TAR-DNA binding protein-43 (TDP-43) proteinopathy is seen in multiple brain diseases. A standardized terminology was recommended recently for common age-related TDP-43 proteinopathy: limbic-predominant, age-related TDP-43 encephalopathy (LATE) and the underlying neuropathological changes, LATE-NC. LATE-NC may be co-morbid with Alzheimer’s disease neuropathological changes (ADNC). However, there currently are ill-defined diagnostic classification issues among LATE-NC, ADNC, and frontotemporal lobar degeneration with TDP-43 (FTLD-TDP). A practical challenge is that different autopsy cohorts are composed of disparate groups of research volunteers: hospital- and clinic-based cohorts are enriched for FTLD-TDP cases, whereas community-based cohorts have more LATE-NC cases. Neuropathological methods also differ across laboratories. Here, we combined both cases and neuropathologists’ diagnoses from two research centres—University of Pennsylvania and University of Kentucky. The study was designed to compare neuropathological findings between FTLD-TDP and pathologically severe LATE-NC. First, cases were selected from the University of Pennsylvania with pathological diagnoses of either FTLD-TDP (n = 33) or severe LATE-NC (mostly stage 3) with co-morbid ADNC (n = 30). Sections from these University of Pennsylvania cases were cut from amygdala, anterior cingulate, superior/mid-temporal, and middle frontal gyrus. These sections were stained for phospho-TDP-43 immunohistochemically and evaluated independently by two University of Kentucky neuropathologists blinded to case data. A simple set of criteria hypothesized to differentiate FTLD-TDP from LATE-NC was generated based on density of TDP-43 immunoreactive neuronal cytoplasmic inclusions in the neocortical regions. Criteria-based sensitivity and specificity of differentiating severe LATE-NC from FTLD-TDP cases with blind evaluation was ∼90%. Another proposed neuropathological feature related to TDP-43 proteinopathy in aged individuals is ‘Alpha’ versus ‘Beta’ in amygdala. Alpha and Beta status was diagnosed by neuropathologists from both universities (n = 5 raters). There was poor inter-rater reliability of Alpha/Beta classification (mean κ = 0.31). We next tested a separate cohort of cases from University of Kentucky with either FTLD-TDP (n = 8) or with relatively ‘pure’ severe LATE-NC (lacking intermediate or severe ADNC; n = 14). The simple criteria were applied by neuropathologists blinded to the prior diagnoses at University of Pennsylvania. Again, the criteria for differentiating LATE-NC from FTLD-TDP was effective, with sensitivity and specificity ∼90%. If more representative cases from each cohort (including less severe TDP-43 proteinopathy) had been included, the overall accuracy for identifying LATE-NC was estimated at >98% for both cohorts. Also across both cohorts, cases with FTLD-TDP died younger than those with LATE-NC (P < 0.0001). We conclude that in most cases, severe LATE-NC and FTLD-TDP can be differentiated by applying simple neuropathological criteria.

Introduction-Autism spectrum disorder (ASD) represents a heterogeneous cluster of clinical phenotypes that are classically diagnosed by the time of adolescence. The possibility of late-life emergence of ASD has been poorly explored.Methods-In order to more fully characterize the possibility of late-life emergence of behaviors characteristic of ASD in MCI and AD, we surveyed caregivers of 142 older persons with cognitive impairment from the University of Kentucky Alzheimer's Disease Center Longitudinal Cohort using the Gilliam Autism Rating Scale-2.Results-Participants with high autism index ratings (Autism 'Possible/Very Likely', n=23) reported significantly (statistically and clinically) younger age at onset of cognitive impairment than those who scored in the Autism 'Unlikely' range (n=119): 71.14±10.9 vs. 76.65±8.25 (p = 0.034). Additionally, those in Autism 'Possible/Very Likely' group demonstrated advanced severity of cognitive impairment, indicated by Clinical Dementia Rating Scale Sum of Boxes scores.Discussion-Data demonstrate that ASD behaviors may appear de novo of degenerative dementia and such behaviors are more prevalent in those with early onset dementia. Further work elucidating a connection between ASD and dementia could shed light on subclinical forms of ASD, identify areas of shared neuroanatomic involvement between ASD and dementias, and provide valuable insights that might hasten the development of therapeutic strategies.

