Efficacy and safety of butylphthalide in patients with mild cognitive impairment: a multicentre, randomised, double-blind, placebo-controlled trial (EBMCI study).

INTRODUCTION: The efficacy of multitarget neuroprotective drug DL-3-n-butylphthalide (NBP) in improving cognitive function has been confirmed in patients with vascular cognitive impairment without dementia. However, its efficacy in patients with symptomatic predementia phase of Alzheimer's disease remains uncertain. This study aims to evaluate the efficacy and safety of NBP in improving cognitive function in patients with mild cognitive impairment (MCI) through a clinical randomised controlled trail. METHODS AND ANALYSIS: This study is a 12-month, randomised, double-blind, placebo-controlled, multicentric trial, involving 270 patients with MCI. Subjects are randomly assigned to receive either NBP soft capsule (200 mg, three times per day) or placebo with an allocation ratio of 1:1. The efficacy and safety of NBP are assessed by comparing the results of neuropsychological, neuroimaging and laboratory tests between the two groups. The primary endpoint is the change in Alzheimer's Disease Assessment Scale-Cognitive Subscale after 12 months. All patients will be monitored for adverse events. ETHICS AND DISSEMINATION: This study involving human participants has been reviewed and approved by Ethics Committee of Xuan Wu Hospital (No.2017058). The participants provide their written informed consent to participate in this study. Results will be published in peer-reviewed medical journals and disseminated to healthcare professionals at local and international conferences. PROTOCOL VERSION: V 3.0, 3 September 2022. TRIAL REGISTRATION NUMBER: ChiCTR1800018362.

Generation of induced pluripotent stem cell line (XWHNi003-A) from a female with APOE gene mutation.

Apolipoprotein E (APOE)is the gene with greatest genetic risk for Alzheimer's disease (AD). We successfully established a human induced pluripotent stem cell(iPSC) line from a woman mutated by APOE gene. The cell line was isolated from this woman's peripheral blood mononuclear cells using a non-integrated Sendai virus, which retained the original genotype, showed a normal karyotype, highly expressed pluripotent markers and could differentiate into three germ layers.

Semantic Variant of Primary Progressive Aphasia With Glycine Receptor α1 Autoantibodies.

This case report describes a 54-year-old woman with naming deficits, comprehension impairment, and memory loss. Initial physical and neurological examination results were unremarkable.

Generation of human induced pluripotent stem cell line (XWHNi004-A) from a male with APOE gene mutation.

Genetic polymorphism of apolipoprotein E (APOE) confers differential susceptibility to Alzheimer's disease (AD), and APOE ɛ4 variants is the most powerful risk factor for this disease. Here, we report the generation of a human induced pluripotent stem cell (iPSC) line carrying the APOE ɛ4/ɛ4 genotype from peripheral blood mononuclear cells (PBMCs) isolated from a male with a family history of AD utilizing non-integrative Sendai virus vector. The iPSC maintains their original genotype, highly express endogenous pluripotency markers, displays a normal karyotype, and retains the ability to differentiate into cells representative of the three germ layers.

Causal Relationship Between Ferritin and Neuropsychiatric Disorders: A Two-Sample Mendelian Randomization Study.

Background: Previous observational research has indicated a correlation between ferritin levels and neuropsychiatric disorders, although the causal relationship remains uncertain. Objective: The objective of this study was to investigate the potential causal link between plasma ferritin levels and neuropsychiatric disorders. Methods: A two-sample Mendelian randomization (MR) study was conducted, wherein genetic instruments associated with ferritin were obtained from a previously published genome-wide association study (GWAS). Summary statistics pertaining to neuropsychiatric disorders were derived from five distinct GWAS datasets. The primary MR analysis employed the inverse variance weighted (IVW) method and was corroborated by additional methods including MR-Egger, weighted median, simple mode, and weighted mode. Sensitivity analyses were employed to identify potential pleiotropy and heterogeneity in the results. Results: The fixed effects IVW method revealed a statistically significant causal relationship between plasma ferritin level and the occurrence of Alzheimer's disease (odds ratio [OR] = 1.06, 95% confidence interval [CI]: 1.00-1.12, p = 0.037), as well as Parkinson's disease (OR = 1.06, 95% CI: 1.00-1.13, p = 0.041). Various sensitivity analyses were conducted, which demonstrated no substantial heterogeneity or pleiotropy. Conversely, no compelling evidence was found to support a causal association between ferritin and amyotrophic lateral sclerosis, schizophrenia, or major depressive disorder. Conclusions: This MR study provides evidence at the genetic level for a causal relationship between plasma ferritin and an increased risk of Alzheimer's disease and Parkinson's disease. The exact genetic mechanisms underlying this connection necessitate further investigation.

