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INTRODUCTION: Cerebral blood flow (CBF) is reduced in cognitively impaired (CI) Alzheimer's disease (AD) patients. We checked the sensitivity of time‐encoded arterial spin labeling (te‐ASL) in measuring CBF alterations in individuals with positive AD biomarkers and associations with relevant biomarkers in cognitively unimpaired (CU) individuals. METHODS: We compared te‐ASL with single‐postlabel delay (PLD) ASL in measuring CBF in 59 adults across the AD continuum, classified as CU amyloid beta (Aβ) negative (−), CU Aβ positive (+), and CI Aβ+. We sought associations of CBF with biomarkers of AD, cerebrovascular disease, synaptic dysfunction, neurodegeneration, and cognition in CU participants. RESULTS: te‐ASL was more sensitive at detecting CBF reduction in the CU Aβ+ and CI Aβ+ groups. In CU participants, lower CBF was associated with altered biomarkers of Aβ, tau, synaptic dysfunction, and neurodegeneration. DISCUSSION: CBF reduction occurs early in the AD continuum. te‐ASL is more sensitive than single‐PLD ASL at detecting CBF changes in AD. Highlights: Lower CBF can be detected in CU subjects in the early AD continuum.te‐ASL is more sensitive than single‐PLD ASL at detecting CBF alterations in AD.CBF is linked to biomarkers of AD, synaptic dysfunction, and neurodegeneration. [ABSTRACT FROM AUTHOR]

INTRODUCTION: This study examined the relationship between blood‐brain‐barrier permeability (BBBp), measured by cerebrospinal fluid/serum albumin ratio (QAlb), and cognitive decline progression in a clinical cohort. METHODS: This prospective observational study included 334 participants from the BIODEGMAR cohort. Cognitive decline progression was defined as an increase in Global Deterioration Scale and/or Clinical Dementia Rating scores. Associations between BBBp, demographics, and clinical factors were explored. RESULTS: Male sex, diabetes mellitus, and cerebrovascular burden were associated with increased log‐QAlb. Vascular cognitive impairment patients had the highest log‐QAlb levels. Among the 273 participants with valid follow‐up data, 154 (56.4%) showed cognitive decline progression. An 8% increase in the hazard of clinical worsening was observed for each 10% increase in log‐QAlb. DISCUSSION: These results suggest that increased BBBp in individuals with cognitive decline may contribute to clinical worsening, pointing to potential targeted therapies. QAlb could be a useful biomarker for identifying patients with a worse prognosis. [ABSTRACT FROM AUTHOR]

Recent advances in blood-based biomarkers of Alzheimer's Disease (AD) show great promise for clinical applications, offering a less invasive alternative to current cerebrospinal fluid (CSF) measures. However, the relationships between these biomarkers and specific cognitive functions, as well as their utility in predicting longitudinal cognitive decline, are not yet fully understood. This descriptive review surveys the literature from 2018 to 2023, focusing on the associations of amyloid-β (Aβ), Total Tau (t-Tau), Phosphorylated Tau (p-Tau), Neurofilament Light (NfL), and Glial Fibrillary Acidic Protein (GFAP) with cognitive measures. The reviewed studies are heterogeneous, varying in design and population (cognitively unimpaired, cognitively impaired, or mixed populations), and show results that are sometimes conflicting. Generally, cognition positively correlates with Aβ levels, especially when evaluated through the Aβ42/Aβ40 ratio. In contrast, t-Tau, p-Tau, Nfl, and GFAP levels typically show a negative correlation with cognitive performance. While p-Tau measures generally exhibit stronger associations with cognitive functions compared to other biomarkers, no single blood marker has emerged as being predominantly linked to a specific cognitive domain. These findings contribute to our understanding of the complex relationship between blood biomarkers and cognitive performance and underscore their potential utility in clinical assessments of cognition. [ABSTRACT FROM AUTHOR]

