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Alzheimer's Research & Therapy

Springer Science and Business Media LLC

Preprints posted in the last 7 days, ranked by how well they match Alzheimer's Research & Therapy's content profile, based on 52 papers previously published here. The average preprint has a 0.07% match score for this journal, so anything above that is already an above-average fit.

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Multilevel connectomes reveal a late-stage shift to neurotransmitter-guided degeneration propagation in Alzheimer's Disease

Gao, K.; Song, Y.; Bao, J.; Maes, M.; Yao, D.; Biswal, B. B.; Wang, P.; Alzheimers Disease Neuroimaging Initiative,

2026-04-22 radiology and imaging 10.64898/2026.04.16.26350695 medRxiv
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INTRODUCTIONAlzheimers disease (AD) manifests a specific spatial progression pattern, but its propagation mechanisms remain unclear. METHODSWe employed nine brain connectomes spanning multiple biological levels to investigate the mechanisms underlying cortical atrophy propagation in AD. Individual gray matter atrophy maps were quantified using normative modeling and were then mapped onto the connectomes by assessing the relationship between regional atrophy and the atrophy of neighboring regions defined by each connectome. RESULTSCross-sectionally, node-neighbor relationship was weak in the preclinical stage, suggesting limited influence of connectome architecture. Longitudinally, atrophy became progressively more aligned with the neurotransmitter receptor similarity connectome in individuals with MCI converting to AD dementia and dementia patients. DISCUSSIONOur findings described a stage-dependent shift in cortical atrophy propagation, with neurotransmitter receptor similarity playing an increasing role as AD progresses.

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Brain-Organ Hypersynchrony and Cognitive Decline in Alzheimer's Disease: Potential Links with Tauopathy and Glymphatic Dysfunction

Wang, L.; Li, L.; Tao, Y.; Jia, Y.; Yue, J.; Zhang, Y.; Wang, Y.; Zhang, Y.; Xin, M.; Liu, J.; Shi, F.; Zhang, C.; Zhang, H.

2026-04-24 neurology 10.64898/2026.04.22.26351474 medRxiv
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Alzheimer's disease (AD) is increasingly recognized to have systemic physiological correlates alongside central neurodegeneration. Here, we explored brain-organ network (BON) connectivity in AD (n=28) and healthy controls (n=23) using time-resolved quasi-dynamic analysis of plateau-phase total-body 18F-tau-PET. We found that AD-related pathophysiology was linked not only to cerebral tau aggregation, but also to altered signal synchronization across the brain-organ network, despite comparable body tracer distribution. Network topology analyses revealed the occipitotemporal cortex and the spinal cord as key nodes in this altered systemic network. Furthermore, exploratory mediation analyses demonstrated that BON dysregulation is cross-sectionally linked to cognitive deficits, with statistical associations observed for both cortical tau burden and imaging markers of impaired glymphatic clearance. This total-body PET study provides first-ever direct evidence repositioning AD as a multi-organ disorganization disease. These findings provide a novel framework for investigating brain-body interactions and systemic vulnerabilities in neurodegenerative disorders.

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Plasma inflammatory markers and brain white matter microstructure in late middle-aged and older adults

Mishra, S.; Pettigrew, C.; Ugonna, C.; Chen, N.-k.; Frye, J. B.; Doyle, K. P.; Ryan, L.; Albert, M.; Ho, S. G.; Moghekar, A.; Soldan, A.; Paitel, E. R.

2026-04-22 neurology 10.64898/2026.04.20.26351124 medRxiv
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Chronic inflammation is a common feature of aging and is observed across various age-related neurodegenerative diseases, including Alzheimers disease (AD). It has, however, been challenging to develop measurements of brain structure directly linked to peripheral measures of neuroinflammation. This cross-sectional study examined whether plasma levels of markers related to inflammation are associated with diffusion magnetic resonance imaging (dMRI) measures of white matter microstructure: mean diffusivity (MD) and Neurite Orientation Dispersion and Density Imaging (NODDI) free water fraction (FWF) and orientation dispersion index (ODI). Participants included 457 dementia-free individuals (mean age=63.82, SD=7.63). Blood plasma markers related to inflammation included two measures of systemic inflammation, (1) high-sensitivity C-reactive protein (CRP), and (2) a composite of pro-inflammatory cytokines (IL-1, IL-1{beta}, IL-2, IL-6, IL-8, TNF-, TNF-{beta}), as well as (3) glial fibrillary acidic protein (GFAP), a measure of astrocytic activation. Higher cytokine composite levels were associated with higher values of all three measures (FWF, ODI, MD) in cerebral white matter, and with higher ODI in the cerebellar peduncles. Higher CRP levels were associated with higher ODI in cerebral and cerebellar white matter. Associations with GFAP were not significant after adjusting for multiple comparisons. Results were consistent after accounting for plasma biomarkers of AD pathology (p-tau181/A{beta}42). Thus, higher levels of peripheral pro-inflammatory markers are associated with white matter microstructure (higher FWF, ODI, and MD), supporting the view that these dMRI-based metrics are sensitive to inflammatory processes. Additionally, the sensitivity of dMRI-based measures to inflammation may differ by inflammatory marker types.

