scholarly journals EEG alpha activity increased in response to transcutaneous electrical nervous stimulation in young healthy subjects but not in the healthy elderly

PeerJ ◽  
2020 ◽  
Vol 8 ◽  
pp. e8330 ◽  
Author(s):  
Ebru Yıldırım ◽  
Bahar Güntekin ◽  
Lütfü Hanoğlu ◽  
Candan Algun
Keyword(s):  
Repeated Measures ◽  
Healthy Subjects ◽  
Alpha Activity ◽  
Elderly Subjects ◽  
Alpha Power ◽  
Nervous Stimulation ◽  
Healthy Elderly ◽  
Young Subjects ◽  
The Brain ◽  
Sensory Functions

Transcutaneous Electrical Nerve Stimulation (TENS) is used not only in the treatment of pain but also in the examination of sensory functions. With aging, there is decreased sensitivity to somatosensory stimuli. It is essential to examine the effect of TENS application on the sensory functions in the brain by recording the spontaneous electroencephalogram (EEG) activity and the effect of aging on the sensory functions of the brain during the application. The present study aimed to investigate the effect of the application of TENS on the brain’s electrical activity and the effect of aging on the sensory functions of the brain during application of TENS. A total of 15 young (24.2 ± 3.59) and 14 elderly (65.64 ± 4.92) subjects were included in the study. Spontaneous EEG was recorded from 32 channels during TENS application. Power spectrum analysis was performed by Fast Fourier Transform in the alpha frequency band (8–13 Hz) for all subjects. Repeated measures of analysis of variance was used for statistical analysis (p < 0.05). Young subjects had increased alpha power during the TENS application and had gradually increased alpha power by increasing the current intensity of TENS (p = 0.035). Young subjects had higher alpha power than elderly subjects in the occipital and parietal locations (p = 0.073). We can, therefore, conclude that TENS indicated increased alpha activity in young subjects. Young subjects had higher alpha activity than elderly subjects in the occipital and somatosensory areas. To our knowledge, the present study is one of the first studies examining the effect of TENS on spontaneous EEG in healthy subjects. Based on the results of the present study, TENS may be used as an objective method for the examination of sensory impairments, and in the evaluative efficiency of the treatment of pain conditions.

The influence of dynamic visual environments on postural sway in the elderly

1999 ◽  
Vol 9 (3) ◽  
pp. 197-205
Author(s):  
L.L. Borger ◽  
S.L. Whitney ◽  
M.S. Redfern ◽  
J.M. Furman
Keyword(s):  
Visual Information ◽  
Postural Sway ◽  
Center Of Pressure ◽  
Age Groups ◽  
The Elderly ◽  
Visual Scene ◽  
Elderly Subjects ◽  
Mean Velocity ◽  
Healthy Elderly ◽  
Young Subjects

Postural sway during stance has been found to be sensitive to moving visual scenes in young adults, children, and those with vestibular disease. The effect of visual environments on balance in elderly individuals is relatively unknown. The purpose of this study was to compare postural sway responses of healthy elderly to those of young subjects when both groups were exposed to a moving visual scene. Peak to peak, root mean squared, and mean velocity of the center of pressure were analyzed under conditions combining four moving scene amplitudes ( 2 . 5 ∘ , 5 ∘ , 7 . 5 ∘ , 10 ∘ ) and two frequencies of scene movement (0.1 Hz, 0.25 Hz). Each visual condition was tested with a fixed floor and sway referenced platform. Results showed that elderly subjects swayed more than younger subjects when experiencing a moving visual scene under all conditions. The elderly were affected more than the young by sway referencing the platform. The differences between the two age groups were greater at increased amplitudes of scene movement. These results suggest that elderly are more influenced by dynamic visual information for balance than the young, particularly when cues from the ankles are altered.

