A Two-Year Follow-Up of Cognitive Deficits and Brain Perfusion in Mild Cognitive Impairment and Mild Alzheimer's Disease

Article type: Research Article

Authors: Alegret, Montserrat^{a; *} | Cuberas-Borrós, Gemma^{b; c} | Vinyes-Junqué, Georgina^a | Espinosa, Ana^a | Valero, Sergi^{a; d} | Hernández, Isabel^a | Roca, Isabel^{b; c} | Ruíz, Agustín^a | Rosende-Roca, Maitée^a | Mauleón, Ana^a | Becker, James T.^{e; f; g} | Castell-Conesa, Joan^{b; c} | Tárraga, Lluís^a | Boada, Mercè^{a; c}

Affiliations: [a] Memory Clinic of Fundació ACE, Institut Català de Neurociències Aplicades, Barcelona, Spain | [b] Nuclear Medicine Department, Hospital Universitari Vall d'Hebron, Barcelona, Spain | [c] Hospital Universitari Vall d'Hebron-Institut de Recerca, Universitat Autònoma de Barcelona (VHIR-UAB), Barcelona, Spain | [d] Psychiatry Department, Hospital Universitari Vall d'Hebron, CIBERSAM, Universitat Autònoma de Barcelona, Barcelona, Spain | [e] Department of Neurology, University of Pittsburgh, Pittsburgh, PA, USA | [f] Department of Psychiatry, University of Pittsburgh, Pittsburgh, PA, USA | [g] Department of Psychology, University of Pittsburgh, Pittsburgh, PA, USA

Correspondence: [*] Correspondence to: Montserrat Alegret, PhD, Memory Clinic of Fundació ACE, Institut Català de Neurociències Aplicades, C/Marquès de Sentmenat, 35-37, 08014 Barcelona, Spain. Tel.: +34 93 4304720; Fax: +34 93 4193542; E-mail: [email protected].

Abstract: The 15-Objects Test (15-OT) provides useful gradation of visuoperceptual impairment from normal aging through Alzheimer's disease (AD) and correlates with temporo-parietal perfusion. The objectives of this study were to analyze progression of 15-OT performance in mild cognitive impairment (MCI) and AD, and its correlates with cognition and single photon emission computerized tomography (SPECT), as well as to examine neuropsychological and SPECT differences between the MCI patients who developed AD and those who did not. From the initial 126 participants (42/group), 38 AD, 39 MCI, and 38 elderly controls (EC) were reassessed (SPECT: 35 AD, 33 MCI, 35 EC) after two years. The progression of cognitive and SPECT scores during this period was compared between groups, and baseline data between converters and non-converters. The 15-OT was the only measure of progression that differed between the three groups; worsening scores on 15-OT were associated with worsening in verbal and visual retention, and decreased perfusion on left postsubicular area. In the MCI patients, cerebral perfusion fell over the two years in medial-posterior cingulate and fronto-temporo-parietal regions; AD showed extensive changes involving almost all cerebral regions. No SPECT changes were detected in controls. At baseline, the MCI patients who developed AD differed from non-converters in verbal recognition memory, but not in SPECT perfusion. In conclusion, SPECT and 15-OT appear to provide a potential measure to differentiate between normal aging, MCI, and AD. Worsening on 15-OT was related to decreased perfusion in postsubicular area; but further longitudinal studies are needed to determine the contribution of 15-OT as a predictor of AD from MCI.

Keywords: 15-objects test, Alzheimer's disease, brain SPECT, cerebral perfusion, longitudinal, mild cognitive impairment, prospective, two-year follow-up, visuoperception

DOI: 10.3233/JAD-2012-111850

Journal: Journal of Alzheimer's Disease, vol. 30, no. 1, pp. 109-120, 2012