scholarly journals Resting-state MEG measurement of functional activation as a biomarker for cognitive decline in MS

2018 ◽  
Vol 25 (14) ◽  
pp. 1896-1906 ◽  
Author(s):  
Deborah N Schoonhoven ◽  
Matteo Fraschini ◽  
Prejaas Tewarie ◽  
Bernard MJ Uitdehaag ◽  
Anand JC Eijlers ◽  
...  
Keyword(s):  
Cognitive Impairment ◽  
Resting State ◽  
Brain Function ◽  
Peak Frequency ◽  
Cognitively Impaired ◽  
Clinical Neurology ◽  
Linear Regression Models ◽  
Eyes Closed ◽  
Gender And Education ◽  
Cognitive Disturbances

Background: Neurophysiological measures of brain function, such as magnetoencephalography (MEG), are widely used in clinical neurology and have strong relations with cognitive impairment and dementia but are still underdeveloped in multiple sclerosis (MS). Objectives: To demonstrate the value of clinically applicable MEG-measures in evaluating cognitive impairment in MS. Methods: In eyes-closed resting-state, MEG data of 83 MS patients and 34 healthy controls (HCs) peak frequencies and relative power of six canonical frequency bands for 78 cortical and 10 deep gray matter (DGM) areas were calculated. Linear regression models, correcting for age, gender, and education, assessed the relation between cognitive performance and MEG biomarkers. Results: Increased alpha1 and theta power was strongly associated with impaired cognition in patients, which differed between cognitively impaired (CI) patients and HCs in bilateral parietotemporal cortices. CI patients had a lower peak frequency than HCs. Oscillatory slowing was also widespread in the DGM, most pronounced in the thalamus. Conclusion: There is a clinically relevant slowing of neuronal activity in MS patients in parietotemporal cortical areas and the thalamus, strongly related to cognitive impairment. These measures hold promise for the application of resting-state MEG as a biomarker for cognitive disturbances in MS in a clinical setting.

scholarly journals Resting State Alpha Electroencephalographic Rhythms Are Differently Related to Aging in Cognitively Unimpaired Seniors and Patients with Alzheimer’s Disease and Amnesic Mild Cognitive Impairment

2021 ◽  
pp. 1-30
Author(s):  
Claudio Babiloni ◽  
Raffaele Ferri ◽  
Giuseppe Noce ◽  
Roberta Lizio ◽  
Susanna Lopez ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Cognitive Impairment ◽  
Mild Cognitive Impairment ◽  
Resting State ◽  
Diagnostic Biomarkers ◽  
Eyes Closed ◽  
Topographical Effects ◽  
And Gender ◽  
International Archive

Background: In relaxed adults, staying in quiet wakefulness at eyes closed is related to the so-called resting state electroencephalographic (rsEEG) rhythms, showing the highest amplitude in posterior areas at alpha frequencies (8–13 Hz). Objective: Here we tested the hypothesis that age may affect rsEEG alpha (8–12 Hz) rhythms recorded in normal elderly (Nold) seniors and patients with mild cognitive impairment due to Alzheimer’s disease (ADMCI). Methods: Clinical and rsEEG datasets in 63 ADMCI and 60 Nold individuals (matched for demography, education, and gender) were taken from an international archive. The rsEEG rhythms were investigated at individual delta, theta, and alpha frequency bands, as well as fixed beta (14–30 Hz) and gamma (30–40 Hz) bands. Each group was stratified into three subgroups based on age ranges (i.e., tertiles). Results: As compared to the younger Nold subgroups, the older one showed greater reductions in the rsEEG alpha rhythms with major topographical effects in posterior regions. On the contrary, in relation to the younger ADMCI subgroups, the older one displayed a lesser reduction in those rhythms. Notably, the ADMCI subgroups pointed to similar cerebrospinal fluid AD diagnostic biomarkers, gray and white matter brain lesions revealed by neuroimaging, and clinical and neuropsychological scores. Conclusion: The present results suggest that age may represent a deranging factor for dominant rsEEG alpha rhythms in Nold seniors, while rsEEG alpha rhythms in ADMCI patients may be more affected by the disease variants related to earlier versus later onset of the AD.