Generation of induced pluripotent stem cell line (XWHNi002-A) from a female with APP gene mutation.

The ß-amyloid precursor protein (APP) is a crucial pathogenic gene linked to Alzheimer's disease (AD). A human induced pluripotent stem cell (iPSC) line was generated from peripheral blood mononuclear cells (PBMCs) isolated from a female with APP gene mutation utilizing non-integrative Sendai virus. The iPSC line exhibits high expression of pluripotency markers, retains the APP mutation, displays a normal karyotype, and has the ability to differentiate into normal teratoma tissue. This iPSC line represents a valuable cell model for investigating the pathological mechanisms and therapeutic strategies of AD.

Proteomic profiling of circulating plasma exosomes reveals novel biomarkers of Alzheimer's disease.

BACKGROUND: Neuronal- and astrocyte-derived exosomes have been identified as an optimal source for screening biomarkers for Alzheimer's disease (AD). However, few studies focus on the bulk exosome population isolated from plasma of AD. This study investigated whether proteins in bulk exosomes can aid in the diagnosis of AD. METHODS: The plasma exosomes were collected by ultracentrifuge. Protein samples were extracted from exosomes. Cerebrospinal fluid levels of amyloid ß (Aß)42 and phosphorylated tau (P-tau)181 were measured for diagnostic purposes. A pilot study (controls, 20; AD, 20) followed by a second dataset (controls, 56; AD, 58) was used to establish a diagnostic model of AD. Mass spectrometry-based proteomics was performed to profile the plasma exosomal proteome. Parallel reaction monitoring was used to further confirm the differentially expressed proteins. RESULTS: In total, 328 proteins in plasma exosomes were quantified. Among them, 31 proteins were altered in AD patients, and 12 were validated. The receiver operating characteristic curve analysis revealed a combination of six proteins (upregulated: Ig-like domain-containing protein (A0A0G2JRQ6), complement C1q subcomponent subunit C (C1QC), complement component C9 (CO9), platelet glycoprotein Ib beta chain (GP1BB), Ras suppressor protein 1 (RSU1); downregulated: disintegrin and metalloproteinase domain 10 (ADA10)) has the capacity to differentiate AD patients from healthy controls with high accuracy. Linear correlation analysis showed that the combination was significantly correlated with cognitive performance. CONCLUSIONS: The combination of plasma exosomal proteins A0A0G2JRQ6, C1QC, CO9, GP1BB, RSU1, and ADA10 acts as a novel candidate biomarker to differentiate AD patients from healthy individuals.

Culture Effects on the Chinese Version Boston Naming Test Performance and the Normative Data in the Native Chinese-Speaking Elders in Mainland China.

Background: The Chinese version of Boston Naming Test (BNT-C) is administered in China widely. However, the neuropsychological parameter of BNT-C in native Chinese-speaking elders in mainland China has not been explored systematically. The aim of this study was to explore cultural influences on BNT-C performance and establish norms among native Chinese-speaking elders in Beijing. Methods: A total of 161 native, Chinese-speaking, cognitively normal elders aged ≥55 years were enrolled from various communities in Beijing. The BNT-C was conducted on all the participants. The internal consistency, participants' familiarity, and naming accuracy were analyzed and compared with data from Chinese areas outside the mainland and from American published previously. The influencing factors and stratified norms for BNT-C were established. Results: The BNT-C showed good internal consistency (α = 0.738). Strong correlation between naming accuracy and object familiarity was found (r = 0.962, P < 0.001). Participants' familiarity and correct naming rate for many items were notably different between the Chinese-speaking elders and English-speaking elders in America. The difference in some items' correct naming rate also existed between Beijing, Taiwan, and Hongkong. Higher education was associated with higher scores, whereas age and gender had no effect on BNT-C performance. The recommended norms of total naming scores for elders with education ≤ 9 and >9 years were 16 and 23, respectively. Conclusion: The participants' familiarity with BNT items differed between different cultures, which further affected the naming accuracy and total scores. The education stratified norms established here are helpful for the better application of BNT-C in mainland China.