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Shared Risk Genes and Casual Relationships across Sex Hormone Related Traits and Alzheimer's Disease

yang, c.; Cook, N.; Zeng, Y.; Sivasankaran, S. K.; FinnGen, ; Decasien, A.; Andrews, S. J.; Belloy, M. E.

2026-04-24 neurology 10.64898/2026.04.23.26351626 medRxiv
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Background: Alzheimer's disease (AD) exhibits marked sex differences. While sex hormone levels across the lifespan likely contribute to this, little remains known about their causal impact and their relation to sex-biased genetic risk for AD. We therefore sought to identify potential shared genetic architectures, as well as causal genes and relationships, between sex hormone-related traits and AD risk. Methods: Large-scale AD sex-stratified genome-wide association study (GWAS) results were available from case-control, proxy-based, and population-based cohorts, including the Alzheimer's Disease Genetics Consortium, Alzheimer's Disease Sequencing Project, UK Biobank, and FinnGen. Sex hormone-related trait GWAS were available for age at menarche, menopause, and voice breaking, as well as testosterone, sex hormone-binding globulin (SHBG), progesterone, follicle stimulating hormone, luteinizing hormone, and estradiol levels. Cross-trait conjunctional analyses were conducted to identify pleiotropic overlap between sex-hormone traits and AD, followed by prioritization of candidate causal sex-biased AD genes through quantitative trait locus genetic colocalization analyses. The potential regulatory impact of sex hormones on these genes was assessed through transcription factor motif analyses. Finally, sex-stratified mendelian randomization analyses were used to infer causal effects of sex hormones on AD risk. Results: Genome-wide pleiotropy analyses demonstrated enrichment of AD with testosterone, SHBG, and age-at-menarche traits in women. We identified 12 high-confidence pleiotropic loci, 9 of which showed stronger AD effect sizes in women (3 in men) and 8 that were novel. Genes at these loci were often causally implicated in brain tissues and enriched for promoter-associated androgen receptor transcription factor binding motifs. Mendelian randomization indicated higher bioavailable testosterone in women (OR:0.88; 95%-CI:0.82-0.96) and higher SHBG levels in men (OR:0.86; 95%-CI:0.77-0.96) were associated with lower AD risk. Conclusions: Our findings reveal sex-specific shared genetic architectures between AD and sex hormone-related traits and nominate related genes that may drive sex-biases in AD risk. Several of the implicated female-biased genes are relevant to phosphatidylinositol and lipid metabolism, including Fatty Acid Desaturase 2 (FADS2). While we observed no causal effect of estradiol-related traits on AD risk, the protective effects of bioavailable testosterone in women and SHBG in men provide targets for sex-informed AD risk stratification and prevention strategies.

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Temporary deterioration of health and behavior during pexidartinib-mediated microglia depletion and repopulation in progranulin-deficient mice

Weyer, M.-P.; Hahnefeld, L.; Franck, L.; Schreiber, Y.; Angioni, C.; Schaefer, M. K. E.; Tegeder, I.

2026-04-21 neuroscience 10.64898/2026.04.20.719642 medRxiv
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Progranulin (PGRN) is a neurotrophic and anti-inflammatory factor produced mainly by neurons and microglia in the central nervous system. Progranulin haploinsufficiency causes frontotemporal dementia (FTD). In a previous study we showed that transgenic restoration of progranulin in neurons in progranulin knockout mice (NestinGrn KOBG knockout background) did not prevent the dementia-like phenotype. Here, we assessed if pharmacologic microglia depletion via PLX3397-diet (CSF1R-antagonist) had therapeutic value in these mice. Microglia depletion and spontaneous repopulation was confirmed in immunofluorescence and rtPCR studies. There was no difference in depletion or repopulation efficiency between NesGrn KOBG, PGRN KO and heterozygous (het) PGRN mice, but microglia repopulated faster than in control Grn-flfl mice, and the morphology of primary PGRN deficient microglia during repopulation was closer to homeostatic microglia, and it was accompanied by a remarkable restoration of dendritic spines and synaptic structures. Regardless of these positive effects, NesGrn KOBG and PGRN het mice experienced serious side effects during microglia depletion which peaked around the microglia nadir. Overactivity and excessive grooming escalated and caused serious skin lesions. Bulk transcriptomic and metabolomic studies in the brain taken 8 weeks after the end of PLX-diet clearly revealed differences between genotypes but mostly no lasting impact of PLX-diet, except for a further increase of proinflammatory genes, cathepsins and complement factors in PLX-treated groups. Cell type specific lipidomic studies revealed a time dependent switch not only in microglia but also astrocytes upon PLX3397 treatment. While nadir-microglia were triglyceride-laden, repopulated microglia returned to normal TG levels but were enriched in ether-bound phosphatidylcholines (PC-O) and lysophosphatidylglycerol species which are pro-inflammatory lipids; and astrocytes overtook the TG burden during repopulation. Our data suggest that microglia depletion may cause a deterioration in progranulin-deficiency.

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Stable episodic memory and high education do not influence the rate of Alzheimer's disease pathology as measured by plasma p-tau217

Avelar-Pereira, B.; Spotorno, N.; Orduna Dolado, A.; Bali, D.; Nordin Adolfsson, A.; Mattsson-Carlgren, N.; Palmqvist, S.; Janelidze, S.; Hansson, O.; Nyberg, L.

