Brain Perfusion Correlates of Visuoperceptual Deficits in Mild Cognitive Impairment and Mild Alzheimer's Disease

Article type: Research Article

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

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

Correspondence: [*] Correspondence to: Montserrat Alegret, PhD, 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: Visuoperceptual processing is impaired early in the clinical course of Alzheimer's disease (AD). The 15-Objects Test (15-OT) detects such subtle performance deficits in mild cognitive impairment (MCI) and mild AD. Reduced brain perfusion in the temporal, parietal, and prefrontal regions have been found in early AD and MCI patients. The objectives of this study were to confirm the role of the 15-OT in the diagnosis of MCI and AD and to investigate the brain perfusion correlates of visuoperceptual dysfunction (15-OT) in subjects with MCI, AD, and normal aging. Forty-two AD, 42 MCI, and 42 healthy elderly control subjects underwent a brain Single Photon Emission Tomography (SPECT) and separately completed the 15-OT. An analysis of variance compared 15-OT scores between groups. SPM5 was used to analyse the SPECT data. 15-OT performace was impaired in the MCI and AD patients. In terms of the SPECT scans, AD patients showed reduced perfusion in temporal-parietal regions, while the MCI subjects had decreased perfusion in the middle and posterior cingulate. When MCI and AD groups were compared, a significant brain perfusion reduction was found in temporo-parietal regions. In the whole sample, 15-OT performance was significantly correlated with the clinical dementia rating scores, and with the perfusion in the bilateral posterior cingulate and the right temporal pole, with no significant correlation in each separate group. Our findings suggest that the 15-OT performance provides a useful gradation of impairment from normal aging to AD, and it seems to be related to perfusion in the bilateral posterior cingulate and the right temporal pole.

Keywords: Alzheimer's disease, brain SPECT, cerebral perfusion, mild cognitive impairment, visuoperception

DOI: 10.3233/JAD-2010-091069

Journal: Journal of Alzheimer's Disease, vol. 21, no. 2, pp. 557-567, 2010