Changes in functional network centrality underlie cognitive dysfunction and physical disability in multiple sclerosis

Mult Scler. 2014 Jul;20(8):1058-65. doi: 10.1177/1352458513516892. Epub 2013 Dec 17.

Abstract

Background: Cognitive dysfunction in multiple sclerosis (MS) has a large impact on the quality of life and is poorly understood.

Objective: The aim of this study was to investigate functional network integrity in MS, and relate this to cognitive dysfunction and physical disability.

Methods: Resting state fMRI scans were included of 128 MS patients and 50 controls. Eigenvector centrality mapping (ECM) was applied, a graph analysis technique that ranks the importance of brain regions based on their connectivity patterns. Significant ECM changes were related to physical disability and cognitive dysfunction.

Results: In MS patients, ECM values were increased in bilateral thalamus and posterior cingulate (PCC) areas, and decreased in sensorimotor and ventral stream areas. Sensorimotor ECM decreases were related to higher EDSS (rho = -0.24, p = 0.007), while ventral stream decreases were related to poorer average cognition (rho = 0.23, p = 0.009). The thalamus displayed increased connectivity to sensorimotor and ventral stream areas.

Conclusion: In MS, areas in the ventral stream and sensorimotor cortex appear to become less central in the entire functional network of the brain, which is associated with clinico-cognitive dysfunction. The thalamus, however, displays increased connectivity with these areas. These findings may aid in further elucidating the function of functional reorganization processes in MS.

Keywords: Multiple sclerosis; cognition; connectivity; functional reorganization; hippocampus; thalamus.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Brain / diagnostic imaging
  • Brain / physiopathology*
  • Brain Mapping / methods
  • Case-Control Studies
  • Cognition Disorders / diagnosis
  • Cognition Disorders / physiopathology*
  • Cognition Disorders / psychology
  • Cognition*
  • Disability Evaluation
  • Female
  • Humans
  • Image Interpretation, Computer-Assisted
  • Magnetic Resonance Imaging
  • Male
  • Middle Aged
  • Motor Activity*
  • Multiple Sclerosis / diagnosis
  • Multiple Sclerosis / physiopathology*
  • Multiple Sclerosis / psychology
  • Nerve Net / diagnostic imaging
  • Nerve Net / physiopathology*
  • Quality of Life
  • Sensorimotor Cortex / physiopathology
  • Thalamus / physiopathology