2026-04-21 neuroscience 10.64898/2026.04.16.718397 medRxiv
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Alzheimers disease (AD) neuropathological changes can be detected with blood-based biomarkers during the long preclinical phase that precedes clinical diagnosis. Tau phosphorylated at threonine 217 (p-tau217) has been found to closely correlate with brain A{beta} burden. A recent large-scale cross-sectional study showed elevated p-tau217 concentrations in older individuals (Aarsland et al., 2025). This increase was higher in those with AD dementia and mild cognitive impairment (MCI), and lower in those with intact cognition and higher educational attainment. Thus, intact cognition and higher education may be associated with lower levels of AD neuropathological changes. Here we tested this hypothesis using longitudinal data from the population-based Betula study (n=1005; 1531 samples). The results revealed increases with increasing age over 10 years in p-tau217, where individuals with accelerated episodic-memory decline had the strongest increase. There were no differences in p-tau217 trajectories between individuals with lower or higher education or with well-maintained or age-typical decline in episodic memory. The lack of association with education was further replicated in the independent BioFINDER-2 cohort. These findings underscore the value of plasma p-tau217 for detecting early pathological changes in population-based settings but provide no support that individuals with well-maintained episodic memory or high educational attainment are spared from neuropathological changes.

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Do Amyloid Trajectories Reach a Physiologic Ceiling? Evidence from Iterative Approximation and Simulation

Gantenberg, J. R.; La Joie, R.; Heston, M. B.; Ackley, S. F.

2026-04-21 epidemiology 10.64898/2026.04.14.26350359 medRxiv
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Qualitative models of Alzheimers pathology often posit that amyloid accumulation follows a sigmoid curve, indicating that the rate of deposition wanes over time. Longitudinal PET data now allow us to investigate amyloid accumulation trajectories with greater detail and over longer follow-up periods. We combine inferences from simulated amyloid trajectories, empirical PET data from the Alzheimers Disease Neuroimaging Initiative (ADNI), and the sampled iterative local approximation algorithm (SILA) to assess whether amyloid accumulation reaches a physiologic ceiling. We find that SILA reliably detects a ceiling, when present, across a range of simulated scenarios that impose a sigmoid shape. When fit to empirical data from ADNI, however, SILA does not appear to indicate the presence of a ceiling. Thus, we conclude that amyloid trajectories may not reach a physiologic ceiling during the stages of Alzheimers disease typically observed while patients remain under follow-up in cohort studies. Fits using SILA indicate that illustrative models of biomarker cascades, while useful tools for conceptualizing and interrogating pathologic processes, may not represent the shapes of amyloid trajectories accurately. Summary for General PublicAmyloid, a protein implicated in Alzheimers disease, is thought to reach a plateau in the brain, but methods that estimate how amyloid changes over time suggest it grows unabated. Gantenberg et al. use one such method and simulations to argue that amyloid does not reach a plateau during the typical course of Alzheimers.

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Integrating α-Synuclein Seeding Activity (SAA) into routine practice: insights from the multicenter ALZAN Cohort

Jourdan, O.; Duchiron, M.; Torrent, J.; Turpinat, C.; Mondesert, E.; Busto, G.; Morchikh, M.; Dornadic, M.; Delaby, C.; Hirtz, C.; Thizy, L.; Barnier-Figue, G.; Perrein, F.; Jurici, S.; Gabelle, A.; Bennys, K.; Lehmann, S.

2026-04-23 neurology 10.64898/2026.04.21.26351389 medRxiv
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Objectives: To evaluate the diagnostic performance of the -synuclein seed amplification assay (SAA) and characterize the impact of -synuclein co-pathology on cognitive and biological profiles in routine clinical practice. Methods: We included 398 patients from the prospective multicenter ALZAN cohort recruited from memory clinics in Montpellier, Nimes, and Perpignan. All participants underwent CSF and blood sampling with measurement of CSF biomarkers (A{beta}42/40, tau, ptau181) and plasma biomarkers (A{beta}42/40, ptau181, ptau217, GFAP, NfL). Cognitive assessment was performed using the Mini-Mental State Examination (MMSE). Clinical diagnoses were independently confirmed by two senior neurologists. Syn status was determined by SAA (RT-QuIC). Results: Of 398 patients, 19 out of 20 patients with Lewy body dementia (LBD) (95.0%) and 32 out of 203 patients with AD (15.8%) were SAA+. SAA-positivity presented a sensitivity of 95% and a specificity of 93.5% for distinguishing LBD from patients without LBD or AD. In the entire cohort, SAA+ patients showed lower MMSE scores (p<0.01), lower CSF A{beta}42/40 ratio (p<0.01), and elevated plasma GFAP (p<0.05). Within the AD group, no significant differences in CSF or blood biomarkers were observed between SAA+ and SAA- patients. Within the AD subgroup, no significant differences in CSF or blood biomarkers were observed between SAA+ and SAA- patients, except for a lower CSF A{beta}42/40 ratio in SAA+ patients (p<0.01). Interpretation: SAA demonstrates good diagnostic capabilities for detecting LBD and confirms notable Syn co-pathology in AD. This study highlights the limitations of routine CSF and emerging blood biomarkers in capturing Syn pathology and the value of integrating SAA into routine neurodegenerative disease assessment.