Clinical Practice Guidelines for the Management of Behavioral and Psychological Symptoms of Dementia: A Systematic Review With AGREE II.

Background: High-quality clinical practice guidelines (CPGs) are important for the effective treatment of behavioral and psychological symptoms of dementia (BPSD). However, recommendations provided by different quality guidelines may lead to varied clinical practice outcomes. Objective: To assess the quality of available CPGs for the management of BPSD and summarize the best recommendations for treating BPSD. Methods: This was a systematic review of CPGs for the management of BPSD with data obtained from electronic databases and evaluated using the Appraisal of Guidelines for Research and Evaluation II instrument, consisting of six domains: "Scope and purpose", "Stakeholder involvement", "Rigor of development", "Clarity of presentation", "Applicability", and "Editorial independence". The criteria for high-quality guidelines were set as: the score of high-quality guidelines in the "Rigor of development" domain should be ≥60% and as well as a score of >60% in at least three other domains. High-quality guidelines were selected for recommendation extraction, and the final recommendations were formed in combination with the latest meta-analysis and randomized clinical-trial results. Results: In term of median scores in each domain for the six included CPGs, "Scope and purpose" (87.5%) scored better than all others, whereas "Applicability" (46.5%) was the domain with the lowest score. Four CPGs (2015 APA, 2018 NICE, 2018 CANADA, 2020 EAN) met the criteria of high-quality guidelines and were used to extract recommendations. From these four CPGs, nine specific recommendations related to the management of BPSD were summarized, of which seven were related to pharmacological treatment and two to non-pharmacological treatment. These recommendations covered the applicability of antipsychotic drugs, medication recommendations, withdrawal times, and several suitable non-pharmacological therapies. Conclusion: The quality of CPGs for the management of BPSD requires improvement, especially for the "Applicability" domain. For psychotic-like symptoms in dementia, the use of antipsychotics should be based on the individual's risk-benefit ratio, and the use of atypical antipsychotics seems to be a better choice. Non-pharmacological treatments may be suitable for emotional symptoms and sleep disorders. Systematic Review Registration: https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42020209204.

Good Performance of the Chinese Version of Mini Social Cognition and Emotional Assessment in the Early Diagnosis of Behavioral Variant Frontotemporal Dementia.

Social cognition impairment has been recognized as an early and characteristic change in behavioral variant frontotemporal dementia (bvFTD). The Mini Social Cognition and Emotional Assessment (mini-SEA) is a clinical tool to rapidly evaluate social cognition. In this study, we explored the diagnostic value of social cognition by assessing the Chinese version of the mini-SEA and other standard neuropsychological tests in 22 patients with mild bvFTD, 26 patients with mild Alzheimer's disease (AD), including mild cognitive impairment (MCI) and mild dementia, and 30 control subjects. The discriminatory powers of these tests were evaluated and compared using the receiver operating characteristic curve (ROC). The mini-SEA scores of the bvFTD patients were significantly lower than those of the controls (Z = -6.850, adjusted P < 0.001) and AD patients (Z = -3.737, adjusted P = 0.001). ROC analysis showed that the mini-SEA had a high discriminatory power for differentiating bvFTD from the controls, with an area under the curve (AUC) value of 0.989 (95% CI = 0.905-1.000, P < 0.001). The AUC value of the mini-SEA for differentiating bvFTD from AD was 0.899 (95% CI = 0.777-0.967, P < 0.001), higher than that of the Auditory Verbal Learning Test Delayed Recall (AUC = 0.793), Boston Naming Test (AUC = 0.685) or Frontal Assessment Battery (AUC = 0.691). The Chinese version of mini-SEA is a good clinical tool for the early diagnosis of bvFTD, and has a high sensitivity and specificity to discriminate bvFTD from AD.

Generation and characterization of a human induced pluripotent stem cell line (XWHNi001-A) derived from an Alzheimer's disease patient with mutation in the APP gene.

Mutations in the APP gene are popularly known as the second cause trigger the familial Alzheimer's disease (AD). We generated a human induced pluripotent stem cell (iPSC) line from the peripheral blood mononuclear cells isolated from an AD patient using non-integrative Sendai virus. The iPSC line highly expresses pluripotency markers, has the capacity to differentiate into the normal teratoma tissue, retains the APP mutation, and displays the normal karyotype. The iPSC line will provide a useful resource to study the pathogenesis and drugs screening of AD.

