Is traumatic brain injury a risk factor for neurodegeneration? A meta-analysis of population-based studies

Chi-Hsien Huang,San-Nan Yang,Hao-Kuang Wang,Ru-Yi Huang,Yi-Cheng Tai,Chih-Yuan Huang,Yi-Che Lee,Chi-Wei Lin,Kuo-Wei Wang,Yuan-Ting Sun

doi:10.1186/s12883-018-1187-0

Abstract

BackgroundTo determine the association of prior traumatic brain injury (TBI) with subsequent diagnosis of neurodegeneration disease.MethodsAll studies from 1980 to 2016 reporting TBI as a risk factor for diagnoses of interest were identified by searching PubMed, Embase, study references, and review articles. The data and study design were assessed by 2 investigators independently. A meta-analysis was performed by RevMan 5.3.ResultsThere were 18 studies comprising 3,263,207 patients. Meta-analysis revealed a significant association of prior TBI with subsequent dementia. The pooled odds ratio (OR) for TBI on development of dementia, FTD and TDP-43 associated disease were 1.93 (95% CI 1.47–2.55, p < 0.001), 4.44 (95% CI 3.86–5.10, p < 0.001), and 2.97 (95% CI 1.35–6.53, p < 0.001). However, analyses of individual diagnoses found no evidence that the risk of Alzheimer’s disease, and Parkinson’s disease in individuals with previous TBI compared to those without TBI.ConclusionsHistory of TBI is not associated with the development of subsequent neurodegeneration disease. Care must be taken in extrapolating from these results because no suitable criteria define post TBI neurodegenerative processes. Therefore, further research in this area is needed to confirm these questions and uncover the link between TBI and neurodegeneration disease.

Highlights

Traumatic brain injury (TBI) occurs when an external force injures the brain
The subgroup meta-analyses There was an association between traumatic brain injury (TBI) and subsequent dementia (Fig. 1)
The studies associated with Alzheimer disease (AD) yielded a pooled odds ratio (OR) of 1.03 with heterogeneity (I2 = 98%, P < 0.001) (Fig. 3)

Summary

Introduction

Traumatic brain injury (TBI) occurs when an external force injures the brain. Motor vehicle accidents cause most TBIs in young adults, while falls are the leading cause of TBIs in people over 65 years of age [1]. Men sustain TBIs more frequently than women do These observations suggest that TBIs result in major health and socioeconomic problems throughout the Neurological damage occurs at the moment of impact (primary injury) in a TBI, and it further develops overtime post-impact. Several processes, such as neurotransmitter release, free-radical generation, calcium-mediated damage, gene activation, mitochondrial dysfunction, and inflammatory responses, have been investigated in studies of the secondary injuries that are associated with TBI [3,4,5]. To determine the association of prior traumatic brain injury (TBI) with subsequent diagnosis of neurodegeneration disease

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