Brain Donation Program Research Articles

Single cell transcriptomes and multiscale networks from persons with and without Alzheimer’s disease

The emergence of single nucleus RNA sequencing (snRNA-seq) offers to revolutionize the study of Alzheimer’s disease (AD). Integration with complementary multiomics data such as genetics, proteomics and clinical data provides powerful opportunities to link cell subpopulations and molecular networks with a broader disease-relevant context. We report snRNA-seq profiles from superior frontal gyrus samples from 101 well characterized subjects from the Banner Brain and Body Donation Program in combination with whole genome sequences. We report findings that link common AD risk variants with CR1 expression in oligodendrocytes as well as alterations in hematological parameters. We observed an AD-associated CD83(+) microglial subtype with unique molecular networks and which is associated with immunoglobulin IgG4 production in the transverse colon. Our major observations were replicated in two additional, independent snRNA-seq data sets. These findings illustrate the power of multi-tissue molecular profiling to contextualize snRNA-seq brain transcriptomics and reveal disease biology.

RNA sequencing of olfactory bulb in Parkinson's disease reveals gene alterations associated with olfactory dysfunction

The olfactory bulb is involved early in the pathophysiology of Parkinson's disease (PD), which is consistent with the early onset of olfactory dysfunction. Identifying the molecular mechanisms through which PD affects the olfactory bulb could lead to a better understanding of the pathophysiology and etiology of olfactory dysfunction in PD. We specifically aimed to assess gene expression changes, affected pathways and co-expression network by whole transcriptomic profiling of the olfactory bulb in subjects with clinicopathologically defined PD. Bulk RNA sequencing was performed on frozen human olfactory bulbs of 20 PD and 20 controls without dementia or any other neurodegenerative disorder, from the Arizona Study of Aging and Neurodegenerative disorders and the Brain and Body Donation Program. Differential expression analysis (19 PD vs 19 controls) revealed 2164 significantly differentially expressed genes (1090 upregulated and 1074 downregulated) in PD. Pathways enriched in downregulated genes included oxidative phosphorylation, olfactory transduction, metabolic pathways, and neurotransmitters synapses while immune and inflammatory responses as well as cellular death related pathways were enriched within upregulated genes. An overrepresentation of microglial and astrocyte-related genes was observed amongst upregulated genes, and excitatory neuron-related genes were overrepresented amongst downregulated genes. Co-expression network analysis revealed significant modules highly correlated with PD and olfactory dysfunction that were found to be involved in the MAPK signaling pathway, cytokine-cytokine receptor interaction, cholinergic synapse, and metabolic pathways. LAIR1 (leukocyte associated immunoglobulin like receptor 1) and PPARA (peroxisome proliferator activated receptor alpha) were identified as hub genes with a high discriminative power between PD and controls reinforcing an important role of neuroinflammation in the olfactory bulb of PD subjects. Olfactory identification test score positively correlated with expression of genes coding for G-coupled protein, glutamatergic, GABAergic, and cholinergic receptor proteins and negatively correlated with genes for proteins expressed in glial olfactory ensheathing cells. In conclusion, this study reveals gene alterations associated with neuroinflammation, neurotransmitter dysfunction, and disruptions of factors involved in the initiation of olfactory transduction signaling that may be involved in PD-related olfactory dysfunction.

Biobanking best practices for research, Banner Sun Health Research Institute Brain and Body Donation Program standards and journey

AbstractThe Arizona Study of Aging and Neurodegenerative Disease (AZSAND)/Brain and Body Donation Program (BBDP) is a unique clinicopathological study of aging and neurodegenerative disease based in Sun City, AZ since 1987. The BBDP has made rapid autopsy a priority, with a constitutive 24‐7 rapid autopsy team and a 3.0‐hour median postmortem interval for the entire collection. Tissue quality is correspondingly high, with a median RNA Integrity Number (RIN) for frozen brain tissue of 8.9. The current holdings include fixed and frozen brain and body tissue, as well as biofluids from more than 850 Alzheimer’s Disease (AD) cases, 250 Parkinson’s Disease (PD) cases and more than 350 elderly control subjects. The program supports and leads national and international research focused on AD, AD related dementias and other debilitating neurodegenerative diseases. It provides basic scientists with de‐identified annual comprehensive standardized cognitive, motor, and non‐motor assessments data and neuropathologically characterized human samples that are suitable for the elucidation of the molecular mechanisms of disease and novel therapeutic targets. The BBDP is committed to distributing human samples and accompanying clinicopathological data to as many researchers as possible. All collected data are available to researchers through the program’s website https://www.brainandbodydonationregistration.org/ and personalized consultations.

