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Human musicality might have co-evolved with social cognition abilities, but common neuroanatomical substrates remain largely unclear. In behavioural variant frontotemporal dementia, social cognitive abilities are profoundly impaired, whereas these are typically spared in Alzheimer's disease. If musicality indeed shares a neuroanatomical basis with social cognition, it could be hypothesized that clinical and neuroanatomical associations of musicality and social cognition should differ between these causes of dementia. We recruited 73 participants from the Amsterdam Dementia Cohort ( n = 30 female; aged 50-78), of whom 23 had behavioural variant frontotemporal dementia, 22 Alzheimer's disease and 28 were healthy controls. Musicality was assessed using a music-emotion recognition test, melody, tempo, accent and tuning subscores, a musicality summed score, the identification of auditory hedonic phenotypes and music emotion induction using skin conductance responses. Social cognition was assessed across multiple levels, including emotion recognition, theory of mind, socio-emotional sensitivity and understanding of social norms. We used ANCOVA to investigate subgroup differences in musicality and social cognition and linear regressions to investigate associations between musicality and social cognition. All analyses were adjusted for age, sex, musical training and mini mental state examination. Finally, we performed voxel-based morphometry analyses on T 1 -weighted MRI to study whether regions for musicality and social cognition overlapped anatomically. We found that patients with behavioural variant frontotemporal dementia performed worse on music-emotion recognition (all P < 0.001) and tempo recognition (all P < 0.05) compared with Alzheimer's disease and on musicality summed score (all P = 0.02) compared to controls only. Furthermore, patients with behavioural variant frontotemporal dementia had lower mean skin conductance responses during emotion-inducing music, compared to Alzheimer's disease (all P < 0.045). Worse music emotion recognition scores were associated with worse facial emotion recognition ( P < 0.0001), worse theory of mind ( P = 0.0005) and worse understanding of social norms ( P = 0.01). Melody and tempo recognition were associated with facial emotion recognition and theory of mind, and accent recognition was associated with the theory of mind. Music emotion recognition and tempo recognition were also associated with executive functions. Worse music emotion recognition, melody recognition, tempo recognition, facial emotion recognition and theory of mind scores were all related to atrophy in the anterior temporal regions and the fusiform gyri, which play a role in multisensory integration, and worse tempo recognition was associated with atrophy of the anterior cingulate cortex. These results support the idea that musicality and social cognition may share a neurobiological basis, which may be vulnerable in behavioural variant frontotemporal dementia., Competing Interests: The authors report no competing interests., (© The Author(s) 2024. Published by Oxford University Press on behalf of the Guarantors of Brain.)

Background:  Primary lateral sclerosis (PLS) is a rare motor neuron disease characterized by upper motor neuron degeneration, diagnosed clinically due to the absence of a (neuropathological) gold standard. Post-mortem studies, particularly TDP-43 pathology analysis, are limited., Methods: This study reports on 5 cases in which the diagnostic criteria for PLS were met, but in which neuropathology findings showed (partially) conflicting results. These discrepancies prompted us to perform a clinico-pathology study focussing on diagnostic challenges and accuracy in PLS. To this end, all cases were reviewed by an international panel of 11 experts using an e-module and structured questionnaires., Results: Autopsy exhibited neuropathological findings consistent with amyotrophic lateral sclerosis (ALS) in one case, while two cases exhibited similar, but more limited lower motor neuron involvement, hinting at PLS or ALS overlap. Another case displayed tau-pathology indicative of progressive supranuclear palsy. The final case displayed extensive myelin loss without a proteinopathy or a clear diagnosis. The expert panel identified 24 different ancillary investigations lacking across cases (e.g. genetic testing, DAT scans, neuropsychological evaluation), listed 28 differential diagnoses, and identified 13 different conditions as the most likely diagnosis. Autopsy results led panel members to change their final diagnosis in 42% of the cases., Conclusions: This study underscores the diagnostic challenges posed by diverse underlying pathologies resulting in upper motor neuron phenotypes. Despite adhering to the same diagnostic criteria, consensus amongst experts was limited. Ensuring the diagnostic consistency is crucial for advancing understanding and treatment of PLS. Explicit guidelines for excluding potential mimics along with a neuropathological gold standard are imperative., Competing Interests: Declarations. Conflicts of interest: E.M.J. de Boer: reports no disclosures relevant to the manuscript. B.S. de Vries: reports no disclosures relevant to the manuscript. W. van Hecke: reports no disclosures relevant to the manuscript. A. Mühlebner: reports no disclosures relevant to the manuscript. K.L. Vincken: reports no disclosures relevant to the manuscript. C.P. Mol: reports no disclosures relevant to the manuscript. W. van Rheenen: reports no disclosures relevant to the manuscript. H-J Westeneng: reports no disclosures relevant to the manuscript. J.H. Veldink: reports to have sponsored research agreements with Biogen and Astra Zeneca. This project has received funding from the European Research Council (ERC) under the European Union’s Horizon 2020 research and innovation programme (grant agreement n° 772376 – EScORIAL. G.U. Höglinger: reports no disclosures relevant to the manuscript. H.R. Morris: reports no disclosures relevant to the manuscript. I. Litvan: reports no disclosures relevant to the manuscript. J. Raaphorst: reports no disclosures relevant to the manuscript. N. Ticozzi: reports no disclosures relevant to the manuscript. P. Corcia: reports no disclosures relevant to the manuscript. W. Vandenberghe: reports no disclosures relevant to the manuscript. Y.A.L. Pijnenburg: reports no disclosures relevant to the manuscript. H. Seelaar: reports no disclosures relevant to the manuscript. C. Ingre: reports no disclosures relevant to the manuscript. P. Van Damme: reports no disclosures relevant to the manuscript. L.H. van den Berg: declares fees to his institution from Biogen, Wave, Amylyx, Ferrer, and Cytokinetics for being on a scientific advisory board; fees to his institution from Amylyx for a lecture; an unrestricted educational grant from Takeda; and is the Chair of ENCALS and TRICALS. B.P.C. van de Warrenburg: reports no disclosures relevant to the manuscript. M.A. van Es: has consulted for Biogen, and has received travel grants from Shire (formerly Baxalta), performed work as a medical monitor for Ferrer (NCT05178810) with fees going to his institution. MAvE receives funding support from the Netherlands Organization for Health Research and Development (Vidi scheme), The Thierry Latran Foundation, the Motor Neurone Disease Association, FIGHT-MND and the ALS Foundation Netherlands. He is also a member of the European Reference Network for Rare Neuromuscular Diseases (ERN-NMD)., (© 2024. Springer-Verlag GmbH Germany, part of Springer Nature.)

Due to methodological reasons, the X-chromosome has not been featured in the major genome-wide association studies on Alzheimer's Disease (AD). To address this and better characterize the genetic landscape of AD, we performed an in-depth X-Chromosome-Wide Association Study (XWAS) in 115,841 AD cases or AD proxy cases, including 52,214 clinically-diagnosed AD cases, and 613,671 controls. We considered three approaches to account for the different X-chromosome inactivation (XCI) states in females, i.e. random XCI, skewed XCI, and escape XCI. We did not detect any genome-wide significant signals (P ≤ 5 × 10 - 8 ) but identified seven X-chromosome-wide significant loci (P ≤ 1.6 × 10 - 6 ). The index variants were common for the Xp22.32, FRMPD4, DMD and Xq25 loci, and rare for the WNK3, PJA1, and DACH2 loci. Overall, this well-powered XWAS found no genetic risk factors for AD on the non-pseudoautosomal region of the X-chromosome, but it identified suggestive signals warranting further investigations., Competing Interests: Competing interests: The authors declare no competing interests. Ethics approval and consent to participate: Written informed consent was obtained from study participants or, for those with substantial cognitive impairment, a caregiver, legal guardian or other proxy. Study protocols for all cohorts were reviewed and approved by the appropriate institutional review boards., (© 2024. The Author(s).)

White matter hyperintensities of presumed vascular origin (WMH) are associated with cognitive impairment and are a key imaging marker in evaluating brain health. However, WMH volume alone does not fully account for the extent of cognitive deficits and the mechanisms linking WMH to these deficits remain unclear. Lesion network mapping (LNM) enables us to infer if brain networks are connected to lesions and could be a promising technique for enhancing our understanding of the role of WMH in cognitive disorders. Our study employed LNM to test the following hypotheses: (i) LNM-informed markers surpass WMH volumes in predicting cognitive performance; and (ii) WMH contributing to cognitive impairment map to specific brain networks. We analysed cross-sectional data of 3485 patients from 10 memory clinic cohorts within the Meta VCI Map Consortium, using harmonized test results in four cognitive domains and WMH segmentations. WMH segmentations were registered to a standard space and mapped onto existing normative structural and functional brain connectome data. We employed LNM to quantify WMH connectivity to 480 atlas-based grey and white matter regions of interest (ROI), resulting in ROI-level structural and functional LNM scores. We compared the capacity of total and regional WMH volumes and LNM scores in predicting cognitive function using ridge regression models in a nested cross-validation. LNM scores predicted performance in three cognitive domains (attention/executive function, information processing speed, and verbal memory) significantly better than WMH volumes. LNM scores did not improve prediction for language functions. ROI-level analysis revealed that higher LNM scores, representing greater connectivity to WMH, in grey and white matter regions of the dorsal and ventral attention networks were associated with lower cognitive performance. Measures of WMH-related brain network connectivity significantly improve the prediction of current cognitive performance in memory clinic patients compared to WMH volume as a traditional imaging marker of cerebrovascular disease. This highlights the crucial role of network integrity, particularly in attention-related brain regions, improving our understanding of vascular contributions to cognitive impairment. Moving forward, refining WMH information with connectivity data could contribute to patient-tailored therapeutic interventions and facilitate the identification of subgroups at risk of cognitive disorders., (© The Author(s) 2024. Published by Oxford University Press on behalf of the Guarantors of Brain.)

The integration of quantitative trait loci (QTLs) with disease genome-wide association studies (GWASs) has proven successful in prioritizing candidate genes at disease-associated loci. QTL mapping has been focused on multi-tissue expression QTLs or plasma protein QTLs (pQTLs). We generated a cerebrospinal fluid (CSF) pQTL atlas by measuring 6,361 proteins in 3,506 samples. We identified 3,885 associations for 1,883 proteins, including 2,885 new pQTLs, demonstrating unique genetic regulation in CSF. We identified CSF-enriched pleiotropic regions on chromosome (chr)3q28 near OSTN and chr19q13.32 near APOE that were enriched for neuron specificity and neurological development. We integrated our associations with Alzheimer's disease (AD) through proteome-wide association study (PWAS), colocalization and Mendelian randomization and identified 38 putative causal proteins, 15 of which have drugs available. Finally, we developed a proteomics-based AD prediction model that outperforms genetics-based models. These findings will be instrumental to further understand the biology and identify causal and druggable proteins for brain and neurological traits., Competing Interests: Competing interests: C.C. has received research support from GSK and Eisai. The funders of the study had no role in the collection, analysis or interpretation of data; in the writing of the report; or in the decision to submit the paper for publication. C.C. is a member of the advisory board of Circular Genomics and owns stocks in this company. D.J.P. is an employee of GSK and holds stock in GSK. M.d.C.M. has been an invited speaker at Eisai. M.d.C.M. is an associate editor at Alzheimer’s Research and Therapy. B.T. and P.J.V. are inventors on a patent (WO2020197399A1, owned by Stichting VUmc). C.E.T. has a collaboration contract with ADx Neurosciences, Quanterix and Eli Lilly and performed contract research or received grants from AC Immune, Axon Neuroscience, BioConnect, Bioorchestra, Brainstorm Therapeutics, Celgene, EIP Pharma, Eisai, Grifols, Novo Nordisk, PeopleBio, Roche, Toyama and Vivoryon. She serves on editorial boards of Medidact Neurologie–Springer, Alzheimer’s Research and Therapy and Neurology: Neuroimmunology and Neuroinflammation and is an editor of the Neuromethods book (Springer). She had speaker contracts for Roche, Grifols and Novo Nordisk. The rest of the authors declare no competing interest., (© 2024. The Author(s), under exclusive licence to Springer Nature America, Inc.)

