Evidence map›Paper›PMID 39449097›Full record

ArticleAlzheimer's research & therapy2024

EEG biomarkers in Alzheimer's and prodromal Alzheimer's: a comprehensive analysis of spectral and connectivity features.

Chowtapalle Anuraag Chetty, Harsha Bhardwaj, G Pradeep Kumar, T Devanand, C S Aswin Sekhar, Tuba Aktürk, Ilayda Kiyi, Görsev Yener, Bahar Güntekin, Justin Joseph and 1 more

Abstract read
In one paragraph

Article in Alzheimer's research & therapy, 2024. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 32 papers, 1 of them a synthesis that pooled it.

0numbers the graph read from it
0cells of the map it votes in
32citing papers in PubMed, 1 pooled it
–field-weighted citation impact
1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

The trial behind it

Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.

Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.

3 · Its place in the literature

Who cites it

32 citing papers in PubMed, 1 synthesis or guideline pooled it.

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4 · The record

Corrections and comments

PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

11 authors.

Chowtapalle Anuraag Chetty *Centre for Brain Research, Indian Institute of Science, CV Raman Avenue, Bangalore, 560 012, India.
Harsha Bhardwaj *Centre for Brain Research, Indian Institute of Science, CV Raman Avenue, Bangalore, 560 012, India.
G Pradeep Kumar *Centre for Brain Research, Indian Institute of Science, CV Raman Avenue, Bangalore, 560 012, India.
T DevanandCentre for Brain Research, Indian Institute of Science, CV Raman Avenue, Bangalore, 560 012, India.
C S Aswin SekharCentre for Brain Research, Indian Institute of Science, CV Raman Avenue, Bangalore, 560 012, India.
Tuba AktürkNeuroscience Research Center, Research Institute for Health Sciences and Technologies (SABITA), Istanbul Medipol University, Istanbul, 34810, Turkey.
Ilayda KiyiDepartment of Neuroscience, Health Sciences Institute, Dokuz Eylül University, Izmir, 35330, Turkey.
Görsev YenerFaculty of Medicine, Izmir University of Economics, Izmir, 35330, Turkey.
Bahar GüntekinNeuroscience Research Center, Research Institute for Health Sciences and Technologies (SABITA), Istanbul Medipol University, Istanbul, 34810, Turkey.
Justin JosephCentre for Brain Research, Indian Institute of Science, CV Raman Avenue, Bangalore, 560 012, India.
Chinnakkaruppan AdaikkanCentre for Brain Research, Indian Institute of Science, CV Raman Avenue, Bangalore, 560 012, India. chinna@cbr-iisc.ac.in.

Funding

DBT-Wellcome Trust India Alliance A/E/22/1/506784DBT-Wellcome Trust India Alliance IA/I/22/1/506257This work was supported by the CBR start-up fund (CA) and the India Alliance DBT Wellcome Trust grant (IA/I/22/1/506257; CA) IA/I/22/1/506257Wellcome Trust
6 · The paper itself

Abstract

backgroundBiomarkers of Alzheimer's disease (AD) and mild cognitive impairment (MCI, or prodromal AD) are highly significant for early diagnosis, clinical trials and treatment outcome evaluations. Electroencephalography (EEG), being noninvasive and easily accessible, has recently been the center of focus. However, a comprehensive understanding of EEG in dementia is still needed. A primary objective of this study is to investigate which of the many EEG characteristics could effectively differentiate between individuals with AD or prodromal AD and healthy individuals.

methodsWe collected resting state EEG data from individuals with AD, prodromal AD, and normal cognition. Two distinct preprocessing pipelines were employed to study the reliability of the extracted measures across different datasets. We extracted 41 different EEG features. We have also developed a stand-alone software application package, Feature Analyzer, as a comprehensive toolbox for EEG analysis. This tool allows users to extract 41 EEG features spanning various domains, including complexity measures, wavelet features, spectral power ratios, and entropy measures. We performed statistical tests to investigate the differences in AD or prodromal AD from age-matched cognitively normal individuals based on the extracted EEG features, power spectral density (PSD), and EEG functional connectivity.

resultsSpectral power ratio measures such as theta/alpha and theta/beta power ratios showed significant differences between cognitively normal and AD individuals. Theta power was higher in AD, suggesting a slowing of oscillations in AD; however, the functional connectivity of the theta band was decreased in AD individuals. In contrast, we observed increased gamma/alpha power ratio, gamma power, and gamma functional connectivity in prodromal AD. Entropy and complexity measures after correcting for multiple electrode comparisons did not show differences in AD or prodromal AD groups. We thus catalogued AD and prodromal AD-specific EEG features.

conclusionsOur findings reveal that the changes in power and connectivity in certain frequency bands of EEG differ in prodromal AD and AD. The spectral power, power ratios, and the functional connectivity of theta and gamma could be biomarkers for diagnosis of AD and prodromal AD, measure the treatment outcome, and possibly a target for brain stimulation.

Indexed as

Alzheimer DiseaseBiomarkersCognitive DysfunctionElectroencephalographyProdromal SymptomsAgedAged, 80 and overBrainFemaleHumansMaleMiddle AgedBiomarkersAgingBrain connectivityEEG-based biomarkerEyes closed EEGGammaPairwise phase consistencySlowing of oscillationsTheta-alpha power ratio

Identifiers

PMID39449097
PMCPMC11515355

What OpenQuestion holds

Textmetadata
LicenceCC BY-NC-ND
Read underepoch 390

Registered trials

None linked

Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.