Left frontal cortex connectivity underlies cognitive reserve in prodromal Alzheimer disease

Franzmeier, Nicolai; Düring, Marco; Weiner, Michael; Dichgans, Martin und Ewers, Michael (2017): Left frontal cortex connectivity underlies cognitive reserve in prodromal Alzheimer disease. In: Neurology, Bd. 88, Nr. 11: S. 1054-1061

Abstract

Objective: To test whether higher global functional connectivity of the left frontal cortex (LFC) in Alzheimer disease (AD) is associated with more years of education (a proxy of cognitive reserve [CR]) and mitigates the association between AD-related fluorodeoxyglucose (FDG)-PET hypometabolism and episodic memory. Methods: Forty-four amyloid-PET-positive patients with amnestic mild cognitive impairment (MCI-A beta 1) and 24 amyloid-PET-negative healthy controls (HC) were included. Voxel-based linear regression analyses were used to test the association between years of education and FDG-PET in MCI-Ab1, controlled for episodic memory performance. Global LFC (gLFC) connectivity was computed through seed-based resting-state fMRI correlations between the LFC (seed) and each voxel in the gray matter. In linear regression analyses, education as a predictor of gLFC connectivity and the interaction of gLFC connectivity 3 FDG-PET hypometabolism on episodic memory were tested. Results: FDG-PET metabolism in the precuneus was reduced in MCI-A beta 1 compared to HC (p = 0.028), with stronger reductions observed in MCI-A beta 1 with more years of education (p = 0.006). In MCI-A beta 1, higher gLFC connectivity was associated with more years of education (p = 0.021). At higher levels of gLFC connectivity, the association between precuneus FDG-PET hypometabolism and lower memory performance was attenuated (p = 0.027). Conclusions: Higher gLFC connectivity is a functional substrate of CR that helps to maintain episodic memory relatively well in the face of emerging FDG-PET hypometabolism in earlystage AD.

• Dokumententyp: Zeitschriftenartikel
• Fakultät: Medizin
• Themengebiete: 600 Technik, Medizin, angewandte Wissenschaften > 610 Medizin und Gesundheit
• ISSN: 0028-3878
• Allianz-/Nationallizenz: Dieser Beitrag ist mit Zustimmung des Rechteinhabers aufgrund einer (DFG-geförderten) Allianz- bzw. Nationallizenz frei zugänglich.
• Sprache: Englisch