Combining plasma Aβ and p-tau217 improves detection of brain amyloid in non-demented elderly

BACKGROUND

Maximizing the efficiency to screen amyloid-positive individuals in asymptomatic and non-demented aged population using blood-based biomarkers is essential for future success of clinical trials in the early stage of Alzheimer's disease (AD). In this study, we elucidate the utility of combination of plasma amyloid-β (Aβ)-related biomarkers and tau phosphorylated at threonine 217 (p-tau217) to predict abnormal Aβ-positron emission tomography (PET) in the preclinical and prodromal AD.

METHODS

We designed the cross-sectional study including two ethnically distinct cohorts, the Japanese trial-ready cohort for preclinica and prodromal AD (J-TRC) and the Swedish BioFINDER study. J-TRC included 474 non-demented individuals (CDR 0: 331, CDR 0.5: 143). Participants underwent plasma Aβ and p-tau217 assessments, and Aβ-PET imaging. Findings in J-TRC were replicated in the BioFINDER cohort including 177 participants (cognitively unimpaired: 114, mild cognitive impairment: 63). In both cohorts, plasma Aβ(1-42) (Aβ42) and Aβ(1-40) (Aβ40) were measured using immunoprecipitation-MALDI TOF mass spectrometry (Shimadzu), and p-tau217 was measured with an immunoassay on the Meso Scale Discovery platform (Eli Lilly).

RESULTS

Aβ-PET was abnormal in 81 participants from J-TRC and 71 participants from BioFINDER. Plasma Aβ42/Aβ40 ratio and p-tau217 individually showed moderate to high accuracies when detecting abnormal Aβ-PET scans, which were improved by combining plasma biomarkers and by including age, sex and APOE genotype in the models. In J-TRC, the highest AUCs were observed for the models combining p-tau217/Aβ42 ratio, APOE, age, sex in the whole cohort (AUC = 0.936), combining p-tau217, Aβ42/Aβ40 ratio, APOE, age, sex in the CDR 0 group (AUC = 0.948), and combining p-tau217/Aβ42 ratio, APOE, age, sex in the CDR 0.5 group (AUC = 0.955), respectively. Each subgroup results were replicated in BioFINDER, where the highest AUCs were seen for models combining p-tau217, Aβ42/40 ratio, APOE, age, sex in cognitively unimpaired (AUC = 0.938), and p-tau217/Aβ42 ratio, APOE, age, sex in mild cognitive impairment (AUC = 0.914).

CONCLUSIONS

Combination of plasma Aβ-related biomarkers and p-tau217 exhibits high performance when predicting Aβ-PET positivity. Adding basic clinical information (i.e., age, sex, APOE ε genotype) improved the prediction in preclinical AD, but not in prodromal AD. Combination of Aβ-related biomarkers and p-tau217 could be highly useful for pre-screening of participants in clinical trials of preclinical and prodromal AD.

Simplifying Alzheimer's Disease Monitoring: A Novel Machine-Learning Approach to Estimate the Clinical Dementia Rating Sum of Box Changes Using the Mini-Mental State Examination and Functional Activities Questionnaire

Background

Primary outcome measure in the clinical trials of disease modifying therapy (DMT) drugs for Alzheimer's disease (AD) has often been evaluated by Clinical Dementia Rating sum of boxes (CDRSB). However, CDR testing requires specialized training and 30-50 minutes to complete, not being suitable for daily clinical practice.

Objective

Herein, we proposed a machine-learning method to estimate CDRSB changes using simpler cognitive/functional batteries (Mini-Mental State Examination [MMSE] and Functional Activities Questionnaire [FAQ]), to replace CDR testing.

Methods

Baseline data from 944 ADNI and 171 J-ADNI amyloid-positive participants were used to build machine-learning models predicting annualized CDRSB changes between visits, based on MMSE and FAQ scores. Prediction performance was evaluated with mean absolute error (MAE) and R2 comparing predicted to actual rmDeltaCDRSB/rmDeltayear. We further assessed whether decline in cognitive function surpassing particular thresholds could be identified using the predicted rmDeltaCDRSB/rmDeltayear.

RESULTS

The models achieved the minimum required prediction errors (MAE <  1.0) and satisfactory prediction accuracy (R2>0.5) for mild cognitive impairment (MCI) patients for changes in CDRSB over periods of 18 months or longer. Predictions of annualized CDRSB progression>0.5, >1.0, or >1.5 demonstrated a consistent performance (i.e., Matthews correlation coefficient>0.5). These results were largely replicated in the J-ADNI case predictions.

CONCLUSIONS

Our method effectively predicted MCI patient deterioration in the CDRSB based solely on MMSE and FAQ scores. It may aid routine practice for disease-modifying therapy drug efficacy evaluation, without necessitating CDR testing at every visit.

Advertisement by medical facilities as an opportunity route of APOE genetic testing in Japan: a website analysis

The APOE-ε4 allele(s) is a strong risk factor for Alzheimer's disease (AD). A significant point of access for this allele testing is through services provided by medical facilities in Japan, which advertise out-of-insurance APOE testing on their websites. There is a concern that website advertisements for APOE testing may influence the ability for individuals to adequately self-determine whether to undergo APOE testing. We conducted a cross-sectional survey on medical facility websites in Japan advertising APOE genetic testing. We predefined desirable features for advertisement descriptions based on legal regulations and guidelines published by relevant professional societies and evaluated each website according to these features. We identified 220 medical facilities that had posted advertisements on their websites for the provision of APOE genetic testing, of which 85% were small clinics. Contact information, details, and costs of testing were described in most of the websites. Meanwhile, features such as "explaining APOE as a risk gene," "notes on interpreting APOE results," or "explaining examination methods" (e.g., blood sampling) were described to a variable degree depending on individual facilities. "Notes on genetic testing" or "referring to genetic counseling" were hardly referred to, and specialists with appropriate expertise were considered to participate in clinical practice in approximately one-third of these facilities providing APOE testing services. These website evaluation results showed moderate to substantial reliability between independent raters. These results suggest that self-determination of pursuing out-of-insurance APOE testing at some medical facilities in Japan may possibly be influenced in an inappropriate manner, at least in its entry route of taking the test.

Presenilin-1 mutation position influences amyloidosis, small vessel disease, and dementia with disease stage

INTRODUCTION

Amyloidosis, including cerebral amyloid angiopathy, and markers of small vessel disease (SVD) vary across dominantly inherited Alzheimer's disease (DIAD) presenilin-1 (PSEN1) mutation carriers. We investigated how mutation position relative to codon 200 (pre-/postcodon 200) influences these pathologic features and dementia at different stages.

METHODS

Individuals from families with known PSEN1 mutations (n = 393) underwent neuroimaging and clinical assessments. We cross-sectionally evaluated regional Pittsburgh compound B-positron emission tomography uptake, magnetic resonance imaging markers of SVD (diffusion tensor imaging-based white matter injury, white matter hyperintensity volumes, and microhemorrhages), and cognition.

RESULTS

Postcodon 200 carriers had lower amyloid burden in all regions but worse markers of SVD and worse Clinical Dementia Rating® scores compared to precodon 200 carriers as a function of estimated years to symptom onset. Markers of SVD partially mediated the mutation position effects on clinical measures.

DISCUSSION

We demonstrated the genotypic variability behind spatiotemporal amyloidosis, SVD, and clinical presentation in DIAD, which may inform patient prognosis and clinical trials.