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Pulse-wave harmonic signatures of cardiovascular regulatory coherence to a cognitive challenge in mild cognitive impairment: a community-based cross-sectional study

Hsiao, K.-Y.

2026-04-27 geriatric medicine 10.64898/2026.04.24.26351647 medRxiv
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To evaluate whether hemodynamic responses to acute cognitive stress, measured via pulse-wave harmonic analysis, can characterize cardiovascular regulatory coherence and differentiate older adults with mild cognitive impairment (MCI) from cognitively intact individuals, this exploratory cross-sectional observational study utilized a within-session pre-post cognitive task design. A total of 101 community-dwelling older adults in southern Taiwan were stratified by Montreal Cognitive Assessment (MoCA) scores into Reference (MoCA [&ge;]26, n=12, paired n=10), MCI (MoCA 18-25; n=50, paired n=45), and dementia-level (MoCA <18; n=39) groups, the latter being excluded from task-evoked analyses. The primary outcome was the Harmonic Response Consistency Score (HRCS), quantifying the directional uniformity of cardiovascular regulatory responses, alongside secondary measures of harmonic amplitudes (Cn) and phase angles (Pn). Although mean pre-post changes were subtle, response organization differed by cognitive status. The Reference group exhibited high response consistency (mean HRCS = 9.00), characterized by coordinated harmonic down-modulation. Conversely, the MCI group showed attenuated, directionally heterogeneous responses. Compared to the Reference group, the MCI group demonstrated significantly lower HRCS values for the Cn domain (Mean difference: 2.60, 95% CI 0.29-4.91; p=0.020) and PnSD domain (Mean difference: 1.98, 95% CI 0.04-3.92; p=0.030), indicating a breakdown in regulatory coherence. These findings suggest that acute cognitive stimulus reveals coherent harmonic down-modulation in cognitively intact older adults but fragmented responses in MCI. Pulse-harmonic profiling thus serves as a robust physiological index of cardiovascular regulatory coherence, which, when integrated with neuropsychological assessments, may enhance the sensitivity of non-invasive, community-based screening frameworks for early cognitive aging.

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Menopausal hormone therapy at age 45 to 60 years old, future dementia or cognitive decline: Systematic review and meta-analysis

Law, S. Y. R.; Mukadam, N.; Pourhadi, N.; Chaudry, A.; Shiakalli, A.; Rai, U.; Livingston, G.

2026-04-22 psychiatry and clinical psychology 10.64898/2026.04.20.26351058 medRxiv
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ObjectiveTo examine whether menopausal women who initiate systemic menopausal hormone therapy (MHT) around menopause (45-60 years old) have a different risk of developing dementia than those not taking MHT. DesignSystematic review and meta-analysis of randomised controlled trials and longitudinal observational studies. Risk of bias was assessed using ROB-2 and ROBINS I-V2. Data sourcesMEDLINE, Web of Science, EMBASE, and Cochrane Library to 27 March 2026. Eligibility criteria for selecting studiesStudies which measured dementia or cognitive decline in women who initiated systemic MHT between ages 45-60 or within 5 years of menopause, compared with placebo or no MHT. Authors contacted for additional details if needed. Main outcome measuresDementia, Alzheimers disease (AD), cognitive decline. Results10 studies totalling 213,678 participants (189,525 in studies with the primary population). There was no significant increased risk in women with a uterus for all cause dementia (pooled hazard ratio (HR): 1.12; 95% CI 0.91-1.31, N=78,613, I2 = 96.9%), but increased AD risk (HR: 1.14; 95% CI 1.02, 1.29, N=134,865, I2 = 35.6%). Results were similar in sensitivity analyses including women with or without a uterus. Results for cognitive decline were variable. ConclusionsMHT initiated around the age of menopause should not be prescribed for cognition or dementia prevention. It is not protective against dementia and may increase risk slightly. The magnitude of risk was similar in AD and dementia, but the latter with larger confidence intervals. Studies which followed up individuals rather than on health records lost people to follow up. This may account for difference in cognitive decline outcomes between studies, as people with cognitive impairment and dementia are more likely not to attend. MHT prescribing should balance benefits against risks, including evidence of a small increased dementia risk. There are few high-quality studies, so further research would inform recommendations. Systematic review registration Prospero CRD420251010663 What is already known on this topic?O_LIMenopausal hormone therapy (MHT) is effective for alleviating vasomotor symptoms. Contemporary guidelines recommend treatment should be initiated for such symptoms under age 60 and or within 10 years of menopause onset. C_LIO_LIA large randomised trial on the topic found increased risk of dementia in women initiating MHT after the age of 65. C_LIO_LIIt is unknown whether initiating MHT around the age of menopause impacts the risk of dementia or cognitive decline. C_LI What this study addsO_LIThere was no evidence that taking MHT around the time of menopause decreases the risk of dementia or cognitive impairment. C_LIO_LIThey should not be prescribed for these indications. C_LIO_LIWe were able to find more studies which examine this question by contacting authors for additional data. C_LIO_LIInitiating MHT in women with a uterus around the age of menopause increased the risk of Alzheimers disease slightly, by over 10%, and there is a similar but not significant effect in the fewer studies of all cause dementia. Women with or without a uterus show similar results. C_LIO_LIWe found no significant difference shown in cognitive decline, possibly due to loss to follow up. This may be because most studies of cognitive decline follow up C_LI

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BETA: Resting-state fMRI Biotypes for tDCS Efficacy in Anxiety Among Older Adults At Risk For Alzheimer's Disease

Stolte, S. E.; Cheng, J.; Acharya, C.; Gu, L.; O'Shea, A.; Indahlastari, A.; Woods, A. J.; Fang, R.