Background and Purpose: Behavioral variant frontotemporal dementia (bvFTD) and primary psychiatric disorders (PPD), such as mood, psychotic, and autism spectrum disorders, share similar clinical characteristics of behavior and social cognition. Better understanding of clinical progression in bvFTD and PPD is essential for adequate disease monitoring and trial design., Methods: In this longitudinal study (N = 89), patients with bvFTD and PPD with at least one follow-up assessment were included from the Social Brain Project of the Alzheimer Center Amsterdam. Behavioral change and social cognitive decline were assessed via informant-rated questionnaires (Cambridge Behavioral Inventory-Revised, Frontal Behavioral Inventory [FBI], Stereotypy Rating Inventory, Frontotemporal Dementia Rating Scale, Revised Self-Monitoring Scale [RSMS]-caregiver) and patient assessment (Ekman 60-Faces Test, RSMS-patient, Emotional Contagion Scale). Clinical trajectories (median = 1.4 years, interquartile range = 1.0-2.2) were examined using linear mixed models. In a subsample, associations with baseline serum neurofilament light (sNfL) were examined., Results: At baseline, behavioral and social cognitive symptoms were similar between diagnosis groups, except for poorer emotion recognition in bvFTD. Over time, behavioral symptoms worsened in bvFTD, whereas most measures remained stable and the FBI improved in PPD. Regarding social cognition, emotion recognition and caregiver-reported socioemotional sensitivity worsened in bvFTD and remained stable in PPD. Patient-reported social cognitive measures did not change over time. Higher sNfL was associated with faster behavioral change., Conclusions: Trajectories of behavior and social cognition differentiate bvFTD from PPD, provided that social cognition is not patient-reported. Therefore, we stress the need to optimize longitudinal social cognitive assessment in bvFTD. sNfL may be a useful prognostic marker of behavioral progression in neuropsychiatric populations., (© 2024 The Author(s). European Journal of Neurology published by John Wiley & Sons Ltd on behalf of European Academy of Neurology.)

Introduction: Plasma phosphorylated tau-217 (p-tau217) and neurofilament light (NfL) can differentiate between different dementias in selected cohorts. We aim to test the discrimination potential of these markers in a real-world cohort., Methods: We measured p-tau217 (ALZpath) and NfL (Quanterix) in 415 (unselected) consecutive memory clinic patients. Biomarker levels were dichotomized as low/high to create four biomarker profiles based on p-tau217 and NfL levels., Results: p-Tau217 levels were highest in patients with Alzheimer's disease (AD) dementia, whereas NfL levels were highest in patients with frontotemporal dementia (FTD). Low p-tau217/low NfL was associated mostly with non-neurological diagnoses (79%), and high p-tau217/low NfL indicated AD pathology at any stage (84%). Low p-tau217/high NfL indicated FTD (38%) and high p-tau217/high NfL indicated AD dementia (87%)., Discussion: p-Tau217 can identify AD pathology at any disease stage. NfL can differentiate FTD from other diagnoses (e.g., AD dementia). Plasma p-tau217 and NfL can support clinical decision-making, and we suggest using them as complements to standard clinical assessment., Highlights: Phosphorylated tau-2017 (p-tau217) can detect Alzheimer's disease (AD) across the clinical continuum.Neurofilament light (NfL) can differentiate frontotemporal dementia (FTD) from other diagnoses (AD dementia, dementia with Lewy bodies [DLB], and Psychiatry).p-Tau217 may detect AD co-pathology in other diseases or dementia types (e.g., DLB).p-Tau217 and NfL show potential for clinical implementation., Competing Interests: Andreas Jeromin is an employee of ALZpath, Inc. and has stock options. Charlotte E. Teunissen has research contracts with Acumen, ADx Neurosciences, AC‐Immune, Alamar, ALZpath, Aribio, Axon Neurosciences, Beckman‐Coulter, BioConnect, Bioorchestra, Brainstorm Therapeutics, Celgene, Cognition Therapeutics, EIP Pharma, Eisai, Eli Lilly, Fujirebio, Grifols, Instant Nano Biosensors, Merck, Novo Nordisk, Olink, PeopleBio, Quanterix, Roche, Toyama, and Vivoryon. She is editor in chief of Alzheimer's Research and Therapy, and serves on editorial boards of Medidact Neurologie/Springer, and Neurology: Neuroimmunology & Neuroinflammation. She had speaker contracts for Eli Lilly, Novo Nordisk, Olink and Roche. Research programs of Wiesje van der Flier have been funded by ZonMW, Dutch Research council (NWO), EU‐Joint Programme ‐ Neurodegenerative Disease Research, EU‐Innovative Health Initiative, Alzheimer Nederland, Hersenstichting CardioVascular Onderzoek Nederland, Health∼Holland, Topsector Life Sciences & Health, stichting Dioraphte, Gieskes‐Strijbis fonds, stichting Equilibrio, Edwin Bouw fonds, Pasman stichting, stichting Alzheimer & Neuropsychiatrie Foundation, Philips, Biogen MA Inc., Novartis‐NL, Life‐MI, Advancement Via Individual Determination, Roche BV, Fujifilm, Eisai, and Combinostics. Wiesje M. van der Flier holds the Pasman chair. Wiesje M. van der Flier has been an invited speaker at Biogen MA Inc., Danone, Eisai, WebMD Neurology (Medscape), NovoNordisk, Springer Healthcare, European Brain Council. Wiesje M. van der Flier is consultant to Oxford Health Policy Forum CIC, Roche, Biogen MA Inc., and Eisai. Wiesje M. van der Flier is member of steering cie of NovoNordisk evoke/evoke+. Wiesje M. van der Flier participated in advisory boards of Biogen MA Inc., Roche, and Eli Lilly. Wiesje M. van der Flier is member of the steering committee of evoke/evoke+ (NovoNordisk) (NCT04777296/NCT04777409). All funding is paid to her institution. Wiesje M. van der Flier is member of the steering committee of Project Alzheimer's Value Europe and Think Brain Health. Wiesje M. van der Flier was associate editor of Alzheimer, Research & Therapy in 2020/2021. Wiesje M. van der Flier is associate editor at Brain. Rebecca Z. Rousset, Thomas Claessen, Argonde C. van Harten, Afina W. Lemstra, Yolande A. L. Pijnenburg, and Inge M. W. Verberk have no potential conflicts of interest to disclose. Author disclosures are available in the Supporting information., (© 2024 The Author(s). Alzheimer's & Dementia: Diagnosis, Assessment & Disease Monitoring published by Wiley Periodicals LLC on behalf of Alzheimer's Association.)

Objective: To study information needs after receiving abnormal amyloid-PET results, and how individual characteristics moderate effects of different communication strategies on information recall., Methods: In an online video-vignette experiment, seven vignettes each depicted a consultation of a physician sharing abnormal amyloid-PET results with a patient with Mild Cognitive Impairment(MCI), using different communication strategies. Healthy individuals (N = 1017; age 64 ± 8, 808(79 %) female), instructed to imagine themselves as the video-patient, viewed a randomly-assigned vignette and completed questionnaires to assess information needs and test moderation effects of gender, age, care-partner experience, health literacy, and coping., Results: Sixty-three percent of participants (645/1017) would have liked to receive more information, e.g., on prognosis, additional information sources, lifestyle advice, and/or treatment. Emotional support benefited information recall in women, but not men. Emotional support and visually presenting the PET-scan were less beneficial for individuals with a stronger avoidant coping style, compared to most other strategies., Conclusion: Most people wanted more information on varying topics, and gender and coping style influenced how communication strategies impacted information recall. PRACTICE IMPLICATIONS The importance of personalized information provision was emphasized, both in terms of what information is provided and how physicians share information, by paying attention to individuals' needs and characteristics., Competing Interests: Declaration of Competing Interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Research programs of Wiesje van der Flier (WF) have been funded by ZonMW, NWO, EU-JPND, EU-IHI, Alzheimer Nederland, Hersenstichting CardioVascular Onderzoek Nederland, Health∼Holland, Topsector Life Sciences & Health, stichting Dioraphte, Gieskes-Strijbis fonds, stichting Equilibrio, Edwin Bouw fonds, Pasman stichting, stichting Alzheimer & Neuropsychiatrie Foundation, Philips, Biogen MA Inc, Novartis-NL, Life-MI, AVID, Roche BV, Fujifilm, Eisai, Combinostics. WF holds the Pasman chair. WF has been an invited speaker at Biogen MA Inc, Danone, Eisai, WebMD Neurology (Medscape), NovoNordisk, Springer Healthcare, European Brain Council. All funding is paid to her institution. WF is consultant to Oxford Health Policy Forum CIC, Roche, Biogen MA Inc, and Eisai. WF is member of steering cie of NovoNordisk evoke/evoke+ . All funding is paid to her institution. WF participated in advisory boards of Biogen MA Inc, Roche, and Eli Lilly. WF is member of the steering committee of PAVE and Think Brain Health. WF was associate editor of Alzheimer, Research & Therapy in 2020/2021. WF is associate editor at Brain. Leonie Visser (LNCV) has been invited speaker for the Schwabe Group, and her research has been funded by ZonMW, Health Holland, Eisai, the Amsterdam Public Health research institute, and Alzheimer Nederland. All fees and funding are paid to her institution. JvdS wrote a book for a layman's audience about the personal impact of dominantly inherited AD, for which she received grants or contracts from Aegon Nederland and Alzheimer Nederland and royalties from Uitgeverij Prometheus. She is a member of the advisory board for the National Dementia Strategy of the Dutch Ministry of Health, Welfare and Sport. All other authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier B.V. All rights reserved.)

Genome-wide association studies have successfully identified many genetic risk loci for dementia, but exact biological mechanisms through which genetic risk factors contribute to dementia remains unclear. Integrating CSF proteomic data with dementia risk loci could reveal intermediate molecular pathways connecting genetic variance to the development of dementia. We tested to what extent effects of known dementia risk loci can be observed in CSF levels of 665 proteins [proximity extension-based (PEA) immunoassays] in a deeply-phenotyped mixed memory clinic cohort [n = 502, mean age (standard deviation, SD) = 64.1 (8.7) years, 181 female (35.4%)], including patients with Alzheimer's disease (AD, n = 213), dementia with Lewy bodies (DLB, n = 50) and frontotemporal dementia (FTD, n = 93), and controls (n = 146). Validation was assessed in independent cohorts (n = 99 PEA platform, n = 198, mass reaction monitoring-targeted mass spectroscopy and multiplex assay). We performed additional analyses stratified according to diagnostic status (AD, DLB, FTD and controls separately), to explore whether associations between CSF proteins and genetic variants were specific to disease or not. We identified four AD risk loci as protein quantitative trait loci (pQTL): CR1-CR2 (rs3818361, P = 1.65 × 10-8), ZCWPW1-PILRB (rs1476679, P = 2.73 × 10-32), CTSH-CTSH (rs3784539, P = 2.88 × 10-24) and HESX1-RETN (rs186108507, P = 8.39 × 10-8), of which the first three pQTLs showed direct replication in the independent cohorts. We identified one AD-specific association between a rare genetic variant of TREM2 and CSF IL6 levels (rs75932628, P = 3.90 × 10-7). DLB risk locus GBA showed positive trans effects on seven inter-related CSF levels in DLB patients only. No pQTLs were identified for FTD loci, either for the total sample as for analyses performed within FTD only. Protein QTL variants were involved in the immune system, highlighting the importance of this system in the pathophysiology of dementia. We further identified pQTLs in stratified analyses for AD and DLB, hinting at disease-specific pQTLs in dementia. Dissecting the contribution of risk loci to neurobiological processes aids in understanding disease mechanisms underlying dementia., (© The Author(s) 2024. Published by Oxford University Press on behalf of the Guarantors of Brain.)

