Alzheimer's disease (AD) is the most common type of neurodegenerative disorder, typically causing dementia along aging. AD is mainly characterized by a pathological extracellular accumulation of ...amyloid-beta peptides that affects excitatory and inhibitory synaptic transmission, inducing aberrant patterns in neuronal circuits. 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 synchronization likelihood (linear and nonlinear) or spectral coherence (linear), the latter by granger causality or information theory indexes. Here we reviewed literature concerning EEG studies in condition of resting state in AD and mild cognitive impairment (MCI) 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.
Abstract Occipital sources of resting-state electroencephalographic (EEG) alpha rhythms are abnormal, at the group level, in patients with amnesic mild cognitive impairment (MCI) and Alzheimer's ...disease (AD). Here, we evaluated the hypothesis that amplitude of these occipital sources is related to neurodegeneration in occipital lobe as measured by magnetic resonance imaging. Resting-state eyes-closed EEG rhythms were recorded in 45 healthy elderly (Nold), 100 MCI, and 90 AD subjects. Neurodegeneration of occipital lobe was indexed by weighted averages of gray matter density, estimated from structural MRIs. EEG rhythms of interest were alpha 1 (8–10.5 Hz) and alpha 2 (10.5–13 Hz). EEG cortical sources were estimated by low-resolution brain electromagnetic tomography. Results showed a positive correlation between occipital gray matter density and amplitude of occipital alpha 1 sources in Nold, MCI, and AD subjects as a whole group (r = 0.3, p = 0.000004, N = 235). Furthermore, there was a positive correlation between the amplitude of occipital alpha 1 sources and cognitive status as revealed by Mini Mental State Examination score across all subjects (r = 0.38, p = 0.000001, N = 235). Finally, amplitude of occipital alpha 1 sources allowed a moderate classification of individual Nold and AD subjects (sensitivity: 87.8%; specificity: 66.7%; area under the receiver operating characteristic curve: 0.81). These results suggest that the amplitude of occipital sources of resting-state alpha rhythms is related to AD neurodegeneration in occipital lobe along pathologic aging.
Playing music in ensemble represents a unique human condition/performance where musicians should rely on empathic relationships. Recent theories attribute to frontal Brodmann areas (BAs) 44/45 and ...10/11 a neural basis for “emotional” and “cognitive” empathy. We hypothesized that activity of these structures reflects empathy trait in professional musicians playing in ensemble. Simultaneous electroencephalographic (EEG) alpha rhythms (8–12Hz) were recorded in three saxophone quartets during music performance in ensemble (EXECUTION), video observation of their own performance (OBSERVATION), a control task (CONTROL), and resting state (RESTING). EEG source estimation was performed. Results showed that the higher the empathy quotient test score, the higher the alpha desynchronization in right BA 44/45 during the OBSERVATION referenced to RESTING condition. Empathy trait score and alpha desynchronization were not correlated in other control areas or in EXECUTION/CONTROL conditions. These results suggest that alpha rhythms in BA 44/45 reflect “emotional” empathy in musicians observing own performance.
► Playing music in ensemble represents human performance relying on empathic relation. ► BA 44/45 and 10/11 activity could reflect empathy trait of musicians in ensemble. ► Empathy trait score and alpha desynchronization were correlated in right BA 44/45. ► Observing own performance, BA 44/45 alpha rhythm could reflect emotional empathy.
Here we tested two working hypotheses on spatially selective cortical activation (“neural efficiency”) in experts: (i) compared to non-athletes, elite karate athletes are characterized by a reduced ...cortical activation during the judgment of karate actions; (ii) compared to non-athletes and elite karate athletes, amateur karate athletes are characterized by an intermediate cortical activation during the judgment of karate actions. Electroencephalographic (EEG) data were recorded in 16 elite karate athletes, 15 amateur athletes and 17 non-athletes. They observed a series of 120 karate videos. At the end of each video, the subjects had to judge the technical/athletic level of the exercise by a scale from 0 to 10. The mismatch between their judgment and that of the coach indexed the degree of action judgment. The EEG cortical sources were estimated by sLORETA. With reference to a pre-stimulus period, the power decrease of alpha (8–12
Hz) rhythms during the video indexed the cortical activation (event-related desynchronization, ERD). Regarding the hypothesis of reduced activity in elite karate athletes, low- and high-frequency alpha ERD was less pronounced in dorsal and “mirror” pathways in the elite karate athletes than in the non-athletes. Regarding the hypothesis of intermediate cortical activity in amateur karate athletes, low- and high-frequency alpha ERD was less pronounced in dorsal pathways across the non-athletes, the amateur karate athletes, and the elite karate athletes. In conclusion, athletes’ judgment of observed sporting actions is related to less pronounced alpha ERD, as a possible index of “neural efficiency” in experts engaged in social cognition.
Background
Fatigue is one of the most distressing symptoms of cancer patients. Its characteristics and impact on quality of life have not been fully explored and treatment of cancer-related fatigue ...in Italian oncological centers has not been codified.
Methods
A cross-sectional study was carried out on all patients attending for any reason the 24 participating centers in two non-consecutive days. Patients with fatigue filled out the Brief Fatigue Inventory (BFI) questionnaire and reported any pharmacological or non-pharmacological treatment for fatigue.
