A Perfusion fMRI Study of the Neural Correlates of Sustained-Attention and Working-Memory Deficits in Chronic Traumatic Brain Injury
Neurorehabilitation and Neural Repair, 08/09/2012
Kim J et al. – ASL perfusion functional MRI (fMRI) demonstrated differences between individuals with traumatic brain injury (TBI) and healthy controls in resting perfusion and in task–evoked cerebral blood flow (CBF) changes as well as different patterns of performance–activation correlation. These results are consistent with the notion that sensory/attentional modulation deficits contribute to higher cognitive dysfunction in TBI.Methods
- A total of 18 to 21 individuals with moderate to severe TBI and 14 to 18 demographically matched healthy controls completed 3 continuous 6-minute perfusion fMRI scans (resting, visual sustained attention, and 2-back working memory).
- For both tasks, TBI participants showed worse behavioral performance than controls.
- Voxelwise neuroimaging analysis of the 2-back task found that group differences in task-induced CBF changes were localized to bilateral superior occipital cortices and the left superior temporal cortex.
- Whereas controls deactivated these areas during task performance, TBI participants tended to activate these same areas.
- These regions were among those found to be disproportionately hypoperfused at rest after TBI.
- For both tasks, the control and TBI groups showed different patterns of correlation between performance and task-related CBF changes.