Detection of plasma Aß seeding activity by a newly developed analyzer for diagnosis of Alzheimer's disease.

OBJECTIVE: To evaluate the diagnostic value of plasma ß-amyloid (Aß) seeding activity measured using a newly developed instrument to distinguish Alzheimer's disease (AD) from other forms of dementia. METHODS: Seventy-nine AD patients, 64 non-AD dementia (NADD) patients, and 75 cognitively normal (NC) subjects were recruited in the study. To measure the levels of Aß seeding activity in the plasma samples, we have developed an AD-seeds protein analyzer. We used receiver operating characteristic (ROC) curves to quantify the ability of plasma Aß seeding activity to distinguish between AD and NADD or NC individuals. Spearman's correlation was used to examine the associations between plasma Aß seeding activity and global cognitive function or conventional AD biomarkers. RESULTS: The Aß seeding activities were 0.83 (0.58-1.16) A.U. in AD, 0.42 (0.04-0.74) A.U. in NADD and 0.42 (0.09-0.69) A.U. in NC, respectively. The Aß seeding activity was able to identify AD patients and distinguish them from NC or NADD with high accuracy (AUC = 0.85-0.86). In addition, the plasma Aß seeding activity showed a strong correlation with cognitive performance (mini-mental state examination, r = - 0.188; Montreal cognitive assessment, r = - 0.189; clinical dementia rating, r = 0.205) and conventional biomarkers (cerebrospinal fluid [CSF] Aß42/40, r = -0.227; CSF T-tau/Aß42, r = 0.239; CSF P-tau/Aß42, r = 0.259). CONCLUSION: Our results confirmed that plasma Aß seeding activity is an antibody-free and low-cost biomarker for the diagnosis of AD. TRIAL REGISTRATION: Trial registration number NCT04850053.

A Comparative Study of Structural and Metabolic Brain Networks in Patients With Mild Cognitive Impairment.

Background: Changes in the metabolic and structural brain networks in mild cognitive impairment (MCI) have been widely researched. However, few studies have compared the differences in the topological properties of the metabolic and structural brain networks in patients with MCI. Methods: We analyzedmagnetic resonance imaging (MRI) and fluoro-deoxyglucose positron emission tomography (FDG-PET) data of 137 patients with MCI and 80 healthy controls (HCs). The HC group data comes from the Alzheimer's Disease Neuroimaging Initiative (ADNI) database. The permutation test was used to compare the network parameters (characteristic path length, clustering coefficient, local efficiency, and global efficiency) between the two groups. Partial Pearson's correlation analysis was used to calculate the correlations of the changes in gray matter volume and glucose intake in the key brain regions in MCI with the Alzheimer's Disease Assessment Scale-Cognitive (ADAS-cog) sub-item scores. Results: Significant changes in the brain network parameters (longer characteristic path length, larger clustering coefficient, and lower local efficiency and global efficiency) were greater in the structural network than in the metabolic network (longer characteristic path length) in MCI patients than in HCs. We obtained the key brain regions (left globus pallidus, right calcarine fissure and its surrounding cortex, left lingual gyrus) by scanning the hubs. The volume of gray matter atrophy in the left globus pallidus was significantly positively correlated with comprehension of spoken language (p = 0.024) and word-finding difficulty in spontaneous speech item scores (p = 0.007) in the ADAS-cog. Glucose intake in the three key brain regions was significantly negatively correlated with remembering test instructions items in ADAS-cog (p = 0.020, p = 0.014, and p = 0.008, respectively). Conclusion: Structural brain networks showed more changes than metabolic brain networks in patients with MCI. Some brain regions with significant changes in betweenness centrality in both structural and metabolic networks were associated with MCI.

Prominent Striatum Amyloid Retention in Early-Onset Familial Alzheimer's Disease With PSEN1 Mutations: A Pilot PET/MR Study.