Postural Control in Young and Elderly Adults When Stance is Challenged: Clinical versus Laboratory Measurements

1993 ◽  
Vol 102 (7) ◽  
pp. 508-517 ◽  
Author(s):  
Neil T. Shepard ◽  
Albert Schultz ◽  
Mian Ju Gu ◽  
Neil B. Alexander ◽  
Thomas Boismier
Keyword(s):  
Postural Control ◽  
Laboratory Study ◽  
Lower Limbs ◽  
Measuring System ◽  
Elderly Subjects ◽  
Dynamic Posturography ◽  
Clinical Interpretation ◽  
Healthy Elderly ◽  
Young Subjects

The use of dynamic posturography (EquiTest) for the characterization of postural control biomechanics would be aided by specific knowledge of what the measured data imply about body segment movements. To investigate this issue, the biomechanics of a group of 15 healthy elderly subjects were compared to those of healthy young subjects by using both dynamic posturography and a laboratory movement and force measuring system. The results from EquiTest were analyzed by 1) routine clinical interpretation of data and 2) a clinical research interpretation by subjecting the EquiTest parameters to additional statistical comparison of mean performance of the young and elderly groups. The young-elderly differences from the 2 EquiTest analyses were then compared to the young-elderly differences derived from the laboratory protocol. The routine clinical interpretation of EquiTest data identified the same increases in sway shown by the laboratory study, but did not reveal the more subtle differences indicated by the laboratory study. When the EquiTest data were subjected to additional statistical analysis, the characterization of difference between young and elderly subjects was the same as that of the laboratory study, with the exception of issues of head versus trunk movement, a measure not made by EquiTest. This essential similarity in the characterization of elderly compared to young subjects by both systems suggests 1) that EquiTest is able to detect subtle differences in biomechanics of postural control between young and elderly healthy adult groups and 2) that implied movements of center of gravity, trunk versus lower limbs, and strength of reaction measures are consistently detected by both EquiTest and the laboratory kinematics and dynamics measurement systems.

scholarly journals Alpha absolute power: motor learning of practical pistol shooting

2008 ◽  
Vol 66 (2b) ◽  
pp. 336-340 ◽  
Author(s):  
Clayton Amaral Domingues ◽  
Sergio Machado ◽  
Emerson Garcia Cavaleiro ◽  
Vernon Furtado ◽  
Mauricio Cagy ◽  
...  
Keyword(s):  
Motor Learning ◽  
Repeated Measures ◽  
Healthy Subjects ◽  
Learning Task ◽  
Alpha Power ◽  
Motor Execution ◽  
Task Execution ◽  
Post Hoc Analysis ◽  
Post Hoc ◽  
One Way Anova

The present study aimed at investigating changes in behavior (shooting precision) and electrophysiological variables (absolute alpha power) during the motor learning of practical pistol shooting. The sample was composed of 23 healthy subjects, right-handed, male, between 18 and 20 years of age. The task consisted of four learning blocks. A One-way ANOVA with repeated measures and a post hoc analysis were employed to observe modifications on behavioral and electrophysiological measures (p<0.05). The results showed significative differences between blocks according to motor learning, and a significant improvement in shooting's accuracy from both blocks. It was observed a decrease in alpha power in all electrodes examined during task execution when compared with baseline and learning control blocks. The findings suggest that alpha power decreases as the function of the motor learning task when subjects are engaged in the motor execution.

Effect of ‘Autonomic Blockade’ on Cardiac β-Adrenergic Chronotropic Responsiveness in Healthy Young, Healthy Elderly and Endurance-Trained Elderly Subjects

1994 ◽  
Vol 87 (3) ◽  
pp. 297-302 ◽  
Author(s):  
G. A. Ford ◽  
O. F. W. James
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Geometric Mean ◽  
Cardiovascular Responses ◽  
The Elderly ◽  
Elderly Subjects ◽  
Healthy Elderly ◽  
Age Related ◽  
Autonomic Blockade ◽  
Young Subjects

