Resilience and MRI correlates of cognitive impairment in community dwelling elders
Topiwala A., Allan CL., Valkanova V., Zsoldos E., Filippini N., Sexton CE., Mahmood A., Singh-Manoux A., Mackay CE., Kivimäki M., Ebmeier KP.
Background – The contribution of education and intelligence to resilience against age-related cognitive decline is not clear, particularly in the presence of “normal for age” minor brain abnormalities. Methods - Participants (N=208, mean age 69.2 ± 5.4 years) in the Whitehall II imaging sub-study attended for neuropsychological testing and multi-sequence 3T brain MRI. Images were independently rated by three trained clinicians for global and hippocampal atrophy, periventricular and deep white matter changes. Results – Although none of the participants qualified for a clinical diagnosis of dementia, a screen for cognitive impairment (Montreal Cognitive Assessment (MoCA) <26) was abnormal in 22%. Hippocampal atrophy, in contrast to other brain measures, was associated with a reduced MoCA score even after controlling for age, sex, socio-economic status, years of education and premorbid IQ. Premorbid IQ and socio-economic status were associated with resilience in the presence of hippocampal atrophy. Conclusions – Independent contribution from a priori risk (age, hippocampal atrophy) and resilience (premorbid function, socio-economic status) combine to predict measured cognitive impairment.