HIGHLIGHTS

Mutation position influences Aβ burden, SVD, and dementia. PSEN1 pre-200 group had stronger associations between Aβ burden and disease stage. PSEN1 post-200 group had stronger associations between SVD markers and disease stage. PSEN1 post-200 group had worse dementia score than pre-200 in late disease stage. Diffusion tensor imaging-based SVD markers mediated mutation position effects on dementia in the late stage.

Usability of a Web-Based Registry for Preclinical Alzheimer's Disease: Implications from a Cross-Sectional Online Survey

BACKGROUND

We have been conducting a Japanese trial-ready cohort web study since 2019 as a web-based online registry to enroll individuals with preclinical Alzheimer's disease to facilitate trials on Alzheimer's disease prevention. The usability of a website might be an important factor in determining user participation and retention.

OBJECTIVES

We conducted a user questionnaire survey to analyze the usability of the Japanese trial-ready cohort website and user characteristics for future website improvement.

DESIGN

This was a cross-sectional prospective observational study.

SETTING

Online survey using Google Forms.

PARTICIPANTS

Among the Japanese trial-ready cohort web study participants, we enrolled those who provided consent to participate in the study and had completed one or more Cognitive Function Instrument tests before May 2, 2023. We sent an invitation e-mail, including the questionnaire web address, to eligible participants on July 21 and 22, 2023.

MEASUREMENTS

We analyzed the questionnaire answers, including the system usability scale score and time of response (in 24 h). We also compared the respondents' characteristics with that of all the Japanese trial-ready cohort web study participants to identify features associated with an increased/decreased response rate to the questionnaire.

RESULTS

Among the 10,112 Japanese trial-ready cohort web study participants that we sent invitation e-mails, we received 1,574 eligible responses (15.6%) within three weeks of the response acceptance period. The mean system usability scale score was 67.6, and no difference in system usability scale scores was observed in terms of age or sex. Approximately half of the respondents of the Japanese trial-ready cohort web study heard about it online, whereas one-fourth heard about it via newspapers. Contribution to drug development for dementia treatment was the most frequent motivation for participating in the Japanese trial-ready cohort web study (51.5%), followed by participation in the latest research (48.1%), concerns about self-memory (43.4%), and a family history of dementia (34.6%). Female respondents responded approximately 1.5 h later than male respondents. Lastly, those who had participated in the Japanese trial-ready cohort onsite study, were in their 70's, or had a larger number of Cognitive Function Instrument or Cogstate tests completion history were more likely to respond to the current online survey (relative risk of response > 1).

CONCLUSIONS

We conducted an online survey using Google Forms for participants in the Japanese trial-ready cohort web study to determine the usability. The results of this study might help to improve the user experience of the Japanese trial-ready cohort website itself, increase the web study registrants, maintain user retention, facilitate future online surveys, and serve as a reference for other web-based registries of presymptomatic disease status.

Advanced structural brain aging in preclinical autosomal dominant Alzheimer disease

BACKGROUND

"Brain-predicted age" estimates biological age from complex, nonlinear features in neuroimaging scans. The brain age gap (BAG) between predicted and chronological age is elevated in sporadic Alzheimer disease (AD), but is underexplored in autosomal dominant AD (ADAD), in which AD progression is highly predictable with minimal confounding age-related co-pathology.

METHODS

We modeled BAG in 257 deeply-phenotyped ADAD mutation-carriers and 179 non-carriers from the Dominantly Inherited Alzheimer Network using minimally-processed structural MRI scans. We then tested whether BAG differed as a function of mutation and cognitive status, or estimated years until symptom onset, and whether it was associated with established markers of amyloid (PiB PET, CSF amyloid-β-42/40), phosphorylated tau (CSF and plasma pTau-181), neurodegeneration (CSF and plasma neurofilament-light-chain [NfL]), and cognition (global neuropsychological composite and CDR-sum of boxes). We compared BAG to other MRI measures, and examined heterogeneity in BAG as a function of ADAD mutation variants, APOE ε4 carrier status, sex, and education.

RESULTS

Advanced brain aging was observed in mutation-carriers approximately 7 years before expected symptom onset, in line with other established structural indicators of atrophy. BAG was moderately associated with amyloid PET and strongly associated with pTau-181, NfL, and cognition in mutation-carriers. Mutation variants, sex, and years of education contributed to variability in BAG.

CONCLUSIONS

We extend prior work using BAG from sporadic AD to ADAD, noting consistent results. BAG associates well with markers of pTau, neurodegeneration, and cognition, but to a lesser extent, amyloid, in ADAD. BAG may capture similar signal to established MRI measures. However, BAG offers unique benefits in simplicity of data processing and interpretation. Thus, results in this unique ADAD cohort with few age-related confounds suggest that brain aging attributable to AD neuropathology can be accurately quantified from minimally-processed MRI.

[Survey on the Current Advertising and Sales of Mucuna pruriens in Consumer-to-consumer Internet Trading in Japan]

Mucuna pruriens (MP) is leguminous plant which contains 5% of L-3,4-dihydroxyphenylalanine (levodopa) in its seeds. It may have a potential to be used as an alternative therapy for Parkinson's disease (PD). Meanwhile, there is a concern in terms of public health that MP products can be overused by patients with PD. As an entry for patients with PD to acquire MP products in Japan, they are often purchased via internet auctions or free markets. MP products are not reagrded as 'pharmatheutical' by Japanese law as long as the specific legal requirements on advertisements are met, so that the MP products can be advertised or sold without any permission from the authorities. In this study, we aimed to conduct internet survey as to the complianse status of these legal requirements. Several major internet auction or free market websites in Japan were surveyed in May-June 2023 by the authors, and 1157 MP product pages were examined. We found approximately 30-40% of the MP products were suspected to have potential legal risks in terms of their advertisements in their website descriptions, such as claiming pharmatheutical efficacy or describing pharmatheutical-like dosages. In addition, approximately 30-40% of the MP products also did not refer to cautions not to take MP products excessively because of the levodopa ingredients. Current study suggested the need of careful description of the MP products in the auction or free market websites for the MP products exhibitors or sellers, in order to fullfill legal requirements as well as to prevent MP abuse.

Sphingolipid abnormalities in encephalomyeloradiculoneuropathy (EMRN) are associated with an anti-neutral glycolipid antibody

Accumulating evidence suggests that various sphingolipids and glycosphingolipids can act as mediators for inflammation or signaling molecules in the nervous system. In this article, we explore the molecular basis of a new neuroinflammatory disorder called encephalomyeloradiculoneuropathy (EMRN), which affects the brain, spinal cord, and peripheral nerves; in particular, we discuss whether glycolipid and sphingolipid dysmetabolism is present in patients with this disorder. This review will focus on the pathognomonic significance of sphingolipid and glycolipid dysmetabolism for the development of EMRN and the possible involvement of inflammation in the nervous system.

