44 research outputs found
Different abnormalities of electroencephalographic (EEG) markers in quiet wakefulness are related to motor visual hallucinations in patients with Parkinson's and Lewy body diseases
AbstractBackgroundParkinson's disease (PD) is the secondâmost common neurodegenerative disorder that affects 2â3% of the population â„ 65 years of age and may belong to cognitive deficits and dementia in 50% of cases. Disease with Lewy Bodies (DLB) is emerging as another important cause of dementia in pathological aging. PD and DLB are both due to intraâneuronal Lewy bodies and are characterized not only by motor dysfunctions but also by cognitive and/or psychiatric symptoms. An open issue is the extent to which these diseases are distinct entities. In this respect, here we compared cortical sources of resting state eyesâclosed electroencephalographic (rsEEG) rhythms in PD and DLB patients having visual hallucinations.MethodClinical and rsEEG rhythms in demographic matched PD (N = 93), DLB (N = 46), Alzheimer's disease dementia (AD, N= 70) and healthy elderly (Nold, N = 60) subjects were available from an international archive. Pathological groups were matched for cognitive status. Individual alpha frequency peak was used to determine the delta, theta, alpha1, alpha2, and alpha3 frequency band ranges. Fixed beta1, beta2, and gamma bands were considered. The eLORETA freeware estimated rsEEG cortical sources.ResultAs a confirmation of previous studies, compared to the Nold subjects, the AD, LBD, and PD patients showed higher widespread delta source activities and lower posterior alpha source activities. Specifically, posterior alpha source activities were more abnormal in the AD than the LBD and PD groups, while widespread delta source activities were more abnormal in the PD and DLB than the AD group. As novel results, in relation to the LBD and PD patients without visual hallucinations and the control groups (Nold, AD), those with visual hallucinations were characterized by higher parietal delta source activities (LBD, Figure 1) and parietoâoccipital alpha sources activities (PD, Figure 2).ConclusionThese novel results suggest that in LBD and PD patients resting in the quiet wakefulness, abnormalities in cortical neural synchronization at delta and alpha frequencies in parietal cortex are differently related to visual hallucinations despite the essence of alphaâsynucleinopathy
Functional cortical source connectivity of resting state electroencephalographic alpha rhythms shows similar abnormalities in patients with mild cognitive impairment due to Alzheimer's and Parkinson's diseases
Objective: This study tested the hypothesis that markers of functional cortical source connectivity of resting state eyes-closed electroencephalographic (rsEEG) rhythms may be abnormal in subjects with mild cognitive impairment due to Alzheimer's (ADMCI) and Parkinson's (PDMCI) diseases compared to healthy elderly subjects (Nold). Methods: rsEEG data had been collected in ADMCI, PDMCI, and Nold subjects (N = 75 for any group). eLORETA freeware estimated functional lagged linear connectivity (LLC) from rsEEG cortical sources. Area under receiver operating characteristic (AUROC) curve indexed the accuracy in the classification of Nold and MCI individuals. Results: Posterior interhemispheric and widespread intrahemispheric alpha LLC solutions were abnormally lower in both MCI groups compared to the Nold group. At the individual level, AUROC curves of LLC solutions in posterior alpha sources exhibited moderate accuracies (0.70-0.72) in the discrimination of Nold vs. ADMCI-PDMCI individuals. No differences in the LLC solutions were found between the two MCI groups. Conclusions: These findings unveil similar abnormalities in functional cortical connectivity estimated in widespread alpha sources in ADMCI and PDMCI. This was true at both group and individual levels. Significance: The similar abnormality of alpha source connectivity in ADMCI and PDMCI subjects might reflect common cholinergic impairment. (C) 2018 International Federation of Clinical Neurophysiology. Published by Elsevier B.V. All rights reserved
Heart rate variability reduction is related to a high amount of visceral adiposity in healthy young women.
