Profound regional spectral, connectivity, and network changes reflect visual deficits in posterior cortical atrophy: an EEG study

• Published in: Neurobiology of aging Vol. 96; pp. 1 - 11
• Main Authors: Briels, Casper T., Eertink, Jakoba J., Stam, Cornelis J., van der Flier, Wiesje M., Scheltens, Philip, Gouw, Alida A.
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 01.12.2020
• Subjects: Alzheimer's disease (AD); Electroencephalography (EEG); Functional connectivity; Functional networks; Oscillatory activity; Posterior cortical atrophy (PCA); Functional connectivity; Alzheimer's disease (AD); Electroencephalography (EEG); Posterior cortical atrophy (PCA); Oscillatory activity; Functional networks
• ISSN: 0197-4580; 1558-1497; 1558-1497
• DOI: 10.1016/j.neurobiolaging.2020.07.029

Patients with posterior cortical atrophy (PCA-AD) show more severe visuospatial and perceptual deficits than those with typical AD (tAD). The aim of this study was to investigate whether functional alterations measured by electroencephalography can help understand the mechanisms that explain this clinical heterogeneity. 21-channel electroencephalography recordings of 29 patients with PCA-AD were compared with 29 patients with tAD and 29 controls matched for age, gender, and disease severity. Patients with PCA-AD and tAD both showed a global decrease in fast and increase in slow oscillatory activity compared with controls. This pattern was, however, more profound in patients with PCA-AD which was driven by more extensive slowing of the posterior regions. Alpha band functional connectivity showed a similar decrease in PCA-AD and tAD. Compared with controls, a less integrated network topology was observed in PCA-AD, with a decrease of posterior and an increase of frontal hubness. In PCA-AD, decreased right parietal peak frequency correlated with worse performance on visual tasks. Regional vulnerability of the posterior network might explain the atypical pattern of neurodegeneration in PCA-AD. •PCA-AD subjects show more profound posterior oscillatory slowing compared to typical AD.•Right parietal peak frequency correlates with visual performance in PCA-AD.•PCA-AD functional networks show a decrease of posterior and increase of frontal hubness.