Objectives: We aimed to compare and link the total scores of the Mini-Mental State Examination (MMSE) and Montreal Cognitive Assessment (MoCA), two common global cognitive screeners., Methods: 2,325 memory clinic patients (63.2 ± 8.6 years; 43% female) with a variety of diagnoses, including subjective cognitive decline, mild cognitive impairment, and dementia due to various etiologies completed the MMSE and MoCA concurrently. We described both screeners, including at the item level. Then, using linear regressions, we investigated how age, sex, education, and diagnosis affected total scores on both instruments. Next, in linear mixed models, we treated the two screeners as repeated measures and analyzed the influence of these characteristics on the relationship between the instruments' total scores. Finally, we linked total scores using equipercentile equating, accounting for relevant patient characteristics., Results: MMSE scores (mean ± standard deviation: 25.0 ± 4.6) were higher than MoCA scores (21.2 ± 5.4), and MMSE items generally showed less variation than MoCA items. Both instruments' scores were individually influenced by age, sex, education, and diagnosis. The relationship between the screeners was moderated by age (estimate = -0.01, 95% confidence interval = [-0.03, -0.00]), education (0.14 [0.10, 0.18]), and diagnosis. These were accounted for when producing crosswalk tables based on equipercentile equating., Conclusions: Accounting for the influence of patient characteristics, we created crosswalk tables to convert MMSE scores to MoCA scores, and vice versa. These tables may facilitate collaboration between clinicians and researchers and could allow larger, pooled analyses of global cognitive functioning in older adults.

Introduction: We developed a multimarker blood test result interpretation tool for the clinical dementia practice, including phosphorylated (P-)tau181, amyloid-beta (Abeta)42/40, glial fibrillary acidic protein (GFAP), and neurofilament light (NfL)., Methods: We measured the plasma biomarkers with Simoa (n = 1199), applied LASSO regression for biomarker selection and receiver operating characteristics (ROC) analyses to determine diagnostic accuracy. We validated our findings in two independent cohorts and constructed a visualization approach., Results: P-tau181, GFAP, and NfL were selected. This combination had area under the curve (AUC) = 83% to identify amyloid positivity in pre-dementia stages, AUC = 87%-89% to differentiate Alzheimer's or controls from frontotemporal dementia, AUC = 74%-76% to differentiate Alzheimer's or controls from dementia with Lewy bodies. Highly reproducible AUCs were obtained in independent cohorts. The resulting visualization tool includes UpSet plots to visualize the stand-alone biomarker results and density plots to visualize the biomarker results combined., Discussion: Our multimarker blood test interpretation tool is ready for testing in real-world clinical dementia settings., Highlights: We developed a multimarker blood test interpretation tool for clinical dementia practice. Our interpretation tool includes plasma biomarkers P-tau, GFAP, and NfL. Our tool is particularly useful for Alzheimer's and frontotemporal dementia diagnosis., (© 2024 The Author(s). Alzheimer's & Dementia published by Wiley Periodicals LLC on behalf of Alzheimer's Association.)

Traumatic brain injury (TBI) and Alzheimer's disease (AD) have overlapping mechanisms but it remains unknown if pathophysiological characteristics and cognitive trajectories in AD patients are influenced by TBI history. Here, we studied AD patients (stage MCI or dementia) with TBI history (AD TBI+, n=110), or without (AD TBI- , n=110) and compared baseline CSF concentrations of amyloid beta 1-42 (Aβ42), phosphorylated tau181 (pTau181), total tau, neurofilament light chain (NfL), synaptosomal associated protein-25kDa (SNAP25), neurogranin (Ng), neuronal pentraxin-2 (NPTX2) and glutamate receptor-4 (GluR4), as well as differences in cognitive trajectories using linear mixed models. Explorative, analyses were repeated within stratified TBI groups by TBI characteristics (timing, severity, number). We found no differences in baseline CSF biomarker concentrations nor in cognitive trajectories between AD TBI+ and AD TBI- patients. TBI >5 years ago was associated with higher NPTX2 and a tendency for higher SNAP25 concentrations compared to TBI ≤ 5 years ago, suggesting that TBI may be associated with long-term synaptic dysfunction only when occurring before onset or in a pre-clinical disease stage of AD., Competing Interests: Declaration of Competing Interest SA: no competing interest SD: is employee of ADx Neurosciences, Gent Belgium SK: no competing interest JG: is employee of ADx Neurosciences, Gent Belgium BB: no competing interest YALP: no competing interest EV: is cofounder of ADx Neurosciences EGBV: no competing interest relevant to the manuscript CET: performed contract research for ADx NeuroSciences, AC-Immune, Aribio, Axon Neurosciences, Beckman-Coulter, BioConnect, Bioorchestra, Brainstorm Therapeutics, Celgene, Cognition Therapeutics, EIP Pharma, Eisai, Eli Lilly, Fujirebio, Grifols, Instant Nano Biosensors, Merck, Novo Nordisk, Olink, PeopleBio, Quanterix, Roche, Siemens, Toyama and Vivoryon. She serves on editorial boards of Medidact Neurologie/Springer, Alzheimer Research and Therapy, Neurology: Neuroimmunology & Neuroinflammation, and is the editor of a Neuromethods book Springer. IMWV: no competing interest During the preparation of this work the authors used ChatGPT 3.5 in order to improve readability. After using this tool, the authors reviewed and edited the content as needed and take full responsibility for the content of the publication., (Copyright © 2024 The Authors. Published by Elsevier Inc. All rights reserved.)

Background: Alzheimer's disease (AD) is a common, complex and multifactorial disease that may require screening across multiple routes of referral to enable early detection and subsequent future implementation of tailored interventions. Blood- and eye-based biomarkers show promise as low-cost, scalable and patient-friendly tools for early AD detection given their ability to provide information on AD pathophysiological changes and manifestations in the retina, respectively. Eye clinics provide an intriguing real-world proof-of-concept setting to evaluate the performance of these potential AD screening tools given the intricate connections between the eye and brain, presumed enrichment for AD pathology in the aging population with eye disorders, and the potential for an accelerated diagnostic pathway for under-recognized patient groups., Methods: The BeyeOMARKER study is a prospective, observational, longitudinal cohort study aiming to include individuals visiting an eye-clinic. Inclusion criteria entail being ≥ 50 years old and having no prior dementia diagnosis. Excluded eye-conditions include traumatic insults, superficial inflammation, and conditions in surrounding structures of the eye that are not engaged in vision. The BeyeOMARKER cohort (n = 700) will undergo blood collection to assess plasma p-tau217 levels and a brief cognitive screening at the eye clinic. All participants will subsequently be invited for annual longitudinal follow-up including remotely administered cognitive screening and questionnaires. The BeyeOMARKER + cohort (n = 150), consisting of 100 plasma p-tau217 positive participants and 50 matched negative controls selected from the BeyeOMARKER cohort, will additionally undergo Aβ-PET and tau-PET, MRI, retinal imaging including hyperspectral imaging (primary), widefield imaging, optical coherence tomography (OCT) and OCT-Angiography (secondary), and cognitive and cortical vision assessments., Results: We aim to implement the current protocol between April 2024 until March 2027. Primary outcomes include the performance of plasma p-tau217 and hyperspectral retinal imaging to detect AD pathology (using Aβ- and tau-PET visual read as reference standard) and to detect cognitive decline. Initial follow-up is ~ 2 years but may be extended with additional funding., Conclusions: We envision that the BeyeOMARKER study will demonstrate the feasibility of early AD detection based on blood- and eye-based biomarkers in alternative screening settings, and will improve our understanding of the eye-brain connection., Trial Registration: The BeyeOMARKER study (Eudamed CIV ID: CIV-NL-23-09-044086; registration date: 19th of March 2024) is approved by the ethical review board of the Amsterdam UMC., (© 2024. The Author(s).)

Diagnosis of Frontotemporal dementia (FTD) and the specific underlying neuropathologies (frontotemporal lobar degeneration; FTLD- Tau and FTLD-TDP) is challenging, and thus fluid biomarkers are needed to improve diagnostic accuracy. We used proximity extension assays to analyze 665 proteins in cerebrospinal fluid (CSF) samples from a multicenter cohort including patients with FTD (n = 189), Alzheimer's Disease dementia (AD; n = 232), and cognitively unimpaired individuals (n = 196). In a subset, FTLD neuropathology was determined based on phenotype or genotype (FTLD-Tau = 87 and FTLD-TDP = 68). Forty three proteins were differentially regulated in FTD compared to controls and AD, reflecting axon development, regulation of synapse assembly, and cell-cell adhesion mediator activity pathways. Classification analysis identified a 14- and 13-CSF protein panel that discriminated FTD from controls (AUC: 0.96) or AD (AUC: 0.91). Custom multiplex panels confirmed the highly accurate discrimination between FTD and controls (AUCs > 0.96) or AD (AUCs > 0.88) in three validation cohorts, including one with autopsy confirmation (AUCs > 0.90). Six proteins were differentially regulated between FTLD-TDP and FTLD-Tau, but no reproducible classification model could be generated (AUC: 0.80). Overall, this study introduces novel FTD-specific biomarker panels with potential use in diagnostic setting.

Introduction: Although frontotemporal dementia (FTD) with right anterior temporal lobe (RATL) predominance has been recognized, a uniform description of the syndrome is still missing. This multicenter study aims to establish a cohesive clinical phenotype., Methods: Retrospective clinical data from 18 centers across 12 countries yielded 360 FTD patients with predominant RATL atrophy through initial neuroimaging assessments., Results: Common symptoms included mental rigidity/preoccupations (78%), disinhibition/socially inappropriate behavior (74%), naming/word-finding difficulties (70%), memory deficits (67%), apathy (65%), loss of empathy (65%), and face-recognition deficits (60%). Real-life examples unveiled impairments regarding landmarks, smells, sounds, tastes, and bodily sensations (74%). Cognitive test scores indicated deficits in emotion, people, social interactions, and visual semantics however, lacked objective assessments for mental rigidity and preoccupations., Discussion: This study cumulates the largest RATL cohort unveiling unique RATL symptoms subdued in prior diagnostic guidelines. Our novel approach, combining real-life examples with cognitive tests, offers clinicians a comprehensive toolkit for managing these patients., Highlights: This project is the first international collaboration and largest reported cohort. Further efforts are warranted for precise nomenclature reflecting neural mechanisms. Our results will serve as a clinical guideline for early and accurate diagnoses., (© 2024 The Author(s). Alzheimer's & Dementia published by Wiley Periodicals LLC on behalf of Alzheimer's Association.)

Objective: We investigated how well a visual associative learning task discriminates Alzheimer's disease (AD) dementia from other types of dementia and how it relates to AD pathology., Methods: 3,599 patients (63.9 ± 8.9 years old, 41% female) from the Amsterdam Dementia Cohort completed two sets of the Visual Association Test (VAT) in a single test session and underwent magnetic resonance imaging. We performed receiver operating curve analysis to investigate the VAT's discriminatory ability between AD dementia and other diagnoses and compared it to that of other episodic memory tests. We tested associations between VAT performance and medial temporal lobe atrophy (MTA), and amyloid status ( n = 2,769, 77%)., Results: Patients with AD dementia performed worse on the VAT than all other patients. The VAT discriminated well between AD and other types of dementia (area under the curve range 0.70-0.86), better than other episodic memory tests. Six-hundred forty patients (17.8%) learned all associations on VAT-A, but not on VAT-B, and they were more likely to have higher MTA scores (odds ratios range 1.63 (MTA 0.5) through 5.13 for MTA ≥ 3, all p < .001) and to be amyloid positive (odds ratio = 3.38, 95%CI = [2.71, 4.22], p < .001) than patients who learned all associations on both sets., Conclusions: Performance on the VAT, especially on a second set administered immediately after the first, discriminates AD from other types of dementia and is associated with MTA and amyloid positivity. The VAT might be a useful, simple tool to assess early episodic memory deficits in the presence of AD pathology.

