Encefalopatía traumática crónica (ETC) en boxeadores: una revisión sistemática de factores pronóstico.

Abstract

Abstract Chronic traumatic encephalopathy (CTE) is a neurodegenerative disease caused by repetitive brain trauma, where the tau protein is the main responsible, with 4 stages of development. There are few evidence syntheses on CTE that follow the reporting and methodological recommendations of international guidelines. Objective: To identify, evaluate and synthesize the findings of the best empirical evidence to determine the association between exposure to repetitive traumatic brain injury on all-cause mortality, health-related quality of life (HRQoL) and brain atrophy in boxers. Methods: This systematic review was reported following the criteria and recommendations of the protocol extension of the PRISMA-P statement. We searched MEDLINE (via PubMed), SCOPUS, Embase (Elsevier), EBSCO (via SPORTDiscus), gray literature repositories such as Google Scholar, and screened study registry repositories such as Clinical Trials. The review was registered in the Open Science Framework (OSF). A risk of bias assessment was performed. Several stages of the review were performed by at least two blinded and independent reviewers. Results: We examined 654 unique citations to include 9 studies (1065 participants). Study populations were mostly professional and amateur boxers. For the mortality outcome, 1 study was reported with data from 10 boxers, but only 1 diagnosed with CTE. For the outcome of brain atrophy, 4 studies were detected with reduced volume of the thalamus, hippocampus, hypothalamus, amygdala, caudate nucleus, putamen, cavum septum

pellucidum, periventricular white matter disease, and subcortical white matter disease. Finally on the health- related quality of life outcome, in 7 (78%) studies, the exposed cohort resulted in inferior performance compared to the unexposed cohort, or no significant changes were reported between the two cohorts on the indirect tests.

Conclusion: The current evidence is not sufficient, because no study presented the diagnosis of the prognostic factor of interest, that is, CTE and its presence in boxers, because, although one of the included studies did diagnose the disease, there was no follow-up of the prognostic factor during the lifetime of the athletes that would allow us to see the neurodegenerative clinical course. Therefore, it is recommended to perform more observational studies in the future that adequately measure the outcomes addressed in this review.