Low circulating choline levels correlate with Alzheimer’s disease pathology severity and cognitive impairment

AbstractBackgroundModifiable environmental risk factors may help reduce Alzheimer’s disease (AD) incidence. Choline plays key roles in healthy body and brain function (Blusztajn, 1998) and supplementation above the adequate daily intake (ADI) reduces AD pathology (Velazquez et al., 2019). Choline deficiency increases AD risk and pathology (Dave et al., 2023; Yuan et al., 2022). Notably, recent reports estimate that ∼90% of Americans do not reach the ADI for dietary choline (Zeisel, 2017), making it imperative to better understand the link between choline and AD risk.MethodWe obtained serum samples from severe AD (AD‐Sev; Braak stage VI), moderate AD (AD‐Mod; Braak stage IV), and healthy control (CON; < Braak stage III) subjects (n = 12/group; balanced for sex) from the Banner Sun Health Research Institute’s Brain and Body Donation Program. Cognitive test scores (Mini‐Mental State Examination (MMSE)), plaque burden, and Braak stage was characterized by Banner Sun Health. We assessed free choline, acetylcholine (ACh), and TNFα levels. Gas‐chromatography‐mass spectrometry was used to profile aqueous metabolites and short‐chain fatty acids.ResultThere were no significant group differences for post‐mortem interval (M = 3.79). We found disease associated differences, where AD‐Sev and AD‐Mod patients had lower levels of free choline and ACh, and higher levels of pro‐inflammatory cytokine TNFα, than CON. AD‐Mod showed a significant difference in all these measurements compared to AD‐Sev. Free choline and ACh were positively correlated to MMSE scores, whereas free choline and ACh levels were negatively correlated with total plaque and Braak Stage. Free choline and ACh were negatively correlated with TNFα. Metabolomics analysis revealed significant differences (p < 0.05) in the metabolisms of beta‐alanine, linoleic acid, and of taurine and hypotaurine.ConclusionCollectively, as free choline and ACh levels decreased, AD pathology increased. Free choline was also associated with MMSE score. Increased TNFα was observed in cases with lower choline, illustrating increased inflammation. Together, this data expands on our recent (Dave et al., 2023) and others (Yuan et al., 2022) publications, highlighting links between low choline and AD risk.

The Human Brain Nucleus Incertus: A New Target in Dementia?

AbstractBackgroundThe brainstem nucleus incertus (NI) or ‘uncertain nucleus’, was originally described by Streeter in 1903 as a midline region in the floor of the fourth ventricle of the human brain with an ‘unknown’ function. A century later, the NI has been shown to play a key role in memory formation in rodents, through direct and indirect inhibition of the hippocampus; and the anatomy of the NI and its projections throughout the brain have been systematically mapped in rats, mice, and primates, but not in humans. In these novel studies, we mapped the human NI using the neuropeptide, relaxin‐3 (RLN3), as neurochemical marker. In rodents, RLN3 is produced mostly in NI neurons with some subsidiary positive cells in the periaqueductal gray and an area dorsal to the substantia nigra.MethodsSerial, free‐floating coronal sections of formalin‐fixed postmortem tissue were prepared from the pons of an adult female (aged 96 years) without a history of dementia or other neurological disorders, provided by the Banner Brain and Body Donation Program, Sun City, Arizona, USA. Using immunohistochemistry, we first identified the NI by mapping the distribution of microtubule‐associated protein‐2 (MAP2) and RLN3. The specificity of the RLN3 antibody used was verified in a dot‐blot using native RLN3 peptide. We also investigated the presence of markers detected in the NI of rats ‐ glutamic acid dehydrogenase‐65/67 (GAD65/67) and corticotropin‐releasing factor type 1 receptor (CRF1); and used a phosphorylated‐tau (AT8) to determine if the NI displayed tau accumulation.ResultsDetection of MAP2‐immunoreactivity revealed the neuronal distribution throughout the pons. RLN3‐immunoreactivity was detected in neurons in the dorsal, anterior‐medial region, revealing the broad anatomy of the human NI. Neurons within this same area were also positive for GAD65/67‐ and CRF1‐immunoreactivity, in line with previous studies; and AT8‐immunoreactivity was also detected.ConclusionsRLN3 is present in neurons of the human NI and aspects of its anatomy are shared across species, including the macaque. Accumulation of phosphorylated‐tau in the NI suggests its possible involvement in the pathology of Alzheimer’s disease and related dementias. Further comparative studies are required to better understand the neurochemical anatomy of the human NI.

Uncovering distinct spatial‐temporal trajectories of Lewy‐type α‐synuclein pathology: a Subtype and Stage Inference model analysis