Background: Patients displaying clinical features of behavioural variant of frontotemporal dementia (bvFTD) but lacking both neuroimaging abnormalities and clinical progression are considered to represent the phenocopy syndrome of bvFTD (phFTD). Extensive clinical overlap between early phase bvFTD and phFTD hampers diagnostic distinction. We aimed to assess the diagnostic value of clinician-rated, self-reported and caregiver-reported symptoms for clinical distinction between phFTD and bvFTD., Methods: There were 33 phFTD and 95 probable bvFTD patients included in the study (total N = 128). Clinician-rated, self-reported tests and caregiver-reported symptoms were compared between phFTD and bvFTD on social cognition, behaviour, mood and activities of daily living (ADL). Scores were compared between groups, followed by multiple logistic regression analysis, adjusted for age and sex. Receiver operating characteristic curves were plotted to assess diagnostic value., Results: Using clinician-rated and self-reported tests, phFTD patients performed better on facial emotion recognition and reported more depressive symptoms. Caregiver-reported behavioural symptoms indicated higher behavioural and ADL impairment in phFTD compared to bvFTD. Facial emotion recognition provided highest diagnostic accuracy for distinction of phFTD from bvFTD (area under the curve (AUC) 0.813 95% CI 0.735-0.892, P < 0.001, sensitivity 81%, specificity 74%) followed by depressive symptoms (AUC 0.769 95% 0.674-0.864, P < 0.001 sensitivity 81%, specificity of 63%)., Conclusion: Social cognition tests are most suitable for distinction of phFTD from bvFTD. Caregiver-reported questionnaires and phFTD diagnosis seemed inversely correlated, showing more symptoms in phFTD. Further research is needed on phFTD aetiology and in caregivers taking into account disease burden to assess what explains this discrepancy between clinician-rated and caregiver-based tools., (© 2024 The Authors. Psychogeriatrics published by John Wiley & Sons Australia, Ltd on behalf of Japanese Psychogeriatric Society.)

Background: The use of amyloid-PET in dementia workup is upcoming. At the same time, amyloid-PET is costly and limitedly available. While the appropriate use criteria (AUC) aim for optimal use of amyloid-PET, their limited sensitivity hinders the translation to clinical practice. Therefore, there is a need for tools that guide selection of patients for whom amyloid-PET has the most clinical utility. We aimed to develop a computerized decision support approach to select patients for amyloid-PET., Methods: We included 286 subjects (135 controls, 108 Alzheimer's disease dementia, 33 frontotemporal lobe dementia, and 10 vascular dementia) from the Amsterdam Dementia Cohort, with available neuropsychology, APOE, MRI and [18F]florbetaben amyloid-PET. In our computerized decision support approach, using supervised machine learning based on the DSI classifier, we first classified the subjects using only neuropsychology, APOE, and quantified MRI. Then, for subjects with uncertain classification (probability of correct class (PCC) < 0.75) we enriched classification by adding (hypothetical) amyloid positive (AD-like) and negative (normal) PET visual read results and assessed whether the diagnosis became more certain in at least one scenario (PPC≥0.75). If this was the case, the actual visual read result was used in the final classification. We compared the proportion of PET scans and patients diagnosed with sufficient certainty in the computerized approach with three scenarios: 1) without amyloid-PET, 2) amyloid-PET according to the AUC, and 3) amyloid-PET for all patients., Results: The computerized approach advised PET in n = 60(21%) patients, leading to a diagnosis with sufficient certainty in n = 188(66%) patients. This approach was more efficient than the other three scenarios: 1) without amyloid-PET, diagnostic classification was obtained in n = 155(54%), 2) applying the AUC resulted in amyloid-PET in n = 113(40%) and diagnostic classification in n = 156(55%), and 3) performing amyloid-PET in all resulted in diagnostic classification in n = 154(54%)., Conclusion: Our computerized data-driven approach selected 21% of memory clinic patients for amyloid-PET, without compromising diagnostic performance. Our work contributes to a cost-effective implementation and could support clinicians in making a balanced decision in ordering additional amyloid PET during the dementia workup., Competing Interests: We have read the journal’s policy and the authors of this paper have the following competing interests: Hanneke F.M. Rhodius-Meester performs contract research for Combinostics; all funding is paid to her institution. Ingrid van Maurik received a consultancy fee (paid to the university) from Roche. Lyduine E. Collij has received consultancy fees from GE Healthcare; all funding is paid to her institution. Juha Koikkalainen and Jyrki Lötjönen report that Combinostics Oy owns the following IPR related to the paper: 1. J. Koikkalainen and J. Lotjonen, “A method for inferring the state of a system,” US7,840,510 B2, PCT/FI2007/050277. 2. J. Lotjonen, J. Koikkalainen and J. Mattila, “State Inference in a heterogeneous system,” PCT/FI2010/050545, FI20125177. Koikkalainen and Lötjönen are shareholders in Combinostics Oy. Yolande A.L. Pijnenburg has received funding from Dioraphte Foundation, Zabawas Foundation, JPND, ZonMW, NWO, Team Alzheimer and the Dutch Brain Foundation. Frederik Barkhof is member of the Steering committee or Data Safety Monitoring Board member for Biogen, Merck, ATRI/ACTC and Prothena. Barkhof is a consultant for Roche, Celltrion, Rewind Therapeutics, Merck, IXICO, Jansen, Combinostics. Barkhof has research agreements with Merck, Biogen, GE Healthcare, Roche. Co-founder and shareholder of Queen Square Analytics LTD. Elsmarieke van de Giessen has received research support from NWO, ZonMw, Hersenstichting and KWF. van de Giessen has performed contract research for Heuron Inc., Roche and 1st Biotherapeutics. van deGiessen has a consultancy agreement with IXICO for the reading of PET scans. Wiesje M van der Flier performs contract research for Biogen. Research programs of van der Flier have been funded by ZonMW, NWO, EU-FP7, EU-JPND, Alzheimer Nederland, CardioVascular Onderzoek Nederland, Health~Holland, Topsector Life Sciences & Health, stichting Dioraphte, Gieskes-Strijbis fonds, stichting Equilibrio, Pasman stichting, stichting Alzheimer & NeuroPsychiatry Foundation, Philips, Biogen MA Inc, Novartis-NL, Life-MI, AVID, Roche BV, Fujifilm, Combinostics. van der Flier has performed contract research for Biogen MA Inc, and Boehringer Ingelheim. van der Flier has been an invited speaker at Boehringer Ingelheim, Biogen MA Inc, Danone, Eisai, WebMD Neurology (Medscape), Springer Healthcare. van der Flier is consultant to Oxford Health Policy Forum CIC, Roche and Biogen MA Inc. van der Flier participated in advisory boards of Biogen MA Inc. and Roche. All funding is paid to her institution. van der Flier was associate editor of Alzheimer, Research & Therapy in 2020/2021. van der Flier is associate editor at Brain. This does not alter our adherence to PLOS ONE policies on sharing data and materials., (Copyright: © 2024 Rhodius-Meester et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)

Introduction: White matter hyperintensities (WMH) are associated with key dementia etiologies, in particular arteriolosclerosis and amyloid pathology. We aimed to identify WMH locations associated with vascular risk or cerebral amyloid-β 1-42 (Aβ42)-positive status., Methods: Individual patient data (n = 3,132; mean age 71.5 ± 9 years; 49.3% female) from 11 memory clinic cohorts were harmonized. WMH volumes in 28 regions were related to a vascular risk compound score (VRCS) and Aß42 status (based on cerebrospinal fluid or amyloid positron emission tomography), correcting for age, sex, study site, and total WMH volume., Results: VRCS was associated with WMH in anterior/superior corona radiata (B = 0.034/0.038, p < 0.001), external capsule (B = 0.052, p < 0.001), and middle cerebellar peduncle (B = 0.067, p < 0.001), and Aß42-positive status with WMH in posterior thalamic radiation (B = 0.097, p < 0.001) and splenium (B = 0.103, p < 0.001)., Discussion: Vascular risk factors and Aß42 pathology have distinct signature WMH patterns. This regional vulnerability may incite future studies into how arteriolosclerosis and Aß42 pathology affect the brain's white matter., Highlights: Key dementia etiologies may be associated with specific patterns of white matter hyperintensities (WMH). We related WMH locations to vascular risk and cerebral Aβ42 status in 11 memory clinic cohorts. Aβ42 positive status was associated with posterior WMH in splenium and posterior thalamic radiation. Vascular risk was associated with anterior and infratentorial WMH. Amyloid pathology and vascular risk have distinct signature WMH patterns., (© 2024 The Authors. Alzheimer's & Dementia published by Wiley Periodicals LLC on behalf of Alzheimer's Association.)

Objective: Methylation of plasma cell-free DNA (cfDNA) has potential as a marker of brain damage in neurodegenerative diseases such as frontotemporal dementia (FTD). Here, we study methylation of cfDNA in presymptomatic and symptomatic carriers of genetic FTD pathogenic variants, next to healthy controls., Methods: cfDNA was isolated from cross-sectional plasma of 10 presymptomatic carriers (4 C9orf72, 4 GRN, and 2 MAPT), 10 symptomatic carriers (4 C9orf72, 4 GRN, and 2 MAPT), and 9 healthy controls. Genome-wide methylation of cfDNA was determined using a high-resolution sequencing technique (MeD-seq). Cumulative scores based on the identified differentially methylated regions (DMRs) were estimated for presymptomatic carriers (vs. controls and symptomatic carriers), and reevaluated in a validation cohort (8 presymptomatic: 3 C9orf72, 3 GRN, and 2 MAPT; 26 symptomatic: 7 C9orf72, 6 GRN, 12 MAPT, and 1 TARDBP; 13 noncarriers from genetic FTD families)., Results: Presymptomatic carriers showed a distinctive methylation profile compared to healthy controls and symptomatic carriers. Cumulative DMR scores in presymptomatic carriers enabled to significantly differentiate presymptomatic carriers from healthy controls (p < 0.001) and symptomatic carriers (p < 0.001). In the validation cohort, these scores differentiated presymptomatic carriers from symptomatic carriers (p ≤ 0.007) only. Transcription-start-site methylation in presymptomatic carriers, generally associated with gene downregulation, was enriched for genes involved in ubiquitin-dependent processes, while gene body methylation, generally associated with gene upregulation, was enriched for genes involved in neuronal cell processes., Interpretation: A distinctive methylation profile of cfDNA characterizes the presymptomatic stage of genetic FTD, and could reflect neuronal death in this stage., (© 2024 The Authors. Annals of Clinical and Translational Neurology published by Wiley Periodicals LLC on behalf of American Neurological Association.)

Background: Lack of early molecular biomarkers in sporadic behavioral variants of frontotemporal dementia (bvFTD) and its clinical overlap with primary psychiatric disorders (PPD) hampers its diagnostic distinction. Synaptic dysfunction is an early feature in bvFTD and identification of specific biomarkers might improve its diagnostic accuracy. Our goal was to understand the differential diagnostic potential of cerebrospinal fluid (CSF) synaptic biomarkers in bvFTD versus PPD and their specificity towards bvFTD compared with Alzheimer's disease (AD) and controls. Additionally, we explored the association of CSF synaptic biomarkers with social cognition, cognitive performance, and disease severity in these clinical groups., Methods: Participants with probable bvFTD (n = 57), PPD (n = 71), AD (n = 60), and cognitively normal controls (n = 39) with available CSF, cognitive tests, and disease severity as frontotemporal lobar degeneration-modified clinical dementia rating scale (FTLD-CDR) were included. In a subset of bvFTD and PPD cases, Ekman 60 faces test scores for social cognition were available. CSF synaptosomal-associated protein 25 (SNAP25), neurogranin (Ng), neuronal pentraxin 2 (NPTX2), and glutamate receptor 4 (GluR4) were measured, along with neurofilament light (NfL), and compared between groups using analysis of covariance (ANCOVA) and logistic regression. Diagnostic accuracy was assessed using ROC analyses, and biomarker panels were selected using Wald's backward selection. Correlations with cognitive measures were performed using Pearson's partial correlation analysis., Results: NPTX2 concentrations were lower in the bvFTD group compared with PPD (p < 0.001) and controls (p = 0.003) but not compared with AD. Concentrations of SNAP25 (p < 0.001) and Ng (p < 0.001) were elevated in patients with AD versus those with bvFTD and controls. The modeled panel for differential diagnosis of bvFTD versus PPD consisted of NfL and NPTX2 (AUC = 0.96, CI: 0.93-0.99, p < 0.001). In bvFTD versus AD, the modeled panel consisted of NfL, SNAP25, Ng, and GluR4 (AUC = 0.86, CI: 0.79-0.92, p < 0.001). In bvFTD, lower NPTX2 (Pearson's r = 0.29, p = 0.036) and GluR4 (Pearson's r = 0.34, p = 0.014) concentrations were weakly associated with worse performance of total cognitive score. Lower GluR4 concentrations were also associated with worse MMSE scores (Pearson's r = 0.41, p = 0.002) as well as with worse executive functioning (Pearson's r = 0.36, p = 0.011) in bvFTD. There were no associations between synaptic markers and social cognition or disease severity in bvFTD., Conclusion: Our findings of involvement of NTPX2 in bvFTD but not PPD contribute towards better understanding of bvFTD disease pathology., (© 2024. The Author(s).)