Assessing the Retest Reliability of Prefrontal EEG Markers of Brain Rhythm Slowing in the Eyes-Closed Resting State

2020 ◽  
Vol 51 (5) ◽  
pp. 348-356 ◽  
Author(s):  
Jungmi Choi ◽  
Eunjo Lim ◽  
Min-Goo Park ◽  
Wonseok Cha
Keyword(s):  
Resting State ◽  
Brain Aging ◽  
Low Cost ◽  
Peak Frequency ◽  
Brain Regions ◽  
Median Frequency ◽  
Brain Functions ◽  
Eyes Closed ◽  
Alpha Beta ◽  
Prefrontal Lobe

Objective. We examined whether prefrontal lobe EEG markers of slower brain rhythms, which are correlated with functional brain aging, can reliably reflect those of other brain lobes, as measured by a multichannel device. Methods. EEG measurements were taken of 112 healthy individuals aged 20 to 69 years in the eyes-closed resting state. A 5-minute measurement was taken at 8 regions (Fp1, Fp2, F3, F4, T3, T4, O1, O2). Indices (median frequency [MDF], peak frequency [PF]) that quantitatively reflect the characteristics of EEG slowing, and traditional commonly used spectral indices (absolute powers as delta, theta, alpha, beta, and relative power as alpha-to-theta ratio [ATR]), were extracted from the EEG signals. For these indices, the differences between the prefrontal lobe and other areas were analyzed and the test-retest reproducibility was investigated. Results. The EEG slowing indicators showed high conformity over all brain lobes and stable reproducibility. On the other hand, the typical EEG spectral indicators delta, theta, alpha, beta, and ATR differed between brain regions. Conclusion. It was found that EEG slowing markers, which were used for assessing the aging or degeneration of brain functions, could be reliably extracted from a prefrontal EEG alone. Significance. These findings suggest that EEG prefrontal markers may reflect markers of other brain regions when a multi-channel device is used. Thus, this method may constitute a low-cost, wearable, wireless, easily accessible, and noninvasive tool for neurological assessment that could be used in the early detection of cognitive decline and in the prevention of dementia.

scholarly journals Mechanisms of Network Changes in Cognitive Impairment in Multiple Sclerosis

Neurology ◽  
2021 ◽  
pp. 10.1212/WNL.0000000000012834
Author(s):  
Danka Jandric ◽  
Ilona Lipp ◽  
David Paling ◽  
David Rog ◽  
Gloria Castellazzi ◽  
...  
Keyword(s):  
Multiple Sclerosis ◽  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Cognitive Impairment ◽  
Functional Connectivity ◽  
Resting State ◽  
Structural Connectivity ◽  
Cognitively Impaired ◽  
Anatomical Connectivity ◽  
Cross Sectional

Background and Objectives:Cognitive impairment in multiple sclerosis (MS) is associated with functional connectivity abnormalities. While there have been calls to use functional connectivity measures as biomarkers there remains to be a full understanding of why they are affected in MS. In this cross-sectional study we tested the hypothesis that functional network regions may be susceptible to disease-related ‘wear-and-tear’ and that this can be observable on co-occuring abnormalities on other MR metrics. We tested whether functional connectivity abnormalities in cognitively impaired MS patients co-occur with either 1) overlapping, 2) local, or 3) distal changes in anatomical connectivity and cerebral blood flow abnormalities.Methods:Multimodal 3T MRI and assessment with the Brief Repeatable Battery of Neuropsychological tests was performed in 102 relapsing-remitting MS patients and 27 healthy controls. MS patients were classified as cognitively impaired if they scored ≥1.5 standard deviations below the control mean on ≥2 tests (n=55), or else cognitively preserved (n=47). Functional connectivity was assessed with Independent Component Analysis and dual regression of resting-state fMRI images. Cerebral blood flow maps were estimated and anatomical connectivity was assessed with anatomical connectivity mapping and fractional anisotropy of diffusion-weighted MRI. Changes in cerebral blood flow and anatomical connectivity were assessed within resting state networks that showed functional connectivity abnormalities in cognitively impaired MS patients.Results:Functional connectivity was significantly decreased in the anterior and posterior default mode networks and significantly increased in the right and left frontoparietal networks in cognitively impaired relative to cognitively preserved MS patients (TFCE-corrected at p≤0.05, two-sided). Networks showing functional abnormalities showed altered cerebral blood flow and anatomical connectivity locally and distally but not in overlapping locations.Discussion:We provide the first evidence that FC abnormalities are accompanied with local cerebral blood flow and structural connectivity abnormalities but also demonstrate that these effects do not occur in exactly the same location. Our findings suggest a possibly shared pathological mechanism for altered functional connectivity in brain networks in MS.

scholarly journals Abnormalities of Cortical Sources of Resting State Alpha Electroencephalographic Rhythms are Related to Education Attainment in Cognitively Unimpaired Seniors and Patients with Alzheimer’s Disease and Amnesic Mild Cognitive Impairment

