Metabolic Correlates of Rey Auditory Verbal Learning Test in Elderly Subjects with Memory Complaints

Article type: Research Article

Authors: Brugnolo, Andrea^{a; *} | Morbelli, Silvia^b | Arnaldi, Dario^a | De Carli, Fabrizio^c | Accardo, Jennifer^a | Bossert, Irene^b | Dessi, Barbara^a | Famà, Francesco^a | Ferrara, Michela^a | Girtler, Nicola^{a; b; c; d} | Picco, Agnese^a | Rodriguez, Guido^e | Sambuceti, Gianmario^b | Nobili, Flavio^a

Affiliations: [a] Clinical Neurology, Dept of Neuroscience (DINOGMI), University of Genoa, Italy | [b] Nuclear Medicine, Department of Internal Medicine, University of Genoa, Genoa, Italy | [c] Institute of Bioimaging and Molecular Physiology, National Research Council, Genoa, Italy | [d] Clinical Psychology, San Martino Hospital, Genoa, Italy | [e] University of Genoa, Genoa, Italy

Correspondence: [*] Correspondence to: Andrea Brugnolo, Clinical Neurology, Department of Neuroscience (DINOGMI), University of Genoa, Largo Daneo, 3, 16132 Genoa, Italy. Tel.: +39 010 3537778; Fax: +39 010 5556893; E-mail: Andrea.Brugnolo@unige.it.

Abstract: We evaluated the brain metabolic correlates of main indexes of a widely used word list learning test, the Rey Auditory Verbal Memory Test (RAVLT), in a group of elderly subjects with memory complaints. Fifty-four subjects (age: 72.02 ± 7.45; Mini-Mental State Examination (MMSE) score: 28.9 ± 1.24) presenting at a memory clinic complaining of memory deficit, but not demented, and thirty controls (age: 71.87 ± 7.08; MMSE score: 29.1 ± 1.1) were included. Subjects with memory complaints included both patients with (amnestic mild cognitive impairment, aMCI) and without (subjective memory complaints, SMC) impairment on memory tests. All subjects underwent 18F-fluorodeoxyglucose positron emission tomography (FDG-PET), analyzed with statistical parametric. Patients with aMCI but not those with SMC showed the expected posterior cingulate-precuneus and parietal hypometabolism as compared to controls. Correlation was determined for between four indexes of the RAVLT and brain metabolism. The results show a significant correlation between the delayed recall score and metabolism in posterior cingulate gyrus of both hemispheres and in left precuneus, as well as between a score of long-term percent retention and metabolism in left posterior cingulate gyrus, precuneus, and orbitofrontal areas. These correlations survived correction for age, education, and MMSE score. No correlation was found between immediate or total recall scores and glucose metabolism. These data show the relevant role of posterior cingulate-precuneus and orbitofrontal cortices in retention and retrieval of de-contextualized verbal memory material in a group of elderly subjects with memory complaints and shed light on the topography of synaptic dysfunction in these subjects, overlapping that found in the earliest stages of Alzheimer-type neurodegeneration.

Keywords: Brain FDG-PET, memory, mild cognitive impairment, Rey Auditory Verbal Learning Test

DOI: 10.3233/JAD-121684

Journal: Journal of Alzheimer's Disease, vol. 39, no. 1, pp. 103-113, 2014