Supplementary Material for: Interactions between Traumatic Brain Injury and Frontotemporal Degeneration

<b><i>Background/Aims:</i></b> Prior work in smaller cohorts suggests that traumatic brain injury (TBI) may be a risk factor for frontotemporal degeneration (FTD). We sought to confirm and extend these results using the National Alzheimer's Coordinating Center Uniform Data Set. <b><i>Methods:</i></b> We compared the TBI prevalence between FTD subjects and matched normal controls. Indices of cognitive, behavioral, functional, and global dementia severity were compared between FTD subjects with and without prior TBI. <b><i>Results:</i></b> Remote TBI with extended loss of consciousness (TBI-ext) was more common in individuals with FTD than in controls (OR: 1.67; 95% CI: 1.004-2.778). With TBI-ext, less functional and global impairment was seen in the behavioral variant of FTD, but more behavioral pathology was seen in the semantic variant. <b><i>Conclusion:</i></b> TBI may increase the FTD risk and influence clinical symptomatology and severity in FTD subtypes

Supplementary Material for: Cerebrospinal Fluid Biomarkers in Clinical Subtypes of Early-Onset Alzheimer's Disease

<b><i>Background/Aims:</i></b> Accurate diagnosis of sporadic early-onset Alzheimer's disease (EOAD) can be challenging, and cerebrospinal fluid (CSF) biomarkers may assist in this process. We compared CSF indices between three EOAD subtypes: amnestic, logopenic progressive aphasia (LPA), and posterior cortical atrophy (PCA). <b><i>Methods:</i></b> We identified 21 amnestic EOAD, 20 LPA, and 12 PCA patients with CSF data, which included amyloid β_1-42 (Aβ42), total tau (t-tau), phospho-tau₁₈₁ (p-tau), and Aβ42/t-tau index (ATI) levels. <b><i>Results:</i></b> Aβ42 and ATI levels were similar across groups, but t-tau and p-tau levels were significantly lower in PCA patients. <b><i>Conclusions:</i></b> The Aβ42 and ATI data confirm the commonality of the Aβ pathology in EOAD. The lower tau indices in PCA patients may reflect differences in the distribution of neurofibrillary tangles or rates of neurodegeneration

Supplementary Material for: Low Plasma ApoE Levels Are Associated with Smaller Hippocampal Size in the Alzheimer's Disease Neuroimaging Initiative Cohort

Apolipoprotein E <i>(APOE)</i> genotype is the strongest known genetic risk factor for sporadic Alzheimer's disease (AD), but the utility of plasma ApoE levels for assessing the severity of underlying neurodegenerative changes remains uncertain. Here, we examined cross-sectional associations between plasma ApoE levels and volumetric magnetic resonance imaging indices of the hippocampus from 541 participants [57 with normal cognition (NC), 375 with mild cognitive impairment (MCI), and 109 with mild AD] who were enrolled in the Alzheimer's Disease Neuroimaging Initiative. Across the NC and MCI groups, lower plasma ApoE levels were significantly correlated with smaller hippocampal size, as measured by either hippocampal volume or hippocampal radial distance. These associations were driven primarily by findings from carriers of an <i>APOE </i>ε4 allele and are consistent with prior reports that lower plasma ApoE levels correlate with greater global cortical Pittsburgh Compound B retention. In this high-risk group, plasma ApoE levels may represent a peripheral marker of underlying AD neuropathology in nondemented elderly individuals