Neuroradiological and neuropathological investigations have found
evidence of diffuse brain damage in the frontal and temporal lobes,
corpus callosum, and fornices in patients who have sustained a mild
traumatic brain injury (TBI). However, neuropsychological assessments
of these patients do not typically target many of the subtle
information processing deficits that may arise from diffuse damage
involving the frontotemporal regions of the brain as well as white
matter pathology, including the corpus callosum. Consequently, we have
a limited understanding of the deficits that may be attributable to
temporary or permanent disruptions to these functional pathways. This
study assessed a group of mild TBI patients (N = 40) and a
matched control group (N = 40) on a number of standard
neuropsychological tests of selective and sustained attention, verbal
and non-verbal fluency, and verbal memory. In addition, reaction time
(RT) tasks, requiring both the inter- and intra-hemispheric processing
of visual and tactile information, were used to assess the functional
integrity of the tracts that are likely to be affected by diffuse
damage. In the 1st month after sustaining their injury, the mild TBI
group demonstrated deficits in attention, non-verbal fluency, and
verbal memory. They also demonstrated slower visual and tactile RTs,
with the visual RTs of mild TBI patients being more affected by
increased task difficulty and the need to transfer information across
the corpus callosum, than did their matched controls. (JINS,
2004, 10, 286–297.)
Delayed degeneration of the left fornical crus with verbal memory impairment in a patient with mild traumatic brain injury
