Environmental enrichment may protect against hippocampal atrophy in the chronic stages of traumatic brain injury

Front Hum Neurosci. 2013 Sep 24:7:506. doi: 10.3389/fnhum.2013.00506. eCollection 2013.

Abstract

Objective: To examine the relationship between environmental enrichment (EE) and hippocampal atrophy in the chronic stages of moderate to severe traumatic brain injury (TBI).

Design: Retrospective analysis of prospectively collected data; observational, within-subjects.

Participants: Patients (N = 25) with moderate to severe TBI.

Measures: Primary predictors: (1) An aggregate of self-report rating of EE (comprising hours of cognitive, physical, and social activities) at 5 months post-injury; (2) pre-injury years of education as a proxy for pre-morbid EE (or cognitive reserve).

Primary outcome: bilateral hippocampal volume change from 5 to 28 months post-injury.

Results: As predicted, self-reported EE was significantly negatively correlated with bilateral hippocampal atrophy (p < 0.05), with greater EE associated with less atrophy from 5 to 28 months. Contrary to prediction, years of education (a proxy for cognitive reserve) was not significantly associated with atrophy.

Conclusion: Post-injury EE may serve as a buffer against hippocampal atrophy in the chronic stages of moderate-severe TBI. Clinical application of EE should be considered for optimal maintenance of neurological functioning in the chronic stages of moderate-severe TBI.

Keywords: adult; environmental enrichment; moderate to severe; subacute atrophy; traumatic brain injury.