title: Odor identification deficit in mild cognitive impairment and Alzheimer's disease is associated with hippocampal and deep gray matter atrophy.
abstract: Even in early stages, Alzheimer's disease (AD) is associated with olfactory deficit. We assess the association of volumetric differences in subcortical deep gray matter (DGM) structures and odor identification deficit (OID) in subjects with amnestic mild cognitive impairment (aMCI), AD and normal controls (NCs), and relate findings to the current gold standard right sided memory measure, visual reproduction. Eighty subjects (19 aMCI; 42 CE; 19 NC) were included in this study. We obtained olfactory testing and normalized structural brain volumes from 3T T1 MRI scans. Associations between MRI, olfactory- and memory impairment were studied using Pearson- and partial-correlation adjusted for age. AD patients had significantly higher olfactory deficits, lower visual reproduction scores, and reduced brain volumes (p<0.05). Within aMCI, OID was associated with lower right hippocampal- and left amygdala volume (p<0.05). In AD, OID was associated with bilaterally lower hippocampus and left amygdala volumes. In contrast, visual reproduction was associated with bilateral volume loss regardless of study group. OID is a more specific marker of early pathological right mesial-temporal involvement than the currently regarded gold standard of right sided-memory (visual reproduction). OID may be valuable in the longitudinal evaluation of disease modifying treatments in early disease course.
authors: Buffalo Neuroimaging Analysis Center, Department of Neurology, School of Medicine and Biomedical Sciences, University at Buffalo, State University of New York, Buffalo, NY, USA. Electronic address: jhagemeier@bnac.net.
authors: Jesper
authors: J
authors: Hagemeier
authors: Department of Neurology, School of Medicine and Biomedical Sciences, University at Buffalo, State University of New York, Buffalo, USA.
authors: Matthew R
authors: MR
authors: Woodward
authors: Department of Neurology, School of Medicine and Biomedical Sciences, University at Buffalo, State University of New York, Buffalo, USA.
authors: Usama A
authors: UA
authors: Rafique
authors: Department of Neurology, School of Medicine and Biomedical Sciences, University at Buffalo, State University of New York, Buffalo, USA.
authors: Chaitanya V
authors: CV
authors: Amrutkar
authors: Buffalo Neuroimaging Analysis Center, Department of Neurology, School of Medicine and Biomedical Sciences, University at Buffalo, State University of New York, Buffalo, NY, USA; IRCCS Don Gnocchi Foundation, Milan, Italy.
authors: Niels
authors: N
authors: Bergsland
authors: Buffalo Neuroimaging Analysis Center, Department of Neurology, School of Medicine and Biomedical Sciences, University at Buffalo, State University of New York, Buffalo, NY, USA.
authors: Michael G
authors: MG
authors: Dwyer
authors: Department of Neurology, School of Medicine and Biomedical Sciences, University at Buffalo, State University of New York, Buffalo, USA.
authors: Ralph
authors: R
authors: Benedict
authors: Buffalo Neuroimaging Analysis Center, Department of Neurology, School of Medicine and Biomedical Sciences, University at Buffalo, State University of New York, Buffalo, NY, USA; MRI Clinical Translational Research Center, School of Medicine and Biomedical Sciences, University at Buffalo, State University of New York, Buffalo, NY, USA.
authors: Robert
authors: R
authors: Zivadinov
authors: Department of Neurology, School of Medicine and Biomedical Sciences, University at Buffalo, State University of New York, Buffalo, USA.
authors: Kinga
authors: K
authors: Szigeti
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000544:Alzheimer Disease / Q000150:complications / Q000000981:diagnostic imaging / Q000473:pathology*; D001284:Atrophy / Q000150:complications / Q000000981:diagnostic imaging / Q000473:pathology*; D001931:Brain Mapping; D060825:Cognitive Dysfunction / Q000150:complications / Q000000981:diagnostic imaging / Q000473:pathology*; D005260:Female; D066128:Gray Matter / Q000000981:diagnostic imaging / Q000473:pathology*; D006624:Hippocampus / Q000000981:diagnostic imaging / Q000473:pathology*; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008568:Memory / Q000502:physiology; D008569:Memory Disorders / Q000150:complications / Q000000981:diagnostic imaging / Q000473:pathology; D009483:Neuropsychological Tests; D009812:Odorants; D010468:Perceptual Disorders / Q000150:complications / Q000000981:diagnostic imaging / Q000473:pathology*
keywords: Alzheimer's; Deep gray matter; MRI; Mild cognitive impairment; Olfactory; Smelling