Impaired self-awareness after traumatic brain injury: A systematic review. Part 2. Consequences and predictors of poor self-awareness.

Background: Impaired self-awareness (ISA) has frequently been found both frequent and deleterious in patients with moderate to severe traumatic brain injury (TBI).

Objectives: This is the second of a two-part systematic review on ISA after TBI, focusing on the consequences and predictors of ISA after TBI.

Methods: Following the PRISMA guidelines, 95 articles meeting the inclusion criteria were included; 46 were specifically related to this second part of the review.

Results: Among 16 studies that investigated the effect of ISA on outcome, most (n=13) found poor self-awareness associated with poor rehabilitation, functional, social and vocational outcome and with increased burden on relatives. Multiple factors have been found associated with increased frequency of ISA. ISA was found significantly related to injury severity in 8 of 10 studies, impaired executive functions in 12 of 15 studies, and poor social cognition in 3 studies, but paradoxically inverse associations were repeatedly found between self-awareness and emotional status (11 of 12 studies). Finally, although research in the field is still scarce, ISA seems associated with a dysfunction within brain networks involving the anterior cingulate cortex, anterior insula and fronto-parietal control network.

Conclusions: ISA is a complex and multifaceted disorder associated with poor rehabilitation outcome, severe injuries, and deficits of executive functions and social cognition but has an inverse association with mood impairments.