Brain network decoupling with increased serum neurofilament and reduced cognitive function in Alzheimer's disease

Neurofilament light chain, a putative measure of neuronal damage, is measurable in blood and CSF and is predictive of cognitive function in individuals with Alzheimer's disease. There has been limited prior work linking neurofilament light and functional connectivity, and no prior work has investigated neurofilament light associations with functional connectivity in autosomal dominant Alzheimer's disease. Here, we assessed relationships between blood neurofilament light, cognition, and functional connectivity in a cross-sectional sample of 106 autosomal dominant Alzheimer's disease mutation carriers and 76 non-carriers. We employed an innovative network-level enrichment analysis approach to assess connectome-wide associations with neurofilament light. Neurofilament light was positively correlated with deterioration of functional connectivity within the default mode network and negatively correlated with connectivity between default mode network and executive control networks, including the cingulo-opercular, salience, and dorsal attention networks. Further, reduced connectivity within the default mode network and between the default mode network and executive control networks was associated with reduced cognitive function. Hierarchical regression analysis revealed that neurofilament levels and functional connectivity within the default mode network and between the default mode network and the dorsal attention network explained significant variance in cognitive composite scores when controlling for age, sex, and education. A mediation analysis demonstrated that functional connectivity within the default mode network and between the default mode network and dorsal attention network partially mediated the relationship between blood neurofilament light levels and cognitive function. Our novel results indicate that blood estimates of neurofilament levels correspond to direct measurements of brain dysfunction, shedding new light on the underlying biological processes of Alzheimer's disease. Further, we demonstrate how variation within key brain systems can partially mediate the negative effects of heightened total serum neurofilament levels, suggesting potential regions for targeted interventions. Finally, our results lend further evidence that low-cost and minimally invasive blood measurements of neurofilament may be a useful marker of brain functional connectivity and cognitive decline in Alzheimer's disease.

A pilot study assessing sphingolipids and glycolipids dysmetabolism in idiopathic normal pressure hydrocephalus

Idiopathic normal pressure hydrocephalus usually exhibits triad of symptoms including gait disturbance, urinary incontinence, and dementia with ventriculomegaly. Currently, its pathogenesis remains to be fully elucidated. To provide a better understanding of this order, we examined whether dysmetabolism of sphingolipids as major lipid components in the brain present in cerebrospinal fluid (CSF) of the patients. Here, we measured various sphingolipidsincluding ceramide and sphingomyelin and glycolipids by electrospray ionization-tandem mass spectrometry in the cerebrospinal fluid of 19 consecutive idiopathic normal pressure hydrocephalus patients, 49 Parkinson's disease patients, and 17 neurologically normal controls. The data showed that there was a significant and specific reduction of all galactosylceramide subspecies levels in idiopathic normal pressure hydrocephalus patients compared with other groups, whereas ceramide and sphingomyelin levels as well as other neutral glycolipids such as glucosylceramide and lactosylceramide were similar in both disease states. Multiple regression analysis of sex and age did not show any correlation with galactosylceramide levels. We also examined whether MMSE scores are correlated with sphingolipid levels in iNPH patients. A specific subspecies of sphingomyelin (d18:1/18:0) only exhibited a statistically significant negative correlation (p = 0.0473, R = -0.4604) with MMSE scores but no other sphingolipids in iNPH patients. These data strongly suggest that myelin-rich galactosylceramide metabolism is severely impaired in idiopathic normal pressure hydrocephalus patients and might serve as the basis of biomarker for this disorder.

Change in long‐term care service usage in Japan following the COVID ‐19 pandemic: A survey using a nationwide statistical summary in 2018–2021

Aim

Social restrictions due to the coronavirus disease (COVID‐19) pandemic forced many long‐term care (LTC) service‐users to refrain from using services. We aimed to evaluate the degree of change in the use of LTC services.

Methods

We retrospectively analyzed data from the publicly distributed nationwide statistics summarizing the monthly number of public LTC insurance users in Japan between April 2018 and March 2021. The degree of decline was quantified as a ratio, where the ratio of a certain month to the reference month was divided by the ratio in the previous year.

Results

The use of LTC services started to decline in March 2020 and reached its largest decline in May 2020. Thereafter, it recovered but insufficiently, even as of late 2020. The degree of decline was particularly large for services provided in facilities for community‐dwelling elderly individuals [Ratio to the previous year = 0.717 (95% CI: 0.645–0.796) in short‐stay services, and Ratio = 0.876 (95% CI: 0.802–0.957) in outpatient services], but was non‐significant in other types of services, including those provided for elderly individuals living in nursing homes.

Conclusions

Community‐dwelling elderly individuals who had used outpatient or short‐stay services were especially affected by the COVID‐19 pandemic in 2020. This underlines the need for further investigation of the medium‐ or long‐term influence of the decline in service usage on the mental and physical health of the LTC service‐users and their caregivers. Geriatr Gerontol Int 2022; 22: 803–809.

Multi-cohort and longitudinal Bayesian clustering study of stage and subtype in Alzheimer's disease

Understanding Alzheimer's disease (AD) heterogeneity is important for understanding the underlying pathophysiological mechanisms of AD. However, AD atrophy subtypes may reflect different disease stages or biologically distinct subtypes. Here we use longitudinal magnetic resonance imaging data (891 participants with AD dementia, 305 healthy control participants) from four international cohorts, and longitudinal clustering to estimate differential atrophy trajectories from the age of clinical disease onset. Our findings (in amyloid-β positive AD patients) show five distinct longitudinal patterns of atrophy with different demographical and cognitive characteristics. Some previously reported atrophy subtypes may reflect disease stages rather than distinct subtypes. The heterogeneity in atrophy rates and cognitive decline within the five longitudinal atrophy patterns, potentially expresses a complex combination of protective/risk factors and concomitant non-AD pathologies. By alternating between the cross-sectional and longitudinal understanding of AD subtypes these analyses may allow better understanding of disease heterogeneity.

Automated Evaluation of Conventional Clock-Drawing Test Using Deep Neural Network: Potential as a Mass Screening Tool to Detect Individuals With Cognitive Decline

Introduction

The Clock-Drawing Test (CDT) is a simple cognitive tool to examine multiple domains of cognition including executive function. We aimed to build a CDT-based deep neural network (DNN) model using data from a large cohort of older adults, to automatically detect cognitive decline, and explore its potential as a mass screening tool.

Methods

Over 40,000 CDT images were obtained from the National Health and Aging Trends Study (NHATS) database, which collects the annual surveys of nationally representative community-dwelling older adults in the United States. A convolutional neural network was utilized in deep learning architecture to predict the cognitive status of participants based on drawn clock images.

Results

The trained DNN model achieved balanced accuracy of 90.1 ± 0.6% in identifying those with a decline in executive function compared to those without [positive likelihood ratio (PLH) = 16.3 ± 6.8, negative likelihood ratio (NLH) = 0.14 ± 0.03], and 77.2 ± 2.7 % balanced accuracy for identifying those with probable dementia from those without (PLH = 5.1 ± 0.5, NLH = 0.37 ± 0.07).

Conclusions

This study demonstrated the feasibility of implementing conventional CDT to be automatically evaluated by DNN with a fair performance in a larger scale than ever, suggesting its potential as a mass screening test for ruling-in or ruling-out those with executive dysfunction or with probable dementia.

