Selective cognitive dysfunction is related to a specific pattern of cerebral damage in persons with severe traumatic brain injury

Objective: Cognitive dysfunction is a common sequela of traumatic brain injury (TBI); indeed, patients show a heterogeneous pattern of cognitive deficits. This study was aimed at investigating whether patients who show selective cognitive dysfunction after TBI present a selective pattern of cerebral damage. Setting: Post-Coma Unit, IRCCS Santa Lucia Foundation, Rome, Italy. Participants: We collected data from 8 TBI patients with episodic memory disorder and without executive deficits, 7 patients with executive function impairment and preserved episodic memory capacities, and 16 healthy controls. Design: We used 2 complementary analyses: (1) an exploratory and qualitative approach in which we investigated the distribution of lesions in the TBI groups, and (2) a hypothesisdriven and quantitative approach in which we calculated the volume of hippocampi of individuals in the TBI and control groups. Main Measures: Neuropsychological scores and hippocampal volumes. Results: We found that patients with TBI and executive functions impairment presented focal lesions involving the frontal lobes, whereas patients with TBI and episodic memory disorders showed atrophic changes of the mesial temporal structure (hippocampus). Conclusion: The complexity of TBI is due to several heterogeneous factors. Indeed, studying patients with TBI and selective cognitive dysfunction should lead to a better understanding of correlations with specific brain impairment and damage, better follow-up of long-term outcome scenarios, and better planning of selective and focused rehabilitation programs.