2026-04-27 neurology 10.64898/2026.04.24.26351493 medRxiv
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Anxiety is usually gauged by self-report, yet a single symptom level can reflect disparate neural circuitry. In Alzheimer's disease and related dementias (ADRD) this heterogeneity becomes a barrier to effective neuromodulation: some patients may benefit from transcranial direct-current stimulation (tDCS), while others may not. To overcome this obstacle, we introduced BETA (Biotypes for tDCS Efficacy in Anxiety), a data-driven pipeline that uses resting-state fMRI functional connectivity to derive anxiety subtypes that are intrinsically linked to tDCS response. A transformer-based variational autoencoder compresses high-dimensional connectivity into a 50-dimensional latent embedding that emphasizes networks implicated in cognitive aging and anxiety. A deep-embedded clustering loss, regularized by a clinically informed term that pulls together individuals who exhibit similar post-tDCS anxiety change, yields four distinct subtypes. Across all subtypes, disrupted coupling between sensory-processing and higher-order cognitive regions emerges as a common hallmark. Crucially, one cluster is resistant to frontal-lobe tDCS, whereas two clusters demonstrate significant anxiety reduction following stimulation. The responsive subtypes are defined by strengthened connectivity between the lateral occipital cortex-superior division (sLOC) and medial frontal cortex (MedFC), and between sLOC and the intracalcarine cortex (ICC). BETA demonstrates that fMRI-based subtyping can directly identify which patients are likely to benefit from tDCS, providing a concrete roadmap for precision psychiatry in ADRD and facilitating tailored therapeutic strategies for anxiety.

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Repurposed COMT Inhibitors Tolcapone and Entacapone Selectively Suppress Aggregation and Seeding of P301 Mutant TAU in Human Neuronal Models

Kozlov, I.; Hung, Y.-S.; Roy, S.; Goud, A. C.; Kouril, R.; Wong, Y.-H.; Das, V.

2026-04-22 neuroscience 10.64898/2026.04.20.719548 medRxiv
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Background and PurposePathogenic aggregation and propagation of seed-competent TAU assemblies drive tauopathies. MAPT P301 mutations accelerate aggregation and enhance seed competence, yet pharmacological strategies selectively targeting these pathogenic species remain limited. We investigated whether the clinically approved catechol-O-methyltransferase inhibitors tolcapone (TOL) and entacapone (ENT) preferentially modulate mutant TAU aggregation and seeding. Experimental ApproachTOL and ENT effects on TAU aggregation were evaluated via cell-free assays, surface plasmon resonance (SPR), and in silico docking. Functional consequences of compound-modified fibrils were assessed in mutant TAU-expressing SH-SY5Y cells. Translational relevance was examined in human induced pluripotent stem cell (hiPSC)-derived neurons exposed to pathogenic K18 fibrils, followed by post-seeding compound treatment. Key ResultsBoth compounds dose-dependently inhibited TAU aggregation, exhibiting greater potency, stronger SPR binding affinities, and more favorable computed interaction energies for P301S mutant versus wild-type TAU. Fibrils formed with TOL or ENT induced less downstream TAU oligomerization and phosphorylation in SH-SY5Y cells, with TOL showing superior protection. In hiPSC-derived neurons, post-seeding treatment with either compound decreased fibril-induced, sarkosyl-insoluble TAU aggregation and phosphorylation without overt cytotoxicity. Conclusion and ImplicationsTOL and ENT preferentially inhibit the aggregation and seeding of pathogenic P301 mutant TAU. This supports mutation-focused pharmacological strategies and highlights catechol scaffolds as viable starting points for the development of disease-modifying therapeutics. Future research must determine the precise interaction mechanisms with aggregation intermediates and evaluate in vivo efficacy in animal models.

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Behavioral and psychological symptoms of dementia: insights from a multivariate and network-based brain proteome-wide study

Vattathil, S. M.; Duong, D. M.; Gearing, M.; Seyfried, N. T.; Wilson, R. S.; Bennett, D. A.; Woltjer, R. L.; Wingo, T. S.; Wingo, A. P.

2026-04-24 genetic and genomic medicine 10.64898/2026.04.23.26351110 medRxiv
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Behavioral and psychological symptoms of dementia (BPSD) are common, profoundly troubling to patients and caregivers, and difficult to treat, yet their molecular underpinnings remain poorly understood. Here, we generated the first brain proteomic dataset with BPSD phenotyping, profiling the dorsolateral prefrontal cortex of 376 donors from three cohorts spanning nine BPSD domains assessed in life. Protein associations with BPSD were examined using complementary approaches - domain-specific BPSD, multi-domain BPSD, and latent factor modeling - and integrated via cross-cohort meta-analysis. Four proteins (NMT1, DCAKD, DNPH1, and HIBADH) were associated with anxiety in dementia and five proteins (ABL1, SAP18, PLXND1, CTRB2, and LDHD) with multi-domain BPSD or BPSD latent factors after adjusting for sex, age, and other covariates (FDR < 0.05). Additionally, eight protein co-expression networks were associated with BPSD across cohorts. These results link BPSD to dysregulation of synaptic signaling, protein folding, and humoral immune response, providing a molecular framework for therapeutic discovery.

