Abnormal structural brain connectome in individuals with preclinical Alzheimer's disease

Research output: Contribution to journalArticle

Abstract

Alzheimer's disease has a long preclinical phase during which amyloid pathology and neurodegeneration accumulate in the brain without producing overt cognitive deficits. It is currently unclear whether these early disease stages are associated with a progressive disruption in the communication between brain regions that subsequently leads to cognitive decline and dementia. In this study we assessed the organization of structural networks in cognitively normal (CN) individuals harboring amyloid pathology (A+N-), neurodegeneration (A-N+), or both (A+N+) from the prospective and longitudinal Swedish BioFINDER study. We combined graph theory with diffusion tensor imaging to investigate integration, segregation, and centrality measures in the brain connectome in the previous groups. At baseline, our findings revealed a disrupted network topology characterized by longer paths, lower efficiency, increased clustering and modularity in CN A-N+ and CN A+N+, but not in CN A+N-. After 2 years, CN A+N+ showed significant abnormalities in all global network measures, whereas CN A-N+ only showed abnormalities in the global efficiency. Network connectivity and organization were associated with memory in CN A+N+ individuals. Altogether, our findings suggest that amyloid pathology is not sufficient to disrupt structural network topology, whereas neurodegeneration is.

Details

Authors
Organisations
External organisations
  • Aging Research Center
  • Karolinska Institutet
  • Skåne University Hospital
  • Lund University
  • University of Gothenburg
Research areas and keywords

Subject classification (UKÄ) – MANDATORY

  • Neurology

Keywords

  • amyloid, diffusion tensor imaging, graph theory, neurodegeneration, structural connectivity
Original languageEnglish
Pages (from-to)3638-3649
Number of pages12
JournalCerebral Cortex
Volume28
Issue number10
Publication statusPublished - 2018 Oct 1
Publication categoryResearch
Peer-reviewedYes