2020 ◽  
Author(s):  
Claudio Babiloni ◽  
Raffaele Ferri ◽  
Giuseppe Noce ◽  
Roberta Lizio ◽  
Susanna Lopez ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Cognitive Impairment ◽  
Mild Cognitive Impairment ◽  
Resting State ◽  
Compensatory Mechanisms ◽  
Neuroprotective Effects ◽  
Diagnostic Biomarkers ◽  
Cortical Sources ◽  
Gender And Education

Abstract In normal old (Nold) and Alzheimer’s disease (AD) persons, a high cognitive reserve (CR) makes them more resistant and resilient to brain neuropathology and neurodegeneration. Here, we tested whether these effects may affect neurophysiological oscillatory mechanisms generating dominant resting state electroencephalographic (rsEEG) alpha rhythms in Nold and patients with mild cognitive impairment (MCI) due to AD (ADMCI). Data in 60 Nold and 70 ADMCI participants, stratified in higher (Edu+) and lower (Edu–) educational attainment subgroups, were available in an Italian–Turkish archive. The subgroups were matched for age, gender, and education. RsEEG cortical sources were estimated by eLORETA freeware. As compared to the Nold-Edu– subgroup, the Nold-Edu+ subgroup showed greater alpha source activations topographically widespread. On the contrary, in relation to the ADMCI-Edu– subgroup, the ADMCI-Edu+ subgroup displayed lower alpha source activations topographically widespread. Furthermore, the 2 ADMCI subgroups had matched cerebrospinal AD diagnostic biomarkers, brain gray–white matter measures, and neuropsychological scores. The current findings suggest that a high CR may be related to changes in rsEEG alpha rhythms in Nold and ADMCI persons. These changes may underlie neuroprotective effects in Nold seniors and subtend functional compensatory mechanisms unrelated to brain structure alterations in ADMCI patients.

scholarly journals Dynamics of brain function in chronic pain patients assessed by microstate analysis of resting-state electroencephalography

2020 ◽  
Author(s):  
Elisabeth S. May ◽  
Cristina Gil Ávila ◽  
Son Ta Dinh ◽  
Henrik Heitmann ◽  
Vanessa D. Hohn ◽  
...  
Keyword(s):  
Chronic Pain ◽  
Resting State ◽  
Brain Function ◽  
Temporal Dynamics ◽  
Brain Activity ◽  
Relevant Information ◽  
Eyes Closed ◽  
Eyes Open ◽  
Eeg Recordings ◽  
Microstate Analysis

AbstractChronic pain is a highly prevalent and severely disabling disease, which is associated with substantial changes of brain function. Such changes have mostly been observed when analyzing static measures of brain activity during the resting-state. However, brain activity varies over time and it is increasingly recognized that the temporal dynamics of brain activity provide behaviorally relevant information in different neuropsychiatric disorders. Here, we therefore investigated whether the temporal dynamics of brain function are altered in chronic pain. To this end, we applied microstate analysis to eyes-open and eyes-closed resting-state electroencephalography (EEG) data of 101 patients suffering from chronic pain and 88 age- and gender-matched healthy controls. Microstate analysis describes EEG activity as a sequence of a limited number of topographies termed microstates, which remain stable for tens of milliseconds. Our results revealed that sequences of 5 microstates, labelled with the letters A to E, described resting-state brain activity in both groups and conditions. Bayesian analysis of the temporal characteristics of microstates revealed that microstate D has a less predominant role in patients than in healthy participants. This difference was consistently found in eyes-open and eyes-closed EEG recordings. No evidence for differences in other microstates was found. As microstate D has been previously related to attentional networks and functions, abnormalities of microstate D might relate to dysfunctional attentional processes in chronic pain. These findings add to the understanding of the pathophysiology of chronic pain and might eventually contribute to the development of an EEG-based biomarker of chronic pain.

The cumulative effect of frailty and cognition on mortality – results of a prospective cohort study

2016 ◽  
Vol 29 (4) ◽  
pp. 535-543 ◽  
Author(s):  
Philip D. St. John ◽  
Suzanne L. Tyas ◽  
Lauren E. Griffith ◽  
Verena Menec
Keyword(s):  
Cohort Study ◽  
Cognitive Impairment ◽  
Prospective Cohort Study ◽  
Prospective Cohort ◽  
Proportional Hazards ◽  
Reference Group ◽  
Frailty Index ◽  
Cox Proportional Hazards ◽  
Cognitively Impaired ◽  
Gender And Education

