Cognitive fatigue after TBI linked with activation of caudate

Individuals with neurological damage often report difficulties with cognitive fatigue, a subjective lack of mental energy that is perceived to interfere with daily activities. Because of poor correlation between self-reports of cognitive fatigue and tests of cognitive performance, scientists are looking at more objective measures, such as correlations with neuroimaging findings. In the Kessler study, brain activation patterns were compared in 22 individuals with moderate to severe TBI and 20 healthy controls. Both groups performed tasks of working memory during functional MRI imaging of the brain; the TBI group reported more fatigue, although performance was comparable between the groups. The results showed that the experience of self-reported fatigue is associated with activation changes in the caudate nucleus of the basal ganglia.

"These results are consistent with findings in our related research in the multiple sclerosis (MS) population," said Dr. Wylie, the lead author, "which suggests that the TBI and MS populations share a mechanism for cognitive fatigue." This has important implications for the development of effective treatments. "This study points to the caudate nucleus as a likely target for clinical interventions to alleviate fatigue," explained Dr. Wylie, who is associate director of Neuroscience Research and the Rocco Ortenzio Neuroimaging Center at Kessler Foundation.