Time to onset of drug-induced parkinsonism: Analysis using a large Japanese adverse event self-reporting database

Whether there are differences in the time to onset of drug-induced parkinsonism (DIP) depending on the type of drugs causing DIP remains uncertain, so that question was investigated here using a large real-world database. Fourteen DIP-related drug categories were defined to perform a disproportionality analysis using a large Japanese pharmacovigilance database containing more than 600,000 self-reported adverse events (AEs) recorded between April 2004 and September 2021 to identify AEs indicating "parkinsonism" in association with the defined drug categories. The time from drug administration to the onset of DIP was comparatively analyzed. Results indicated that the median time to onset was shorter than 1 month in more than half of the cases of DIP; it was shortest with peripheral dopamine antagonists (median: 0.1 weeks), followed by benzodiazepine (median: 0.5 weeks), butyrophenone (median: 0.7 weeks), novel antidepressants (median: 2.5 weeks), atypical antipsychotics (median: 3.3 weeks), other antidepressants (e.g., lithium, median: 3.7 weeks), and benzamide (median: 4.5 weeks). In contrast, anti-dementia drugs, tricyclic antidepressants, and antiepileptic drugs resulted in a relatively longer time to onset (median: 9.9, 17.2, and 28.4 weeks, respectively). In addition, a maximum delay of even longer than 2 years was reported for benzamide (846 weeks), anti-Parkinsonism drugs (382 weeks), phenothiazine (232 weeks), atypical antipsychotics (167 weeks), anti-dementia drugs (161 weeks), and benzodiazepines (120 weeks). The current results suggested that the characteristics of the time to onset of DIP may substantially differ depending on the type of drug causing that DIP. This finding may help when diagnosing patients with parkinsonism.

Soluble TREM2 in CSF and its association with other biomarkers and cognition in autosomal-dominant Alzheimer's disease: a longitudinal observational study

BACKGROUND

Therapeutic modulation of TREM2-dependent microglial function might provide an additional strategy to slow the progression of Alzheimer's disease. Although studies in animal models suggest that TREM2 is protective against Alzheimer's pathology, its effect on tau pathology and its potential beneficial role in people with Alzheimer's disease is still unclear. Our aim was to study associations between the dynamics of soluble TREM2, as a biomarker of TREM2 signalling, and amyloid β (Aβ) deposition, tau-related pathology, neuroimaging markers, and cognitive decline, during the progression of autosomal dominant Alzheimer's disease.

METHODS

We did a longitudinal analysis of data from the Dominantly Inherited Alzheimer Network (DIAN) observational study, which includes families with a history of autosomal dominant Alzheimer's disease. Participants aged over 18 years who were enrolled in DIAN between Jan 1, 2009, and July 31, 2019, were categorised as either carriers of pathogenic variants in PSEN1, PSEN2, and APP genes (n=155) or non-carriers (n=93). We measured amounts of cleaved soluble TREM2 using a novel immunoassay in CSF samples obtained every 2 years from participants who were asymptomatic (Clinical Dementia Rating [CDR]=0) and annually for those who were symptomatic (CDR>0). CSF concentrations of Aβ40, Aβ42, total tau (t-tau), and tau phosphorylated on threonine 181 (p-tau) were measured by validated immunoassays. Predefined neuroimaging measurements were total cortical uptake of Pittsburgh compound B PET (PiB-PET), cortical thickness in the precuneus ascertained by MRI, and hippocampal volume determined by MRI. Cognition was measured using a validated cognitive composite (including DIAN word list test, logical memory delayed recall, digit symbol coding test [total score], and minimental status examination). We based our statistical analysis on univariate and bivariate linear mixed effects models.

FINDINGS

In carriers of pathogenic variants, a high amyloid burden at baseline, represented by low CSF Aβ42 (β=-4·28 × 10-2 [SE 0·013], p=0·0012), but not high cortical uptake in PiB-PET (β=-5·51 × 10-3 [0·011], p=0·63), was the only predictor of an augmented annual rate of subsequent increase in soluble TREM2. Augmented annual rates of increase in soluble TREM2 were associated with a diminished rate of decrease in amyloid deposition, as measured by Aβ42 in CSF (r=0·56 [0·22], p=0·011), in presymptomatic carriers of pathogenic variants, and with diminished annual rate of increase in PiB-PET (r=-0·67 [0·25], p=0·0060) in symptomatic carriers of pathogenic variants. Presymptomatic carriers of pathogenic variants with annual rates of increase in soluble TREM2 lower than the median showed a correlation between enhanced annual rates of increase in p-tau in CSF and augmented annual rates of increase in PiB-PET signal (r=0·45 [0·21], p=0·035), that was not observed in those with rates of increase in soluble TREM2 higher than the median. Furthermore, presymptomatic carriers of pathogenic variants with rates of increase in soluble TREM2 above or below the median had opposite associations between Aβ42 in CSF and PiB-PET uptake when assessed longitudinally. Augmented annual rates of increase in soluble TREM2 in presymptomatic carriers of pathogenic variants correlated with decreased cortical shrinkage in the precuneus (r=0·46 [0·22]), p=0·040) and diminished cognitive decline (r=0·67 [0·22], p=0·0020).

INTERPRETATION

Our findings in autosomal dominant Alzheimer's disease position the TREM2 response within the amyloid cascade immediately after the first pathological changes in Aβ aggregation and further support the role of TREM2 on Aβ plaque deposition and compaction. Furthermore, these findings underpin a beneficial effect of TREM2 on Aβ deposition, Aβ-dependent tau pathology, cortical shrinkage, and cognitive decline. Soluble TREM2 could, therefore, be a key marker for clinical trial design and interpretation. Efforts to develop TREM2-boosting therapies are ongoing.

FUNDING

German Research Foundation, US National Institutes of Health.

Editorial: Alzheimer's Disease Research in Japan: A Short History, Current Status and Future Perspectives toward Prevention

A recent report from the Hisayama study, a representative regional cohort in Japan, showed that the lifetime risk of dementia in the Japanese elderly population has exceeded 50%, in which >50% of all dementia cause is comprised by Alzheimer’s disease (AD) (1). The total number of individuals with dementia in Japan is more than >5 million, and the global costs of dementia is estimated to exceed 14.5 trillion yen (equivalent to ~133 billion USD). Thus, there is an urgent and compelling need for the prevention of dementia, especially that of AD.

A Japanese Multicenter Study on PET and Other Biomarkers for Subjects with Potential Preclinical and Prodromal Alzheimer's Disease

BACKGROUND

PET (positron emission tomography) and CSF (cerebrospinal fluid) provide the "ATN" (Amyloid, Tau, Neurodegeneration) classification and play an essential role in early and differential diagnosis of Alzheimer's disease (AD).

OBJECTIVE

Biomarkers were evaluated in a Japanese multicenter study on cognitively unimpaired subjects (CU) and early (E) and late (L) mild cognitive impairment (MCI) patients.

MEASUREMENTS

A total of 38 (26 CU, 7 EMCI, 5 LMCI) subjects with the age of 65-84 were enrolled. Amyloid-PET and FDG-PET as well as structural MRI were acquired on all of them, with an additional tau-PET with 18F-flortaucipir on 15 and CSF measurement of Aβ1-42, P-tau, and T-tau on 18 subjects. Positivity of amyloid and tau was determined based on the positive result of either PET or CSF.

RESULTS

The amyloid positivity was 13/38, with discordance between PET and CSF in 6/18. Cortical tau deposition quantified with PET was significantly correlated with CSF P-tau, in spite of discordance in the binary positivity between visual PET interpretation and CSF P-tau in 5/8 (PET-/CSF+). Tau was positive in 7/9 amyloid positive and 8/16 amyloid negative subjects who underwent tau measurement, respectively. Overall, a large number of subjects presented quantitative measures and/or visual read that are close to the borderline of binary positivity, which caused, at least partly, the discordance between PET and CSF in amyloid and/or tau. Nine subjects presented either tau or FDG-PET positive while amyloid was negative, suggesting the possibility of non-AD disorders.

