Page 84 - MEGIN Book Of Abstracts - 2023

connectivity in cortical and subcortical regions in MEG Oscillatory Slowing in Cognitive Impairment
patients with early symptomatic amyotrophic lateral is Associated with the Presence of Subjective
sclerosis (ALS) resemble those of behavioural variant Cognitive Decline (2023)
frontotemporal dementia (bvFTD). In a cross-sectional
design, eyes-closed resting-state magnetoencephalog- Bruña, Ricardo; López-Sanz, David; Maestú, Fernando;
raphy (MEG) data of 34 ALS patients, 18 bvFTD patients Cohen, Ann D; Bagic, Anto; Huppert, Ted; Kim, Tae;
and 18 age- and gender-matched healthy controls Roush, Rebecca E; Snitz, Betz; Becker, James T
(HCs) were projected to source-space using an atlas-
based beamformer. Group differences in peak frequen- Centro de Tecnología Biomédica, Universidad Politécnica de
cy, band-specific oscillatory activity and functional con- Madrid, Pozuelo de Alarcón, Madrid, Spain; Psicobiología y
nectivity (corrected amplitude envelope correlation) Metodología en Ciencias del Comportamiento, Universidad
in 78 cortical regions and 12 subcortical regions were Complutense de Madrid, Madrid, Madrid, Spain; Center for
determined. False discovery rate was used to correct for Biomedical Technology, Universidad Politécnica de Madrid,
multiple comparisons. BvFTD patients, as compared to Pozuelo de Alarcón, Madrid, Spain; Neurosurgery, University
ALS and HCs, showed lower relative beta power in pa- of Pittsburgh, Pittsburgh, Pennsylvania, USA; Neurology,
rietal, occipital, temporal and nearly all subcortical re- University of Pittsburgh Medical Center Health System, Pitts-
gions. Compared to HCs, patients with ALS and patients burgh, Pennsylvania, USA; Electrical Engineering, University
with bvFTD had a higher delta (0.5-4 Hz) and gamma of Pittsburgh, Pittsburgh, Pennsylvania, USA; Radiology, Uni-
(30-48 Hz) band resting-state functional connectivity versity of Pittsburgh, Pittsburgh, Pennsylvania, USA; Psychia-
in a high number of overlapping regions in the fron- try, University of Pittsburgh, Pittsburgh, Pennsylvania, USA;
tal lobe and in limbic and subcortical regions. Higher Psychology, University of Pittsburgh, Pittsburgh, Pennsylvania,
delta band connectivity was widespread in the bvFTD USA
patients compared to HCs. ALS showed a more wide-
spread higher gamma band functional connectivity ABSTRACT The mechanisms behind Alzheimer's
compared to bvFTD. In conclusion, MEG in early symp- disease are not yet fully described, and changes in the
tomatic ALS patients shows resting-state functional electrophysiology of patients across the continuum
connectivity changes in frontal, limbic and subcortical of the disease could help to understand them. In this
regions that overlap considerably with bvFTD. The find- work, we study the power spectral distribution of a
ings show the potential of MEG to detect brain changes set of 129 individuals from the Connectomics of Brian
in early symptomatic phases of ALS and contribute to Aging and Dementia project.From this sample, we ac-
our understanding of the disease spectrum, with ALS quired task-free data, with eyes closed, and estimated
and bvFTD at the two extreme ends. the power spectral distribution in source space. We
compared the spectral profiles of three groups of indi-
Keywords: Amyotrophic lateral sclerosis, Behavioural viduals: 70 healthy controls, 27 patients with amnestic
variant frontotemporal dementia, Functional connectiv- MCI, and 32 individuals showing cognitive impairment
ity, Magnetoencephalography, Oscillatory brain activity, without subjective complaints (IWOC).The results
Resting-state showed a slowing of the brain activity in the aMCI
patients, when compared to both the healthy controls
NeuroImage. Clinical (2022), Vol. 34 (35217500) (1 citation) and the IWOC individuals. These differences appeared
both as a decrease in power for high frequency oscil-
lations and an increase in power in alpha oscillations.
The slowing of the spectrum was significant mainly in
parietal and medial frontal areas.We were able to vali-
date the slowing of the brain activity in individuals with
aMCI, appearing in our sample in areas related to the
default mode network. However, this pattern did not

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