Several heart rate variability (HRV) studies show abnormalities in autonomic nervous control in obese and overweight subjects. However, some of the results appear to be controversial. Here we investigate the HRV profile in seventy adult normotensive women and its association with general and visceral adiposity. Specifically, we recorded the electrocardiographic (ECG) activity in subjects during a supine resting state for five minutes in a quiet room late in the morning. Total fat mass (TFM) and visceral adipose tissue (VAT) were instead estimated using dual-energy X-ray absorptiometry (DXA). Finally, we used simple a linear regression analysis of frequency and time-domain parameters to study the relationship between HRV and adiposity. Our data showed an overall reduction of the HRV related to an increase of TFM although this regression appeared significant only for high frequencies (HF). When the linear regression was applied between HRV variables and VAT, the slope of the line increases, thus unveiling a statistically significant relation (i.e. the more VAT, the lower HRV). Finally, a control analysis showed that age does not alter the relation between HRV and VAT when used as a confounding factor in multiple regression. To conclude, these findings point to abnormal activity of the autonomic nervous system (ANS) in subjects with an excess of VAT and represent a starting point to determine a non-invasive index of cardiac wellness for clinical and nutritional application
Heart rate variability is reduced in underweight and overweight healthy adult women
Heart rate variability (HRV) is altered in obese subjects, but whether this is true also in underweight (UW) subjects is still under debate. We investigated the HRV profile in a sample of healthy adult women and its association with adiposity. Five-minute resting state electrocardiographic activity was recorded in 69 subjects grouped according to their body mass index, [23 normal weight (NW), 23 overweight/obese (OW) and 23 UW). Body fat mass (FM) was measured by bio-impedance. Frequency- and time-domain analyses were performed. Compared to NW, UW and OW subjects showed a significant decrease in HRV indices, as revealed by spectral analysis. No differences were observed between UW and OW subjects. A second-order polynomial regression unveiled an inverted U-shaped relationship between FM extent and HRV indices. A decrease of HRV indices was associated with changes in FM extent, proving that in UW and OW subjects, the adaptive flexibility of autonomic cardiac function was reduced. These findings provide important clues to guide future studies addressed to determine how changes in adiposity and autonomic cardiac function may contribute to health risk
Brain neural synchronization and functional coupling in Alzheimer's disease as revealed by resting state EEG rhythms
Alzheimer's disease (AD) is the most frequent neurodegenerative disorder and cause of dementia along with aging. It is characterized by a pathological extracellular accumulation of amyloid-beta peptides that affects excitatory and inhibitory synaptic transmission. It also triggers aberrant patterns of neuronal circuit activity at the network level. Growing evidence shows that AD targets cortical neuronal networks related to cognitive functions including episodic memory and visuospatial attention. This is partially reflected by the abnormal mechanisms of cortical neural synchronization and coupling that generate resting state electroencephalographic (EEG) rhythms. The cortical neural synchronization is typically indexed by EEG power density. The EEG coupling between electrode pairs probes functional (inter-relatedness of EEG signals) and effective (casual effect from one over the other electrode) connectivity. The former is typically indexed by EEG spectral coherence (linear) or synchronization likelihood (linear-nonlinear), the latter by Granger causality or information theory indexes. Here we revised resting state EEG studies in mild cognitive impairment (MCI) and AD subjects as a window on abnormalities of the cortical neural synchronization and functional and effective connectivity. Results showed abnormalities of the EEG power density at specific frequency bands (<12Hz) in the MCI and AD populations, associated with an altered functional and effective EEG connectivity among long range cortical networks (i.e., fronto-parietal and fronto-temporal). These results suggest that resting state EEG rhythms reflect the abnormal cortical neural synchronization and coupling in the brain of prodromal and overt AD subjects, possibly reflecting dysfunctional neuroplasticity of the neural transmission in long range cortical networks
Parachute jumping induces more sympathetic activation than cortisol secretion in first-time parachutists
Background: The word âstressâ describes the status of the body affected by external or internal forces, or âstressorsâ, threatening to alter its dynamic balance or homeostasis. The adaptive changes which occur in reply to stressors are either behavioral or physical. Once a given threshold is surpassed, a systemic reaction takes place involving the âstress systemâ in the brain together with its peripheral components, the hypothalamic-pituitary-adrenal axis and autonomic sympathetic. Objectives: Stress induces an activation of the sympathetic nervous system (SNS) and the hypothalamic-pituitary-adrenal (HPA) axis. The purpose of this study was to investigate whether the SNS and the HPA axis would show parallel or divergent stress response patterns in a session of first parachute jump. Patients and Methods: Activation of the SNS was evaluated by dosage of salivary alpha-amylase, galvanic skin responses, and heart rate in seven male novice parachutists. Activation of HPA axis was tested by dosage of cortisol. These variables were measured before and 1 minute and 90 minute after the jump. Results: All variables reached a peak at 1 minute post-jump. Salivary alpha-amylase, galvanic skin responses and heart rate did not return to basal value at 90 minutes post-jump, while cortisol returned to basal value at 90 minutes post-jump. Conclusions: This evidence indicates that parachute jumping is accompanied by a dissociation of SNS and HPA response patterns in novice parachutists, showing a slower recovery in sympathetic activity than in cortisol secretion
Parachute jumping induces more sympathetic activation than cortisol secretion in first-time parachutists
Background: The word âstressâ describes the status of the body affected by external or internal forces, or âstressorsâ, threatening to alter its dynamic balance or homeostasis. The adaptive changes which occur in reply to stressors are either behavioral or physical. Once a given threshold is surpassed, a systemic reaction takes place involving the âstress systemâ in the brain together with its peripheral components, the hypothalamic-pituitary-adrenal axis and autonomic sympathetic.