AbstractBackgrounda‐synuclein aggregation is a pathologic hallmark of several Lewy body disorders with differing symptoms. This symptom heterogeneity may be due to varying underlying disease trajectories. Here, we use a data‐driven approach to identify and characterize distinct spatial‐temporal progression patterns of α‐synuclein deposition.MethodThe Subtype and Stage Inference (SuStaIn) model evaluates the optimal grouping of individuals into subtypes with distinct orderings of events/stages. We applied Ordinal SuStaIn to post‐mortem Lewy‐type α‐synuclein (LTS) density scores measured in 10 regions (including olfactory bulb and tract [OBT], limbic, brainstem, and cortical regions) of 814 subjects from the Sun Health Research Institute Brain Donation Program (Table‐1). The optimal SuStaIn model was selected according to the Cross‐Validation Information Criteria. We selected 781 subjects with stage>0 (n excluded = 13) and subtype probability>50% (n excluded = 20) to assess differences in subtypes. Hierarchical multinomial logistic regressions were performed to compare subtypes on (1) age at death, sex, APOE‐e4 copies, and post‐mortem interval; (2) total amyloid plaque load; and (3) total tau tangle load. In a subset of individuals (n = 355), we additionally compared subtypes on MMSE scores and the motor section of the Unified Parkinson Disease Rating Scale (UPDRS). All models were adjusted for SuStaIn stage and significant predictors of preceding models.ResultSuStaIn identified three subtypes with distinct LTS trajectories, which we termed “OBT/Limbic‐first”, “OBT/Brainstem‐first”, and “OBT‐sparing/Brainstem‐first” based on the first regions to show deposition (Figure‐1). The majority of individuals were assigned to OBT/Limbic‐first (N = 475,60.8%), followed by OBT/Brainstem‐first (N = 165,21.1%), and OBT‐sparing/Brainstem‐first (N = 141,18.1%) subtypes (Table‐1). We observed a higher frequency of homozygous APOE‐e4 carriers and amyloid and tau burden in the OBT/Limbic‐first subtype compared to the OBT/Brainstem‐first (ßAPOE ‐e4 = 0.82±0.40, pAPOE‐e4 = .042; ßamyloid= 0.08±0.42, pamyloid<.001; ßtau= 0.17±0.03, ptau<.001) and OBT‐sparing/Brainstem‐first (ßAPOE‐e4 = 0.98±0.48, pAPOE‐e4 = .042; ßamyloid= 0.14±0.27, pamyloid<.001; ßtau= 0.18±0.03, ptau<.001) subtypes. In addition, the OBT/Brainstem‐first subtype showed a higher amyloid burden (ß = 0.06±0.02, p = .012) and higher MMSE (ß = 0.08±0.04, p = 0.030) compared to the OBT‐sparing/Brainstem‐first (Table‐1, Figure‐2).ConclusionIn this large post‐mortem SuStaIn study, we identified three subtypes of α‐synuclein deposition, possibly reflecting different epicenters and spreading trajectories of misfolded α‐synuclein, where OBT/Limbic‐first was associated with Alzheimer’s co‐pathology. Follow‐up work will study how these subtypes differ in clinical diagnosis and symptomatology.

Uncovering distinct spatial‐temporal trajectories of Lewy‐type α‐synuclein pathology: a Subtype and Stage Inference model analysis

AbstractBackgrounda‐synuclein aggregation is a pathologic hallmark of several Lewy body disorders with differing symptoms. This symptom heterogeneity may be due to varying underlying disease trajectories. Here, we use a data‐driven approach to identify and characterize distinct spatial‐temporal progression patterns of a‐synuclein deposition.MethodThe Subtype and Stage Inference (SuStaIn) model evaluates the optimal grouping of individuals into subtypes with distinct orderings of events/stages. We applied Ordinal SuStaIn to post‐mortem Lewy‐type a‐synuclein (LTS) density scores measured in 10 regions (including olfactory bulb and tract [OBT], limbic, brainstem, and cortical regions) of 814 subjects from the Sun Health Research Institute Brain Donation Program (Table‐1). The optimal SuStaIn model was selected according to the Cross‐Validation Information Criteria. We selected 781 subjects with stage>0 (nexcluded = 13) and subtype probability>50% (nexcluded = 20) to assess differences in subtypes. Hierarchical multinomial logistic regressions were performed to compare subtypes on (1) age at death, sex, APOE‐e4 copies, and post‐mortem interval; (2) total amyloid plaque load; and (3) total tau tangle load. In a subset of individuals (n = 355), we additionally compared subtypes on MMSE scores and the motor section of the Unified Parkinson Disease Rating Scale (UPDRS). All models were adjusted for SuStaIn stage and significant predictors of preceding models.ResultSuStaIn identified three subtypes with distinct LTS trajectories, which we termed “OBT/Limbic‐first”, “OBT/Brainstem‐first”, and “OBT‐sparing/Brainstem‐first” based on the first regions to show deposition (Figure‐1). The majority of individuals were assigned to OBT/Limbic‐first (N = 475,60.8%), followed by OBT/Brainstem‐first (N = 165,21.1%), and OBT‐sparing/Brainstem‐first (N = 141,18.1%) subtypes (Table‐1). We observed a higher frequency of homozygous APOE‐e4 carriers and amyloid and tau burden in the OBT/Limbic‐first subtype compared to the OBT/Brainstem‐first (ßAPOE‐e4 = 0.82±0.40, pAPOE‐e4 = .042; ßamyloid = 0.08±0.42, pamyloid<.001; ßtau = 0.17±0.03, ptau<.001) and OBT‐sparing/Brainstem‐first (ßAPOE‐e4 = 0.98±0.48, pAPOE‐e4 = .042; ßamyloid = 0.14±0.27, pamyloid<.001; ßtau = 0.18±0.03, ptau<.001) subtypes. In addition, the OBT/Brainstem‐first subtype showed a higher amyloid burden (ß = 0.06±0.02, p = .012) and higher MMSE (ß = 0.08±0.04, p = 0.030) compared to the OBT‐sparing/Brainstem‐first (Table‐1, Figure‐2).ConclusionIn this large post‐mortem SuStaIn study, we identified three subtypes of a‐synuclein deposition, possibly reflecting different epicenters and spreading trajectories of misfolded a‐synuclein, where OBT/Limbic‐first was associated with Alzheimer’s co‐pathology. Follow‐up work will study how these subtypes differ in clinical diagnosis and symptomatology.

