Display Settings:

Format

Send to:

Choose Destination
Neurology. 2011 Feb 8;76(6):511-7. doi: 10.1212/WNL.0b013e31820af94e. Epub 2011 Jan 12.

Default mode network connectivity in stable vs progressive mild cognitive impairment.

Author information

  • 1Department of Radiology and Brain Imaging and Analysis Center, Duke University Medical Center, Durham, NC, USA. jeffrey.petrella@duke.edu

Abstract

OBJECTIVE:

Dysfunction of the default mode network (DMN) has been identified in prior cross-sectional fMRI studies of Alzheimer disease (AD) and mild cognitive impairment (MCI); however, no studies have examined its utility in predicting future cognitive decline.

METHODS:

fMRI scans during a face-name memory task were acquired from a cohort of 68 subjects (25 normal control, 31 MCI, and 12 AD). Subjects with MCI were followed for 2.4 years (±0.8) to determine progression to AD. Maps of DMN connectivity were compared with a template DMN map constructed from elderly normal controls to obtain goodness-of-fit (GOF) indices of DMN expression. Indices were compared between groups and correlated with cognitive decline.

RESULTS:

GOF indices were highest in normal controls, intermediate in MCI, and lowest in AD (p < 0.0001). In a predictive model (that included baseline GOF indices, age, education, Mini-Mental State Examination score, and an index of DMN gray matter volume), the effect of GOF index on progression from MCI to dementia was significant. In MCI, baseline GOF indices were correlated with change from baseline in functional status (Clinical Dementia Rating-sum of boxes) (r = -0.40, p < 0.04). However, there was no additional predictive value for DMN connectivity when baseline delayed recall was included in the models.

CONCLUSIONS:

fMRI 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 follow-up period. Our data support the notion of different functional brain connectivity endophenotypes for "early" vs "late" MCI, which are associated with different baseline memory scores and different rates of progression and conversion.

Comment in

PMID:
21228297
[PubMed - indexed for MEDLINE]
PMCID:
PMC3053179
Free PMC Article

Images from this publication.See all images (3)Free text

Figure 1
Figure 2
Figure 3
PubMed Commons home

PubMed Commons

0 comments
How to join PubMed Commons

    Supplemental Content

    Full text links

    Icon for HighWire Icon for PubMed Central
    Loading ...
    Write to the Help Desk