Introduction: Direct comparisons of the main blood phosphorylated tau immunoassays in memory clinic populations are needed to understand possible differences. Methods: In the BIODEGMAR study, 197 participants presenting with cognitive complaints were classified into an Alzheimer's disease (AD) or a non‐AD cerebrospinal fluid (CSF) profile group, according to their amyloid beta 42/ phosphorylated tau (Aβ42/p‐tau) ratio. We performed a head‐to‐head comparison of nine plasma and nine CSF tau immunoassays and determined their accuracy to discriminate abnormal CSF Aβ42/p‐tau ratio. Results: All studied plasma tau biomarkers were significantly higher in the AD CSF profile group compared to the non‐AD CSF profile group and significantly discriminated abnormal CSF Aβ42/p‐tau ratio. For plasma p‐tau biomarkers, the higher discrimination accuracy was shown by Janssen p‐tau217 (r = 0.76; area under the curve [AUC] = 0.96), ADx p‐tau181 (r = 0.73; AUC = 0.94), and Lilly p‐tau217 (r = 0.73; AUC = 0.94). Discussion: Several plasma p‐tau biomarkers can be used in a specialized memory clinic as a stand‐alone biomarker to detect biologically‐defined AD. Highlights: Patients with an Alzheimer's disease cerebrospinal fluid (AD CSF) profile have higher plasma phosphorylated tau (p‐tau) levels than the non‐AD CSF profile group.All plasma p‐tau biomarkers significantly discriminate patients with an AD CSF profile from the non‐AD CSF profile group.Janssen p‐tau217, ADx p‐tau181, and Lilly p‐tau217 in plasma show the highest accuracy to detect biologically defined AD.Janssen p‐tau217, ADx p‐tau181, Lilly p‐tau217, Lilly p‐tau181, and UGot p‐tau231 in plasma show performances that are comparable to their CSF counterparts. [ABSTRACT FROM AUTHOR]

Background: Cardiovascular risk factors (CVRF) have been associated with an increased risk of cognitive decline and dementia. Increase of blood‐brain barrier permeability (BBBp) measured by CSF/serum albumin ratio (Qalb) have been associated with CVRF. The aim of this study was to analyze the possible role of Qalb as a predictor of conversion to dementia in patients with mild cognitive impairment (MCI). Method: A total of 144 individuals with MCI were recruited from the BIODEGMAR cohort at Hospital del Mar (Barcelona) from 2017 to 2021. Study protocol included neuropsychological assessment, blood sampling, lumbar puncture and brain MRI. Follow‐up visits were performed yearly (12 +‐2 months) until January 2023. The endpoint of the study was a diagnosis of dementia (Global Deterioration Scale –GDS‐ > 3 and/or Clinical Dementia Rating ‐CDR‐ score > 0.5). BBBp was measured by CSF/serum albumin ratio (Qalb). Azheimer's Disease (AD) was biologically‐defined according to CSF Aβ42/p‐tau ratio (AD+/‐). A composite vascular score (CVS) was calculated by assigning one point for the presence of each of the following CVRF (hypertension, hyperlipidemia and diabetes mellitus) plus another point if Fazekas scale higher than 1 or presence of brain infarcts on MRI. We performed a multivariate Cox regression analysis including the following variables: age, sex, AD and CVS. Result: Sixty‐two cases (39.2%) developed dementia in a median follow‐up of 25.89 +/‐ 13.98 months. Univariate analysis showed that Qalb (p < 0.01), AD+ (p < 0.01) and CVS (p = 0.016) were associated with dementia. The regression model results showed an independent relationship between conversion to dementia and Qalb, HR = 1.333 (95% CI 1.185‐1.499) and AD+, HR = 4.118 (2.202‐7.699). Conclusion: An increase in BBBp was independently associated with a higher risk of conversion to dementia in MCI patients. This result points to a potential role of Qalb as a useful biomarker of clinical prognosis of MCI patients. [ABSTRACT FROM AUTHOR]

Introduction: Cerebral blood flow (CBF) is reduced in cognitively impaired (CI) Alzheimer's disease (AD) patients. We checked the sensitivity of time-encoded arterial spin labeling (te-ASL) in measuring CBF alterations in individuals with positive AD biomarkers and associations with relevant biomarkers in cognitively unimpaired (CU) individuals., Methods: We compared te-ASL with single-postlabel delay (PLD) ASL in measuring CBF in 59 adults across the AD continuum, classified as CU amyloid beta (Aβ) negative (-), CU Aβ positive (+), and CI Aβ+. We sought associations of CBF with biomarkers of AD, cerebrovascular disease, synaptic dysfunction, neurodegeneration, and cognition in CU participants., Results: te-ASL was more sensitive at detecting CBF reduction in the CU Aβ+ and CI Aβ+ groups. In CU participants, lower CBF was associated with altered biomarkers of Aβ, tau, synaptic dysfunction, and neurodegeneration., Discussion: CBF reduction occurs early in the AD continuum. te-ASL is more sensitive than single-PLD ASL at detecting CBF changes in AD., Highlights: Lower CBF can be detected in CU subjects in the early AD continuum. te-ASL is more sensitive than single-PLD ASL at detecting CBF alterations in AD. CBF is linked to biomarkers of AD, synaptic dysfunction, and neurodegeneration., (© 2024 The Author(s). Alzheimer's & Dementia published by Wiley Periodicals LLC on behalf of Alzheimer's Association.)

