Evidence of neurodegeneration in brains of older adults who do not yet fulfill MCI criteria

• Published in: Neurobiology of aging Vol. 31; no. 3; pp. 368 - 377
• Main Authors: Chao, L.L, Mueller, S.G, Buckley, S.T, Peek, K, Raptentsetseng, S, Elman, J, Yaffe, K, Miller, B.L, Kramer, J.H, Madison, C, Mungas, D, Schuff, N, Weiner, M.W
• Format: Journal Article
• Language: English
• Published: London Elsevier Inc 01.03.2010; Elsevier
• Subjects: Aged; Aged, 80 and over; Aging; Biological and medical sciences; Brain - metabolism; Brain - pathology; Cognition Disorders - diagnosis; Cognition Disorders - metabolism; Cognition Disorders - pathology; Development. Senescence. Regeneration. Transplantation; Female; Fundamental and applied biological sciences. Psychology; Humans; Internal Medicine; Magnetic Resonance Imaging; Magnetic Resonance Spectroscopy; Male; MCI; Middle Aged; MRS; Nerve Degeneration - metabolism; Nerve Degeneration - pathology; Neurology; Neuropsychological Tests; Protons; Psychiatric Status Rating Scales; Structural MRI; Vertebrates: nervous system and sense organs; Aging; Structural MRI; MCI; AD; MRS; Senescence; Central nervous system; Degeneration; Nuclear magnetic resonance imaging; Encephalon
• ISSN: 0197-4580; 1558-1497
• DOI: 10.1016/j.neurobiolaging.2008.05.004

Abstract We sought to determine whether there are structural and metabolic changes in the brains of older adults with cognitive complaints yet who do not meet MCI criteria (i.e., preMCI). We compared the volumes of regional lobar gray matter (GM) and medial temporal lobe structures, including the hippocampus, entorhinal cortex (ERC), fusiform and parahippocampal gyri, and metabolite ratios from the posterior cingulate in individuals who had a Clinical Demetia Rating (CDR) of 0.5, but who did not meet MCI criteria (preMCI, N = 17), patients with mild cognitive impairment (MCI, N = 13), and cognitively normal controls ( N = 18). Controls had more ERC, fusiform, and frontal gray matter volume than preMCI and MCI subjects and greater parahippocampal volume and more posterior cingulate N -acetylaspartate (NAA)/myoinosotil (mI) than MCI. There were no significant differences between MCI and preMCI subjects on any of these measures. These findings suggest there are neurodegenerative changes in the brains of older adults who have cognitive complaints severe enough to qualify for CDR = 0.5 yet show no deficits on formal neuropsychological testing. The results further support the hypothesis that detection of individuals with very mild forms of Alzheimer's disease (AD) may be facilitated by use of the CDR, which emphasizes changes in cognition over time within individuals rather than comparison with group norms.