Background: With the advancements of amyloid imaging in recent years, this new imaging diagnostic method has aroused great interest from researchers. Till now, little is known regarding amyloid deposition specialty in patients with early-onset familial Alzheimer's disease (EOFAD), and even less is known about its role in cognitive impairments. Objectives: Our study aimed to evaluate the amyloid deposition in five patients with EOFAD, 15 patients with late-onset sporadic AD, and 12 healthy subjects utilizing 11C-labeled Pittsburgh compound-B (11C-PiB) amyloid PET imaging. Moreover, we figured out the correlation between striatal and cortical standardized uptake value ratios (SUVRs). We also investigated the correlation between 11C-PiB retention and cognitive presentation. Results: All patients with EOFAD showed high amyloid deposition in the striatum, a pattern that is not usually seen in patients with late-onset sporadic AD. The SUVR in the striatum, especially in the amygdala, showed significant correlations with cortex SUVR in EOFAD. However, neither striatal nor cortical 11C-PiB retention was related to cognitive decline. Conclusions: The amyloid distribution in patients with EOFAD differs from late-onset sporadic AD, with higher amyloid deposits in the striatum. Our study also demonstrated positive correlations in 11C-PiB retention between the striatum and other cortical areas. We revealed that the distribution of amyloid in the brain is not random but diffuses following the functional and anatomical connections. However, the degree and pattern of amyloid deposition were not correlated with cognitive deficits.

Current Review of Leptomeningeal Amyloidosis Associated With Transthyretin Mutations.

INTRODUCTION: Leptomeningeal amyloidosis (LA) represents a rare subtype of familial transthyretin (TTR) amyloidosis, characterized by deposition of amyloid in cranial and spinal leptomeninges. Of >120 TTR mutations identified, few have been associated with LA. CASE REPORT: A 27-year-old male presented with a 2-year history of progressive symptoms including cognitive decline and right-sided weakness and numbness. Cerebrospinal fluid (CSF) analyses demonstrated high protein level. Gadolinium-enhanced magnetic resonance imaging (MRI) revealed extensive leptomeningeal enhancement over the surface of the brain and spinal cord. Pathologic analyses revealed a TTR mutation c.113A>G (p.D38G). REVIEW SUMMARY: Fifteen mutations and genotype-phenotype correlation of 72 LA patients have been summarized to provide an overview of LA associated with transthyretin mutations. The mean age of clinical onset was 44.9 years and the neurological symptoms primarily included cognitive impairment, headache, ataxia seizures and hearing, visual loss. CSF analysis showed elevated high CSF protein level and MRI revealed extensive leptomeningeal enhancement. CONCLUSION: Clinicians should be aware of this rare form of familial transthyretin amyloidosis as well as its typical MRI enhancement and high CSF protein. The important role of biopsy, genetic testing and the potential early diagnosis value of contrast MRI were suggested. Early recognition of these characteristics is important to provide misdiagnosis and shorten the time before correct diagnosis. These findings expand the phenotypic spectrum of TTR gene and have implications for the diagnosis, treatment, and systematic study of LA.

White Matter Fractional Anisotropy Is a Superior Predictor for Cognitive Impairment Than Brain Volumes in Older Adults With Confluent White Matter Hyperintensities.

Older patients with confluent white matter hyperintensities (WMHs) on magnetic resonance imaging have an increased risk for the onset of vascular cognitive impairment (VCI). This study investigates the predictive effects of the white matter (WM) fractional anisotropy (FA) and brain volumes on cognitive impairment for those with confluent WMHs. This study enrolled 77 participants with confluent WMHs (Fazekas grade 2 or 3), including 44 with VCI-no dementia (VCIND) and 33 with normal cognition (NC). The mean FA of 20 WM tracts was calculated to evaluate the global WM microstructural integrity, and major WM tracts were reconstructed using probabilistic tractography. Voxel-based morphometry was used to calculate brain volumes for the total gray matter (GM), the hippocampus, and the nucleus basalis of Meynert (NbM). All volumetric assays were corrected for total intracranial volume. All regression analyses were adjusted for age, gender, education, and apolipoprotein E (ApoE) gene ε4 status. Logistic regression analysis revealed that the mean FA value for global WM was the only independent risk factor for VCI (z score of FA: OR = 4.649, 95%CI 1.576-13.712, p = 0.005). The tract-specific FAs were not associated with the risk of cognitive impairment after controlling the mean FA for global WM. The mean FA value was significantly associated with scores of Mini-Mental State Examination (MMSE) and Auditory Verbal Learning Test. A lower FA was also associated with smaller volumes of total GM, hippocampus, and NbM. However, brain volumes were not found to be directly related to cognitive performances, except for an association between the hippocampal volume and MMSE. In conclusion, the mean FA for global WM microstructural integrity is a superior predictor for cognitive impairment than tract-specific FA and brain volumes in people with confluent WMHs.