Year-by-Year Blood Pressure Variability From Midlife to Death and Lifetime Dementia Risk

High visit-to-visit blood pressure variability (BPV) in late life may reflect increased dementia risk better than mean systolic blood pressure (SBP). Evidence from midlife to late life could be crucial to understanding this association. To determine whether visit-to-visit BPV at different ages was differentially associated with lifetime incident dementia risk in community-dwelling individuals. This cohort study analyzed data from the Adult Changes in Thought (ACT) study, an ongoing population-based prospective cohort study in the US. Participants were 65 years or older at enrollment, community-dwelling, and without dementia. The study focused on a subset of deceased participants with brain autopsy data and whose midlife to late-life blood pressure data were obtained from Kaiser Permanente Washington medical archives and collected as part of the postmortem brain donation program. In the ACT study, participants underwent biennial medical assessments, including cognitive screening. Data were collected from 1994 (ACT study enrollment) through November 2019 (data set freeze). Data analysis was performed between March 2020 and September 2023. Visit-by-visit BPV at ages 60, 70, 80, and 90 years, calculated using the coefficient of variation of year-by-year SBP measurements over the preceding 10 years. All-cause dementia, which was adjudicated by a multidisciplinary outcome adjudication committee. A total of 820 participants (mean [SD] age at enrollment, 77.0 [6.7] years) were analyzed and included 476 females (58.0%). A mean (SD) of 28.4 (8.4) yearly SBP measurements were available over 31.5 (9.0) years. The mean (SD) follow-up time was 32.2 (9.1) years in 27 885 person-years from midlife to death. Of the participants, 372 (45.4%) developed dementia. The number of participants who were alive without dementia and had available data for analysis ranged from 280 of those aged 90 years to 702 of those aged 70 years. Higher BPV was not associated with higher lifetime dementia risk at age 60, 70, or 80 years. At age 90 years, BPV was associated with 35% higher dementia risk (hazard ratio [HR], 1.35; 95% CI, 1.02-1.79). Meta-regression of HRs calculated separately for each age (60-90 years) indicated that associations of high BPV with higher dementia risk were present only at older ages, whereas the association of SBP with dementia gradually shifted direction linearly from being incrementally to inversely associated with older ages. In this cohort study, high BPV indicated increased lifetime dementia risk in late life but not in midlife. This result suggests that high BPV may indicate increased dementia risk in older age but might be less viable as a midlife dementia prevention target.

Brain Bank Questionnaire Helps in Differential Diagnosis of Movement Disorders: An Autopsy Study of 150 Patients.

As part of the CurePSP brain donation program, a questionnaire was developed to gather basic clinical information on donors; however, its usefulness has not been evaluated. To assess the value of information obtained from the questionnaire in differentiating between parkinsonian disorders. We reviewed 150 questionnaires, including 50 patients, each with a neuropathologic diagnosis of Lewy body disease (LBD), multiple system atrophy (MSA), or progressive supranuclear palsy. The frequency of clinical features recorded in the questionnaires was compared for the three disorders, and a machine learning algorithm was used to identify features predicting neuropathologic diagnosis. The information from the questionnaires correlated with core clinical features for each disorder, such as hallucinations for LBD and autonomic dysfunction for MSA. Hallucinations and disorientations were identified as the key variables that contributed most to the prediction of neuropathology. The questionnaire provides useful clinical information for clinicopathological correlative studies.

Neuropathological evidence that the association between APOE‐e4 genotype and higher medial temporal lobe tau burden is mediated by higher local amyloid‐β levels