CONCLUSION

Positivity rate of amyloid and tau, together with their relationship, was consistent with previous reports. Multicenter study on subjects with very mild or no cognitive impairment may need refining the positivity criteria and cutoff level as well as strict quality control of the measurements.

Facial nerve palsy following the administration of COVID-19 mRNA vaccines: analysis of a self-reporting database

Objectives: Facial nerve palsy (or Bell's palsy) has occasionally been reported following the administration of coronavirus disease 2019 (COVID-19) mRNA vaccines (BNT162b2 and mRNA-1273). Our study investigated such cases using a large self-reporting database from the USA (Vaccine Adverse Event Reporting System [VAERS]).

Methods: A disproportionality analysis, adjusted for age and sex, was conducted for VAERS reports from individuals who were vaccinated at the age of 18 years or over, between January 2010 and April 2021.

Results: The analysis revealed that the adverse events following immunization (AEFI) of facial nerve palsy, after administration of COVID-19 mRNA vaccines, was significantly highly reported, both for BNT162b2 (reporting odds ratio [ROR] 1.84; 95% confidence interval [CI] 1.65–2.06) and mRNA-1273 (ROR 1.54; 95% CI 1.39–1.70). These levels were comparable to that following influenza vaccination reported before the COVID-19 pandemic (ROR 2.04; 95% CI 1.76–2.36).

Conclusions: Our pharmacovigilance study results suggest that the incidence of facial nerve palsy as a non-serious AEFI may be lower than, or equivalent to, that for influenza vaccines. This information might be of value in the context of promoting worldwide vaccination, but needs to be validated in future observational studies.

Comparison of CSF biomarkers in Down syndrome and autosomal dominant Alzheimer's disease: a cross-sectional study

BACKGROUND

Due to trisomy of chromosome 21 and the resultant extra copy of the amyloid precursor protein gene, nearly all adults with Down syndrome develop Alzheimer's disease pathology by the age of 40 years and are at high risk for dementia given their increased life expectancy compared with adults with Down syndrome in the past. We aimed to compare CSF biomarker patterns in Down syndrome with those of carriers of autosomal dominant Alzheimer's disease mutations to enhance our understanding of disease mechanisms in these two genetic groups at high risk for Alzheimer's disease.

METHODS

We did a cross-sectional study using data from adults enrolled in the Alzheimer's Biomarker Consortium-Down Syndrome (ABC-DS) study, a multisite longitudinal study of Alzheimer's disease in Down syndrome, as well as a cohort of carriers of autosomal dominant Alzheimer's disease mutations and non-carrier sibling controls enrolled in the Dominantly Inherited Alzheimer Network (DIAN) study. For ABC-DS, participants with baseline CSF, available clinical diagnosis, and apolipoprotein E genotype as of Jan 31, 2019, were included in the analysis. DIAN participants with baseline CSF, available clinical diagnosis, and apolipoprotein E genotype as of June 30, 2018, were evaluated as comparator groups. CSF samples obtained from adults with Down syndrome, similarly aged carriers of autosomal dominant Alzheimer's disease mutations, and non-carrier siblings (aged 30-61 years) were analysed for markers of amyloid β (Aβ1-40, Aβ1-42); tau phosphorylated at threonine 181-related processes; neuronal, axonal, or synaptic injury (total tau, visinin-like protein 1, neurofilament light chain [NfL], synaptosomal-associated protein 25); and astrogliosis and neuroinflammation (chitinase-3-like protein 1 [YKL-40]) via immunoassay. Biomarker concentrations were compared as a function of dementia status (asymptomatic or symptomatic), and linear regression was used to evaluate and compare the relationship between biomarker concentrations and age among groups.

FINDINGS

We assessed CSF samples from 341 individuals (178 [52%] women, 163 [48%] men, aged 30-61 years). Participants were adults with Down syndrome (n=41), similarly aged carriers of autosomal dominant Alzheimer's disease mutations (n=192), and non-carrier siblings (n=108). Individuals with Down syndrome had patterns of Alzheimer's disease-related CSF biomarkers remarkably similar to carriers of autosomal dominant Alzheimer's disease mutations, including reductions (all p<0·0080) in Aβ1-42 to Aβ1-40 ratio and increases in markers of phosphorylated tau-related processes; neuronal, axonal, and synaptic injury (p<0·080); and astrogliosis and neuroinflammation, with greater degrees of abnormality in individuals with dementia. Differences included overall higher concentrations of Aβ and YKL-40 (both p<0·0008) in Down syndrome and potential elevations in CSF tau (p<0·010) and NfL (p<0·0001) in the asymptomatic stage (ie, no dementia symptoms).

FUNDING

National Institute on Aging, Eunice Kennedy Shriver National Institute of Child Health and Human Development, German Center for Neurodegenerative Diseases, and Japan Agency for Medical Research and Development.

Efficacy and Cost-effectiveness of Promotion Methods to Recruit Participants to an Online Screening Registry for Alzheimer Disease Prevention Trials: Observational Study

Background

Web-based screening may be suitable for identifying individuals with presymptomatic latent diseases for recruitment to clinical studies, as such people do not often visit hospitals in the presymptomatic stage. The promotion of such online screening studies is critical to their success, although it remains uncertain how the effectiveness of such promotion can differ, depending on the different promotion methods, domains of interest, or countries of implementation.

Objective

The Japanese Trial-Ready Cohort (J-TRC) web study is our ongoing online screening registry to identify individuals with presymptomatic Alzheimer disease (AD), aimed at facilitating the clinical trials for AD prevention. Within the first 9 months of its 2019 launch, the J-TRC web study recruited thousands of online participants via multiple methods of promotion, including press releases, newspaper advertisements, web advertisements, or direct email invitations. Here, we aimed to quantitatively evaluate efficacy and cost-effectiveness of each of these multimodal promotion methods.

Methods

We applied the vector-autoregression model to assess the degree of contribution of each type of promotion to the following target metrics: number of daily visitors to the J-TRC website, number of daily registrants to the J-TRC web study, daily rate of registration among visitors, daily rate of eligible participants among registrants, and median age of daily registrants. The average cost-effectiveness for each promotion method was also calculated using the total cost and the coefficients in the vector-autoregression model.

Results

During the first 9 months of the reviewed period from October 31, 2019 to June 17, 2020, there were 48,334 website visitors and 4429 registrations (9.16% of 48,334 visitors), of which 3081 (69.56%) were eligible registrations. Initial press release reports and newspaper advertisements had a marked effect on increasing the number of daily visitors and daily registrants. Web advertisements significantly contributed to the increase in daily visitors (P<.001) but not to the daily registrants, and it also lowered the rate of registrations and the median age of daily registrants. Website visitors from the direct email invitation sent to other cognitive registries seem to have registered with the highest reliability. The calculated average cost-effectiveness for the initial press release was US $24.60 per visitor and US $96.10 per registrant, while the calculated average cost-effectiveness for the newspaper advertisements was US $28.60 per visitor and US $227.90 per registrant.

Conclusions

Our multivariate time-series analysis showed that each promotion method had different features in their effect of recruiting participants to the J-TRC web study. Under the advertisement condition settings thus far, newspaper advertisements and initial press releases were the most effective promotion methods, with fair cost-effectiveness that was equivalent to earlier online studies. These results can provide important suggestions for future promotions for the recruitment of presymptomatic participants to AD clinical trials in Japan.