Comprehensive Management of Daily Living Activities, behavioral and Psychological Symptoms, and Cognitive Function in Patients with Alzheimer's Disease: A Chinese Consensus on the Comprehensive Management of Alzheimer's Disease.

Alzheimer's disease (AD) is the most common cognitive disorder in the elderly. Its main clinical manifestations are cognitive decline (C), behavioral and psychological symptoms (B), and a decline in the activities of daily living (A), also known as ABC symptoms. Early identification and evaluation of ABC symptoms are helpful for establishing the accurate diagnosis, comprehensive treatment, and prognosis of AD. To guide Chinese clinical practice for optimization of the comprehensive management of AD, in 2018, The Academy of Cognitive Disorder of China gathered 22 neurologists and gerontologists in China to build a consensus on the comprehensive management of AD. Based on a review of the evidence, the consensus summarizes the pathogenesis, pathological changes, clinical manifestations, evaluation, diagnosis, drug and non-drug treatment, and patient care for AD. Focus group discussion was used to establish a flowchart of comprehensive ABC management for AD patients. The new consensus provides a feasible AD management process for clinicians.

Prediction of Alzheimer's disease using multi-variants from a Chinese genome-wide association study.

Previous genome-wide association studies have identified dozens of susceptibility loci for sporadic Alzheimer's disease, but few of these loci have been validated in longitudinal cohorts. Establishing predictive models of Alzheimer's disease based on these novel variants is clinically important for verifying whether they have pathological functions and provide a useful tool for screening of disease risk. In the current study, we performed a two-stage genome-wide association study of 3913 patients with Alzheimer's disease and 7593 controls and identified four novel variants (rs3777215, rs6859823, rs234434, and rs2255835; Pcombined = 3.07 × 10-19, 2.49 × 10-23, 1.35 × 10-67, and 4.81 × 10-9, respectively) as well as nine variants in the apolipoprotein E region with genome-wide significance (P < 5.0 × 10-8). Literature mining suggested that these novel single nucleotide polymorphisms are related to amyloid precursor protein transport and metabolism, antioxidation, and neurogenesis. Based on their possible roles in the development of Alzheimer's disease, we used different combinations of these variants and the apolipoprotein E status and successively built 11 predictive models. The predictive models include relatively few single nucleotide polymorphisms useful for clinical practice, in which the maximum number was 13 and the minimum was only four. These predictive models were all significant and their peak of area under the curve reached 0.73 both in the first and second stages. Finally, these models were validated using a separate longitudinal cohort of 5474 individuals. The results showed that individuals carrying risk variants included in the models had a shorter latency and higher incidence of Alzheimer's disease, suggesting that our models can predict Alzheimer's disease onset in a population with genetic susceptibility. The effectiveness of the models for predicting Alzheimer's disease onset confirmed the contributions of these identified variants to disease pathogenesis. In conclusion, this is the first study to validate genome-wide association study-based predictive models for evaluating the risk of Alzheimer's disease onset in a large Chinese population. The clinical application of these models will be beneficial for individuals harbouring these risk variants, and particularly for young individuals seeking genetic consultation.

Blood neuro-exosomal synaptic proteins predict Alzheimer's disease at the asymptomatic stage.

INTRODUCTION: Exosomes are an emerging candidate for biomarkers of Alzheimer's disease (AD). This study investigated whether exosomal synaptic proteins can predict AD at the asymptomatic stage. METHODS: We conducted a two-stage-sectional study (discovery stage: AD, 28; amnestic mild cognitive impairment [aMCI], 25; controls, 29; validation stage: AD, 73; aMCI, 71; controls, 72), a study including preclinical AD (160) and controls (160), and a confirmation study in familial AD (mutation carriers: 59; non-mutation carriers: 62). RESULTS: The concentrations of growth associated protein 43 (GAP43), neurogranin, synaptosome associated protein 25 (SNAP25), and synaptotagmin 1 were lower in AD than in controls (P < .001). Exosomal biomarker levels were correlated with those in cerebrospinal fluid (R2  = 0.54-0.70). The combination of exosomal biomarkers detected AD 5 to 7 years before cognitive impairment (area under the curve = 0.87-0.89). DISCUSSION: This study revealed that exosomal GAP43, neurogranin, SNAP25, and synaptotagmin 1 act as effective biomarkers for prediction of AD 5 to 7 years before cognitive impairment.