Verbal episodic memory impairment and hippocampal atrophy in chronic moderate-to-severe traumatic brain injury.

Objective: The primary objective was to investigate the association between and the predictive value of hippocampal volume on verbal episodic memory (VEM), in participants with chronic moderate-to-severe TBI (MS-TBI).

Method: Nighty-one individuals with MS-TBI (males = 82, females = 9) were included (mean age = 33.57 years; mean educational level = 12.20 years; mean time since injury = 5.16 years). To assess VEM the Immediate Recall 1st Try, AVLT Total, Short and Long Delay Recall and Recognition trials of the Auditory Verbal Learning Test (AVLT) Greek Version, and the Immediate and Delayed Recall tasks from the Logical Memory subtest (Wechsler Memory Scale-III) were implemented. T1-weighted magnetic resonance images were used to extract global volumes and unilateral and bilateral hippocampal volume.

Results: Bilateral hippocampal volume was positively associated with the AVLT Long Delay Recall scores. Also, the left hippocampal volume was positively correlated with the AVLT Long Delay Recall and the LM Delayed Recall scores. Finally, the left hippocampal volume predicted performance on the LM Delayed and the AVLT Long Delay Recall tasks.

Conclusion: These findings suggest a potential role of the hippocampus in VEM performance in chronic MS-TBI and highlight the need for further research to clarify these associations and guide the development of targeted memory interventions.