Background: Alzheimer’s disease (AD) pathology and hypertension (HTN) are risk factors for development of white matter (WM) alterations and might be independently associated with these alterations in older adults. Objective: To evaluate the independent and synergistic effects of HTN and AD pathology on WM alterations. Methods: Clinical measures of CVD risk were collected from 62 participants in University of Kentucky Alzheimer’s Disease Center studies who also had CSF sampling and MRI brain scans. CSF Aβ1–42 levels were measured as a marker of AD, and fluid-attenuated inversion recovery imaging and diffusion tensor imaging were obtained to assess WM macro and microstructural properties. Linear regression analyses were used to assess the relationships among WM alterations, CVD risk and AD pathology. Voxelwise analyses were performed to examine spatial patterns of WM alteration associated with each pathology. Results: HTN and CSF Aβ1–42 levels were each associated with white matter hyper-intensities (WMH). Also, CSF Aβ1–42 levels were associated with alterations in normal appearing white matter fractional anisotropy (NAWM-FA), whereas HTN was marginally associated with alterations in NAWM-FA. Linear regression analyses demonstrated significant main effects of HTN and CSF Aβ1–42 on WMH volume, but no significant HTN × CSF Aβ1–42 interaction. Furthermore, voxelwise analyses showed unique patterns of WM alteration. associated with hypertension and CSF Aβ1–42. Conclusion: Associations of HTN and lower CSF Aβ1–42 with WM alteration were statistically and spatially distinct, suggesting independent rather than synergistic effects. Considering such spatial distributions may improve diagnostic accuracy to address each underlying pathology.

In addition to the memory disorders and global cognitive impairment that accompany neurodegenerative diseases, behavioral and psychological symptoms of dementia (BPSD) commonly impair quality of life and complicate clinical management. To investigate clinical-pathological correlations of BPSD, we analyzed data from autopsied participants from the community-based University of Kentucky Alzheimer’s Disease Research Center longitudinal cohort (n = 368 research volunteers met inclusion criteria, average age at death 85.4 years). Data assessing BPSD were obtained approximately annually, including parameters for agitation, anxiety, apathy, appetite problems, delusions, depression, disinhibition, hallucinations, motor disturbance, and irritability. Each BPSD was scored on a severity scale (0–3) via the Neuropsychiatric Inventory Questionnaire (NPI-Q). Further, Clinical Dementia Rating (CDR)-Global and -Language evaluations (also scored on 0–3 scales) were used to indicate the degree of global cognitive and language impairment. The NPI-Q and CDR ratings were correlated with neuropathology findings at autopsy: Alzheimer’s disease neuropathological changes (ADNC), neocortical and amygdala-only Lewy bodies (LBs), limbic predominant age-related TDP-43 encephalopathy neuropathologic changes (LATE-NC), primary age-related tauopathy (PART), hippocampal sclerosis, and cerebrovascular pathologies. Combinations of pathologies included the quadruple misfolding proteinopathy (QMP) phenotype with co-occurring ADNC, neocortical LBs, and LATE-NC. Statistical models were used to estimate the associations between BPSD subtypes and pathologic patterns. Individuals with severe ADNC (particularly those with Braak NFT stage VI) had more BPSD, and the QMP phenotype was associated with the highest mean number of BPSD symptoms: > 8 different BPSD subtypes per individual. Disinhibition and language problems were common in persons with severe ADNC but were not specific to any pathology. “Pure” LATE-NC was associated with global cognitive impairment, apathy, and motor disturbance, but again, these were not specific associations. In summary, Braak NFT stage VI ADNC was strongly associated with BPSD, but no tested BPSD subtype was a robust indicator of any particular “pure” or mixed pathological combination.

Purpose: Subjective memory complaints (SMCs) have been shown to be associated with lower neuropsychological test scores cross-sectionally. However, it remains unclear if such findings hold true for African American (AA) older adults.Methods: Baseline visit data from the National Alzheimer's Coordinating Center database collected from September 2005 through March 2018 were used. Generalized linear mixed models specifying binomial distributions were used to examine how neuropsychological test scores affect the likelihood of reporting SMCs.Patients: Inclusion criteria were participants who reported AA as their primary race, 60-80 years of age, were cognitively unimpaired, and had a Mini-Mental Status Exam ≥26. 1021 older AA adults without missing data met the criteria.Results: 258 participants reported a SMC. SMCs were more likely with lower scores on measures of episodic memory and processing; however, SMCs were also more likely with higher scores on a measure of working memory. Working memory appeared to mediate reporting of SMC among participants with lower episodic memory scores.Discussion: These findings demonstrate that SMCs are associated with lower scores on objective neuropsychological measures among older AAs. Additional work is needed to determine if SMCs are further associated with a risk for clinical transition to mild cognitive impairment or dementia among AA older adults.