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How can AI be compatible with evidence-based medicine?: with an example of analysis of lung cancer recurrence

Usuzaki, T.; Matsunbo, E.; Inamori, R.

2026-04-25 radiology and imaging 10.64898/2026.04.17.26351114 medRxiv
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Despite the remarkable progress of artificial intelligence represented by large language models, how AI technologies can contribute to the construction of evidence in evidence-based medicine (EBM) remains an overlooked issue. Now, we need an AI that can be compatible with EBM. In the present paper, we aim to propose an example analysis that may contribute to this approach using variable Vision Transformer.

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AT(N) Framework in Older Adults with Epilepsy: Plasma Biomarkers and Associations with Demographic, Clinical, and Cognitive Features

Arrotta, K.; Williams, M.; Thompson, N. R.; Bangen, K. J.; Reyes, A.; Zawar, I.; Punia, V.; Wang, I.; Shih, J. J.; Bekris, L. M.; Ferguson, L.; Almane, D. N.; Jones, J. E.; Hermann, B. P.; Busch, R. M.; McDonald, C. R.

2026-04-27 neurology 10.64898/2026.04.24.26351489 medRxiv
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Background and Objectives: Older adults with epilepsy have a 2- to 4-fold increased risk of dementia, including Alzheimer's disease (AD), yet underlying mechanisms remain poorly defined. The NIA-AA classifies AD using amyloid (A), tau (T), and neurodegeneration [(N)] biomarkers. We applied this framework to characterize AT(N) profiles and clinical correlates in epilepsy. Methods: Eighty-four older adults with focal epilepsy (mean age=66.3 years) from the Brain Aging and Cognition in Epilepsy (BrACE) study were classified as A+, T+, and/or (N)+ using plasma {beta}-amyloid (A{beta}) 42/40 ratio, phosphorylated tau 181 (p-tau181), and neurofilament light chain (NfL) levels, and grouped into normal, AD-continuum, and non-AD pathologic change. Demographic, clinical, and cognitive characteristics were compared. Cognition was assessed using the International Classification of Cognitive Disorders in Epilepsy (IC-CoDE) and the Montreal Cognitive Assessment (MoCA). Memory was examined using IC-CoDE memory domain classification, with word-list delayed recall analyzed separately. Associations with cognition were modeled using logistic and linear regression. Secondary analyses examined biomarkers continuously, including p-tau217, and substituted hippocampal volume for NfL. Results: Only 32% of participants had normal biomarkers, while 37% were on the AD-continuum and 31% showed non-AD pathologic change. Participants with normal biomarkers were younger with shorter epilepsy duration, whereas APOE-{epsilon}4 carriers were enriched in the AD-continuum group. Early-onset compared to late-onset epilepsy (cutoff: [&ge;]55 years) showed higher odds of biomarker abnormality (aOR=8.84, 95% CI [2.35, 41.89], P=0.003), driven by elevated p-tau217, NfL, and greater amyloid burden. While categorical AT(N) profiles were not associated with cognition, higher p-tau181 levels were independently associated with lower word-list delayed recall (95% CI [-10.31, -0.86], P=0.021). Substituting hippocampal volume for NfL shifted more participants to normal profiles (48% vs. 32%) and fewer to non-AD pathologic change (15% vs. 31%). Discussion: AT(N) biomarker profiles showed substantial heterogeneity, with higher abnormality rates than in aging populations, particularly among those with early-onset epilepsy. Continuous p-tau181 was associated with memory performance while categorical AT(N) profiles were not, and NfL and hippocampal volume showed discordant classifications, highlighting divergence across neurodegeneration markers. These findings underscore the complexity of applying AD-centric frameworks to epilepsy and support multimodal, epilepsy-adapted biomarker approaches to characterize neurodegenerative risk.

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A composite measure of cerebral small vessel disease predicts cognitive change after stroke

Khan, M. H.; Chakraborty, S.; Marin-Pardo, O.; Barisano, G.; Borich, M. R.; Cole, J. H.; Cramer, S. C.; Fokas, E. E.; Fullmer, N. H.; Hayes, L.; Kim, H.; Kumar, A.; Rosario, E. R.; Schambra, H. M.; Schweighofer, N.; Taga, M.; Winstein, C.; Liew, S.-L.

