# EEG network reorganization across Alzheimer's disease, frontotemporal dementia, and dementia with Lewy bodies

## TL;DR

EEG shows unique brain network changes in Alzheimer's, frontotemporal dementia, and Lewy body dementia, which could help in understanding and diagnosing these conditions.

## Contribution

The study identifies syndrome-specific EEG network reorganization patterns in three major dementias.

## Key findings

- AD shows theta hypersynchrony and posterior alpha-beta disconnection.
- FTD displays widespread beta hypoconnectivity with focal theta increase.
- DLB exhibits global theta hyperconnectivity and posterior hub loss.

## Abstract

Electroencephalography (EEG) provides a temporally precise index of neural dysfunction, capturing changes in oscillatory activity, connectivity, and network organization. While spectral slowing is well documented in Alzheimer's disease (AD), frontotemporal dementia (FTD), and dementia with Lewy bodies (DLB), less is known about how these alterations extend to large‐scale networks.

We studied 173 participants: 56 AD, 59 FTD, 26 DLB, and 32 healthy controls (HC). Resting‐state EEG was analyzed to quantify spectral power and amplitude‐envelope correlation‐based connectivity across frequency bands.

AD showed canonical slowing with delta/theta increases and posterior alpha loss. FTD exhibited preserved alpha but frontal beta reductions, while DLB displayed delta/theta excess, posterior alpha attenuation, and uniquely reduced gamma. Connectivity analyses revealed syndrome‐specific patterns of network reorganization with distinct frequency‐dependent signatures.

EEG network metrics capture distinct disease signatures and may inform mechanistic models of dementia.

Electroencephalography (EEG) reveals distinct network alterations in Alzheimer's disease (AD), frontotemporal dementia (FTD), and dementia with Lewy bodies (DLB)AD shows theta hypersynchrony and posterior alpha‐beta disconnectionFTD displays widespread beta hypoconnectivity with focal theta increaseDLB exhibits global theta hyperconnectivity and posterior hub lossGraph metrics capture disease‐specific network reorganization patterns

Electroencephalography (EEG) reveals distinct network alterations in Alzheimer's disease (AD), frontotemporal dementia (FTD), and dementia with Lewy bodies (DLB)

AD shows theta hypersynchrony and posterior alpha‐beta disconnection

FTD displays widespread beta hypoconnectivity with focal theta increase

DLB exhibits global theta hyperconnectivity and posterior hub loss

Graph metrics capture disease‐specific network reorganization patterns