Results
From October 2014 to May 2015, 1394 cancer patients agreed to participate in the study. Fatigue was referred by 866 (62.1%) of patients; its duration was > 4 months in 441 patients (50.9%). In the investigators’ opinion, the most important (probable or almost sure) determinants of fatigue were reduced physical activity (271 patients), anxiety (149), pain (131), insomnia (125), anemia (123), and depression (123). Fatigue of moderate/severe intensity was reported by 43%/29.2% of patients, while usual fatigue in the last 24 h by 45%/33.1%, and the worst fatigue in the last 24 h by 33%/54.8%, respectively. Concerning the impact on quality of life, fatigue interfered moderately/severely with general activity in 30.8%/38.6% of patients, with mood in 26.1%/32.8%, with the ability to work in 27.9%/35.6%, with normal work in 26.7%/38.9%, with relationships with others in 21%/23.4% and with the ability to amuse themselves in 22.2%/33.1%. Only 117/866 patients (13.5%) received a pharmacological treatment represented by a corticosteroid in 101 patients (86.3%) while 188 patients (21.7%) received a non-pharmacological treatment such as physical exercise (120 patients, 63.8%) and various alimentary supplements (52 patients, 27.6%).
Conclusions
Cancer-related fatigue is frequently reported by oncological patients; its intensity and impact on quality of life is relevant.
It is not known whether frontal cerebral rhythms of the two hemispheres are implicated in fine motor control and balance.
To address this issue, electroencephalographic (EEG) and stabilometric ...recordings were simultaneously performed in 12 right-handed
expert golfers. The subjects were asked to stand upright on a stabilometric force platform placed at a golf green simulator
while playing about 100 golf putts. Balance during the putts was indexed by body sway area. Cortical activity was indexed
by the power reduction in spatially enhanced alpha (8â12 Hz) and beta (13â30 Hz) rhythms during movement, referred to as the
pre-movement period. It was found that the body sway area displayed similar values in the successful and unsuccessful putts.
In contrast, the high-frequency alpha power (about 10â12 Hz) was smaller in amplitude in the successful than in the unsuccessful
putts over the frontal midline and the arm and hand region of the right primary sensorimotor area; the stronger the reduction
of the alpha power, the smaller the error of the unsuccessful putts (i.e. distance from the hole). These results indicate
that high-frequency alpha rhythms over associative, premotor and non-dominant primary sensorimotor areas subserve motor control
and are predictive of the golfer's performance.
We tested the hypothesis of a relationship between heart rate variability (HRV) and Rolandic mu rhythms in relaxed condition of resting state. Resting state eyes-closed electroencephalographic (EEG) ...and electrocardiographic (ECG) data were recorded (10–20 System) in 42 healthy adults. EEG rhythms of interest were high-frequency alpha (10.5–13Hz) and low-frequency beta (13–20Hz), which are supposed to form Rolandic mu rhythms. Rolandic and occipital (control) EEG sources were estimated by LORETA software. Results showed a statistically significant (p<0.05, corrected) negative correlation across all subjects between Rolandic cortical sources of low-frequency beta rhythms and the low-frequency band power (LF, 0.04–0.15Hz) of tachogram spectrum as an index of HRV. The lower the amplitude of Rolandic sources of low-frequency beta rhythms (as a putative sign of activity of somatomotor cortex), the higher the LF band power of tachogram spectrum (as a putative sign of sympathetic activity). This effect was specific as there was neither a similar correlation between these EEG rhythms and high-frequency band power of tachogram spectrum (as a putative sign of parasympathetic vagal activity) neither between occipital sources of low-frequency beta rhythms (as a putative sign of activity of visual cortex) and LF band power of tachogram spectrum. These results suggest that Rolandic low-frequency beta rhythms are related to sympathetic activity regulating heart rate, as a dynamic neurophysiologic oscillatory mechanism sub-serving the interaction between brain neural populations involved in somatomotor control and brain neural populations regulating ANS signals to heart for on-going homeostatic adaptations.
The present study tested the two following hypotheses: (i) compared to non-athletes, elite athletes are characterized by a reduced cortical activation during the judgment of sporting observed ...actions; (ii) in elite athletes, a good judgment of observed sporting actions is related to a low cortical activation. To address these issues, electroencephalographic (EEG) data were recorded in 15 elite rhythmic gymnasts and 13 non-gymnasts. They observed a series of 120 rhythmic gymnastic videos. At the end of each video, the subjects had to judge the artistic/athletic level of the exercise by a scale from 0 to 10. The mismatch between their judgment and that of the coach indexed the degree of action judgment. The EEG cortical sources were estimated by sLORETA. With reference to a pre-stimulus period, the power decrease of alpha (8–12 Hz) rhythms during the videos indexed the cortical activation (event related desynchronization, ERD). Regarding the hypothesis (i), low- and high-frequency alpha ERD was lower in amplitude in the elite rhythmic gymnasts compared to the non-gymnasts in occipital and temporal areas (ventral pathway) and in dorsal pathway. Regarding the hypothesis (ii), in the elite rhythmic gymnasts high-frequency alpha ERD was higher in amplitude with the videos characterized by a high judgment error than those characterized by a low judgment error; this was true in inferior posterior parietal and ventral premotor areas (“mirror” pathway). These results globally suggest that the judgment of observed sporting actions is related to low amplitude of alpha ERD, as a possible index of spatially selective cortical activation (“neural efficiency”).
PDF
