Epub ahead of print: Hawellek et al. Increased functional connectivity indicates the severity of cognitive impairment in multiple sclerosis. Proc Natl Acad Sci U S A. 2011 Nov 7.
The investigators studied the impact of MS, which leads to the severe disintegration of the central white matter, on functional connectivity patterns in spontaneous cortical activity.
Using a data driven approach based on the strength of a salient pattern of cognitive pathology, we identified distinct brain networks that exhibit increases in functional connectivity despite the presence of strong and diffuse reductions of the central white-matter integrity.
The findings imply a complex and diverging relation of anatomical and functional connectivity in early MS.
Fig: Functional MRI showing connectivity between two areas of the brain in opposite hemispheres.
"This is rather complex study; the science is difficult to understand. However, what the findings are saying is that although MS causes substantial damage to brain and hence affects cognition (higher processes) the brain adapts by increasing connections between areas of the cortex (functional connectivity). The degree of this increased functional connectivity correlates with the amount of cognitive impairment. Functional connectivity helps MS'ers cope despite having a large lesion load."