Traumatic brain injury and post-traumatic stress disorder are not associated with Alzheimer's disease pathology measured with biomarkers

Alzheimers Dement. 2023 Mar;19(3):884-895. doi: 10.1002/alz.12712. Epub 2022 Jun 29.

Abstract

Introduction: Epidemiological studies report an association between traumatic brain injury (TBI) and post-traumatic stress disorder (PTSD) and clinically diagnosed Alzheimer's disease (AD). We examined the association between TBI/PTSD and biomarker-defined AD.

Methods: We identified 289 non-demented veterans with TBI and/or PTSD and controls who underwent clinical evaluation, cerebrospinal fluid (CSF) collection, magnetic resonance imaging (MRI), amyloid beta (Aβ) and tau positron emission tomography, and apolipoprotein E testing. Participants were followed for up to 5.2 years.

Results: Exposure groups (TBI, PTSD, and TBI + PTSD) had higher prevalence of mild cognitive impairment (MCI: P < .0001) and worse Mini-Mental State Examination scores (PTSD: P = .008; TBI & PTSD: P = .009) than controls. There were no significant differences in other cognitive scores, MRI volumes, Aβ or tau accumulation, or in most longitudinal measures.

Discussion: TBI and/or PTSD were not associated with elevated AD biomarkers. The poorer cognitive status of exposed veterans may be due to other comorbid pathologies.

Keywords: Alzheimer's disease; amyloid; cerebrovascular disease; cognitive decline; head injury; neurodegeneration; post‐traumatic stress disorder; tau; traumatic brain injury; veterans.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Aged
  • Alzheimer Disease* / diagnostic imaging
  • Alzheimer Disease* / pathology
  • Amyloid beta-Peptides* / cerebrospinal fluid
  • Apolipoproteins E / genetics
  • Biomarkers* / cerebrospinal fluid
  • Brain Injuries, Traumatic* / complications
  • Brain Injuries, Traumatic* / diagnostic imaging
  • Cognitive Dysfunction* / cerebrospinal fluid
  • Female
  • Humans
  • Magnetic Resonance Imaging*
  • Male
  • Middle Aged
  • Neuropsychological Tests / statistics & numerical data
  • Positron-Emission Tomography*
  • Stress Disorders, Post-Traumatic*
  • Veterans*
  • tau Proteins* / cerebrospinal fluid

Substances

  • Biomarkers
  • Amyloid beta-Peptides
  • tau Proteins
  • Apolipoproteins E