Seeing into the traumatically injured brain

Traumatic brain injury (TBI) is a major cause of long-term disability in the developed world.¹ TBI is associated with abnormalities in neuropsychological function, with particular deficits in working memory and attention. Perhaps surprisingly, the proportion of patients with long-term cognitive problems is largely independent of injury severity,² but there are opposing opinions on the extent to which these deficits recover over time, particularly in the more mildly injured patient. Some reports show ongoing problems at 12 months,³ while others suggest that a complex interaction of neurobiological, psychosocial, and legal factors may obscure the true level of cognitive disability.⁴

One reason for the continuing discussion of how brain injury affects cognitive function has been the difficulty in visualizing the true extent of CNS damage. While CT and MRI can depict acute focal injury, conventional imaging is relatively insensitive to diffuse injury, resulting in only weak correlations between imaging findings and cognitive performance.⁵ Recent developments …