A pilot study on Alzheimer’s disease‐related biological and cognitive markers in dementia and history of mild traumatic brain injury

Abstract Mild traumatic brain injury (mTBI) accelerates the rate of age-associated brain atrophy, whose pattern resembles the cortical neurodegeneration pattern observed in Alzheimer’s disease (AD). Because the ratio R of T1-to-T2-weighted magnetic resonance imaging (MRI) intensities is a surrogate measure of cortical myelin concentration, mapping and quantifying changes in this ratio can improve our understanding of demyelination after geriatric mTBI and AD. T1- and T2-weighted MRIs were acquired acutely and ~6 months post-injury from 68 healthy controls (HCs, age (years, y): μ = 76 y, σ = 4 y), 19 mTBIs (age μ = 70 y, σ = 5 y), and 33 ADs (age μ = 77, σ = 6). Volumes were co-registered using 3D Slicer’s BRAINSFit module, and T2-constrained segmentations of T1 volumes were obtained using FreeSurfer. R and its time changes were computed at each cortical location. When comparing mTBI and AD patients to HCs, significant differences in R were found across ~10% and ~23% of the cortex, respectively (p < 0.05). When comparing mTBI to AD, the former exhibited significantly less myelin content in the lateral, medial, and ventral temporal lobes (p < 0.05), on the medial aspects of superior parietal lobules and superior frontal gyri (p < 0.05), and in orbital gyri (p < 0.05), whereas AD subjects had less myelin content on lateral aspect of the parietal lobe (p < 0.05). These results highlight demyelination differences in mTBI and AD. Future studies should examine the long-term trajectories to quantify the risk of neurodegenerative disease after mTBI.

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Alzheimer’s disease‐like brain atrophy patterns after mild traumatic brain injury can be predicted based on acute cognitive deficit

Alzheimer s & Dementia ◽

10.1002/alz.054779 ◽

2021 ◽

Vol 17 (S5) ◽

Author(s):

Kenneth A. Rostowsky ◽

Anar Amgalan ◽

Andrei Irimia

Keyword(s):

Alzheimer’S Disease ◽

Alzheimer's Disease ◽

Traumatic Brain Injury ◽

Brain Injury ◽

Mild Traumatic Brain Injury ◽

Brain Atrophy ◽

Cognitive Deficit

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A-010 Traumatic Brain Injury, APOE, and Age at Diagnosis of Alzheimer’s Disease

Archives of Clinical Neuropsychology ◽

10.1093/arclin/acaa068.010 ◽

2020 ◽

Vol 35 (6) ◽

pp. 800-800

Author(s):

Alexander C ◽

Suhr J

Keyword(s):

Alzheimer’S Disease ◽

Alzheimer's Disease ◽

Traumatic Brain Injury ◽

Brain Injury ◽

Age Of Onset ◽

Inclusion Criteria ◽

Health History ◽

Health Factors ◽

Age Of Diagnosis ◽

History Of

Abstract Objective Traumatic brain injury (TBI) is potentially a risk factor for Alzheimer’s disease (AD). This relationship may depend on the severity of TBI as well as other risk factors including APOE. We examined whether TBI status affects age of onset of AD, while improving on prior literature’s methodological issues. Method Data from the National Alzheimer’s Coordinating Centers were used. Inclusion criteria included: normal cognition at baseline; eventual diagnosis of AD; adults aged 50 and older; at least 3 years of follow-up data. Covariates included age at baseline and history of TIA, stroke, or hypertension. The resulting sample (N = 485) was 65.2% female; 89.1% White, 9.1% Black; and 4.5% Hispanic; 8% with TBI; and 42% with APOE4. Average age at baseline was 79.2 (SD = 7.6). ANCOVAs were used to determine whether TBI status (no TBI; TBI with brief LOC; TBI with extended LOC) was associated with earlier age of diagnosis for AD, controlling for age at baseline and health factors. APOE status was added to a second ANCOVA. Results Age at baseline (p < .001), but not health history (p = .777), was related to age of AD diagnosis. TBI status was not associated with age of AD diagnosis (p = .737). When APOE and the interaction between APOE and TBI status were added to the model, neither was significant (p’s = .150, .647). Conclusions When controlling for baseline cognition, age at baseline, and health factors, there was no relationship between TBI status and age of diagnosis of AD. However, use of more stringent inclusion criteria as compared to previous studies may have reduced power significantly.

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