Aberrant interhemispheric functional connectivity within default mode network and its relationships with neurocognitive features in cognitively normal APOE ɛ 4 elderly carriers

Hanna LU, Suk Ling MA, Wai Ho Savio WONG, Cindy W. C. TAM, Sheung-Tak CHENG, Sandra S. M. CHAN, Linda C. W. LAM

Research output: Contribution to journalArticles

4 Citations (Scopus)

Abstract

Background: Default mode network (DMN) is vulnerable to the effects of APOE genotype. Given the reduced brain volumes and APOE ɛ 4-related brain changes in elderly carriers, it is less known that whether these changes would influence the functional connectivity and to what extent. This study aimed to examine the functional connectivity within DMN, and its diagnostic value with age-related morphometric alterations considered.

Methods: Whole brain and seed-based resting-state functional connectivity (RSFC) analysis were conducted in cognitively normal APOE ɛ 4 carriers and matched non-carriers (N=38). The absolute values of mean correlation coefficients (z-values) were used as a measure of functional connectivity strength (FCS) between DMN subregions, which were also used to estimate their diagnostic value by receiver-operating characteristic (ROC) curves.

Results: APOE ɛ 4 carriers demonstrated decreased interhemispheric FCS, particularly between right hippocampal formation (R.HF) and left inferior parietal lobular (L.IPL) (t=3.487, p<0.001). ROC analysis showed that the FCS of R.HF and L.IPL could differentiate APOE ɛ 4 carriers from healthy counterparts (AUC value=0.734, p=0.025). Moreover, after adjusting the impact of morphometry, the differentiated value of FCS of R.HF and L.IPL was markedly improved (AUC value=0.828, p=0.002).

Conclusions: Our findings suggest that APOE ɛ 4 allele affects the functional connectivity within posterior DMN, particularly the atrophy-corrected interhemispheric FCS before the clinical expression of neurodegenerative disease. Copyright © 2017 International Psychogeriatric Association.
Original languageEnglish
Pages (from-to)805-814
JournalInternational Psychogeriatrics
Volume29
Issue number5
Early online date26 Jan 2017
DOIs
Publication statusPublished - May 2017

Citation

Lu, H., Ma, S. L., Wong, S. W. H., Tam, C. W. C., Cheng, S.-T., Chan, S. S. M., & Lam, L. C. W. (2017). Aberrant interhemispheric functional connectivity within default mode network and its relationships with neurocognitive features in cognitively normal APOE ɛ 4 elderly carriers. International Psychogeriatrics, 29(5), 805-814. doi: 10.1017/S1041610216002477

Keywords

  • Apolipoprotein E
  • Functional connectivity
  • Default mode network
  • Neurocognitive disorder
  • Alzheimer's disease

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