Introduction: We investigated whether mortality in memory clinic patients changed due to coronavirus disease 2019 (COVID-19) pandemic., Methods: We included patients from the Amsterdam Dementia Cohort: (1) n  = 923 pandemic patients (baseline visit: 2017-2018, follow-up: until 2021), and (2) n  = 830 historical control patients (baseline visit: 2015-2016, follow-up: until 2019). Groups were well-balanced. We compared mortality during pandemic with historical control patients using Cox regression. Differences in cause of death between groups were explored using Fisher's exact test., Results: Pandemic patients had a higher risk of mortality than historical control patients (hazard ratio [HR] [95% confidence interval {CI}] = 1.34 [1.05-1.70]). Stratified for syndrome diagnosis, the effect remained significant in dementia patients (HR [95% CI] = 1.35 [1.03-1.78]). Excluding patients who died of COVID-19-infection, the higher mortality risk in pandemic patients attenuated (HR [95% CI] = 1.24 [0.97-1.58]). Only the difference in cause of death between pandemic patients and historical control patients for death to COVID-19-infection ( p  = 0.001) was observed., Conclusion: Memory clinic patients had increased mortality risk during COVID-19 compared to historical control patients, attributable to dementia patients., Highlights: We investigated if mortality rates in memory clinic patients changed due to COVID-19 pandemic.We included patients along the cognitive continuum, including SCD, MCI, and dementia.We used a well-balanced historical control group.Memory clinic patients had higher risk for mortality during COVID-19 lockdown.Our results indicate that excess mortality is mainly caused by death to COVID-19 infection., Competing Interests: Research programs of W.M.F. have been funded by ZonMW, NWO, EU‐FP7, EU‐JPND, Alzheimer Nederland, CardioVascular Onderzoek Nederland, Health∼Holland, Topsector Life Sciences & Health, stichting Dioraphte, Gieskes‐Strijbis fonds, stichting Equilibrio, Pasman Stichting, Biogen MA Inc, Boehringer Ingelheim, Life‐ MI, AVID, Roche BV, Fujifilm, Combinostics. W.M.F. is consultant to Oxford Health Policy Forum CIC, Roche, and Biogen MA Inc. W.M.F. has been an invited speaker at Boehringer Ingelheim, Biogen MA Inc, Danone, Eisai, WebMD Neurology (Medscape). All funding is paid to her institution. W.M.F. participated in an advisory board of Biogen MA Inc. W.M.F. is associate editor at Brain. I.S.M. received a consultancy fee (paid to the university) from Roche. F.H.B. received Optina diagnostics payments and roche, biogen payments to her institution. Y.A.L.P. has received funding from the Dutch Brain Foundation and the Mooiste Contact Fonds (both paid to her institution). The other authors report no financial disclosures or conflicts of interest. The sponsors had no involvement in the study design; in the collection, analysis and interpretation of data; in the writing of the report; or in the decision to submit the manuscript for publication. Author disclosures are available in the Supporting Information., (© 2024 The Authors. Alzheimer's & Dementia: Diagnosis, Assessment & Disease Monitoring published by Wiley Periodicals LLC on behalf of Alzheimer's Association.)

Objectives: On phenotypic and neuroanatomical grounds, music exposure might potentially affect the clinical expression of behavioural variant frontotemporal dementia (bvFTD). However, this has not been clarified., Methods: 14 consecutive patients with bvFTD fulfilling consensus diagnostic criteria were recruited via a specialist cognitive clinic. Earlier life musical experience, current musical listening habits and general socio-emotional behaviours were scored using a bespoke semi-quantitative musical survey and standardised functional scales, completed with the assistance of patients' primary caregivers. Associations of musical scores with behavioural scales were assessed using a linear regression model adjusted for age, sex, educational attainment and level of executive and general cognitive impairment., Results: Greater earlier life musical experience was associated with significantly lower Cambridge Behavioural Inventory (Revised) scores (β ± SE = -17.2 ± 5.2; p  = 0.01) and higher Modified Interpersonal Reactivity Index (MIRI) perspective-taking scores (β ± SE = 2.8 ± 1.1; p  = 0.03), after adjusting for general cognitive ability. Number of hours each week currently spent listening to music was associated with higher MIRI empathic concern (β ± SE = 0.7 ± 0.21; p  = 0.015) and MIRI total scores (β ± SE = 1.1 ± 0.34; p  = 0.014)., Discussion: Musical experience in earlier life and potentially ongoing regular music listening may ameliorate socio-emotional functioning in bvFTD. Future work in larger cohorts is required to substantiate the robustness of this association, establish its mechanism and evaluate its clinical potential., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2024 van’t Hooft, Benhamou, Albero Herreros, Jiang, Levett, Core, Requena-Komuro, Hardy, Tijms, Pijnenburg and Warren.)

Background: The behavioral variant of frontotemporal dementia (bvFTD) is very heterogeneous in pathology, genetics, and disease course. Unlike Alzheimer's disease, reliable biomarkers are lacking and sporadic bvFTD is often misdiagnosed as a primary psychiatric disorder (PPD) due to overlapping clinical features. Current efforts to characterize and improve diagnostics are centered on the minority of genetic cases., Objective: The multi-center study DIPPA-FTD aims to develop diagnostic and prognostic algorithms to help distinguish sporadic bvFTD from late-onset PPD in its earliest stages., Methods: The prospective DIPPA-FTD study recruits participants with late-life behavioral changes, suspect for bvFTD or late-onset PPD diagnosis with a negative family history for FTD and/or amyotrophic lateral sclerosis. Subjects are invited to participate after diagnostic screening at participating memory clinics or recruited by referrals from psychiatric departments. At baseline visit, participants undergo neurological and psychiatric examination, questionnaires, neuropsychological tests, and brain imaging. Blood is obtained to investigate biomarkers. Patients are informed about brain donation programs. Follow-up takes place 10-14 months after baseline visit where all examinations are repeated. Results from the DIPPA-FTD study will be integrated in a data-driven approach to develop diagnostic and prognostic models., Conclusions: DIPPA-FTD will make an important contribution to early sporadic bvFTD identification. By recruiting subjects with ambiguous or prodromal diagnoses, our research strategy will allow the characterization of early disease stages that are not covered in current sporadic FTD research. Results will hopefully increase the ability to diagnose sporadic bvFTD in the early stage and predict progression rate, which is pivotal for patient stratification and trial design.

Alzheimer's disease (AD) is heterogenous at the molecular level. Understanding this heterogeneity is critical for AD drug development. Here we define AD molecular subtypes using mass spectrometry proteomics in cerebrospinal fluid, based on 1,058 proteins, with different levels in individuals with AD (n = 419) compared to controls (n = 187). These AD subtypes had alterations in protein levels that were associated with distinct molecular processes: subtype 1 was characterized by proteins related to neuronal hyperplasticity; subtype 2 by innate immune activation; subtype 3 by RNA dysregulation; subtype 4 by choroid plexus dysfunction; and subtype 5 by blood-brain barrier impairment. Each subtype was related to specific AD genetic risk variants, for example, subtype 1 was enriched with TREM2 R47H. Subtypes also differed in clinical outcomes, survival times and anatomical patterns of brain atrophy. These results indicate molecular heterogeneity in AD and highlight the need for personalized medicine., (© 2024. The Author(s).)

Introduction: We conducted a systematic literature review and meta-analysis of empirical evidence on expected and experienced implications of sharing Alzheimer's disease (AD) biomarker results with individuals without dementia., Methods: PubMed, Embase, APA PsycInfo, and Web of Science Core Collection were searched according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Results from included studies were synthesized, and quantitative data on psychosocial impact were meta-analyzed using a random-effects model., Results: We included 35 publications. Most personal stakeholders expressed interest in biomarker assessment. Learning negative biomarker results led to relief and sometimes frustration, while positive biomarkers induced anxiety but also clarity. Meta-analysis of five studies including 2012 participants (elevated amyloid = 1324 [66%], asymptomatic = 1855 [92%]) showed short-term psychological impact was not significant (random-effect estimate = 0.10, standard error = 0.23, P = 0.65). Most professional stakeholders valued biomarker testing, although attitudes and practices varied considerably., Discussion: Interest in AD biomarker testing was high and sharing their results did not cause psychological harm., Highlights: Most personal stakeholders expressed interest in Alzheimer's disease biomarker assessment. Personal motivations included gaining insight, improving lifestyle, or preparing for the future. There was no short-term psychological impact of sharing biomarker status, implying it can be safe. Most professional stakeholders valued biomarker testing, believing the benefits outweigh the risk. Harmonized guidelines on biomarker testing and sharing results are required., (© 2023 The Authors. Alzheimer's & Dementia published by Wiley Periodicals LLC on behalf of Alzheimer's Association.)

The ScreeLing is a screening instrument developed to assess post-stroke aphasia, via the linguistic levels Syntax, Phonology, and Semantics. It could also be a useful test for the clinical subtypes of frontotemporal dementia (FTD) and Alzheimer's dementia (AD), as specific and often selective disorders are expected. Its ability to differentiate between the clinical subtypes of FTD and AD is, however, still unknown. We investigated differences in ScreeLing total and subscores, linguistic-level disorders' relationship with disease severity, and classification abilities, in patients with behavioral variant FTD (bvFTD; n = 46), patients with primary progressive aphasia (PPA; n = 105) (semantic variant primary progressive aphasia [svPPA], non-fluent variant primary progressive aphasia [nfvPPA], and logopenic variant primary progressive aphasia [lvPPA], AD [ n = 20] and controls [ n = 35]). We examined group differences in ScreeLing total and subscores, and one-, two- or three-level linguistic disorders using one-way analyses of covariance (ANCOVAs) or Quade's rank ANCOVA. We used frequency analyses to obtain the occurrence of the linguistic-level disorders. We determined sensitivity and specificity by the area under the curve by receiver-operating characteristics analyses to investigate classification abilities. The total score was lower in patients (bvFTD: 63.8 ± 8.5, svPPA: 58.8 ± 11.3, nfvPPA: 63.5 ± 8.4, lvPPA: 61.7 ± 6.6, AD: 63.8 ± 5.5) than controls (71.3 ± 1.0) ( p < .001). Syntax subscores were lower in svPPA (19.4 ± 4.6; p < .001) and lvPPA (20.3 ± 3.2; p = .002) than controls (23.8 ± 0.4). Phonology subscores were lower in lvPPA (19.8 ± 2.6) than bvFTD (21.7 ± 2.8) ( p = .010). Semantics subscores were lowest in svPPA (17.8 ± 5.0; p < .002). A selective phonological disorder was most prevalent in lvPPA (34.9%). The higher the disease severity, the more linguistic-level disorders. The optimal cutoff for the total score was 70, and 23 for all three subscores. Good classification abilities were found for the Semantics (svPPA vs. bvFTD), Phonology (lvPPA vs. svPPA), and Syntax (nfvPPA vs. lvPPA) subscores. This easy to administer test gives information about language processing with the potential to improve differential diagnosis in memory clinics and in the future potentially also clinical trial planning., Competing Interests: Declaration of Conflicting InterestsThe author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

