The Effects of Cortical Hypometabolism and Hippocampal Atrophy on Clinical Trajectories in Mild Cognitive Impairment with Suspected Non-Alzheimer’s Pathology: A Brief Report

Article type: Short Communication

Authors: Chung, Jun Ku^{a; b} | Plitman, Eric^{a; b} | Nakajima, Shinichiro^{b; c; d; e} | Caravaggio, Fernando^{b; c} | Shinagawa, Shunichiro^h | Iwata, Yusuke^{b; d} | Gerretsen, Philip^{b; c; e} | Kim, Julia^{a; b} | Takeuchi, Hiroyoshi^{c; d} | Patel, Raihaan^{f; g} | Chakravarty, M. Mallar^{f; g} | Strafella, Antonio^{i; j; k} | Graff-Guerrero, Ariel^{a; b; c; d; e; *} | for the Alzheimer’s Disease Neuroimaging Initiative¹

Affiliations: [a] Institute of Medical Science, Faculty of Medicine, University of Toronto, Toronto, ON, Canada | [b] Multimodal Imaging Group – Research Imaging Centre, Centre for Addiction and Mental Health, Toronto, ON, Canada | [c] Department of Psychiatry, University of Toronto, Toronto, ON, Canada | [d] Department of Neuropsychiatry, School of Medicine, Keio University, Tokyo, Japan | [e] Geriatric Mental Health Division, Centre for Addiction and Mental Health, Toronto, ON, Canada | [f] Cerebral Imaging Centre, Douglas Mental Health Institute, McGill University, Montreal, QC, Canada | [g] Department of Psychiatry and Biomedical Engineering, McGill University, Montreal, QC, Canada | [h] The Jikei University School of Medicine, Tokyo, Japan | [i] Research Imaging Centre, Campbell Family Mental Health Research Institute, Centre for Addiction and Mental Health, University of Toronto, Toronto, ON, Canada | [j] Division of Brain, Imaging and Behaviour – Systems Neuroscience, Krembil Research Institute, UHN, University of Toronto, Toronto, ON, Canada | [k] Morton and Gloria Shulman Movement Disorder Unit and E.J. Safra Parkinson Disease Program, Neurology Division, Department of Medicine, Toronto Western Hospital, UHN, University of Toronto, Toronto, ON, Canada

Correspondence: [*] Correspondence to: Ariel Graff-Guerrero, MD, PhD, Multimodal Imaging Group – Research Imaging Centre, Centre for Addiction and Mental Health, 250 College Street, Toronto, ON, M5T 1R8, Canada. Tel.: +1 416 535 8501/Ext. 4834; E-mail: [email protected].

Note: [1] Some data used in preparation of this article were obtained from the Alzheimer’s Disease Neuroimaging Initiative (ADNI) database (http://adni.loni.usc.edu). As such, the investigators within the ADNI contributed to the design and implementation of ADNI and/or provided data but did not participate in analysis or writing of this report. A complete listing of ADNI investigators can be found at: http://adni.loni.usc.edu/wp-content/uploads/how_to_apply/ADNI_Acknowledgement_List.pdf

Abstract: The clinical and structural trajectories of suspected non-Alzheimer’ pathology (SNAP) remain elusive due to its heterogeneous etiology. Baseline and longitudinal clinical (global cognition, daily functioning, symptoms of dementia, and learning memory) and hippocampal volume trajectories over two years were compared between patients with amnestic mild cognitive impairment (aMCI) with SNAP with reduced hippocampal volumes (SNAP+HIPPO) and aMCI patients with SNAP without reduced hippocampal volumes. SNAP+HIPPO showed overall worse baseline cognitive functions. Longitudinally, SNAP+HIPPO showed faster deterioration of clinical symptoms of dementia. Having both hippocampal atrophy and cortical hypometabolism without amyloid pathology may exacerbate symptoms of dementia in aMCI.

Keywords: Functional decline, hippocampus, mild cognitive impairment, suspected non-Alzheimer’s pathology

DOI: 10.3233/JAD-170098

Journal: Journal of Alzheimer's Disease, vol. 60, no. 2, pp. 341-347, 2017