The impact of COVID-19 pandemic on the utilization of ambulatory care for patients with chronic neurological diseases in Japan: Evaluation of an administrative claims database

The COVID-19 pandemic has affected not only the emergency medical system, but also patients' regular ambulatory care, as such decrease in the number of patients visiting outpatient clinics decreased in 2020 than in 2019, or the ban lifting of subsequent visits by telephone for outpatient clinics since March 2020 in lieu of ambulatory care for chronic diseases. In this context, we investigate the impact of the COVID-19 pandemic on ambulatory care at Japanese outpatient clinics for patients with chronic neurological diseases during 2020. We collected data from the administrative claims database (DeSC database) covering more than 1 million individuals. Serial changes in the frequency of subsequent outpatient visits to clinics or hospitals (excluding large hospitals) for chronic ambulatory care of epilepsy, migraine, Parkinson's disease (PD), and Alzheimer's disease (AD) in 2020 were measured. As a result, since April 2020, the monthly outpatient visits for epilepsy, PD, and AD decreased slightly but significantly (approximately 0.90 in relative risk [RR]) but visits for migraine increased (RR = 1.15). Telephone visit was most frequently used in April-May, in less than 5% of monthly outpatient clinic visits for the examined neurological diseases. Outpatient visits for migraine treatment were more likely to be done by telephone than in case of other diseases (adjusted Odds ratio = 2.08). These results suggest that the impact of COVID-19 pandemic on regular ambulatory care for several chronic neurological diseases yielded different effect depending on the disease, in terms of the frequency or type of outpatient visits.

Magnetic Resonance Neurography in a Patient with Distal Neuralgic Amyotrophy

The pathophysiology of neuralgic amyotrophy (NA) remains to be elucidated. However, high-resolution magnetic resonance imaging and ultrasound sonography have provided new insights into the mechanism underlying the development of NA and its diagnosis. We report a case of idiopathic distal NA with hyperintensity and thickening in the inferior trunk extending to the posterior and medial fasciculus of the left brachial plexus, which was detected by magnetic resonance neurography (MRN) with diffusion-weighted whole-body imaging with background body signal suppression (DWIBS). The abnormal signal intensity diminished after the improvement of symptoms following corticosteroid treatment. MRN with DWI can help diagnose distal NA and evaluate the post-therapeutic response.

Predicting amyloid risk by machine learning algorithms based on the A4 screen data: Application to the Japanese Trial-Ready Cohort study

BACKGROUND

Selecting cognitively normal elderly individuals with higher risk of brain amyloid deposition is critical to the success of prevention trials for Alzheimer's disease (AD).

METHODS

Based on the Anti-Amyloid Treatment in Asymptomatic Alzheimer's Disease study data, we built machine-learning models and applied them to our ongoing Japanese Trial-Ready Cohort (J-TRC) webstudy participants registered within the first 9 months (n = 3081) of launch to predict standard uptake value ratio (SUVr) of amyloid positron emission tomography.

RESULTS

Age, family history, online Cognitive Function Instrument and CogState scores were important predictors. In a subgroup of J-TRC webstudy participants with known amyloid status (n = 37), the predicted SUVr corresponded well with the self-reported amyloid test results (area under the curve = 0.806 [0.619-0.992]).

DISCUSSION

Our algorithms may be usable for automatic prioritization of candidate participants with higher amyloid risks to be preferentially recruited from the J-TRC webstudy to in-person study, maximizing efficiency for the identification of preclinical AD participants.

Cerebrospinal Fluid Profiles in Parkinson's Disease: No Accumulation of Glucosylceramide, but Significant Downregulation of Active Complement C5 Fragment

BACKGROUND

As mutations in glucocerebrosidase 1 (GBA1) are a major risk factor for Parkinson's disease (PD), decreased GBA1 activity might play an important role in the pathogenesis of the disease. However, there are currently no reports on glucosylceramide levels in the cerebrospinal fluid (CSF) in PD.

OBJECTIVE

We investigated whether glucosylceramide accumulation and abnormal immune status in the brain are associated with PD.

METHODS

We measured glucosylceramide by liquid chromatography-electrospray ionization-tandem mass spectrometry (LC-ESI-MS/MS) as well as levels of the active fragment of complement C5, C5a, in the CSF of 33 PD, 15 amyotrophic lateral sclerosis (ALS) and 22 neurologically normal control (NNC) subjects. Serum C5a levels in all PD and ALS cases and in a limited number of NNC subjects (n = 8) were also measured.

RESULTS

C5a levels in CSF were significantly downregulated in PD compared with NNC. Moreover, CSF C5a/serum C5a ratio showed pronounced perturbations in PD and ALS patients. LC-ESI-MS/MS revealed a statistically significant accumulation of a specific subspecies of glucosylceramide (d18 : 1/C23 : 0 acyl chain fatty acid) in ALS, but not in PD. Interestingly, CSF glucosylceramide (d18 : 1/C23 : 0) exhibited a significant correlation with CSF C5a levels in PD, but not ALS. No correlation was observed between C5a levels or glucosylceramide subspecies content and disease duration, levodopa equivalent daily dose or Hoehn & Yahr staging in PD.

CONCLUSION

Our findings demonstrate complement dysregulation without glucosylceramide accumulation in PD CSF. Furthermore, we found an association between a specific glucosylceramide subspecies and immune status in PD.

Cohort-Specific Optimization of Models Predicting Preclinical Alzheimer's Disease, to Enhance Screening Performance in the Middle of Preclinical Alzheimer's Disease Clinical Studies

BACKGROUND

Models that can predict brain amyloid beta (Aβ) status more accurately have been desired to identify participants for clinical trials of preclinical Alzheimer's disease (AD). However, potential heterogeneity between different cohorts and the limited cohort size have been the reasons preventing the development of reliable models applicable to the Asian population, including Japan.

OBJECTIVES

We aim to propose a novel approach to predict preclinical AD while overcoming these constraints, by building models specifically optimized for ADNI or for J-ADNI, based on the larger samples from A4 study data.

DESIGN AND PARTICIPANTS

This is a retrospective study including cognitive normal participants (CDR-global = 0) from A4 study, Alzheimer Disease Neuroimaging Initiative (ADNI), and Japanese-ADNI (J-ADNI) cohorts.

MEASUREMENTS

The model is made up of age, sex, education years, history of AD, Clinical Dementia Rating-Sum of Boxes, Preclinical Alzheimer Cognitive Composite score, and APOE genotype, to predict the degree of amyloid accumulation in amyloid PET as Standardized Uptake Value ratio (SUVr). The model was at first built based on A4 data, and we can choose at which SUVr threshold configuration the A4-based model may achieve the best performance area under the curve (AUC) when applied to the random-split half ADNI or J-ADNI subset. We then evaluated whether the selected model may also achieve better performance in the remaining ADNI or J-ADNI subsets.

RESULT

When compared to the results without optimization, this procedure showed efficacy of AUC improvement of up to approximately 0.10 when applied to the models "without APOE;" the degree of AUC improvement was larger in the ADNI cohort than in the J-ADNI cohort.

