Quantitative multi-modal MRI of the Hippocampus and cognitive ability in community-dwelling older subjects

Benjamin S. Aribisala, Natalie A. Royle, Susana Muñoz Maniega, Maria C. Valdés Hernández, Catherine Murray, Lars Penke, Alan Gow, John M. Starr, Mark E. Bastin, Ian J. Deary, Joanna M. Wardlaw
2014 Cortex  
Hippocampal structural integrity is commonly quantified using volumetric measurements derived from brain magnetic resonance imaging (MRI). Previously reported associations with cognitive decline have not been consistent. We investigate hippocampal integrity using quantitative MRI techniques and its association with cognitive abilities in older age. Participants from the Lothian Birth Cohort 1936 underwent brain MRI at mean age 73 years. Longitudinal relaxation time (T1), magnetization transfer
more » ... atio (MTR), fractional anisotropy (FA) and mean diffusivity (MD) were measured in the hippocampus. General factors of fluidtype intelligence (g), cognitive processing speed (speed) and memory were obtained at age 73 years, as well as childhood IQ test results at age 11 years. Amongst 565 older adults, multivariate linear regression showed that, after correcting for ICV, gender and age 11 IQ, larger left hippocampal volume was significantly associated with better memory ability (β = 0.11, p=0.003), but not with speed or g. Using quantitative MRI and after correcting for multiple testing, higher T1 and MD were significantly associated with lower scores of g (β range = -0.11 to -0.14, p<0.001), speed (β range = -0.15 to -0.20, p<0.001) and memory (β range = -0.10 to -0.12, p<0.001). Higher MTR and FA in the hippocampus were also significantly associated with higher scores of g (β range = 0.17 to 0.18, p<0.0001) and speed (β range = 0.10 to 0.15, p<0.0001), but not memory. Quantitative multi-modal MRI assessments were more sensitive at detecting cognitionhippocampal integrity associations than volumetric measurements, resulting in stronger associations between MRI biomarkers and age-related cognition changes.
doi:10.1016/j.cortex.2013.12.012 pmid:24561387 pmcid:PMC3979658 fatcat:3le23cl4jrdtdgthcaipe5jd3y