SPECT Predictors of Cognitive Decline and Alzheimer's Disease in Mild Cognitive Impairment

Article type: Research Article

Authors: Nobili, Flavio^{a; *} | De Carli, Fabrizio^b | Frisoni, Giovanni B.^c | Portet, Florence^d | Verhey, Frans^e | Rodriguez, Guido^a | Caroli, Anna^{c; f} | Touchon, Jacques^d | Morbelli, Silvia^g | Guerra, Ugo P.^h | Dessi, Barbara^a | Brugnolo, Andrea^a | Visser, Pieter Jelle^{e; i}

Affiliations: [a] Clinical Neurophysiology Unit, Dept of Endocrinological and Medical Sciences, University of Genoa, Genoa, Italy | [b] Institute of Molecular Bioimaging and Physiology, National Research Council, Genoa, Italy | [c] LENITEM – Laboratory of Epidemiology Neuroimaging & Telemedicine, IRCCS San Giovanni di Dio Fatebenefratelli, Brescia, Italy | [d] Centre Memoire de Ressource et de Recherche, Service de Neurologie, CHU Guy de Chauliac, Montpellier, France | [e] Department of Psychiatry and Neuropsychology, University of Maastricht, The Netherlands | [f] Medical Imaging Unit, Biomedical Engineering Department, Mario Negri Institute, Bergamo, Italy | [g] Nuclear Medicine Unit, Department of Internal Medicine, University of Genoa, Genoa, Italy | [h] Nuclear Medicine Unit, Ospedali Riuniti of Bergamo, Bergamo, Italy | [i] Department of Neurology, VU University Medical Centre, Amsterdam, The Netherlands

Correspondence: [*] Corresponding author: Flavio Nobili, Clinical Neurophysiology Unit, Department of Endocrinological and Medical Sciences, Viale Benedetto XV, 6, University of Genoa, 16132 Genoa, Italy. Tel.: +39 010 3537568; Fax: +39 010 5556893; E-mail: [email protected].

Note: [] Communicated by Patrizia Mecocci

Abstract: Baseline brain single photon emission computed tomography (SPECT) was evaluated in eighty subjects with mild cognitive impairment (MCI) who were followed for a mean of about two years, when twelve patients developed Alzheimer's disease (AD), nineteen showed memory decline (D), and forty-three had normal cognition assessment (stable: S) (six drop-out). Volumetric Regions of Interest (VROI) analysis was performed in six associative cortical areas in each hemisphere. ANOVA for repeated measures showed significant effects for both the group (S, D, and AD; p < 0.004) and VROI (p < 0.0001) factors, with significant group*region interaction (p < 0.01). At post-hoc comparison, hippocampal VROIs values were lower in AD than in D and S, while parietal VROIs values were lower in D and AD than in S. These four VROI significantly correlated with verbal delayed recall score at follow-up visit. Receiver operating characteristic (ROC) curves for the mean hippocampal VROI value showed 0.81 sensitivity with 0.86 specificity in separation of S+D from AD (p < 0.0001), and 0.69 sensitivity with 0.75 specificity in separation of S from D+AD (p < 0.0002). ROC curves for the mean parietal VROI value showed 0.62 sensitivity with 0.70 specificity in separation of S from D+AD (p < 0.0002). Baseline SPECT can support outcome prediction in subjects with MCI.

Keywords: Alzheimer's disease, amnestic MCI, brain SPECT, cognitive decline, non-amnestic MCI, subjective cognitive impairment

DOI: 10.3233/JAD-2009-1091

Journal: Journal of Alzheimer's Disease, vol. 17, no. 4, pp. 761-772, 2009