AbstractBackgroundEvidence from previous PET imaging studies suggests that increased neocortical tau seen in APOE‐ε4 carriers can be explained by the higher levels of neocortical amyloid‐β (Aβ) pathology also seen in this group. However, these studies also suggest an amyloid‐independent association between APOE‐ε4 and medial temporal lobe (MTL) tau. Using neuropathological data, we investigated whether amyloid‐β in the MTL, which is difficult to accurately measure with PET, may fully mediate the association between APOE‐ε4 carriership and MTL tau burden.MethodAmyloid‐β and tau pathology in MTL and neocortical areas have been measured in a total of 2,704 individuals from two independent neuropathological datasets (Arizona Study of Aging and Neurodegenerative Disorders, Brain and Body Donation Program, n=1,117 and ROSMAP, n=1,587; Table 1). Regression models were used to investigate the associations between APOE‐ε4 carriership and neocortical and local (MTL) amyloid‐β on MTL tau, adjusting for age, sex and presence of co‐pathologies. Based on these results, we also tested whether local (MTL) amyloid‐β mediated the association between APOE‐ε4 carriership and MTL tau.ResultSupporting results from previous studies, APOE‐e4 carriers showed higher tau burden in the MTL (p<0.001) when amyloid‐β was not included in the model in both datasets. In independent models, both local and neocortical amyloid‐β were associated with MTL tau, with local amyloid‐β showing a stronger association with MTL tau in both datasets (Arizona: βMTL=0.93 vs. βneoc=0.76; ROSMAP: βMTL=0.42 vs. βneoc=0.40). When both measures were included in the model, local amyloid‐β also showed a stronger association with MTL tau in ROSMAP (βMTL=0.28 vs. βneoc=0.19). In the Arizona dataset, neocortical amyloid‐β effect became non‐significant (p=0.252) when local amyloid‐β was also included in the model. Finally, with mediation analyses we observed that MTL amyloid‐β fully mediated the APOE‐ε4 effect on MTL tau in both datasets (Figure 1). All statistics are reported in Table 2.ConclusionIn two large neuropathological datasets, we showed that the association between APOE‐ε4 genotype and higher medial temporal lobe tau burden is mediated by higher local amyloid‐β levels. This finding contradicts some previous imaging literature, where only global amyloid‐β burden was considered.

Head‐to‐Head Comparison of Four Plasma Phospho‐Tau Immunoassays in the Neuropathological Diagnosis of Alzheimer’s Disease

AbstractBackgroundPlasma ptau is a promising indicator of amyloid‐β (Aβ) mediated tau pathophysiology. We previously characterized the ability of Lilly’s MesoScale Discovery (MSD)‐based plasma ptau217 and ptau181 assays to discriminate between those with and without the neuropathological diagnosis of Alzheimer’s disease (AD) in Banner research participants with near‐end‐of‐life blood samples and extensive postmortem neuropathological assessments. We now extend this work in a head‐to‐head comparison of those assays to the University of Gothenburg’s Single molecule array (Simoa)‐based plasma ptau181 and 231 assays.MethodAssays were performed blindly in plasma samples acquired 1.0±0.7 years before death from up to 106 Banner research participants with and without cognitive impairment and different neuropathological diagnoses. ROC analyses were used to discriminate between those with and without the neuropathological diagnosis of AD and presence or absence of neuritic Aβ plaques. Spearman correlations were used to characterize their associations with mean cortical neuritic plaque counts and with mean cortical tau tangle counts in those with and without the diagnosis of AD or neuritic plaques.ResultLilly’s ptau217 assay was better than Lilly’s ptau181 and Gothenburg’s ptau231 and ptau181 assays in discriminating between the neuropathological diagnosis of Intermediate/High Likelihood versus Low Likelihood/No AD (respective AUCs=0.86, 0.67, 0.62 and 0.61), the diagnosis of High Likelihood versus Low Likelihood/No AD (AUCs=0.95, 0.83, 0.67 and 0.67), and presence or absence of neuritic Aβ plaques (AUCs=0.86, 0.70, 0.61 and 0.62). It also provided better indicators of mean cortical neuritic plaque (r’s=0.69, 0.35, 0.26 and 0.29) and tangle counts (r’s=0.73, 0.60, 0.19, ‐0.04) in those with the neuropathological diagnosis of AD or at least moderately frequent neuritic plaques (r’s=0.71, 0.59, 0.22, 0.01). The assays were not correlated with tangle counts in those without AD or neuritic plaques.ConclusionLilly’s MSD‐based plasma ptau217 assay performed better than the other three ptau assays in the neuropathological diagnosis of AD, discriminating between those with and without neuritic Aβ plaques, and providing an indicator of Aβ‐related tau tangle burden. Banner Sun Health Research Institute's growing brain donation program resources could help characterize and compare blood‐based biomarkers in the neuropathological diagnosis of AD, Parkinson’s disease and related diseases.

Rationale and design of the “NEurodegeneration: Traumatic brain injury as Origin of the Neuropathology (NEwTON)” study: a prospective cohort study of individuals at risk for chronic traumatic encephalopathy

