Traumatic brain injury (TBI) results in varied levels of cognitive impairment. One challenge to understanding the degree of TBI-related cognitive disruption is a lack of baseline evaluations of cognitive function prior to sustaining an injury. To address this problem, a group of researchers studied a unique population of individuals who were given cognitive assessments prior to sustaining TBIs as part of an aptitude test for the Israeli Defense Forces. The researchers administered cognitive assessments to 50 adults who had since suffered TBIs, as well as to 35 healthy controls, and assessed changes in cognitive ability as a result of TBI. They tested skills such as abstract reasoning, verbal abstraction, and mathematical reasoning. In addition, imaging techniques were used to correlate changes in cognitive ability with differences in brain composition between the test group and the healthy controls.
The researchers observed a decline in abstract reasoning skills in individuals who suffered TBI across the range of injury severity, as well as a decline in verbal abstraction in individuals who suffered moderate or severe TBIs. In addition, a decline in non-verbal abstract reasoning correlated with decreased brain volume in the insular cortex, which could be associated with declines in cognitive ability, higher order executive functioning, emotional processing, and behavior. These findings help provide a basis for better understanding of the causes of long-term cognitive effects of TBI.
Livny, Abigail, et al. "Cognitive Deficits Post-Traumatic Brain Injury and Their Association with Injury Severity and Gray Matter Volumes." Journal of Neurotrauma. (December 2016).