2026-04-24 neurology 10.64898/2026.04.23.26351403 medRxiv
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Post-stroke cognitive recovery is difficult to predict using focal lesion characteristics alone. The brain's capacity to maintain cognitive function depends also on structural integrity of the whole brain. One way to measure brain health is through the severity of cerebral small vessel disease (CSVD) markers, which reflect aging-related pathologies that erode structural integrity. Here, we propose a composite measure of CSVD (cCSVD) integrating three independently validated biomarkers automatically quantified using T1-weighted MRIs: white matter hyperintensity volume (WMH; representing vascular injury), perivascular space count (PVS; putative glymphatic clearance), and brain-predicted age difference (brain-PAD; structural atrophy). We hypothesize that cCSVD, which captures the shared variance across these CSVD biomarkers, will be a robust indicator of whole-brain structural integrity and predict cognitive changes 3 months after stroke. We analyzed 65 early subacute stroke survivors with assessments within 21 days (baseline) and at 90 days (follow-up) post-stroke. WMH volume, PVS count, and brain-PAD were quantified from baseline T1-weighted MRIs, and then residualized for age, sex, days since stroke, and intracranial volume. Principal component analysis (PCA) of the residualized biomarkers was used to derive cCSVD. Beta regression with stability selection using LASSO was used to model three outcomes: baseline Montreal Cognitive Assessment (MoCA) scores, follow-up MoCA scores, and longitudinal change (follow-up score adjusted for baseline score). Logistic regression was used to test if baseline cCSVD predicted improvement in those with baseline cognitive impairment (MoCA < 26). The PCA revealed that the first principal component (PC1) explained 43.1% of the total variance among WMH volume, PVS count, and brain-PAD. The three biomarkers contributed nearly equally to PC1, which was subsequently used as the baseline cCSVD score. Lower baseline cCSVD was significantly associated with better MoCA scores at follow-up ({beta} = -0.19, p = 0.009), even after adjusting for baseline MoCA ({beta} = -0.12, p = 0.042), and, importantly, outperformed all individual biomarkers. Furthermore, lower cCSVD at baseline significantly increased the likelihood of improving to cognitively unimpaired status at three months (OR = 0.34, p = 0.036), independent of age and education. The composite CSVD captures the additive impact of vascular injury, glymphatic dysfunction, and structural atrophy on recovery in a way that individual measures do not. cCSVD accounts for shared variance across these domains, reflecting a patient's latent capacity for cognitive recovery, where relative integrity in one CSVD domain may mitigate effects of another. This automated, T1-based framework offers a scalable tool for predicting post-stroke recovery.

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cis-gamma-Amino-L-proline peptides as chemical probes of amyloidogenic processing in neurons and APP/PS1 mice

Jacome, D.; Perez-Palau, M.; Martinez-Soria, I.; Lidon, L.; Vergara, C.; Carbajo, D.; Pulido, X.; Sanchez-Navarro, M.; Giralt, E.; Albericio, F.; Royo, M.; Gavin Marin, R.; del Rio, J. A.

2026-04-21 neuroscience 10.64898/2026.04.17.719160 medRxiv
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Alzheimers disease (AD) is characterized by the accumulation of amyloid-{beta} (A{beta}) peptides, which are a key factor in its pathogenesis. In this study, we present the design and evaluation of {gamma}-amino-L-proline peptides as metabolically stable, cell-penetrating molecules that can modulate amyloidogenic processing. We screened a library of {gamma}-peptides in primary neuronal cultures to determine their effects on endogenous A{beta}1-42 production, cytotoxicity, and {beta}-secretase (BACE1) activity. Comparative analysis of structurally related analogues enabled the identification of molecular features associated with A{beta}-lowering activity, establishing a qualitative structure-activity relationship. Peptide 33 (P33) emerged as a lead candidate, selectively reducing BACE1 activity without significantly inhibiting the homologous enzyme, BACE2. In vitro blood-brain barrier (BBB) assays revealed that P33 exhibits favorable transendothelial permeability. Intraperitoneal administration of P33 in APP/PS1 mice decreased A{beta} levels, reduced amyloid plaque burden, and improved performance in a behavioral recognition task without inducing cytotoxicity or systemic toxicity. These results define cis-{gamma}-amino-L-proline peptides as a bioorganically distinct and modular scaffold for the development of intracellular modulators of A{beta} production. HighlightsO_LI{gamma}LJAminoLJLLJproline peptides as metabolically stable modulators of A{beta} production. C_LIO_LIP33 showed BBB permeability and BACE1 inhibition in primary cortical neurons. C_LIO_LIIn APP/PS1 mice, P33 lowers amyloid burden and improves cognition. C_LIO_LIP33 shows good biocompatibility, supporting its therapeutic potential in AD C_LI

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Black Rims at 7 Tesla MRI: Accumulation of Iron Around Perivascular Spaces in Cerebral Amyloid Angiopathy

Kancheva, I. K.; Voigt, S.; Munting, L.; van Dis, V.; Koemans, E.; van Osch, M. J. P.; Wermer, M. J. H.; Hirschler, L.; van Walderveen, M.; Weerd, L. v. d.

