Stroke and Neurodegeneration Induce Different Connectivity Aberrations in the Insula

Stroke. 2015 Sep;46(9):2673-7. doi: 10.1161/STROKEAHA.115.009598. Epub 2015 Jul 16.

Abstract

Background and purpose: Stroke and neurodegeneration cause significant brain damage and cognitive impairment, especially if the insular cortex is compromised. This study explores for the first time whether these 2 causes differentially alter connectivity patterns in the insular cortex.

Methods: Resting state-functional magnetic resonance imaging data were collected from patients with insular stroke, patients with behavioral variant frontotemporal dementia, and healthy controls. Data from the 3 groups were assessed through a correlation function analysis. Specifically, we compared decreases in connectivity as a function of voxel Euclidean distance within the insular cortex.

Results: Relative to controls, patients with stroke showed faster connectivity decays as a function of distance (hypoconnectivity). In contrast, the behavioral variant frontotemporal dementia group exhibited significant hyperconnectivity between neighboring voxels. Both patient groups evinced global hypoconnectivity. No between-group differences were observed in a volumetrically and functionally comparable region without ischemia or neurodegeneration.

Conclusions: Functional insular cortex connectivity is affected differently by cerebral ischemia and neurodegeneration, possibly because of differences in the cause-specific pathophysiological mechanisms of each disease. These findings have important clinical and theoretical implications.

Keywords: cerebral cortex; dementia; magnetic resonance imaging; stroke.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aged
  • Brain Ischemia / physiopathology*
  • Cerebral Cortex / physiopathology*
  • Connectome*
  • Female
  • Frontotemporal Dementia / physiopathology*
  • Humans
  • Magnetic Resonance Imaging
  • Male
  • Middle Aged
  • Stroke / physiopathology*