The Impact of Age and Severity on Dementia After Traumatic Brain Injury: A Comparison Study

Abstract

BACKGROUND Growing evidence associates traumatic brain injury (TBI) with increased risk of dementia, but few studies have evaluated associations in patients younger than 55 yr using non-TBI orthopedic trauma (NTOT) patients as controls to investigate the influence of age and TBI severity, and to identify predictors of dementia after trauma. OBJECTIVE To investigate the relationship between TBI and dementia in an institutional group. METHODS Retrospective cohort study (2000-2018) of TBI patients aged 45 to 100 yr vs NTOT controls. Primary outcome was dementia after TBI (followed ≤10 yr). Cox proportional hazards models were used to assess risk of dementia; logistic regression models assessed predictors of dementia. RESULTS Among 24 846 patients, TBI patients developed dementia (7.5% vs 4.6%) at a younger age (78.6 vs 82.7 yr) and demonstrated higher 10-yr mortality than controls (27% vs 14%; P < .001). Mild TBI patients had higher incidence of dementia (9%) than moderate/severe TBI (5.4%), with lower 10-yr mortality (20% vs 31%; P < .001). Risk of dementia was significant in all mild TBI age groups, even 45 to 54 yr (hazard ratio 4.1, 95% CI 2.7-7.8). A total of 10-yr cumulative incidence was higher in mild TBI (14.4%) than moderate/severe TBI (11.3%) and controls (6.8%) (P < .001). Predictors of dementia include TBI, sex, age, hypertension, hyperlipidemia, stroke, depression, anxiety, and Injury Severity Score. CONCLUSION Mild and moderate/severe TBI patients experienced higher incidence of dementia, even in the youngest group (45-54 yr old), than NTOT controls. All TBI patients, especially middle-aged adults with minor injury who are more likely to be overlooked, should be monitored for dementia.

Association of Traumatic Brain Injury With the Risk of Developing Chronic Cardiovascular, Endocrine, Neurological, and Psychiatric Disorders

“… 14 As was shown previously, the risk of dementia is higher in older individuals with any TBI severity. 14 , 28 This suggests a subacute-chronic disease state rather than simply higher diagnostic scrutiny or an immediate complication of acute brain injury.…”

“…There was a higher risk of psychotic disorders in the middle-aged and older subgroups, replicating the results of prior studies . As was shown previously, the risk of dementia is higher in older individuals with any TBI severity . This suggests a subacute-chronic disease state rather than simply higher diagnostic scrutiny or an immediate complication of acute brain injury.…”

Adolescent traumatic brain injury leads to incremental neural impairment in middle-aged mice: role of persistent oxidative stress and neuroinflammation

“…Brain injuries trigger various neurological complications, including epilepsy, depression, and dementia ( Burke et al, 2021 ; Stopa et al, 2021 ; Wang et al, 2021 ). Our observations revealed that adolescent traumatic brain injury results in spatial memory impairment and anxiety/depression-like behavior in middle-aged mice, which is consistent with the previous study ( Mao et al, 2020 ).…”

Differences in Risk of Alzheimer's Disease Following Later-Life Traumatic Brain Injury in Veteran and Civilian Populations

“…13 A single episode of TBI is considered sufficient for the adverse effect, 14 and chronic pathologies following single versus multiple cases of TBI show many similarities. 14 TBI is a risk factor for Alzheimer's disease (AD) and other dementias, [15][16][17][18] although dissenting opinions based on recent biologic studies question whether TBI causes AD-consistent pathologic changes and suggest that TBI, although associated with neurodegenerative processes, may not be associated with AD specifically. [19][20][21] Independent of the exact biologic mechanism, the prevention of the consequences of dementia, of which AD is the most common pathologic cause, 22 poses the current challenge for the US health system.…”