2026-04-23 neurology 10.64898/2026.04.22.26351134 medRxiv
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A prominent radiological manifestation of cerebral amyloid angiopathy (CAA) is enlargement of perivascular spaces (EPVS), which is suggested to result from fluid stagnation due to impaired perivascular clearance. Here, we report a novel observation of hypointense rims in cerebral white matter surrounding EPVS near haemorrhages on in vivo 7T Gradient Echo MRI. We hypothesised that the observed black rim pattern denotes iron accumulation that may be caused by incomplete clearance following bleeding. We investigated the occurrence and localisation of this marker on in vivo and ex vivo MRI and examined its histopathological correlates. From MRI data of the prospective longitudinal natural history study of hereditary Dutch-type CAA (D-CAA) at Leiden University Medical Centre, we selected the first 20 consecutive patients who underwent 7T imaging and assessed the presence of black rims on MRI. Post-mortem material was available from one donor with black rims on in vivo scans. Formalin-fixed coronal brain slabs were scanned at 7T MRI, including a high-resolution T2*-weighted sequence. Guided by ex vivo MRI, tissue blocks from representative areas with black rims were sampled for histopathological analysis. Serial sections were stained for iron, calcium, myelin, and general tissue morphology. On in vivo 7T MRI, 9 out of 20 participants exhibited one or several black rims, all located close to a haemorrhage. In the D-CAA donor, ex vivo MRI signal loss matched the in vivo contrast changes. Thirty-six vessels with ex vivo-observed black rims were retrieved and histopathologically examined, showing iron accumulation surrounding perivascular spaces, but the pattern and severity of iron deposition varied. Across groups, vessels displayed microvascular degeneration, including hyaline vessel wall thickening, adventitial fibrosis, and perivascular inflammation. We identified black rims on in vivo 7T MRI and confirmed their correspondence on ex vivo imaging. Iron deposition was determined as the underlying correlate of black rims, but the histopathology appears heterogeneous. The preferential deposition of iron around EPVS may indicate incomplete clearance of iron-positive blood-breakdown products after bleeding. The varied pattern of iron accumulation and microvascular alterations may reflect different pathophysiological mechanisms related to the formation and maintenance of black rims in D-CAA.

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Development and Evaluation of iSupport-Malaysia: A Multimedia Web-Based Psychoeducational Intervention for Dementia Caregivers

Loh, K. J.; Lee, W. L.; Ng, A. L. O.; Chung, F. F. L.; Renganathan, E.

2026-04-21 geriatric medicine 10.64898/2026.04.14.26350743 medRxiv
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BackgroundCaring for people with dementia can impose a considerable psychological burden on caregivers, yet access to caregiver support in Malaysia remains limited. The World Health Organizations iSupport for Dementia program provides dementia education via textual, e-learning format. However, a culturally adapted Malaysian version has not been available. ObjectiveThis study aimed to develop and gather user feedback on a culturally adapted, multimedia version of iSupport tailored for Malaysia (iSupport-Malaysia). MethodsGuided by a four-phase cultural adaptation framework, the generic iSupport content was translated into Bahasa Malaysia, adapted to local customs, and transformed into multimedia lessons on an e-learning platform. A mixed-methods design was used to explore user perceptions and evaluate usability through four homogeneous focus group discussions and 15 individual usability test sessions with informal caregivers (FG: n=9; UT: n=9) and healthcare professionals (FG: n=11; UT: n=6). Focus groups examined aesthetics, ease of use, clarity, cultural relevance, comprehensiveness, and satisfaction. Usability testing involved Think Aloud tasks, post-test questionnaires, and brief interviews. Qualitative data was analysed thematically, and descriptive statistics summarised usability performance. ResultsiSupport-Malaysia demonstrated good usability (M=74.3{+/-}18.0), with most tasks completed without assistance. Strengths included interactive learning activities, peer discussion features, and flexible self-paced learning. Content was viewed as culturally appropriate, credible, and useful. Suggested improvements included enhancing visual aesthetics, shortening videos, refining quizzes, and increasing practical relevance. ConclusionUser insights indicate that iSupport-Malaysia is usable and culturally appropriate. These findings will inform refinement of the platform prior to the pilot feasibility study and provide recommendations for future multimedia-based caregiver interventions.

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Mental-state reasoning or downstream vascular burden? Theory of Mind task performance in post-stroke aphasia.

Kurtz, J.; Billot, A.; Falconer, I.; Small, H.; Charidimou, A.; Kiran, S.; Varkanitsa, M.

2026-04-21 neurology 10.64898/2026.04.14.26350532 medRxiv
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BackgroundTheory of Mind (ToM) deficits are well-documented in right-hemisphere stroke but remain understudied in post-stroke aphasia. Prior work suggests that performance on tasks assessing ToM may be relatively preserved in aphasia and dissociable from language impairment, but these findings are based largely on small studies. This study examined performance on nonverbal false-belief tasks in post-stroke aphasia, its relationship with aphasia severity, and whether vascular brain health, operationalized using cerebral small vessel disease (CSVD) markers, contributed to variability in performance. MethodsForty-four individuals with aphasia completed two nonverbal belief-reasoning tasks assessing spontaneous perspective-taking and self-perspective inhibition. Task accuracy served as the primary outcome. Linear regression models examined associations between task performance, aphasia severity (Western Aphasia Battery-Revised Aphasia Quotient), and CSVD markers, including white matter hyperintensities, cerebral microbleeds, lacunes and enlarged perivascular spaces in the basal ganglia and centrum semiovale. ResultsPerformance was heterogeneous across tasks, with reduced performance observed in 23% of participants on the Reality-Unknown task and 36% on the Reality-Known task. Aphasia severity was not associated with task accuracy. Greater cerebral microbleed count was associated with lower accuracy on both tasks, while greater basal ganglia enlarged perivascular spaces burden showed a more selective association with lower performance. ConclusionsPerformance on nonverbal false-belief tasks in aphasia is variable and not explained by aphasia severity alone. These findings suggest that apparent ToM-related difficulties in aphasia may be shaped by broader vascular brain health, supporting a more multidimensional framework for interpreting social-cognitive task performance after stroke.