Introduction: This study examined the relationship between blood-brain-barrier permeability (BBBp), measured by cerebrospinal fluid/serum albumin ratio (QAlb), and cognitive decline progression in a clinical cohort., Methods: This prospective observational study included 334 participants from the BIODEGMAR cohort. Cognitive decline progression was defined as an increase in Global Deterioration Scale and/or Clinical Dementia Rating scores. Associations between BBBp, demographics, and clinical factors were explored., Results: Male sex, diabetes mellitus, and cerebrovascular burden were associated with increased log-QAlb. Vascular cognitive impairment patients had the highest log-QAlb levels. Among the 273 participants with valid follow-up data, 154 (56.4%) showed cognitive decline progression. An 8% increase in the hazard of clinical worsening was observed for each 10% increase in log-QAlb., Discussion: These results suggest that increased BBBp in individuals with cognitive decline may contribute to clinical worsening, pointing to potential targeted therapies. QAlb could be a useful biomarker for identifying patients with a worse prognosis., (© 2023 The Authors. Alzheimer's & Dementia published by Wiley Periodicals LLC on behalf of Alzheimer's Association.)

Introduction: Direct comparisons of the main blood phosphorylated tau immunoassays in memory clinic populations are needed to understand possible differences., Methods: In the BIODEGMAR study, 197 participants presenting with cognitive complaints were classified into an Alzheimer's disease (AD) or a non-AD cerebrospinal fluid (CSF) profile group, according to their amyloid beta 42/ phosphorylated tau (Aβ42/p-tau) ratio. We performed a head-to-head comparison of nine plasma and nine CSF tau immunoassays and determined their accuracy to discriminate abnormal CSF Aβ42/p-tau ratio., Results: All studied plasma tau biomarkers were significantly higher in the AD CSF profile group compared to the non-AD CSF profile group and significantly discriminated abnormal CSF Aβ42/p-tau ratio. For plasma p-tau biomarkers, the higher discrimination accuracy was shown by Janssen p-tau217 (r = 0.76; area under the curve [AUC] = 0.96), ADx p-tau181 (r = 0.73; AUC = 0.94), and Lilly p-tau217 (r = 0.73; AUC = 0.94)., Discussion: Several plasma p-tau biomarkers can be used in a specialized memory clinic as a stand-alone biomarker to detect biologically-defined AD., Highlights: Patients with an Alzheimer's disease cerebrospinal fluid (AD CSF) profile have higher plasma phosphorylated tau (p-tau) levels than the non-AD CSF profile group. All plasma p-tau biomarkers significantly discriminate patients with an AD CSF profile from the non-AD CSF profile group. Janssen p-tau217, ADx p-tau181, and Lilly p-tau217 in plasma show the highest accuracy to detect biologically defined AD. Janssen p-tau217, ADx p-tau181, Lilly p-tau217, Lilly p-tau181, and UGot p-tau231 in plasma show performances that are comparable to their CSF counterparts., (© 2022 The Authors. Alzheimer's & Dementia published by Wiley Periodicals LLC on behalf of Alzheimer's Association.)

Introduction: Hypertrophic pachymeningitis is an infrequent disorder that produces focal or diffuse thickening of the dura mater. It can be idiopathic or secondary to infectious, autoimmune or neoplastic processes. The recently described 'IgG4-related disease' could be the cause of many cases considered cryptogenic., Case Report: A 54-year-old woman, with a history of bronchial asthma, presented with headache, dizziness and hearing loss on her left ear. The brain MRI study with gadolinium showed enhancement and thickening of the dura mater, extending from lateral wall of left cavernous sinus and medial temporal lobe to cerebellopontine angle and ipsilateral tentorium. CSF had 10 leukocytes/µL (90% mononuclear), with 1 g/L protein and without glucose consumption. Pathology showed fibrosis and lymphoplasmacytic infiltrate, with 16 IgG4+ plasma cells per high power field. The rest of analytical and microbiological studies were normal or negative. The plasma IgG4 rate was within normal limits. After treatment with steroids there was clinical improvement accompanied by the virtual disappearance of the alterations detected in neuroimaging., Conclusions: Hypertrophic pachymeningitis as a manifestation of IgG4-related disease can be diagnosed based on MRI findings if plasma IgG4 is elevated. In doubtful cases we must resort to meningeal biopsy. Corticosteroid therapy is usually effective and it is the first line treatment.