Cognitive dysfunction after polytrauma in the absence of traumatic brain injury: A systematic review of incidence

BACKGROUND Polytrauma patients frequently experience long-term health impacts, including cognitive impairments. While traumatic brain injury (TBI) is a recognized nonmodifiable cause, polytrauma patients are likely to face cognitive challenges potentially linked to systemic inflammation and multiple surgical interventions even in the absence of TBI. This review aims to describe the incidence and identify factors associated with cognitive dysfunction in adult multiple injury patients without Frank TBI. METHODS A systematic search was conducted across MEDLINE, CINAHL, EMBASE, and Scopus databases on August 17, 2023, to identify studies reporting on cognitive dysfunction in adults with polytrauma, excluding brain injuries. The Critical Appraisal Skills Programme checklists guided study appraisal, and findings were narratively synthesized. RESULTS From 2719 articles identified (including one through citation searching), 47 were fully screened, yielding 10 cohort studies for inclusion. The reported incidence of cognitive dysfunction among multiple injury patients without TBI varied widely, from 0% to 60%, with a majority (eight out of ten studies) noting incidences of 30% or higher. No consensus was found for a relationship of other studied factors with cognitive dysfunction. Injury Severity Score was found to not be associated with cognitive dysfunction in selected studies which analyzed this factor. CONCLUSION This review suggests a high prevalence of cognitive dysfunction in multiple injury patients without TBI. The evidence base is limited by heterogeneity of the inclusion criteria, and the cognitive outcome measures. IMPLICATIONS OF KEY FINDINGS Multiple injury is associated with long term cognitive dysfunction even without primary brain injury. This aspect of the disease of multiple injury needs further characterization to identify predictors and potential preventive and therapeutic interventions. Standardized reporting is also required to be able to monitor incidence and prevalence. LEVEL OF EVIDENCE Systematic Review; Level II.