The Effect of Mild Traumatic Brain Injury on Cerebral Microbleeds in Aging.

Luca Toth,Peter Horvath,Balint Kornyei,Zoltan Ungvari,Andras Czigler,Attila Schwarcz,Andras Buki,Nikolett Szarka,Peter Toth,Arnold Toth

doi:10.3389/fnagi.2021.717391

Abstract

A traumatic brain injury (TBI) induces the formation of cerebral microbleeds (CMBs), which are associated with cognitive impairments, psychiatric disorders, and gait dysfunctions in patients. Elderly people frequently suffer TBIs, especially mild brain trauma (mTBI). Interestingly, aging is also an independent risk factor for the development of CMBs. However, how TBI and aging may interact to promote the development of CMBs is not well established. In order to test the hypothesis that an mTBI exacerbates the development of CMBs in the elderly, we compared the number and cerebral distribution of CMBs and assessed them by analysing susceptibility weighted (SW) MRI in young (25 ± 10 years old, n = 18) and elder (72 ± 7 years old, n = 17) patients after an mTBI and in age-matched healthy subjects (young: 25 ± 6 years old, n = 20; aged: 68 ± 5 years old, n = 23). We found significantly more CMBs in elder patients after an mTBI compared with young patients; however, we did not observe a significant difference in the number of cerebral microhemorrhages between aged and aged patients with mTBI. The majority of CMBs were found supratentorially (lobar and basal ganglion). The lobar distribution of supratentorial CMBs showed that aging enhances the formation of parietal and occipital CMBs after mTBIs. This suggests that aging and mTBIs do not synergize in the induction of the development of CMBs, and that the different distribution of mTBI-induced CMBs in aged patients may lead to specific age-related clinical characteristics of mTBIs.

Highlights

We found that aging exacerbated the formation of cerebral microbleeds (CMBs) significantly (p < 0.05) compared with young patients (Figure 2A), confirming the results of previous studies showing that aging is an independent risk factor for the development of CMBs (Greenberg et al, 2009; Toth et al, 2015; Irimia et al, 2018)
We found that aging significantly exacerbated (p < 0.05) the incidence of patients with CMBs regardless of the number of bleedings compared with the young patients (Figure 2B), who were not affected by mTBIs (Figure 2B)
It has been shown previously that both traumatic brain injury (TBI) and aging induce the development of CMBs (Huang et al, 2015; Toth et al, 2015; Ungvari et al, 2017; Irimia et al, 2018; Wang et al, 2018; Griffin et al, 2019)

Summary

Introduction

A traumatic brain injury (TBI) has been shown to induce the formation of cerebral microbleeds (CMBs) (Huang et al, 2015; Toth et al, 2016, 2020; Ungvari et al, 2017; Irimia et al, 2018; Griffin et al, 2019). Mechanisms leading to the formation of CMBs, such as cerebrovascular oxidative stress, the activation of matrix metalloproteinases, and the modification of the content of the cerebrovascular wall, are all induced by both aging and TBIs (Lewén et al, 2001; Werring et al, 2010; Rachmany et al, 2013; Abdul-Muneer et al, 2016; Ungvari et al, 2017, 2018; Griffin et al, 2019; Go et al, 2020) It is not well established and characterized how TBIs and aging interact to promote the development of CMBs, especially after an mTBI. We tested the hypothesis that an mTBI exacerbates the development of CMBs in the elderly compared with young patients, and aimed to characterize the location and distribution of CMBs in elderly patients after an mTBI

Methods

Results

Conclusion