Open AccessDiffusion tensor imaging of the hippocampus predicts the risk of dementia; the RUN DMC study
Author(s) -
van Uden I.W.M.,
Tuladhar A.M.,
van der Holst H.M.,
van Leijsen E.M.C.,
van Norden A.G.W.,
de Laat K.F.,
RuttenJacobs L.C.A.,
Norris D.G.,
Claassen J.A.H.R,
van Dijk E.J.,
Kessels R.P.C.,
de Leeuw FE
Publication year - 2016
Publication title -
human brain mapping
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.005
H-Index - 191
eISSN - 1097-0193
pISSN - 1065-9471
DOI - 10.1002/hbm.23029
Subject(s) - fractional anisotropy , dementia , hippocampal formation , diffusion mri , hippocampus , hazard ratio , atrophy , proportional hazards model , medicine , white matter , prospective cohort study , cardiology , psychology , neuroscience , magnetic resonance imaging , disease , confidence interval , radiology
Abstract Introduction Cerebral small vessel disease is one of the most important risk factors for dementia, and has been related to hippocampal atrophy, which is among the first observed changes on conventional MRI in patients with dementia. However, these volumetric changes might be preceded by loss of microstructural integrity of the hippocampus for which conventional MRI is not sensitive enough. Therefore, we investigated the relation between the hippocampal diffusion parameters and the risk of incident dementia, using diffusion tensor imaging, independent of hippocampal volume. Methods The RUNDMC study is a prospective study among 503 elderly with small vessel disease, without dementia, with 5 years follow‐up in 2012 (99.6% response‐rate). Cox regression analysis was performed to calculate hazard ratios for dementia, of fractional anisotropy and mean diffusivity within the hippocampus, adjusted for demographics, hippocampal volume, and white matter. This was repeated in participants without evident hippocampal volume loss, because in these participants the visible damage might not yet have already started, whereas damage might have started on a microstructural level. Results 43 participants developed dementia (8.6%), resulting in a 5.5‐year cumulative risk of 11.1% (95%CI 7.7–14.6). Higher mean diffusivity was associated with an increased 5‐year risk of dementia. In the subgroup of participants with the upper half hippocampal volume, higher hippocampal mean diffusivity, more than doubled the 5‐year risk of dementia. Conclusion This is the first prospective study showing a relation between a higher baseline hippocampal mean diffusivity and the risk of incident dementia in elderly with small vessel disease at 5‐year follow‐up, independent of hippocampal volume and white matter volume. Hum Brain Mapp 37:327–337, 2016 . © 2015 Wiley Periodicals, Inc.