CONCLUSIONS

The obtained AUC had improved mildly when compared to the AUC in case of literature-based predetermined SUVr threshold configuration. This means our procedure allowed us to predict preclinical AD among ADNI or J-ADNI second-half samples with slightly better predictive performance. Our optimizing method may be practically useful in the middle of the ongoing clinical study of preclinical AD, as a screening to further increase the prior probability of preclinical AD before amyloid testing.

Galabiosylceramide is present in human cerebrospinal fluid

Cerebrospinal fluid (CSF) contains glycosphingolipids, including lactosylceramide (LacCer, Galβ(1,4)Glcβ-ceramide). LacCer and its structural isomer, galabiosylceramide (Gb₂, Galα(1,4)Galβ-ceramide), are classified as ceramide dihexosides (CDH). Gb₂ is degraded by α-galactosidase A (GLA) in lysosomes, and genetic GLA deficiency causes Fabry disease, an X-linked lysosomal storage disorder. In patients with Fabry disease, Gb₂ accumulates in organs throughout the body. While Gb₂ has been reported to be in the liver, kidney, and urine of healthy individuals, its presence in CSF has not been reported, either in patients with Fabry disease or healthy controls. Here, we isolated CDH fractions from CSF of patients with idiopathic normal pressure hydrocephalus. Purified CDH fractions showed positive reaction with Shiga toxin, which specifically binds to the Galα(1,4)Galβ structure. The isolated CDH fractions were analyzed by hydrophilic interaction chromatography (HILIC)-electrospray ionization tandem mass spectrometry (ESI-MS/MS). HILIC-ESI-MS/MS separated LacCer and Gb₂ and revealed the presence of Gb₂ and LacCer in the fractions. We also found Gb₂ in CSF from neurologically normal control subjects. This is the first report to show Gb₂ exists in human CSF.

Cauda Equina and Filum Terminale Arteriovenous Fistulas: Anatomic and Radiographic Features

Intradural AVF below the conus medullaris may develop either on the filum terminale or the cauda equina (lumbosacral and coccygeal radicular nerves). Although not a few filum terminale AVFs are found in the literature, only 3 detailed cauda equina AVFs have been reported. Here, we analyze the angiographic and MR imaging findings of our cauda equina and filum terminale AVF cases, supplemented with literature research to characterize the radiologic features of the 2 entities. On angiography, filum terminale AVFs were invariably supplied by the extension of the anterior spinal artery accompanied by a closely paralleling filum terminale vein. Cauda equina AVFs were fed by either a radicular or a spinal artery or both arteries, often with a characteristic wavy radicular-perimedullary draining vein. On thin-section axial MR imaging, the filum terminale AVF draining vein joined the spinal cord at the conus medullaris apex, but that of the cauda equina AVF joined above the conus medullaris apex.

Cavity resonator for circularly polarized microwave irradiation mounted on a cryostat

We have constructed a cylindrical cavity resonator with a hybrid coupler where circularly polarized microwaves can be irradiated to a sample. The polarity of the microwave can be switched by changing the input ports of the hybrid coupler. The cavity resonator is small enough to be mounted on a cryostat which enables us to change the sample temperature in a wide range. To demonstrate the performance of the cavity resonator mounted on a cryostat, Yttrium Iron Garnet (YIG) was used as a test sample. We succeeded in selectively exciting left and right circularly polarized modes with high polarization (>80%). We also evaluated the susceptibility tensor of YIG in the cryostat. The technique presented here would offer a new direction in the fields of spintronics and quantum information.

A Patient With Thiamine Deficiency Exhibiting Muscle Edema Suggested by MRI

Myalgia is sometimes observed in patients with thiamine-deficiency neuropathy. However, the detailed mechanism(s) underlying muscular manifestations have been poorly elucidated. We herein report a possible patient with thiamine-deficiency neuropathy exhibiting muscle weakness and myalgia in lower limbs. The patient exhibited abnormal muscle signal intensities on MRI corresponding to the site of myalgia. After thiamine replacement therapy, rapid improvement of clinical symptoms and abnormal MRI findings were observed. Muscle MRI findings in this case implicated the possible mechanism of myalgia observed in patients with thiamine deficiency neuropathy.

Fatigue evaluated using the 16-item Parkinson Fatigue Scale (PFS-16) predicts Parkinson's disease prognosis

BACKGROUND

Although fatigue is an important nonmotor symptom in Parkinson's Disease (PD) patients, little is known about the pathophysiological details of fatigue in PD, and it is still unknown whether fatigue correlates with PD prognosis. In this study, we investigated whether fatigue in PD correlates with clinical manifestations, treatment, or patient prognosis.

METHODS

We recruited 75 idiopathic PD patients and used the Parkinson Fatigue Scale (PFS-16) to investigate fatigue. We compared PFS-16 scores with clinical details such as age, disease duration, daily levodopa equivalent dosage, and Hoehn & Yahr (H&Y) disease stage in the 56 patients who fully completed the questionnaire.

RESULTS

In total, 62% of subjects suffered from fatigue, as defined by a mean PFS-16 score above 3.3. There was no correlation between PFS-16 scores and disease duration or levodopa equivalent daily dose. However, there was a significant correlation between mean PFS-16 scores and a worsening grade of H&Y staging. The comparison between patients who showed stable H&Y grades (n=26) and patients with severely aggravated H&Y grades (n=7) revealed that the most significant differences were in questions 14 and 16 in the PFS-16 (p<0.001).

CONCLUSION

Fatigue is common in PD patients, as demonstrated in the present study. The PFS-16 questionnaire may be helpful to predict disease prognosis.

Altered regulation of serum lysosomal acid hydrolase activities in Parkinson's disease: A potential peripheral biomarker?

INTRODUCTION

Recent studies have indicated that lysosomal dysfunction contributes to the development of idiopathic Parkinson's disease (PD). It is uncertain whether dysregulation of serum lysosomal acid hydrolase activity exists in sporadic PD patients compared with normal controls (NCs) and parkinsonian syndrome (PS) patients.

METHODS

Sporadic PD patients without GBA1 mutations (n = 68) were matched with normal controls (n = 45), and parkinsonian syndrome patients (n = 32) in terms of family history, age, and sex. We measured the activities of lysosomal enzymes, α-galactosidase, β-galactosidase, and β-hexosaminidase and examined the possible correlations between lysosomal acid hydrolase activities with age in NCs, PD, and PS patients.

RESULTS

β-Galactosidase activity was significantly higher in the PD and PS than in the NC group (P < 0.001). The β-galactosidase to α-galactosidase and β-hexosaminidase to β-galactosidase activity ratios were more useful for distinguishing PD and PS patients from NCs (P < 0.0001). Furthermore, α-galactosidase activity was significantly higher in PS patients than both PD and NC groups (p = 0.04). β-Galactosidase and α-galactosidase activities exhibited a statistically significant negative correlation with age in NCs, and β-hexosaminidase activity showed a positive correlation with age in PS. However, PD patients did not show any of these correlations.

CONCLUSION

Our results suggest the presence of an unknown regulatory mechanism(s) of serum acid hydrolase activities with aging in the normal population and abnormalities in their regulation in PD and PS patients. However, the pattern of dysregulation in these two groups is different. Thus, serum lysosomal acid hydrolase activity can be used as a peripheral biomarker for PD.

Changes in Serial D-Dimer Levels Predict the Prognoses of Trousseau's Syndrome Patients

Background: The development of acute multiple embolic infarctions (AMEI) resulting from cancer is known as Trousseau's syndrome (TS). At present, however, there is no good marker for predicting the prognosis of TS patients. In the present study, we evaluated the use of serial D-dimer levels as a prognostic marker for TS.

