Diffusion tensor imaging and cognition

Epub ahead of printYu et al. Multiple white matter tract abnormalities underlie cognitive impairment in RRMS. Neuroimage. 2011 Oct 29.

Diffusion tensor imaging (DTI) is a sensitive MRI technique for detecting structural tissue damage in the brain and spinal cord. 

In this study, the researchers investigated DTI abnormalities in individuals with RRMS and examined the relations between imaging-based measures of white matter injury and cognitive impairment. 

37 individuals with RRMS were compared to 20 healthy controls. 

Cognitive impairment was assessed with standard tests.

Correlations between DTI-metrics and cognition were explored in regions demonstrating significant differences between the RRMS patients and the control group. 

Lower DTI measurements were found in RRMS participants compared to controls across the tract skeleton (0.40±0.03 vs. 0.43±0.01, p<0.01). 

In the RRMS group, correlations were found between a reduction in DTI-metrics and cognitive impairment in cognitively-relevant white matter tracts.

These findings indicate the important role for DTI in delineating mechanisms underlying MS-associated cognitive impairment and suggest that DTI could play a critical role in monitoring the clinical and cognitive effects of MS.

Fig: DTI image showing white matter tracts in the brain.

"Is this result surprising? Damage to white matter tracts correlates with cognitive impairment. Best not to let the tracts become damaged in the first place; another argument for active treatment ASAP after disease onset. It is better to prevent damage than to try and repair it."

"This type of research not only increases our understanding of MS, but may allow us to monitor the disease more intelligently. DTI may be included as an outcome measure in future clinical trials."