treatment outcome in AN. Method Fasting plasma orexin-A concentrations were measured in 48 females with AN at the start of a day hospital treatment and in 98 normal-eater/healthy-weight controls. The Pittsburgh Sleep Quality Index was administered at the beginning of the treatment as a measure of sleep quality. Other psychopathological variables were evaluated with the S…
Inflammatory cytokines and anorexia nervosa: A meta-analysis of cross-sectional and longitudinal studies
2014
Objective: Although inflammation is increasingly implicated in psychiatric disorders, less is known about its role in anorexia nervosa (AN), an illness with low body mass index (BMI). Methods: We performed a systematic PubMed literature search until 12/31/2013 and meta-analyzed cross-sectional and longitudinal studies comparing circulating pro- and anti-inflammatory cytokines between patients with anorexia nervosa (AN) and healthy controls (HCs) (1) before and (2) after weight gain, and (3) within AN patients before and after weight gain. Standardized mean differences (SMDs). ±. 95% confidence intervals (CIs) for results from ≥2 studies were calculated. Results: Of 999 initial hits, 22 stud…