BackgroundRepetitive head injury in contact sports is associated with cognitive, neurobehavioral, and motor impairments and linked to a unique neurodegenerative disorder: chronic traumatic encephalopathy (CTE). As the clinical presentation is variable, risk factors are heterogeneous, and diagnostic biomarkers are not yet established, the diagnostic process of CTE remains a challenge. The general objective of the NEwTON study is to establish a prospective cohort of individuals with high risk for CTE, to phenotype the study population, to identify potential fluid and neuroimaging biomarkers, and to measure clinical progression of the disease. The present paper explains the protocol and design of this case-finding study.MethodsNEwTON is a prospective study that aims to recruit participants at risk for CTE, with features of the traumatic encephalopathy syndrome (exposed participants), and healthy unexposed control individuals. Subjects are invited to participate after diagnostic screening at our memory clinic or recruited by advertisement. Exposed participants receive a comprehensive baseline screening, including neurological examination, neuropsychological tests, questionnaires and brain MRI for anatomical imaging, diffusion tensor imaging (DTI), resting-state functional MRI (rsfMRI), and quantitative susceptibility mapping (QSM). Questionnaires include topics on life-time head injury, subjective cognitive change, and neuropsychiatric symptoms. Optionally, blood and cerebrospinal fluid are obtained for storage in the NEwTON biobank. Patients are informed about our brain donation program in collaboration with the Netherlands Brain Brank. Follow-up takes place annually and includes neuropsychological assessment, questionnaires, and optional blood draw. Testing of control subjects is limited to baseline neuropsychological tests, MRI scan, and also noncompulsory blood draw.ResultsTo date, 27 exposed participants have finished their baseline assessments. First baseline results are expected in 2023.ConclusionsThe NEwTON study will assemble a unique cohort with prospective observational data of male and female individuals with high risk for CTE. This study is expected to be a primary explorative base and designed to share data with international CTE-related cohorts. Sub-studies may be added in the future with this cohort as backbone.

Rationale and design of the NEwTON study: A prospective cohort study of patients at risk of chronic traumatic encephalopathy

AbstractBackgroundTraumatic brain injury increases the risk of neurodegenerative diseases later in life. Repetitive head injury, more specific in contact sports, is associated with cognitive, neurobehavioral and motor impairments in the light of a unique neurodegenerative disorder: chronic traumatic encephalopathy (CTE). Yet, the clinical presentation, risk factors and diagnostic biomarkers of CTE have remained unclear. The general objective of the NEwTON study is to establish a prospective cohort of patients with high risk of CTE, to further study the link between repetitive head injury and neurodegeneration. We aim to phenotype the study population, identify potential biomarkers and measure clinical progression.MethodNEwTON is a prospective cohort study which aims to recruit approximately 80 patients at risk of CTE (features of the traumatic encephalopathy syndrome, Montenigro 2014) and healthy control subjects. Inclusion criteria are: history of repetitive head injury (contact sports, military service, other exposure), progressive cognitive and/or neurobehavioral symptoms, age 45‐75 years and symptom duration of ≥12 months. The control group will consist of age‐matched healthy participants without history of significant traumatic brain injury or participation in contact sports/professional military service. Subjects are invited to participate after diagnostic screening at our memory clinic or recruited by advertisement.ResultPatients will undergo comprehensive baseline screening, including neurological examination, neuropsychological tests, questionnaires and brain magnetic resonance imaging (MRI) for anatomical imaging, diffusion tensor imaging (DTI), resting state functional MRI (rsfMRI) and Quantitative Susceptibility Mapping (QSM). Questionnaires include topics on life‐time head injury, subjective cognitive change and neuropsychiatric symptoms. Blood and cerebrospinal fluid will be stored in the NEwTON biobank. Patients will be informed about our brain donation program in collaboration with the Netherlands Brain Brank. Testing for control subjects will be limited to baseline neuropsychological tests, blood draw and MRI. Patient follow‐up will take place annually and includes neuropsychological assessment, questionnaires and blood draw.ConclusionThe NEwTON study will contain the first cohort in the Netherlands with prospective observational data of patients with high risk of CTE. This study design will be an umbrella protocol and it is expected that other sub‐studies will use this cohort in the future.

Brain donation for research: Features of the brain donors from the InveCe.Ab population‐based cohort

AbstractBackgroundResearch on brain tissue is essential to understand the biological mechanisms underlying neurodegenerative diseases and brain aging processes.Brain donation for research is influenced by many factors both in clinical and non‐clinical samples. The aim of the present study is to explore the features associated with the decision to join the brain donation program of the Abbiategrasso Brain Bank (ABB) in the context of a population‐based study on brain aging.MethodThe longitudinal cohort study InveCe.Ab enrolled participants aged 70‐75 years and residing in Abbiategrasso (MI). During the second follow‐up of the study (2014), the participants fill a questionnaire to investigate attitudes through brain donation for research purpose (N=1010). We compared socio‐cultural aspects and questionnaire responses between participants who adhere to brain donation (N=163; 16,1%) and those who refuse (N=847) using Student’s t Test and chi‐squared test when appropriate. Variables showing significant differences in the group comparisons were included in a logistic regression model with brain donation status (yes/no) as the dependent variable.ResultThe groups were comparable for age and sex, while ABB donors were significantly more educated (donors: 7,74, non‐donors: 6,70; p=0,000), more frequently prone to organ donation (donors: 93,4%; non‐donors: 64,3%, p=0,000) and to cremation (donors: 76,8%; non‐donors: 44,8%; p=0,000). Among those who were favorable for brain donation in the questionnaire, only 43,6% actually signed up for brain donation (p=0,000). Moreover, brain donation was associated with friends relationship satisfaction (donors: 96,5%; non‐donors: 91,4%; p=0,023) and better self‐reported health (donors: 83,3%; non‐donors: 73,4%; p=0,028), despite no difference between groups was found in the number of chronic disease (p=0,49). Finally, in the multivariable model, being prone to organ donation was the main factor associated with actual registration for brain donation. The availability for cremation remained significant only for males.ConclusionDespite a positive attitude through brain donation in nearly half of the respondents, only a minority of older adults actually engage in a brain donation program. Being prone to organ donation was the main factor associated with brain donation subscription. The donors were more educated, with a positive attitude through their health and their relationships with friends.