Background: Previous studies demonstrated increases in diagnostic confidence and change in patient management after amyloid-PET. However, studies investigating longitudinal outcomes over an extended period of time are limited. Therefore, we aimed to investigate clinical outcomes up to 9 years after amyloid-PET to support the clinical validity of the imaging technique., Methods: We analyzed longitudinal data from 200 patients (M age  = 61.8, 45.5% female, M MMSE  = 23.3) suspected of early-onset dementia that underwent [ 18 F]flutemetamol-PET. Baseline amyloid status was determined through visual read (VR). Information on mortality was available with a mean follow-up of 6.7 years (range = 1.1-9.3). In a subset of 108 patients, longitudinal cognitive scores and clinical etiological diagnosis (eDx) at least 1 year after amyloid-PET acquisition were available (M = 3.06 years, range = 1.00-7.02). VR - and VR + patients were compared on mortality rates with Cox Hazard's model, prevalence of stable eDx using chi-square test, and longitudinal cognition with linear mixed models. Neuropathological data was available for 4 patients (mean delay = 3.59 ± 1.82 years, range = 1.2-6.3)., Results: At baseline, 184 (92.0%) patients were considered to have dementia. The majority of VR + patients had a primary etiological diagnosis of AD (122/128, 95.3%), while the VR - group consisted mostly of non-AD etiologies, most commonly frontotemporal lobar degeneration (30/72, 40.2%). Overall mortality rate was 48.5% and did not differ between VR - and VR + patients. eDx at follow-up was consistent with baseline diagnosis for 92/108 (85.2%) patients, with most changes observed in VR - cases (VR -  = 14/35, 40% vs VR +  = 2/73, 2.7%, χ 2  = 26.03, p < 0.001), who at no time received an AD diagnosis. VR + patients declined faster than VR - patients based on MMSE (β =  - 1.17, p = 0.004), episodic memory (β =  - 0.78, p = 0.003), fluency (β =  - 1.44, p < 0.001), and attention scores (β = 16.76, p = 0.03). Amyloid-PET assessment was in line with post-mortem confirmation in all cases; two cases were VR + and showed widespread AD pathology, while the other two cases were VR - and showed limited amyloid pathology., Conclusion: In a symptomatic population, we observed that amyloid-status did not impact mortality rates, but is predictive of cognitive functioning over time across several domains. Also, we show particular validity for a negative amyloid-PET assessment, as these patients did not receive an AD diagnosis at follow-up., (© 2023. The Author(s).)

Autosomal dominant Alzheimer's disease (ADAD) offers a unique opportunity to study pathophysiological changes in a relatively young population with few comorbidities. A comprehensive investigation of proteome changes occurring in ADAD could provide valuable insights into AD-related biological mechanisms and uncover novel biomarkers and therapeutic targets. Furthermore, ADAD might serve as a model for sporadic AD, but in-depth proteome comparisons are lacking. We aimed to identify dysregulated CSF proteins in ADAD and determine the degree of overlap with sporadic AD. We measured 1472 proteins in CSF of PSEN1 or APP mutation carriers (n = 22) and age- and sex-matched controls (n = 20) from the Amsterdam Dementia Cohort using proximity extension-based immunoassays (PEA). We compared protein abundance between groups with two-sided t-tests and identified enriched biological pathways. Using the same protein panels in paired plasma samples, we investigated correlations between CSF proteins and their plasma counterparts. Finally, we compared our results with recently published PEA data from an international cohort of sporadic AD (n = 230) and non-AD dementias (n = 301). All statistical analyses were false discovery rate-corrected. We detected 66 differentially abundant CSF proteins (65 increased, 1 decreased) in ADAD compared to controls (q < 0.05). The most strongly upregulated proteins (fold change >1.8) were related to immunity (CHIT1, ITGB2, SMOC2), cytoskeletal structure (MAPT, NEFL) and tissue remodelling (TMSB10, MMP-10). Significant CSF-plasma correlations were found for the upregulated proteins SMOC2 and LILR1B. Of the 66 differentially expressed proteins, 36 had been measured previously in the sporadic dementias cohort, 34 of which (94%) were also significantly upregulated in sporadic AD, with a strong correlation between the fold changes of these proteins in both cohorts (rs = 0.730, P < 0.001). Twenty-nine of the 36 proteins (81%) were also upregulated among non-AD patients with suspected AD co-pathology. This CSF proteomics study demonstrates substantial biochemical similarities between ADAD and sporadic AD, suggesting involvement of the same biological processes. Besides known AD-related proteins, we identified several relatively novel proteins, such as TMSB10, MMP-10 and SMOC2, which have potential as novel biomarkers. With shared pathophysiological CSF changes, ADAD study findings might be translatable to sporadic AD, which could greatly expedite therapy development., (© The Author(s) 2023. Published by Oxford University Press on behalf of the Guarantors of Brain.)

Background: The semantic fluency test is one of the most widely used neuropsychological tests in dementia diagnosis. Research utilizing the qualitative, psycholinguistic information embedded in its output is currently underexplored in presymptomatic and prodromal genetic FTD., Methods: Presymptomatic MAPT (n = 20) and GRN (n = 43) mutation carriers, and controls (n = 55) underwent up to 6 years of neuropsychological assessment, including the semantic fluency test. Ten mutation carriers became symptomatic (phenoconverters). Total score and five qualitative fluency measures (lexical frequency, age of acquisition, number of clusters, cluster size, number of switches) were calculated. We used multilevel linear regression modeling to investigate longitudinal decline. We assessed the co-correlation of the qualitative measures at each time point with principal component analysis. We explored associations with cognitive decline and grey matter atrophy using partial correlations, and investigated classification abilities using binary logistic regression., Results: The interrater reliability of the qualitative measures was good (ICC = 0.75-0.90). There was strong co-correlation between lexical frequency and age of acquisition, and between clustering and switching. At least 4 years pre-phenoconversion, GRN phenoconverters had fewer but larger clusters (p < 0.001), and fewer switches (p = 0.004), correlating with lower executive function (r = 0.87-0.98). Fewer switches was predictive of phenoconversion, correctly classifying 90.3%. Starting at least 4 years pre-phenoconversion, MAPT phenoconverters demonstrated an increase in lexical frequency (p = 0.009) and a decline in age of acquisition (p = 0.034), correlating with lower semantic processing (r = 0.90). Smaller cluster size was predictive of phenoconversion, correctly classifying 89.3%. Increase in lexical frequency and decline in age of acquisition were associated with grey matter volume loss of predominantly temporal areas, while decline in the number of clusters, cluster size, and switches correlated with grey matter volume loss of predominantly frontal areas., Conclusions: Qualitative aspects of semantic fluency could give insight into the underlying mechanisms as to why the "traditional" total score declines in the different FTD mutations. However, the qualitative measures currently demonstrate more fluctuation than the total score, the measure that seems to most reliably deteriorate with time. Replication in a larger sample of FTD phenoconverters is warranted to identify if qualitative measures could be sensitive cognitive biomarkers to identify and track mutation carriers converting to the symptomatic stage of FTD., (© 2023. The Author(s).)

Introduction: The history of frontotemporal dementia (FTD) is both old and new. This study explores its historical roots, dating back to the 19th century, while recognizes it as a distinct neurological entity only a few decades ago., Methods: This qualitative study and literature review provides an overview of FTD's historical background, birth, evolution, and future directions., Results: Recognition of FTD was hindered by rigid perceptions of dementia, the division between neurology and psychiatry, reliance on IQ-based assessment, limited neuroimaging capabilities, and lack of pathological proof. Overcoming these barriers involved revisiting early pioneers' approaches, focusing on focal impairment, establishing non-Alzheimer's disease cohorts, fostering collaboration, and developing diagnostic criteria. Current gaps include the need for biology-oriented psychiatry education, biological biomarkers, and culturally sensitive, objective clinical instruments predicting underlying pathology., Discussion: Independent multidisciplinary centers are essential. The future of FTD lies in disease-modifying therapies, presenting new opportunities for healthcare professionals and researchers., (© 2023 The Authors. Alzheimer's & Dementia published by Wiley Periodicals LLC on behalf of Alzheimer's Association.)

Across multiancestry groups, we analyzed Human Leukocyte Antigen (HLA) associations in over 176,000 individuals with Parkinson's disease (PD) and Alzheimer's disease (AD) versus controls. We demonstrate that the two diseases share the same protective association at the HLA locus. HLA-specific fine-mapping showed that hierarchical protective effects of HLA-DRB1 *04 subtypes best accounted for the association, strongest with HLA-DRB1 *04:04 and HLA-DRB1 *04:07, and intermediary with HLA-DRB1 *04:01 and HLA-DRB1 *04:03. The same signal was associated with decreased neurofibrillary tangles in postmortem brains and was associated with reduced tau levels in cerebrospinal fluid and to a lower extent with increased Aβ42. Protective HLA-DRB1 *04 subtypes strongly bound the aggregation-prone tau PHF6 sequence, however only when acetylated at a lysine (K311), a common posttranslational modification central to tau aggregation. An HLA-DRB1 *04-mediated adaptive immune response decreases PD and AD risks, potentially by acting against tau, offering the possibility of therapeutic avenues.

Background and Objectives: Elevated serum neurofilament light chain (NfL) is used to identify carriers of genetic frontotemporal dementia (FTD) pathogenic variants approaching prodromal conversion. Yet, the magnitude and timeline of NfL increase are still unclear. Here, we investigated the predictive and early diagnostic value of longitudinal serum NfL for the prodromal conversion in genetic FTD., Methods: In a longitudinal observational cohort study of genetic FTD pathogenic variant carriers, we examined the diagnostic accuracy and conversion risk associated with cross-sectional and longitudinal NfL. Time periods relative to prodromal conversion (>3, 3-1.5, 1.5-0 years before; 0-1.5 years after) were compared with values of participants who did not convert. Next, we modeled longitudinal NfL and MRI volume trajectories to determine their timeline., Results: We included 21 participants who converted (5 chromosome 9 open-reading frame 72 [ C9orf72 ], 10 progranulin [ GRN ], 5 microtubule-associated protein tau [ MAPT ], and 1 TAR DNA-binding protein [TARDBP]) and 61 who did not (20 C9orf72 , 30 GRN , and 11 MAPT ). Participants who converted had higher NfL levels at all examined periods before prodromal conversion (median values 14.0-18.2 pg/mL; betas = 0.4-0.7, standard error [SE] = 0.1, p < 0.046) than those who did not (6.5 pg/mL) and showed further increase 0-1.5 years after conversion (28.4 pg/mL; beta = 1.0, SE = 0.1, p < 0.001). Annualized longitudinal NfL change was only significantly higher in participants who converted (vs. participants who did not) 0-1.5 years after conversion (beta = 1.2, SE = 0.3, p = 0.001). Diagnostic accuracy of cross-sectional NfL for prodromal conversion (vs. nonconversion) was good-to-excellent at time periods before conversion (area under the curve range: 0.72-0.92), improved 0-1.5 years after conversion (0.94-0.97), and outperformed annualized longitudinal change (0.76-0.84). NfL increase in participants who converted occurred earlier than frontotemporal MRI volume change and differed by genetic group and clinical phenotypes. Higher NfL corresponded to increased conversion risk (hazard ratio: cross-sectional = 6.7 [95% CI 3.3-13.7]; longitudinal = 13.0 [95% CI 4.0-42.8]; p < 0.001), but conversion-free follow-up time varied greatly across participants., Discussion: NfL increase discriminates individuals who convert to prodromal FTD from those who do not, preceding significant frontotemporal MRI volume loss. However, NfL alone is limited in predicting the exact timing of prodromal conversion. NfL levels also vary depending on underlying variant-carrying genes and clinical phenotypes. These findings help to guide participant recruitment for clinical trials targeting prodromal genetic FTD., (Copyright © 2023 The Author(s). Published by Wolters Kluwer Health, Inc. on behalf of the American Academy of Neurology.)