1. Cardiac chronotropic responses to isoprenaline are reduced with ageing in man. It is unclear whether this is due to reduced cardiac β-adrenergic sensitivity or to age-associated differences in reflex cardiovascular responses to the vasodilatory effects of isoprenaline. Age-associated changes in physical activity are also reported to influence β-adrenergic sensitivity. 2. The aim of the present study was to determine the contribution of alterations in reflex changes in parasympathetic and sympathetic influences and physical fitness to the age-associated reduction in cardiac chronotropic responses to β-adrenergic agonists. 3. The effect of ‘autonomic blockade’ with atropine (40 μg/kg intravenously) and clonidine (4 μg/kg intravenously) on blood pressure, heart rate and chronotropic responses to intravenous bolus isoprenaline doses was determined in eight healthy young (mean age 21 years), nine healthy elderly (72 years) and 10 endurance-trained elderly (69 years) subjects. 4. Elderly subjects had a reduced increase in heart rate after atropine (young, 49 ± 9 beats/min; elderly, 36 ± 5 beats/min; endurance-trained elderly, 34 ± 12 beats/min; P < 0.01) and did not demonstrate the transient increase in systolic blood pressure after clonidine observed in young subjects (young, 11 ± 10 mmHg; elderly, −12 ± 16 mmHg; endurance-trained elderly, −18 ± 11 mmHg; P < 0.01). 5. Cardiac chronotropic sensitivity to isoprenaline after ‘autonomic blockade’ increased in the young but decreased in the elderly subjects. The isoprenaline dose that increased heart rate by 25 beats/min before and after autonomic blockade' was: young, before 1.6 μg, after 2.8 μg, P < 0.01 (geometric mean, paired test); elderly, before 6.9 μg, after 3.6 μg, P < 0.05; endurance-trained elderly, before 5.9 μg, after 4.0 μg, P < 0.05. Cardiac chronotropic sensitivity to isoprenaline was significantly reduced in elderly compared with young subjects before (P < 0.01) but was similar after (P = 0.09) ‘autonomic blockade’. Chronotropic sensitivity did not differ between healthy and endurance-trained elderly subjects before or after ‘autonomic blockade’. 6. The age-associated reduction in cardiac chronotropic responses to bolus isoprenaline is primarily due to an age-related reduction in the influence of reflex cardiovascular responses on heart rate and not to an age-related reduction in cardiac β-adrenergic sensitivity. Endurance training is not associated with altered β-adrenergic chronotropic sensitivity in the elderly. The transient pressor response to intravenously administered clonidine may be lost in ageing man.

scholarly journals Stimulus-induced narrowband gamma oscillations are test-retest reliable in healthy elderly in human EEG

2021 ◽  
Author(s):  
Supratim Ray ◽  
Dinavahi V P S Murty ◽  
Wupadrasta Santosh Kumar ◽  
Keerthana Manikandan ◽  
Ranjini Garani Ramesh ◽  
...  
Keyword(s):  
Temporal Evolution ◽  
Intraclass Correlation ◽  
Gamma Oscillations ◽  
Elderly Subjects ◽  
Spectral Profile ◽  
Full Field ◽  
Healthy Elderly ◽  
Gamma Power ◽  
Young Subjects ◽  
Eeg Recordings

Visual stimulus-induced narrowband gamma oscillations in electroencephalogram (EEG) recordings have been recently shown to be compromised in subjects with Mild Cognitive Impairment or Alzheimer′s Disease (AD), suggesting that gamma could be an inexpensive and easily accessible biomarker for early diagnosis of AD. However, to use gamma as a biomarker, its characteristics should remain consistent across multiple recordings, even when separated over long intervals. Previous magnetoencephalography studies in young subjects have reported that gamma power remains consistent over recordings separated by a few weeks to months. Here, we assessed the consistency of slow (20-35 Hz) and fast gamma (36-66 Hz) oscillations induced by static full-field gratings in male (N=20) and female (N=20) elderly subjects (>49 years) in EEG recordings separated by more than a year and tested the consistency in the magnitude of gamma power, its temporal evolution and spectral profile. Gamma oscillations had distinct spectral and temporal characteristics across subjects, which remained consistent across recordings (average intraclass correlation, ICC of ~0.7). Alpha oscillations (8-12 Hz) and steady-state-visually-evoked-potentials (SSVEPs) were also found to be reliable. We further tested how EEG features can be used to identify two recordings as belonging to the same versus different subjects and found high classifier performance (area under ROC curve of ~0.89), with the temporal evolution of slow gamma and spectral profile emerging as the most informative features. These results suggest that EEG gamma oscillations are reliable across recordings and can be used as a clinical biomarker as well as a potential tool for subject identification.

scholarly journals Changes during aging in the electroencephalographic cortical synchronization under visual stimulation

2015 ◽  
Vol 6 (1) ◽  
pp. 15-26
Author(s):  
Guzmán Alba ◽  
Almudena González ◽  
Julián J. González
Keyword(s):  
Repeated Measures ◽  
Visual Stimulation ◽  
Elderly Subjects ◽  
Generalized Synchronization ◽  
Cortical Areas ◽  
Eyes Closed ◽  
Healthy Elderly ◽  
The Mean ◽  
Eeg Recordings ◽  
Healthy Elderly Subjects

