Predicting Cognitive Decline With Default Mode Network


This is the Medscape Neurology Minute. I'm Dr. Alan Jacobs. The default mode network is a network of brain regions that are active when the individual is not focused on the outside world and the brain is at wakeful rest. Researchers from the Department of Radiology and Brain Imaging at Duke University have published a study examining the utility of the default mode network in predicting future cognitive decline from normal through mild cognitive impairment (MCI) to Alzheimer disease (AD). Functional MRI scans during a face-name memory task were acquired from a cohort of 68 participants consisting of 25 normal controls, 31 with MCI, and 12 with AD. Patients with MCI were followed for 2.4 years to determine progression to AD. Maps of default mode network connectivity were compared with a template map constructed from elderly normal participants to obtain goodness-of-fit indices of default mode network expression. Goodness-of-fit indices were highest in normal controls, intermediate in MCI, and lowest in AD. In a predictive model, the effect of goodness-of-fit index on progression from MCI to dementia was significant. The investigators conclude that functional MRI connectivity indices distinguish patients with MCI who undergo cognitive decline and conversion to AD from those who remain stable over a 2- to 3-year period of follow-up. This article was selected from Medscape Best Evidence. I'm Dr. Alan Jacobs.

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