Objectives: Distinguishing sporadic behavioral variant of frontotemporal dementia (bvFTD) from late-onset primary psychiatric disorders (PPD) remains challenging with the lack of robust biomarkers. An early bvFTD misdiagnosis in PPD cases and vice-versa is common. Little is known about diagnostic (in)stability over longer period of time. We investigated diagnostic instability in a neuropsychiatric cohort up to 8 years after baseline visit and identified which clinical hallmarks contribute to diagnostic instability., Design: Diagnoses of participants of the late-onset frontal lobe (LOF) study were collected from the baseline visit (T0) and the 2-year follow-up visit (T2). Clinical outcomes were retrieved 5-8 years after baseline visit (T final ). Endpoint diagnoses were categorized into bvFTD, PPD and other neurological disorders (OND). We calculated the total amount of participants that switched diagnosis between T0-T2 and T2-T final . Clinical records of participants that switched diagnosis were assessed., Results: Of the 137 patients that were included in the study, the final diagnoses at T final were bvFTD 24.1% (n = 33), PPD 39.4% (n = 54), OND 33.6% (n = 46) and unknown 2.9% (n = 4). Between T0 and T2, a total of 29 (21.2%) patients switched diagnosis. Between T2 and T final , 8 (5.8%) patients switched diagnosis. Prolonged follow-up identified few cases with diagnostic instability. Major contributors to diagnostic instability where a nonconverting diagnosis of possible bvFTD and a probable bvFTD diagnosis based on informant-based history and an abnormal FDG-PET scan whilst having a normal MRI., Conclusion: Considering these lessons, a FTD diagnosis remains stable enough to conclude that 2 years is sufficient to say if a patient with late-life behavioral disorder has FTD., (Copyright © 2023 The Authors. Published by Elsevier Inc. All rights reserved.)

The disease trajectory and healthcare requirements of patients with young-onset dementia (YOD) differ from those of older patients. Accurate data about YOD is crucial to improve diagnosis and optimize care. PRECODE-GP aims to set up a prospective national database of patients with YOD to gain insight into the occurrence and characteristics of patients with YOD in memory clinics in the Netherlands. The national database includes data from dementia patients aged <70 years at diagnosis, collected by local memory clinics (MCs). Data included demographic information, clinical variables, and (etiological) diagnoses. Between July 2019 and December 2022, 781 patients with a mean age of 62±6y at diagnosis (range 37 to 69y) were included from 39 MCs. Most ( n = 547,70%) were diagnosed with dementia due to Alzheimer's disease (AD). Patients with Frontotemporal lobe dementia (FTD, n = 87, 11%) were youngest (61±6.0y). Over half (55%) of patients were experiencing symptoms for ≥2 years. We initiated a Dutch national YOD database to improve diagnosis and care for this underrepresented and vulnerable patient group. The database provides a basis for future in-depth studies on YOD., Competing Interests: H.R.M. performs contract research for Combinostics; all funding is paid to her institution. C.B. received grants from the Dutch Alzheimer Society, Gieskes Strijbis fund and the Dutch Young‐onset Dementia Knowledge Study during the course of the study. All funds were paid to his institution. K.P. received grants from Alzheimer Netherlands, Gieskes‐Strijbis Fund, and Dutch Knowledge Center Young Onset Dementia during the conduct of the study. All funding is paid to her institution. F.B. is chair of the Dutch Memory Clinic Network. F.B. has a collaboration contract with Biogen, Optina Dx, Optos, and Roche. Payments are made to the institution of VUMC. N.V. received funds from Het Medisch Specialistisch Bedrijf—Vrijgevestigd Collectief Leeuwarden/Medisch Centrum Leeuwarden and is member of the MODEMproject (ZonMW #10510032120006). M.d V. reported receiving grants from Alzheimer Netherlands, Gieskes‐Strijbis Fund, and Dutch Knowledge Center Young Onset Dementia during the conduct of the study. All funding is paid to her institution. W.F. performs contract research for Biogen. Research programs of W.F. have been funded by ZonMW, NWO, EU‐FP7, EU‐JPND, Alzheimer Nederland, CardioVascular Onderzoek Nederland, Health∼Holland, Topsector Life Sciences & Health, stichting Dioraphte, Gieskes‐Strijbis fonds, stichting Equilibrio, Pasman stichting, stichting Alzheimer & NeuroPsychiatry Foundation, Philips, Biogen MA Inc, Novartis‐NL, Life‐MI, AVID, Roche BV, Fujifilm, Combinostics. W.F. holds the Pasman chair. W.F. is recipient of ABOARD, which is a public–private partnership receiving funding from ZonMW (#73305095007) and Health∼Holland, Topsector Life Sciences & Health (PPP‐allowance; #LSHM20106). W.F. has performed contract research for Biogen MA Inc, and Boehringer Ingelheim. W.F. has been an invited speaker at Boehringer Ingelheim, Biogen MA Inc, Danone, Eisai, WebMD Neurology (Medscape), Springer Healthcare. W.F. is consultant to Oxford Health Policy Forum CIC, Roche, and Biogen MA Inc. W.F. participated in advisory boards of Biogen MA Inc and Roche. All funding is paid to her institution. W.F. was associate editor of Alzheimer's Research & Therapy in 2020/2021. W.F. is associate editor at Brain. A.G. reports no conflicts of interest. All other authors reported no conflicts of interest. Author disclosures are available in the supporting information., (© 2023 The Authors. Alzheimer's & Dementia: Diagnosis, Assessment & Disease Monitoring published by Wiley Periodicals, LLC on behalf of Alzheimer's Association.)

Background and Purpose: Early diagnosis of behavioral variant frontotemporal dementia (bvFTD) is challenging due to symptomatic overlap with primary psychiatric disorders (PPD). As emotion recognition deficits are early and key features of bvFTD, the aim was to explore processes driving social cognition deficits that may aid in the differentiation between bvFTD and PPD., Methods: The total sample (N = 51) included 18 patients with bvFTD, 11 patients with PPD (mood, autism spectrum and psychotic disorders) and 22 controls from the Alzheimer Center Amsterdam of the Amsterdam UMC. Emotion recognition was assessed with the Ekman 60 Faces test, during which eye tracking metrics were collected in the first 5 s a face was presented. Group differences in dwell time on the total image as well as the circumscribed eyes area and mouth area were analysed using ANOVA, with post hoc comparisons., Results: Patients with bvFTD scored lowest, patients with PPD scored intermediate and controls scored highest on emotion recognition. During facial processing, patients with bvFTD spent less dwell time on the total image than controls (mean difference 11.3%, F(2, 48) = 6.095, p = 0.004; bvFTD-controls p = 0.001, 95% confidence interval [CI] -892.64, -239.70). Dwell time on the eyes area did not differ between diagnostic groups, whilst patients with bvFTD spent less dwell time on the mouth area than PPD patients (mean difference 10.7%; F(2, 48) = 3.423, p = 0.041; bvFTD-PPD p = 0.022, 95% CI -986.38, -79.47) and controls (mean difference 7.8%; bvFTD-controls p = 0.043, 95% CI -765.91, -12.76)., Conclusions: In bvFTD, decreased emotion recognition may be related to reduced focus on facial hallmarks. These findings suggest a valuable role for biometrics in social cognition assessment and the differentiation between bvFTD and PPD., (© 2023 The Authors. European Journal of Neurology published by John Wiley & Sons Ltd on behalf of European Academy of Neurology.)

Background: Behavioural symptoms and frontotemporal hypometabolism overlap between behavioural variant of frontotemporal dementia (bvFTD) and primary psychiatric disorders (PPD), hampering diagnostic distinction. Voxel-wise comparisons of brain metabolism might identify specific frontotemporal-(hypo)metabolic regions between bvFTD and PPD. We investigated brain metabolism in bvFTD and PPD and its relationship with behavioural symptoms, social cognition, severity of depressive symptoms and cognitive functioning., Results: Compared to controls, bvFTD showed decreased metabolism in the dorsal anterior cingulate cortex (dACC) (p < 0.001), orbitofrontal cortex (OFC), temporal pole, dorsolateral prefrontal cortex (dlPFC) and caudate, whereas PPD showed no hypometabolism. Compared to PPD, bvFTD showed decreased metabolism in the dACC (p < 0.001, p < 0.05 FWE ), insula, Broca's area, caudate, thalamus, OFC and temporal cortex (p < 0.001), whereas PPD showed decreased metabolism in the motor cortex (p < 0.001). Across bvFTD and PPD, decreased metabolism in the temporal cortex (p < 0.001, p < 0.05 FWE ), dACC and frontal cortex was associated with worse social cognition. Decreased metabolism in the dlPFC was associated with compulsiveness (p < 0.001). Across bvFTD, PPD and controls, decreased metabolism in the PFC and motor cortex was associated with executive dysfunctioning (p < 0.001)., Conclusions: Our findings indicate subtle but distinct metabolic patterns in bvFTD and PPD, most strongly in the dACC. The degree of frontotemporal and cingulate hypometabolism was related to impaired social cognition, compulsiveness and executive dysfunctioning. Our findings suggest that the dACC might be an important region to differentiate between bvFTD and PPD but needs further validation., (© 2023. The Author(s).)

Background & Objectives: Autoimmune encephalitis (AIE) may present with prominent cognitive disturbances without overt inflammatory changes in MRI and CSF. Identification of these neurodegenerative dementia diagnosis mimics is important because patients generally respond to immunotherapy. The objective of this study was to determine the frequency of neuronal antibodies in patients with presumed neurodegenerative dementia and describe the clinical characteristics of the patients with neuronal antibodies., Methods: In this retrospective cohort study, 920 patients were included with neurodegenerative dementia diagnosis from established cohorts at 2 large Dutch academic memory clinics. In total, 1,398 samples were tested (both CSF and serum in 478 patients) using immunohistochemistry (IHC), cell-based assays (CBA), and live hippocampal cell cultures (LN). To ascertain specificity and prevent false positive results, samples had to test positive by at least 2 different research techniques. Clinical data were retrieved from patient files., Results: Neuronal antibodies were detected in 7 patients (0.8%), including anti-IgLON5 (n = 3), anti-LGI1 (n = 2), anti-DPPX, and anti-NMDAR. Clinical symptoms atypical for neurodegenerative diseases were identified in all 7 and included subacute deterioration (n = 3), myoclonus (n = 2), a history of autoimmune disease (n = 2), a fluctuating disease course (n = 1), and epileptic seizures (n = 1). In this cohort, no patients with antibodies fulfilled the criteria for rapidly progressive dementia (RPD), yet a subacute deterioration was reported in 3 patients later in the disease course. Brain MRI of none of the patients demonstrated abnormalities suggestive for AIE. CSF pleocytosis was found in 1 patient, considered as an atypical sign for neurodegenerative diseases. Compared with patients without neuronal antibodies (4 per antibody-positive patient), atypical clinical signs for neurodegenerative diseases were seen more frequently among the patients with antibodies (100% vs 21%, p = 0.0003), especially a subacute deterioration or fluctuating course (57% vs 7%, p = 0.009)., Discussion: A small, but clinically relevant proportion of patients suspected to have neurodegenerative dementias have neuronal antibodies indicative of AIE and might benefit from immunotherapy. In patients with atypical signs for neurodegenerative diseases, clinicians should consider neuronal antibody testing. Physicians should keep in mind the clinical phenotype and confirmation of positive test results to avoid false positive results and administration of potential harmful therapy for the wrong indication., (Copyright © 2023 The Author(s). Published by Wolters Kluwer Health, Inc. on behalf of the American Academy of Neurology.)

Introduction: Impact of white matter hyperintensities (WMH) on cognition likely depends on lesion location, but a comprehensive map of strategic locations is lacking. We aimed to identify these locations in a large multicenter study., Methods: Individual patient data (n = 3525) from 11 memory clinic cohorts were harmonized. We determined the association of WMH location with attention and executive functioning, information processing speed, language, and verbal memory performance using voxel-based and region of interest tract-based analyses., Results: WMH in the left and right anterior thalamic radiation, forceps major, and left inferior fronto-occipital fasciculus were significantly related to domain-specific impairment, independent of total WMH volume and atrophy. A strategic WMH score based on these tracts inversely correlated with performance in all domains., Discussion: The data show that the impact of WMH on cognition is location-dependent, primarily involving four strategic white matter tracts. Evaluation of WMH location may support diagnosing vascular cognitive impairment., Highlights: We analyzed white matter hyperintensities (WMH) in 3525 memory clinic patients from 11 cohorts The impact of WMH on cognition depends on location We identified four strategic white matter tracts A single strategic WMH score was derived from these four strategic tracts The strategic WMH score was an independent determinant of four cognitive domains., (© 2022 The Authors. Alzheimer's & Dementia published by Wiley Periodicals LLC on behalf of Alzheimer's Association.)