Suicide in Older Adult Men Is Not Related to a Personal History of Participation in Football.

Introduction: It is reasonable to estimate that tens of millions of men in the United States played high school football. There is societal concern that participation in football confers risk for later-in-life mental health problems. The purpose of this study is to examine whether there is an association between a personal history of playing high school football and death by suicide.Methods: The subjects were obtained from the Lieber Institute for Brain Development (LIBD) brain donation program in collaboration with the Office of the Medical Examiner at Western Michigan University Homer Stryker MD School of Medicine. Donor history was documented via medical records, mental health records, and telephone interviews with the next-of-kin.Results: The sample included 198 men aged 50 or older (median = 65.0 years, interquartile range = 57–75). There were 34.8% who participated in contact sports during high school (including football), and 29.8% participated in high school football. Approximately one-third of the sample had suicide as their manner of death (34.8%). There was no statistically significant difference in the proportions of suicide as a manner of death among those men with a personal history of playing football compared to men who did not play football or who did not play sports (p = 0.070, Odds Ratio, OR = 0.537). Those who played football were significantly less likely to have a lifetime history of a suicide attempt (p = 0.012, OR = 0.352). Men with mood disorders (p < 0.001, OR = 10.712), substance use disorders (p < 0.020, OR = 2.075), and those with a history of suicide ideation (p < 0.001, OR = 8.038) or attempts (p < 0.001, OR = 40.634) were more likely to have suicide as a manner of death. Moreover, those men with a family history of suicide were more likely to have prior suicide attempts (p = 0.031, OR = 2.153) and to have completed suicide (p = 0.001, OR = 2.927).Discussion: Suicide was related to well-established risk factors such as a personal history of a mood disorder, substance abuse disorder, prior suicide ideation, suicide attempts, and a family history of suicide attempts. This study adds to a steadily growing body of evidence suggesting that playing high school football is not associated with increased risk for suicidality or suicide during adulthood.

Abbiategrasso Brain Bank Protocol for Collecting, Processing and Characterizing Aging Brains

In a constantly aging population, the prevalence of neurodegenerative disorders is expected to rise. Understanding disease mechanisms is the key to find preventive and curative measures. The most effective way to achieve this is through direct examination of diseased and healthy brain tissue. The authors present a protocol to obtain, process, characterize and store good quality brain tissue donated by individuals registered in an antemortem brain donation program. The donation program includes a face-to-face empathic approach to people, a collection of complementary clinical, biological, social and lifestyle information and serial multi-dimensional assessments over time to track individual trajectories of normal aging and cognitive decline. Since many neurological diseases are asymmetrical, our brain bank offers a unique protocol for slicing fresh specimens. Brain sections of both hemispheres are alternately frozen (at -80 °C) or fixed in formalin; a fixed slice on one hemisphere corresponds to a frozen one on the other hemisphere. With this approach, a complete histological characterization of all frozen material can be obtained, and omics studies can be performed on histologically well-defined tissues from both hemispheres thus offering a more complete assessment of neurodegenerative disease mechanisms. Correct and definite diagnosis of these diseases can only be achieved by combining the clinical syndrome with the neuropathological evaluation, which often adds important etiological clues necessary to interpret the pathogenesis. This method can be time consuming, expensive and limited as it only covers a limited geographical area. Regardless of its limitations, the high degree of characterization it provides can be rewarding. Our ultimate goal is to establish the first Italian Brain Bank, all the while emphasizing the importance of neuropathologically verified epidemiological studies.

Abbiategrasso Brain Bank Protocol for Collecting, Processing and Characterizing Aging Brains.

In a constantly aging population, the prevalence of neurodegenerative disorders is expected to rise. Understanding disease mechanisms is the key to find preventive and curative measures. The most effective way to achieve this is through direct examination of diseased and healthy brain tissue. The authors present a protocol to obtain, process, characterize and store good quality brain tissue donated by individuals registered in an antemortem brain donation program. The donation program includes a face-to-face empathic approach to people, a collection of complementary clinical, biological, social and lifestyle information and serial multi-dimensional assessments over time to track individual trajectories of normal aging and cognitive decline. Since many neurological diseases are asymmetrical, our brain bank offers a unique protocol for slicing fresh specimens. Brain sections of both hemispheres are alternately frozen (at -80 °C) or fixed in formalin; a fixed slice on one hemisphere corresponds to a frozen one on the other hemisphere. With this approach, a complete histological characterization of all frozen material can be obtained, and omics studies can be performed on histologically well-defined tissues from both hemispheres thus offering a more complete assessment of neurodegenerative disease mechanisms. Correct and definite diagnosis of these diseases can only be achieved by combining the clinical syndrome with the neuropathological evaluation, which often adds important etiological clues necessary to interpret the pathogenesis. This method can be time consuming, expensive and limited as it only covers a limited geographical area. Regardless of its limitations, the high degree of characterization it provides can be rewarding. Our ultimate goal is to establish the first Italian Brain Bank, all the while emphasizing the importance of neuropathologically verified epidemiological studies.

