Effects of a 6-Month Cognitive Intervention Program on Brain Metabolism in Amnestic Mild Cognitive Impairment and Mild Alzheimer's Disease

Article type: Research Article

Authors: Förster, Stefan^{a; i; 1; *} | Buschert, Verena C.^{b; 1} | Buchholz, Hans-Georg^f | Teipel, Stefan J.^{c; d} | Friese, Uwe^{c; g} | Zach, Christian^a | la Fougere, Christian^a | Rominger, Axel^a | Drzezga, Alexanderⁱ | Hampel, Harald^e | Bartenstein, Peter^a | Buerger, Katharina^{b; h}

Affiliations: [a] Department of Nuclear Medicine, Ludwig-Maximilian University, Munich, Germany | [b] Dementia Research Section and Memory Clinic, Alzheimer Memorial Center and Geriatric Psychiatry Branch, Department of Psychiatry Ludwig-Maximilian University, Munich, Germany | [c] Department of Psychiatry, University Rostock, Rostock, Germany | [d] DZNE, German Center for Neurodegenerative Disorders, Rostock, Germany | [e] Discipline of Psychiatry, School of Medicine & Trinity College Institute of Neuroscience (TCIN), Laboratory of Neuroimaging and Biomarker Research, Trinity College, University of Dublin; The Adelaide and Meath Hospital Incorporating the National Children's Hospital (AMiNCH), Ireland | [f] Department of Nuclear Medicine, University Mainz, Mainz, Germany | [g] Institute of Psychology, University of Osnabrueck, Osnabrueck, Germany | [h] Institute for Stroke and Dementia Research, Klinikum Großhadern, Ludwig-Maximilian University, Munich, Germany | [i] Department of Nuclear Medicine, Technische Universität München, Munich, Germany

Correspondence: [*] Correspondence to: Stefan Förster, MD, Klinik und Poliklinik für Nuklearmedizin, TU München, Ismaninger Str. 22, 81675 München, Germany. Tel.: +49 89 4140 2965; Fax: +49 89 4140 4950; E-mail: stefan-foerster@gmx.de.

Note: [1] Both authors contributed equally.

Abstract: The effect of cognitive intervention on brain metabolism in Alzheimer's disease (AD) is largely unexplored. Therefore, we aimed to investigate clinical cognitive parameters and 18FDG PET to test for effects of a cognitive intervention in patients with amnestic mild cognitive impairment (aMCI) or mild AD. Patients with aMCI (n = 24) or mild AD (n = 15) were randomly assigned either to cognitive intervention groups (IGs), receiving weekly sessions of group-based multicomponent cognitive intervention, or active control groups (CGs), receiving pencil-paper exercises for self-study. We obtained resting-state FDG-PET scans and neuropsychological testing at baseline and after six-months. Normalized FDG-PET images were analyzed using voxel-based SPM5 approaches to determine longitudinal changes, group-by-time interactions, and correlations with neuropsychological outcome parameters. Primary global cognitive outcome was determined by analyses of covariance with MMSE and ADAS-cog scores as dependent measures. Both, aMCI and AD subgroups of CGs showed widespread bilateral cortical declines in FDG uptake, while the AD subgroup of IGs showed discrete decline or rather no decline in case of the aMCI subgroup. Group by time analyses revealed strongest attenuation of metabolic decline in the aMCI subgroup of the IGs, involving left superior temporal- and anterior cingulate gyrus. However, correlation analyses revealed only weak non-significant associations between increased FDG uptake and improvement in primary or secondary outcome parameters. Concurrently, there was significant improvement in global cognitive status in the aMCI subgroup of the IGs. A six-month cognitive intervention imparted cognitive benefits in patients with aMCI, which were concurrent with an attenuated decline of glucose metabolism in cortical regions affected by neurodegenerative AD.

Keywords: Alzheimer's disease, cognitive intervention, cognitive stimulation, cognitive training, FDG PET, mild cognitive impairment

DOI: 10.3233/JAD-2011-100996

Journal: Journal of Alzheimer's Disease, vol. 25, no. 4, pp. 695-706, 2011