ABSTRACTBackground:Both physical frailty and cognitive impairment predict death, but the joint effect of these two factors is uncertain. The objectives are to determine if the Mini-mental state examination (MMSE) and the Frailty Index (FI) predict death over a five-year interval after accounting for the effect of the other; and if there is an interaction in this effect.Methods:An analysis of an existing prospective cohort study of 1,751 community living older adults followed over a five-year time frame. Age, gender, and education were self-reported. The predictor variables were the FI – a measure of frailty based on the “Accumulation of Deficits” model of frailty; and the MMSE. Cox proportional hazards models were constructed for the outcome of time to death.Results:The unadjusted Hazard Ratio (HR) (95% CI) for mortality was 2.17 (1.69, 2.80) for those who were only cognitively impaired, 2.02 (1.53, 2.68) for those who were only frail, and 3.57 (2.75, 4.62) for those who were both frail and cognitively impaired with the reference group of those who were neither frail nor cognitively impaired. Adjusted for age, gender, and education, the HR (95% CI) was 1.49 (1.13. 1.95) for those who were only cognitively impaired, 1.81 (1.35, 2.41) for those who were only frail, and 2.28 (1.69, 3.09) for those who were both frail and cognitively impaired.Conclusions:Both frailty and cognitive impairment are predictors of mortality and the effect is cumulative. There was no interaction in this effect.

scholarly journals Functional connectivity in mild cognitive impairment with Lewy bodies

2021 ◽  
Author(s):  
Julia Schumacher ◽  
John-Paul Taylor ◽  
Calum A. Hamilton ◽  
Michael Firbank ◽  
Paul C. Donaghy ◽  
...  
Keyword(s):  
Cognitive Impairment ◽  
Mild Cognitive Impairment ◽  
Functional Connectivity ◽  
Resting State ◽  
Brain Function ◽  
Lewy Bodies ◽  
Sliding Window ◽  
Resting State Fmri ◽  
Approaches To Study ◽  
Dynamic Connectivity

AbstractPrevious resting-state fMRI studies in dementia with Lewy bodies have described changes in functional connectivity in networks related to cognition, motor function, and attention as well as alterations in connectivity dynamics. However, whether these changes occur early in the course of the disease and are already evident at the stage of mild cognitive impairment is not clear. We studied resting-state fMRI data from 31 patients with mild cognitive impairment with Lewy bodies compared to 28 patients with mild cognitive impairment due to Alzheimer’s disease and 24 age-matched controls. We compared the groups with respect to within- and between-network functional connectivity. Additionally, we applied two different approaches to study dynamic functional connectivity (sliding-window analysis and leading eigenvector dynamic analysis). We did not find any significant changes in the mild cognitive impairment groups compared to controls and no differences between the two mild cognitive impairment groups, using static as well as dynamic connectivity measures. While patients with mild cognitive impairment with Lewy bodies already show clear functional abnormalities on EEG measures, the fMRI analyses presented here do not appear to be sensitive enough to detect such early and subtle changes in brain function in these patients.

scholarly journals Individual alpha peak frequency is slower in schizophrenia and related to deficits in visual perception and cognition

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Ian S. Ramsay ◽  
Peter Lynn ◽  
Brandon Schermitzler ◽  
Scott Sponheim
Keyword(s):  
Visual Perception ◽  
Visual Attention ◽  
Resting State ◽  
Peak Frequency ◽  
Attention Task ◽  
Eyes Closed ◽  
Global Cognition ◽  
The Relationship ◽  
The Brain ◽  
Alpha Peak

AbstractThe brain at rest generates cycles of electrical activity that have been shown to be abnormal in people with schizophrenia. The alpha rhythm (~ 10 Hz) is the dominant resting state electrical cycle and each person has a propensity toward a particular frequency of oscillation for this rhythm. This individual alpha peak frequency (IAPF) is hypothesized to be central to visual perceptual processes and may have downstream influences on cognitive functions such as attention, working memory, or problem solving. In the current study we sought to determine whether IAPF was slower in schizophrenia, and whether lower IAPF predicted deficits in visual perception and cognition that are often observed in schizophrenia. Eyes-closed resting state EEG activity, visual attention, and global cognitive functioning were assessed in individuals with schizophrenia (N = 104) and a group of healthy controls (N = 101). Compared to controls, the schizophrenia group showed slower IAPF and was associated with poorer discrimination of visual targets and nontargets on a computerized attention task, as well as impaired global cognition measured using neuropsychological tests across groups. Notably, disruptions in visual attention fully mediated the relationship between IAPF and global cognition across groups. The current findings demonstrate that slower alpha oscillatory cycling accounts for global cognitive deficits in schizophrenia by way of impairments in perceptual discrimination measured during a visual attention task.

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