Background: Neuropsychiatric symptoms (NPS) are prevalent in the early clinical stages of Alzheimer's disease (AD) according to proxy-based instruments. Little is known about which NPS clinicians report and whether their judgment aligns with proxy-based instruments. We used natural language processing (NLP) to classify NPS in electronic health records (EHRs) to estimate the reporting of NPS in symptomatic AD at the memory clinic according to clinicians. Next, we compared NPS as reported in EHRs and NPS reported by caregivers on the Neuropsychiatric Inventory (NPI)., Methods: Two academic memory clinic cohorts were used: the Amsterdam UMC (n = 3001) and the Erasmus MC (n = 646). Patients included in these cohorts had MCI, AD dementia, or mixed AD/VaD dementia. Ten trained clinicians annotated 13 types of NPS in a randomly selected training set of n = 500 EHRs from the Amsterdam UMC cohort and in a test set of n = 250 EHRs from the Erasmus MC cohort. For each NPS, a generalized linear classifier was trained and internally and externally validated. Prevalence estimates of NPS were adjusted for the imperfect sensitivity and specificity of each classifier. Intra-individual comparison of the NPS classified in EHRs and NPS reported on the NPI were conducted in a subsample (59%)., Results: Internal validation performance of the classifiers was excellent (AUC range: 0.81-0.91), but external validation performance decreased (AUC range: 0.51-0.93). NPS were prevalent in EHRs from the Amsterdam UMC, especially apathy (adjusted prevalence = 69.4%), anxiety (adjusted prevalence = 53.7%), aberrant motor behavior (adjusted prevalence = 47.5%), irritability (adjusted prevalence = 42.6%), and depression (adjusted prevalence = 38.5%). The ranking of NPS was similar for EHRs from the Erasmus MC, although not all classifiers obtained valid prevalence estimates due to low specificity. In both cohorts, there was minimal agreement between NPS classified in the EHRs and NPS reported on the NPI (all kappa coefficients < 0.28), with substantially more reports of NPS in EHRs than on NPI assessments., Conclusions: NLP classifiers performed well in detecting a wide range of NPS in EHRs of patients with symptomatic AD visiting the memory clinic and showed that clinicians frequently reported NPS in these EHRs. Clinicians generally reported more NPS in EHRs than caregivers reported on the NPI., (© 2023. The Author(s).)

In the last decades, numerous post-mortem case series have documented chronic traumatic encephalopathy (CTE) in former contact-sport athletes, though reports of CTE pathology in former soccer players are scarce. This study presents a clinicopathological case of a former professional soccer player with young-onset dementia. The patient experienced early onset progressive cognitive decline and developed dementia in his mid-50 s, after playing soccer for 12 years at a professional level. While the clinical picture mimicked Alzheimer's disease, amyloid PET imaging did not provide evidence of elevated beta-amyloid plaque density. After he died in his mid-60 s, brain autopsy showed severe phosphorylated tau (p-tau) abnormalities fulfilling the neuropathological criteria for high-stage CTE, as well as astrocytic and oligodendroglial tau pathology in terms of tufted astrocytes, thorn-shaped astrocytes, and coiled bodies. Additionally, there were TAR DNA-binding protein 43 (TDP-43) positive cytoplasmic inclusions in the frontal lobe and hippocampus, and Amyloid Precursor Protein (APP) positivity in the axons of the white matter. A systematic review of the literature revealed only 13 other soccer players with postmortem diagnosis of CTE. Our report illustrates the complex clinicopathological correlation of CTE and the need for disease-specific biomarkers., (© 2023. The Author(s).)

The behavioural variant of Alzheimer's disease (bvAD) is characterized by early predominant behavioural changes, mimicking the behavioural variant of frontotemporal dementia (bvFTD), which is characterized by social cognition deficits and altered biometric responses to socioemotional cues. These functions remain understudied in bvAD. We investigated multiple social cognition components (i.e. emotion recognition, empathy, social norms and moral reasoning), using the Ekman 60 faces test, Interpersonal Reactivity Index, empathy eliciting videos, Social Norms Questionnaire and moral dilemmas, while measuring eye movements and galvanic skin response. We compared 12 patients with bvAD with patients with bvFTD (n = 14), typical Alzheimer's disease (tAD, n = 13) and individuals with subjective cognitive decline (SCD, n = 13), using ANCOVAs and age- and sex-adjusted post hoc testing. Patients with bvAD (40.1 ± 8.6) showed lower scores on the Ekman 60 faces test compared to individuals with SCD (49.7 ± 5.0, P < 0.001), and patients with tAD (46.2 ± 5.3, P = 0.05) and higher scores compared to patients with bvFTD (32.4 ± 7.3, P = 0.002). Eye-tracking during the Ekman 60 faces test revealed no differences in dwell time on the eyes (all P > 0.05), but patients with bvAD (18.7 ± 9.5%) and bvFTD (19.4 ± 14.3%) spent significantly less dwell time on the mouth than individuals with SCD (30.7 ± 11.6%, P < 0.01) and patients with tAD (32.7 ± 12.1%, P < 0.01). Patients with bvAD (11.3 ± 4.6) exhibited lower scores on the Interpersonal Reactivity Index compared with individuals with SCD (15.6 ± 3.1, P = 0.05) and similar scores to patients with bvFTD (8.7 ± 5.6, P = 0.19) and tAD (13.0 ± 3.2, P = 0.43). The galvanic skin response to empathy eliciting videos did not differ between groups (all P > 0.05). Patients with bvAD (16.0 ± 1.6) and bvFTD (15.2 ± 2.2) showed lower scores on the Social Norms Questionnaire than patients with tAD (17.8 ± 2.1, P < 0.05) and individuals with SCD (18.3 ± 1.4, P < 0.05). No group differences were observed in scores on moral dilemmas (all P > 0.05), while only patients with bvFTD (0.9 ± 1.1) showed a lower galvanic skin response during personal dilemmas compared with SCD (3.4 ± 3.3 peaks per min, P = 0.01). Concluding, patients with bvAD showed a similar although milder social cognition profile and a similar eye-tracking signature to patients with bvFTD and greater social cognition impairments and divergent eye movement patterns compared with patients with tAD. Our results suggest reduced attention to salient facial features in these phenotypes, potentially contributing to their emotion recognition deficits., (© The Author(s) 2022. Published by Oxford University Press on behalf of the Guarantors of Brain.)

Most neuropsychiatric symptoms (NPS) common in frontotemporal dementia (FTD) are currently not part of the Neuropsychiatric Inventory (NPI). We piloted an FTD Module that included eight extra items to be used in conjunction with the NPI. Caregivers of patients with behavioural variant FTD (n = 49), primary progressive aphasia (PPA; n = 52), Alzheimer's dementia (AD; n = 41), psychiatric disorders (n = 18), presymptomatic mutation carriers (n = 58) and controls (n = 58) completed the NPI and FTD Module. We investigated (concurrent and construct) validity, factor structure and internal consistency of the NPI and FTD Module. We performed group comparisons on item prevalence, mean item and total NPI and NPI with FTD Module scores, and multinomial logistic regression to determine its classification abilities. We extracted four components, together explaining 64.1% of the total variance, of which the largest indicated the underlying dimension 'frontal-behavioural symptoms'. Whilst apathy (original NPI) occurred most frequently in AD, logopenic and non-fluent variant PPA, the most common NPS in behavioural variant FTD and semantic variant PPA were loss of sympathy/empathy and poor response to social/emotional cues (part of FTD Module). Patients with primary psychiatric disorders and behavioural variant FTD showed the most severe behavioural problems on both the NPI as well as the NPI with FTD Module. The NPI with FTD Module correctly classified more FTD patients than the NPI alone. By quantifying common NPS in FTD the NPI with FTD Module has large diagnostic potential. Future studies should investigate whether it can also prove a useful addition to the NPI in therapeutic trials., (© 2023. The Author(s).)

Background: Despite significant symptomatic overlap between behavioral variant frontotemporal dementia (bvFTD) and primary psychiatric disorders (PPDs), a potential overlap in their structural anatomical changes has not been studied systematically., Methods: In this magnetic resonance imaging-based meta-analysis, we included studies on bvFTD, schizophrenia, bipolar disorder, and autism spectrum disorder that 1) used voxel-based morphometry analysis to assess regional gray matter volumes (GMVs) and 2) reported the coordinates of the regional GMV. Separate analyses were performed comparing clusters of coordinate-based changes in the GMVs (n = 24,183) between patients and control subjects, and overlapping brain regions between bvFTD and each PPD were examined., Results: We found that GMV alterations in the prefrontal and anterior cingulate cortices, temporal lobe, amygdala, and insula comprise the transdiagnostic brain alterations in bvFTD and PPD., Conclusions: Our meta-analysis revealed significant anatomical overlap that paves the way for future investigations of shared pathophysiological pathways, and our cross-disorder approach would provide new insights to better understand the relationship between bvFTD and PPD., (Copyright © 2022 Society of Biological Psychiatry. Published by Elsevier Inc. All rights reserved.)

Introduction: Both late-onset Alzheimer's disease (AD) and ageing have a strong genetic component. In each case, many associated variants have been discovered, but how much missing heritability remains to be discovered is debated. Variability in the estimation of SNP-based heritability could explain the differences in reported heritability., Methods: We compute heritability in five large independent cohorts (N = 7,396, 1,566, 803, 12,528 and 3,963) to determine whether a consensus for the AD heritability estimate can be reached. These cohorts vary by sample size, age of cases and controls and phenotype definition. We compute heritability a) for all SNPs, b) excluding APOE region, c) excluding both APOE and genome-wide association study hit regions, and d) SNPs overlapping a microglia gene-set., Results: SNP-based heritability of late onset Alzheimer's disease is between 38 and 66% when age and genetic disease architecture are correctly accounted for. The heritability estimates decrease by 12% [SD = 8%] on average when the APOE region is excluded and an additional 1% [SD = 3%] when genome-wide significant regions were removed. A microglia gene-set explains 69-84% of our estimates of SNP-based heritability using only 3% of total SNPs in all cohorts., Conclusion: The heritability of neurodegenerative disorders cannot be represented as a single number, because it is dependent on the ages of cases and controls. Genome-wide association studies pick up a large proportion of total AD heritability when age and genetic architecture are correctly accounted for. Around 13% of SNP-based heritability can be explained by known genetic loci and the remaining heritability likely resides around microglial related genes., Competing Interests: The authors have read the journal’s policy and have the following competing interests: MH hold shares in Vertex Pharmaceuticals. This does not alter our adherence to PLOS ONE policies on sharing data and materials. There are no patents or patents, products in development or marketed products associated with this research to declare., (Copyright: © 2023 Baker et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)

Providing an accurate prognosis for individual dementia patients remains a challenge since they greatly differ in rates of cognitive decline. In this study, we used machine learning techniques with the aim to identify cerebrospinal fluid (CSF) biomarkers that predict the rate of cognitive decline within dementia patients. First, longitudinal mini-mental state examination scores (MMSE) of 210 dementia patients were used to create fast and slow progression groups. Second, we trained random forest classifiers on CSF proteomic profiles and obtained a well-performing prediction model for the progression group (ROC-AUC = 0.82). As a third step, Shapley values and Gini feature importance measures were used to interpret the model performance and identify top biomarker candidates for predicting the rate of cognitive decline. Finally, we explored the potential for each of the 20 top candidates in internal sensitivity analyses. TNFRSF4 and TGF [Formula: see text]-1 emerged as the top markers, being lower in fast-progressing patients compared to slow-progressing patients. Proteins of which a low concentration was associated with fast progression were enriched for cell signalling and immune response pathways. None of our top markers stood out as strong individual predictors of subsequent cognitive decline. This could be explained by small effect sizes per protein and biological heterogeneity among dementia patients. Taken together, this study presents a novel progression biomarker identification framework and protein leads for personalised prediction of cognitive decline in dementia., (© 2023. The Author(s).)