title: Diffusion tensor imaging surpasses cerebrospinal fluid as predictor of cognitive decline and medial temporal lobe atrophy in subjective cognitive impairment and mild cognitive impairment.
abstract: Neuropathological correlates of Alzheimer's disease (AD) emerge years before dementia. Biomarkers preceding cognitive decline and reflecting the causative processes can potentially aid early intervention and diagnosis. Diffusion tensor imaging (DTI) indirectly reflects tissue microstructure. To answer whether DTI is an early biomarker for AD and to explore the relationship between DTI and the established biomarkers of medial temporal lobe atrophy and cerebrospinal fluid (CSF) Aβ(42), T-tau, and P-tau, we longitudinally studied normal controls and patients with subjective (SCI) or mild (MCI) cognitive impairment. 21 controls and 64 SCI or MCI cases recruited from a university-hospital based memory clinic were re-examined after two to three years. FreeSurfer was used for longitudinal processing of morphometric data, and DTI derived fractional anisotropy, radial diffusivity, and mean diffusivity were analyzed in Tract-Based Spatial Statistics. Using regression models, we explored and compared the predictive powers of DTI and CSF biomarkers in regard to cognitive change and atrophy of the medial temporal lobe. Both DTI and CSF biomarkers significantly predicted cognitive decline and atrophy in the medial temporal lobe. In this population, however, DTI was a better predictor of dementia and AD-specific medial temporal lobe atrophy than the CSF biomarkers. The case for DTI as an early biomarker for AD is strengthened, but further studies are needed to confirm these results.
authors.affiliation: Department of Neurology, Faculty Division, Akershus University Hospital, University of Oslo, Lørenskog, Norway. per.selnes@medisin.uio.no
authors.forename: Per
authors.initials: P
authors.lastname: Selnes
authors.forename: Dag
authors.initials: D
authors.lastname: Aarsland
authors.forename: Atle
authors.initials: A
authors.lastname: Bjørnerud
authors.forename: Leif
authors.initials: L
authors.lastname: Gjerstad
authors.forename: Anders
authors.initials: A
authors.lastname: Wallin
authors.forename: Erik
authors.initials: E
authors.lastname: Hessen
authors.forename: Ivar
authors.initials: I
authors.lastname: Reinvang
authors.forename: Ramune
authors.initials: R
authors.lastname: Grambaite
authors.forename: Eirik
authors.initials: E
authors.lastname: Auning
authors.forename: Veslemøy Krohn
authors.initials: VK
authors.lastname: Kjærvik
authors.forename: Paulina
authors.initials: P
authors.lastname: Due-Tønnessen
authors.forename: Vidar
authors.initials: V
authors.lastname: Stenset
authors.forename: Tormod
authors.initials: T
authors.lastname: Fladby
mesh_terms: D000368:Aged; D016229:Amyloid beta-Peptides / Q000134:cerebrospinal fluid*; D000704:Analysis of Variance; D001284:Atrophy / Q000175:diagnosis; D060825:Cognitive Dysfunction / Q000134:cerebrospinal fluid* / Q000473:pathology*; D056324:Diffusion Tensor Imaging; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009483:Neuropsychological Tests; D010446:Peptide Fragments / Q000134:cerebrospinal fluid*; D011237:Predictive Value of Tests; D013702:Temporal Lobe / Q000473:pathology*; D016875:tau Proteins / Q000134:cerebrospinal fluid*
chemical_list: D016229:Amyloid beta-Peptides; D010446:Peptide Fragments; C075222:amyloid beta-protein (1-42); D016875:tau Proteins