QUANTITATION OF THE BACTERIAL PRODUCT LIPOPOLYSACCHARIDE (LPS) IN POSTMORTEM SERUM AND BRAIN TISSUE FROM AD, MCI, AND CONTROL PATIENTS

Aspects of Alzheimer's disease (AD) pathology suggest a microbial response. Studies indicate that Aβ may act as an anti-microbial peptide. 16S rRNA gene sequencing by our lab and others indicates that many kinds of bacteria are present in brain tissue from AD patients, and to some extent, in normal controls. As 16S analysis is sensitive to contamination and is non-quantitative, we sought a second to assess presence of bacteria in the brain. Lipopolysaccharide (LPS) has been previously localized within amyloid plaques. We quantified LPS from post-mortem serum and brain tissue to 1) confirm that LPS is present and 2) determine if LPS in the brain may originate from the bloodstream or instead indicate the presence of resident bacteria. Tissues were acquired from the Brain and Body Donation Program at the Banner Sun Health Research Institute. Post-mortem serum was tested for LPS by ELISA. Frozen tissue from the superior frontal gyrus of the same subjects was homogenized and sonicated in PBS to create lysates for ELISAs. There were four subject groups (n=12 per group): AD, MCI (mild cognitive impairment), HPC (high pathology controls), and normal non-demented controls. LPS was detected in the serum of most subjects at pg/ml levels. Average levels in AD subjects were significantly higher than in normal controls. In brain tissue, subjects from all groups showed easily detectable levels of LPS, primarily in the ng/ml range. Levels in serum did not correlate well with levels observed in the brain tissue from the same subjects. Our data shows the presence of substantial amounts of LPS in both serum and brain tissue from our MCI and AD subjects, and even in many normal controls. The disconnection of serum LPS levels from brain tissue levels may indicate that the bloodstream is not the primary source of LPS in the brain, although it is possible LPS from blood accumulates in the brain over time. However, given our previous 16s rRNA gene sequencing analysis of brain tissue from these same subjects, which showed DNA from a large variety of bacteria, the LPS most likely derives from resident bacteria in the brain.

Inferior Olivary nucleus degeneration does not lessen tremor in essential tremor

BackgroundIn traditional models of essential tremor, the inferior olivary nucleus was posited to play a central role as the pacemaker for the tremor. However, recent data call this disease model into question.Case presentationOur patient had progressive, long-standing, familial essential tremor. Upper limb tremor began at age 10 and worsened over time. It continued to worsen during the nine-year period he was enrolled in our brain donation program (age 85 – 94 years), during which time the tremor moved from the moderate to severe range on examination. On postmortem examination at age 94, there were degenerative changes in the cerebellar cortex, as have been described in the essential tremor literature. Additionally, there was marked degeneration of the inferior olivary nucleus, which was presumed to be of more recent onset. Such degeneration has not been previously described in essential tremor postmortems. Despite the presence of this degeneration, the patient’s tremor not only persisted but it continued to worsen during the final decade of his life.ConclusionsAlthough the pathophysiology of essential tremor is not completely understood, evidence such as this suggests that the inferior olivary nucleus does not play a critical role in the generation of tremor in these patients.

The Brain Donation Program in South Korea.

PurposeObtaining brain tissue is critical to definite diagnosis and to furthering understanding of neurodegenerative diseases. The present authors have maintained the National Neuropathology Reference and Diagnostic Laboratories for Dementia in South Korea since 2016. We have built a nationwide brain bank network and are collecting brain tissues from patients with neurodegenerative diseases. We are aiming to facilitate analyses of clinic-pathological and image-pathological correlations of neurodegenerative disease and to broaden understanding thereof.Materials and MethodsWe recruited participants through two routes: from memory clinics and the community. As a baseline evaluation, clinical interviews, a neurological examination, laboratory tests, neuropsychological tests, and MRI were undertaken. Some patients also underwent amyloid PET.ResultsWe recruited 105 participants, 70 from clinics and 35 from the community. Among them, 11 died and were autopsied. The clinical diagnoses of the autopsied patients included four with Alzheimer's disease (AD), two with subcortical vascular dementia, two with non-fluent variant primary progressive aphasia, one with leukoencephalopathy, one with frontotemporal dementia (FTD), and one with Creutzfeldt-Jakob disease (CJD). Five patients underwent amyloid PET: two with AD, one with mixed dementia, one with FTD, and one with CJD.ConclusionThe clinical and neuropathological information to be obtained from this cohort in the future will provide a deeper understanding of the neuropathological mechanisms of cognitive impairment in Asia, especially Korea.