Objectives: Stress induces an activation of the sympathetic nervous system (SNS) and the hypothalamic-pituitary-adrenal (HPA) axis. The purpose of this study was to investigate whether the SNS and the HPA axis would show parallel or divergent stress response patterns in a session of first parachute jump.
Patients and Methods: Activation of the SNS was evaluated by dosage of salivary alpha-amylase, galvanic skin responses, and heart rate in seven male novice parachutists. Activation of HPA axis was tested by dosage of cortisol. These variables were measured before and 1 minute and 90 minute after the jump.
Results: All variables reached a peak at 1 minute post-jump. Salivary alpha-amylase, galvanic skin responses and heart rate did not return to basal value at 90 minutes post-jump, while cortisol returned to basal value at 90 minutes post-jump.
Conclusions: This evidence indicates that parachute jumping is accompanied by a dissociation of SNS and HPA response patterns in novice parachutists, showing a slower recovery in sympathetic activity than in cortisol secretion
Heart Rate Changes After Ultra-Endurance Swim From Italy to Albania: A Case Report
To evaluate the effect of a solo ultra-endurance open-water swim upon autonomic and non-autonomic control of heart rate (HR)
Activity of Autonomic Nervous System, Energy Expenditure and Assessment of Oxidative Stress in Menopause-women Using Hormone Replacement Therapy
Aims: Menopause is a period of significant physiological change that may be associated with
increased body weight and obesity-related diseases. Many studies have been carried out to
determine influences of estrogen depletion, resting energy expenditure (REE) decline and aging
during menopause-related obesity.
Methodology: In the present experiment, REE, body composition, activity of the autonomic
nervous system, oxidative stress and food intake were measured in three groups of women: premenopause
(n=40), post-menopause with hormone-replacement therapy (HRT) (n=40) and postmenopause
without HRT (n=40).
Results: In post-menopause women with HRT a significant increase was found in: 1) the
sympathetic activity, measured by the power spectral analysis of the heart rate variability; 2) REE,
measured by indirect calorimetry; 3) oxidative stress, measured by Free Radical Analytical System
4 (Fras-4) compared to the value of the other two, while fat mass, measured by Body Impedance
Analysis (BIA), was reduced in favor of a recovery of free fat mass.
Conclusion: The study emphasizes the important changes due to HRT on various components
influencing body weight in menopause-women
Subjects' hypnotizability level affects somatosensory evoked potentials to non-painful and painful stimuli.
Objective: We evaluated the working hypothesis that the EEG activity associated to non-painful and painful stimuli in condition of waking state (no hypnotic procedure) was related to the hypnotizability level. Methods: Hypnotizability level was measured in 16 healthy subjects through the Italian version of the Stanford Hypnotic Susceptibility Scale (SHSS, score: 0-12). EEG data (56 electrodes) were recorded during non-painful and painful electrical stimuli applied to the left index finger. Cortical activity (vertex N1-P2 complex) was compared in subjects with low hypnotizability level (N = 8, SHSS:0-6) vs. subjects with high hypnotizability level (N = 8, SHSS:7-12). Results: The amplitude of the N1-P2 complex was lower in the High-hypnotizability compared to the Low-hypnotizability group over primary sensorimotor cortex (C3 and C4 electrodes) and centro-parietal midline areas (Cz and Pz electrodes) for non-painful and painful stimuli. The SHSS showed a statistically significant negative correlation with the vertex N1-P2 complex at C3 and Cz (r= -0.5, p< 0.05) electrodes for non-painful stimuli. Conclusion: Compared to the Low-hypnotizability subjects, High-hypnotizability subjects showed a reduced cortical activity related to non-painful and painful stimuli. Significance: The results suggest a relationship between hypnotizability and cortical activity related to non-painful and painful stimuli in the condition of waking state (no hypnotic effect). © 2013