This paper analyzes changes during aging in the electroencephalographic (EEG) synchronization between different areas of the cerebral cortex in healthy elderly subjects under visual stimulation. Two groups were selected: one (A) of 10 adults aged 50-65 years and another (B) of 15 subjects aged 66-80 years. EEG recordings of 16 "monopolar" channels were carried out (digitized at 256 Hz), all referenced to the mean and following the standard 10-20 system, and were performed at rest with eyes closed under visual stimulation. From an index (L) of nonlinear generalized synchronization, the average cortical synchronization (ACS) of each channel with the rest and the corresponding average asymmetry in the synchronization (ACM) was estimated. Changes with age (A vs. B) in cortical synchronization and in average interhemispheric asymmetry for all cortical areas were estimated via a repeated measures MANOVA. The results show that under visual stimulation, the SCM decreases with age for most channels (p < 0.01) except for the frontals. The channels that showed asymmetry in the synchronization (p < 0.01) were the frontals F3, F4 y Fp2, the parietal P3 and the temporal T5, in all of them a significant reduction in asymmetry with age (p < 0.01) was observed.

scholarly journals Changes during aging in the electroencephalographic cortical synchronization under visual stimulation

2015 ◽  
Vol 6 (1) ◽  
pp. 15-26
Author(s):  
Guzmán Alba ◽  
Almudena González ◽  
Julián J. González
Keyword(s):  
Repeated Measures ◽  
Visual Stimulation ◽  
Elderly Subjects ◽  
Generalized Synchronization ◽  
Cortical Areas ◽  
Eyes Closed ◽  
Healthy Elderly ◽  
The Mean ◽  
Eeg Recordings ◽  
Healthy Elderly Subjects

This paper analyzes changes during aging in the electroencephalographic (EEG) synchronization between different areas of the cerebral cortex in healthy elderly subjects under visual stimulation. Two groups were selected: one (A) of 10 adults aged 50-65 years and another (B) of 15 subjects aged 66-80 years. EEG recordings of 16 "monopolar" channels were carried out (digitized at 256 Hz), all referenced to the mean and following the standard 10-20 system, and were performed at rest with eyes closed under visual stimulation. From an index (L) of nonlinear generalized synchronization, the average cortical synchronization (ACS) of each channel with the rest and the corresponding average asymmetry in the synchronization (ACM) was estimated. Changes with age (A vs. B) in cortical synchronization and in average interhemispheric asymmetry for all cortical areas were estimated via a repeated measures MANOVA. The results show that under visual stimulation, the SCM decreases with age for most channels (p < 0.01) except for the frontals. The channels that showed asymmetry in the synchronization (p < 0.01) were the frontals F3, F4 y Fp2, the parietal P3 and the temporal T5, in all of them a significant reduction in asymmetry with age (p < 0.01) was observed.

FRACTAL CHANGES IN HEART RATE DYNAMICS WITH AGING AND HEART FAILURE

2003 ◽  
Vol 03 (01) ◽  
pp. L83-L89 ◽  
Author(s):  
L. GUZMAN-VARGAS ◽  
E. CALLEJA-QUEVEDO ◽  
F. ANGULO-BROWN
Keyword(s):  
Heart Failure ◽  
Congestive Heart Failure ◽  
Fractal Dimension ◽  
Elderly Subjects ◽  
Crossover Point ◽  
Healthy Elderly ◽  
Fractal Organization ◽  
Heart Rate Dynamics ◽  
Young Subjects ◽  
Effects Of Aging

In this work we analyze interbeat cardiac time series arising of three groups: healthy young and healthy elderly subjects and patients with congestive heart failure. We use the fractal dimension method proposed by Higuchi. We find that fractal organization is different for each group. In the case of healthy young subjects only one value of the fractal dimension is necessary to fit the interbeat data, whereas in the cases of healthy elderly and patients with congestive heart failure a crossover behavior in the fractal dimension is present but in opposite directions. By means of a "zoom" on the hinges of the crossover point interesting effects of aging are presented. Finally, we discuss our results in the context of heart interbeat dynamics.

