Evolving Evidence for the Value of Neuroimaging Methods and Biological Markers in Subjects Categorized with Subjective Cognitive Decline

Issue title: Subjective Cognitive Decline

Article type: Review Article

Authors: Lista, Simone^{a; b; *} | Molinuevo, Jose L.^{c; d} | Cavedo, Enrica^{b; e; f} | Rami, Lorena^{c; d} | Amouyel, Philippe^{g; h; i; j} | Teipel, Stefan J.^k | Garaci, Francesco^{l; m} | Toschi, Nicola^{m; n; o} | Habert, Marie-Odile^{p; q} | Blennow, Kaj^{r; s} | Zetterberg, Henrik^{r; t} | O’Bryant, Sid E.^u | Johnson, Leigh^u | Galluzzi, Samantha^f | Bokde, Arun L.W.^{v; w} | Broich, Karl^x | Herholz, Karl^y | Bakardjian, Hovagim^z | Dubois, Bruno^b | Jessen, Frank^{aa; bb} | Carrillo, Maria C.^cc | Aisen, Paul S.^dd | Hampel, Harald^{a; b}

Affiliations: [a] AXA Research Fund & UPMC Chair, Paris, France | [b] Sorbonne Universités, Université Pierre et Marie Curie (UPMC), Paris 06, Institut de la Mémoire et de la Maladie d’Alzheimer (IM2A) & Institut du Cerveau et de la Moelle épinière (ICM), UMR S 1127, Département de Neurologie, Hôpital de la Pitié-Salpêtrière, Paris, France | [c] Alzheimers Disease and Other Cognitive Disorders Unit, Neurology Service, Hospital Clinic, Barcelona, Spain | [d] Institut d’Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Barcelona, Spain | [e] CATI Multicenter Neuroimaging Platform, France | [f] Laboratory of Epidemiology, Neuroimaging and Telemedicine, IRCCS Istituto Centro “San Giovanni diDio-Fatebenefratelli”, Brescia, Italy | [g] Inserm, U1157, Lille, France | [h] Université de Lille, Lille, France | [i] Institut Pasteur de Lille, Lille, France | [j] Centre Hospitalier Régional Universitaire de Lille, Lille, France | [k] Department of Psychosomatic Medicine, University of Rostock, Rostock, Germany & German Center forNeurodegenerative Diseases (DZNE) Rostock/Greifswald, Rostock, Germany | [l] Department of Diagnostic Imaging, Molecular Imaging, Interventional Radiology and Radiotherapy, University Hospital of “Tor Vergata”, Rome, Italy | [m] Department of Biomedicine and Prevention University of Rome “Tor Vergata”, Rome, Italy | [n] Department of Radiology, Athinoula A. Martinos Center for Biomedical Imaging, Boston, MA, USA | [o] Harvard Medical School, Boston, MA, USA | [p] Sorbonne Universités, UPMC Univ Paris 06, Inserm U 1146, CNRS UMR 7371, Laboratoire d’Imagerie Biomédicale, Paris, France | [q] AP-HP, Pitié-Salpêtrière Hospital, Nuclear Medicine Department, Paris, France | [r] Department of Psychiatry and Neurochemistry, Institute of Neuroscience and Physiology, The Sahlgrenska Academy at the University of Gothenburg, Mölndal, Sweden | [s] The Torsten Söderberg Professorship in Medicine at the Royal Swedish Academy of Sciences | [t] Department of Molecular Neuroscience, UCL Institute of Neurology, London, UK | [u] Institute for Aging and Alzheimer’s Disease Research & Department of Internal Medicine, University of North Texas Health Science Center, Fort Worth, TX, USA | [v] Cognitive Systems Group, Discipline of Psychiatry, School of Medicine, Trinity College Dublin, Dublin, Ireland | [w] Trinity College Institute of Neuroscience, Trinity College Dublin, Dublin, Ireland | [x] President, Federal Institute of Drugs and Medical Devices (BfArM), Bonn, Germany | [y] Institute of Brain, Behaviours and Mental Health, University of Manchester, Manchester, UK | [z] IM2A - Institute of Memory and Alzheimer’s Disease, IHU-A-ICM - Paris Institute of Translational Neurosciences, Pitié-Salpêtrière University Hospital, Paris, France | [aa] Department of Psychiatry, University of Cologne, Cologne, Germany | [bb] German Center for Neurodegenerative Diseases (DZNE), Bonn, Germany | [cc] Medical & Scientific Relations, Alzheimer’s Association, Chicago, IL, USA | [dd] Department of Neurosciences, University of California, San Diego, San Diego, CA, USA∥

Correspondence: [*] Correspondence to: Simone Lista, PhD, AXA Research Fund & UPMC Chair, Sorbonne Universités, Université Pierre et Marie Curie (UPMC), Paris 06, Institut de la Mémoire et de la Maladie d’Alzheimer (IM2A), Institut du Cerveau et de la Moelle Épinière (ICM), Département de Neurologie, Pavillon François Lhermitte, Hôpital de la Pitié-Salpêtrière, 47 Boulevard de l’Hôpital, 75651 - Paris, CEDEX 13, France. Tel.: +33 1 57 27 46 74; Fax: +33 1 42 16 75 16; slista@libero.it

Abstract: There is evolving evidence that individuals categorized with subjective cognitive decline (SCD) are potentially at higher risk for developing objective and progressive cognitive impairment compared to cognitively healthy individuals without apparent subjective complaints. Interestingly, SCD, during advancing preclinical Alzheimer’s disease (AD), may denote very early, subtle cognitive decline that cannot be identified using established standardized tests of cognitive performance. The substantial heterogeneity of existing SCD-related research data has led the Subjective Cognitive Decline Initiative (SCD-I) to accomplish an international consensus on the definition of a conceptual research framework on SCD in preclinical AD. In the area of biological markers, the cerebrospinal fluid signature of AD has been reported to be more prevalent in subjects with SCD compared to healthy controls; moreover, there is a pronounced atrophy, as demonstrated by magnetic resonance imaging, and an increased hypometabolism, as revealed by positron emission tomography, in characteristic brain regions affected by AD. In addition, SCD individuals carrying an apolipoprotein ɛ4 allele are more likely to display AD-phenotypic alterations. The urgent requirement to detect and diagnose AD as early as possible has led to the critical examination of the diagnostic power of biological markers, neurophysiology, and neuroimaging methods for AD-related risk and clinical progression in individuals defined with SCD. Observational studies on the predictive value of SCD for developing AD may potentially be of practical value, and an evidence-based, validated, qualified, and fully operationalized concept may inform clinical diagnostic practice and guide earlier designs in future therapy trials.

Keywords: Alzheimer’s disease, biological markers, blood-based biomarkers, cerebrospinal fluid biomarkers, clinical trials, functional MRI markers, molecular imaging markers, preclinical Alzheimer’s disease, structural MRI markers, subjective cognitive decline

DOI: 10.3233/JAD-150202

Journal: Journal of Alzheimer's Disease, vol. 48, no. s1, pp. S171-S191, 2015