Self-reported head injury and risk of late-life impairment and AD pathology in an AD center cohort

Abstract

Aims: To evaluate the relationship between self-reported head injury and cognitive impairment, dementia, mortality, and Alzheimer's disease (AD)-type pathological changes.

Methods: Clinical and neuropathological data from participants enrolled in a longitudinal study of aging and cognition (n = 649) were analyzed to assess the chronic effects of self-reported head injury.

Results: The effect of self-reported head injury on the clinical state depended on the age at assessment: for a 1-year increase in age, the OR for the transition to clinical mild cognitive impairment (MCI) at the next visit for participants with a history of head injury was 1.21 and 1.34 for the transition from MCI to dementia. Without respect to age, head injury increased the odds of mortality (OR = 1.54). Moreover, it increased the odds of a pathological diagnosis of AD for men (OR = 1.47) but not women (OR = 1.18). Men with a head injury had higher mean amyloid plaque counts in the neocortex and entorhinal cortex than men without.

Conclusions: Self-reported head injury is associated with earlier onset, increased risk of cognitive impairment and dementia, increased risk of mortality, and AD-type pathological changes.

Figure 1

Flow diagram of included BRAiNS cohort participants

Figure 2

Estimated mean number of diffuse and neuritic neocortical plaque counts by region; whiskers are SEM (n = 238). The final MANCOVA models included main effects for age at death, clinical dementia status, APOE-ε4, CAA, and an interaction term and main effects for head injury and male gender.

Figure 3

Estimated mean number of NFTs by neocortical region; whiskers are SEM (n = 238). The final MANCOVA models included main effects for age at death, clinical dementia status, APOE ε4, cerebral amyloid angiopathy, and an interaction term and main effects for head injury (HI) and male gender.