scholarly journals Lexical Retrieval or Semantic Knowledge Which One Causes Naming Errors in Patients with Mild and Moderate Alzheimer’s Disease

2017 ◽  
Vol 7 (3) ◽  
pp. 419-429 ◽  
Author(s):  
Masoome Salehi ◽  
Mohsen Reisi ◽  
Leila Ghasisin
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Healthy Subjects ◽  
Conceptual Knowledge ◽  
Semantic Knowledge ◽  
Elderly Subjects ◽  
Lexical Retrieval ◽  
Healthy Elderly ◽  
Written Word ◽  
Healthy Elderly Subjects

Background: The purpose of the study was to analyze naming errors in patients with Alz­heimer’s disease in comparison to healthy subjects and determine the underlying cause of naming errors in these patients. Method: In this study, we included 35 healthy elderly subjects, 23 patients with mild Alzheimer’s disease, and 23 with moderate Alzheimer’s disease. Forty-five images were used to determine the type of naming errors, and to identify the underlying cause of errors, matching an image with a written word was used. Results: Patients with Alz­heimer’s disease had more naming errors compared with the group of healthy elderly, and patients with moderate Alzheimer’s disease showed a slower reaction in matching an image with a written word. Conclusion: Anomia in the initial phase of Alzheimer’s disease is due to problems in lexical retrieval; however, as the disease advances, in addition to lexical retrieval problems, conceptual knowledge causes naming problems.

scholarly journals Hypothalamus-Pituitary-Adrenal Hyperactivity in Human Aging Is Partially Refractory to Stimulation by Mineralocorticoid Receptor Blockade

2005 ◽  
Vol 90 (10) ◽  
pp. 5656-5662 ◽  
Author(s):  
Roberta Giordano ◽  
Mario Bo ◽  
Micaela Pellegrino ◽  
Marco Vezzari ◽  
Matteo Baldi ◽  
...  
Keyword(s):  
Hpa Axis ◽  
Mineralocorticoid Receptor ◽  
Elderly Subjects ◽  
Cortisol Secretion ◽  
Mineralocorticoid Receptors ◽  
Placebo Administration ◽  
Healthy Elderly ◽  
Age Related ◽  
Young Subjects ◽  
Mineralocorticoid Antagonists

Context: The hypothalamus-pituitary-adrenal (HPA) axis is mainly regulated by CRH, arginine vasopressin, and glucocorticoid feedback. Hippocampal mineralocorticoid receptors mediate proactive glucocorticoid feedback and mineralocorticoid antagonists, accordingly, stimulate HPA axis. Age-related HPA hyperactivity reflects impaired glucocorticoid feedback at the suprapituitary level. Design: ACTH, cortisol, and dehydroepiandrosterone (DHEA) secretion were studied in eight healthy elderly (75.1 ± 3.2 yr) and eight young (25.0 ± 4.6 yr) subjects during placebo or canrenoate (CAN) administration (200 mg iv bolus followed by 200 mg infused over 4 h). Results: During placebo administration, ACTH and cortisol areas under the curve (AUCs) in elderly subjects were higher than in young subjects (P ≤ 0.01); conversely, DHEA AUCs in elderly subjects were lower than in young subjects (P = 0.002). CAN increased ACTH, cortisol, and DHEA levels in both groups. In young subjects, ACTH, cortisol, and DHEA levels at the end of CAN infusion were higher (P ≤ 0.05) than after placebo. In elderly subjects, at the end of CAN infusion, ACTH, cortisol, and DHEA levels were higher (P = 0.01) than after placebo. Under CAN, ACTH and cortisol AUCs were persistently higher (P ≤ 0.01) and DHEA AUCs lower (P = 0.006) in elderly than in young subjects. Cortisol AUCs after CAN in young subjects did not become significantly different from those in elderly subjects after placebo. Conclusions: 1) Evening-time ACTH and cortisol secretion in elderly subjects is higher than in young subjects; 2) ACTH and cortisol secretion in elderly subjects is enhanced by CAN but less than that in young subjects; and 3) DHEA hyposecretion in elderly subjects is partially restored by mineralocorticoid antagonism. Age-related variations of HPA activity may be determined by some derangement in mineralocorticoid receptors function at the hippocampal level.

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