Methods: This retrospective cohort study included 1,409 consecutive acute ischemic stroke patients. We selected a group of patients with TS showing AMEI (n = 38; TS group) and a group of patients with atrial fibrillation (Af) and AMEI (n = 35; Af group) as controls. Serial D-dimer levels were measured between days 7 and 28 after stroke (sub-acute phase) in 21 patients of the TS group and 24 patients of the Af group.

Results: D-dimer levels at onset (acute phase) were significantly higher in the TS group (8.45 ± 1.79 μg/mL, n = 38) compared with the Af group (1.14 ± 0.14 μg/mL, n = 35) (p < 0.0001). In patients for whom serial D-dimer measurements were made, D-dimer levels measured at the sub-acute phase decreased to 0.48 ± 0.12 μg/mL (n = 24) in the Af group, but remained elevated in the TS group during the sub-acute phase (11.20 ± 2.77 μg/mL, n = 21) (p < 0.0001). In all TS patients in whom serial D-dimer measurements were made, D-dimer levels in 17 patients who died within 500 days (13.31 ± 3.23 μg/mL) were significantly higher than those of the four surviving patients (2.23 ± 0.38 μg/mL) (cut-off D-dimer level = 3.0 μg/mL) during this period. Moreover, serial D-dimer levels of 10 patients who died within 90 days (17.78 ± 4.60 μg/mL) were significantly higher than those of the 11 patients who survived up to 90 days (5.21 ± 2.12 μg/mL) (p < 0.05).

Conclusions: Serial D-dimer levels may be a good biomarker for TS as well as a useful predictor of the prognosis of TS patients.

Anti-GM1 ganglioside antibodies modulate membrane-associated sphingomyelin metabolism by altering neutral sphingomyelinase activity

Previous studies have shown that patients with Guillain-Barré syndrome express autoantibodies against ganglioside GM1 (GM1), although its pathogenic significance for the development of the disease remains to be elucidated. nSMase2 is the best characterized neutral sphingomyelinase (nSMase) found in neuronal cells. Activation of this enzyme leads to ceramide production, which is a known second messenger of the cell-death program in neuronal cells. We have explored the effects of anti-GM1 antibodies on sphingomyelin metabolism of PC12 cells stably transfected with human trk cDNA (PCtrk cells) by determining their effects on nSMase2 activity. The data we present here strongly suggest that anti-GM1 caused a significant change in sphingomyelin content of the membrane fraction in PCtrk cells. Both nSMase2 activity and the level of nSMase2 protein were significantly decreased by anti-GM1 treatment of PCtrk cells, while acidic SMase activities remained unchanged. Our results indicate, for the first time, that anti-GM1 may produce profound impacts on lipid metabolism in neuronal cell membranes.

Multiple Spinal Perimedullary Arteriovenous Fistulae Associated with the Parkes-Weber Syndrome

We present a rare case of multiple spinal perimedullary arteriovenous fistulae associated with the Parkes-Weber (PW) syndrome.

A 31-year-old male known to have the PW syndrome involving the left leg since birth, presented with a 7-month-history of progressive myelopathy of the lower extremities and dysfunction of the bladder and bowel. Myelography demonstrated dilated intradural vessels. Angiography demonstrated two distinct single hole perimedullary arteriovenous fistulae near the conus at two different metameres. They were supplied by the left posterior spinal artery.

The patient was treated by transarterial embolisation using polyvinyl alcohol particles, which resulted in venous side occlusion of the fistulae. After the treatment, the patient developed transient worsening of the spasticity of the lower extremities, and was treated by heparinization. After heparinization, the patient partially recovered from the pre-embolisation status of his myelopathy.

The follow-up angiogram one year after the embolisation demonstrated persistent obliteration of both fistulae. At long-term follow-up, the patient can ambulate without assistance and work as a farmer.

Occlusion of Posterior Fossa Dural Sinuses in Vein of Galen Malformation

BACKGROUND AND PURPOSE

Spontaneous or progressive occlusion of the posterior fossa dural sinuses is often observed in patients with vein of Galen malformation, which can affect the clinical course. The aim of this study was to examine the patency of the posterior fossa dural sinuses in patients with vein of Galen malformation and to analyze the clinical and angiographic course of this condition.

MATERIALS AND METHODS

We retrospectively reviewed 61 consecutive children with vein of Galen malformations. Clinical presentation, management, outcome, and angiographic change were analyzed for the patients with attention paid to all dural sinus occlusions.

RESULTS

Twenty patients (32.8%) demonstrated spontaneous sinus occlusion, mostly in the sigmoid sinus. This condition was not observed in neonates and was first discovered during infancy or childhood. Progression of sinus occlusion was seen in 10 patients, and the conditions of 6 of them deteriorated in accordance with the progression of sinus occlusion. After total or subtotal obliteration of the malformation by transarterial glue embolization, 13 patients recovered to healthy, 3 patients had only mild developmental delay, and 4 patients remained neurologically disabled.

CONCLUSIONS

Spontaneous sinus occlusion is not a rare condition and can result in neurologic deterioration in the natural history of untreated vein of Galen malformation. If signs of progressive sinus occlusion are noticed, early arteriovenous shunt reduction or elimination by transarterial glue embolization is expected to prevent permanent brain damage.

Strong Suppression of the Spin Hall Effect in the Spin Glass State

We have measured spin Hall effects in spin glass metals, CuMnBi alloys, with the spin absorption method in the lateral spin valve structure. Far above the spin glass temperature T(g) where the magnetic moments of Mn impurities are randomly frozen, the spin Hall angle of a CuMnBi ternary alloy is as large as that of a CuBi binary alloy. Surprisingly, however, it starts to decrease at about 4T(g) and becomes as little as 7 times smaller at 0.5T(g). A similar tendency was also observed in anomalous Hall effects in the ternary alloys. We propose an explanation in terms of a simple model considering the relative dynamics between the localized moment and the conduction electron spin.

The Preventive Effect of Endovascular Treatment for Recurrent Hemorrhage in Patients with Spinal Cord Arteriovenous Malformations

BACKGROUND AND PURPOSE

Spinal cord AVMs represent rare and insufficiently studied pathologic entities. Embolization is thought to play an important role in the management of spinal cord AVMs. Factors for recurrent hemorrhage and the impact of endovascular treatment on prevention of recurrent hemorrhage remain to be confirmed. We aimed to assess recurrent hemorrhagic incidence of spinal cord AVMs and its prevention by endovascular treatment.

MATERIALS AND METHODS

We reviewed 80 patients with spinal cord AVMs by spinal cord angiography who had hemorrhage before the first endovascular treatment at New York University Medical Center, Beth Israel Medical Center, or Roosevelt Hospital in New York. We compared the baseline and radiologic characteristics of patients with and without recurrent hemorrhage by the log-rank test and the Cox proportional hazards model.

RESULTS

We observed recurrent hemorrhage in 35 (44%) patients (1/41 patients with endovascular treatment and 34/39 patients without endovascular treatment). The median length of total follow-up was 659 days (interquartile range, 129-2640 days), and the median length from first-to-recurrent hemorrhage was 369 days (interquartile range, 30-1596 days). The log-rank test revealed that endovascular treatment and venous thrombosis reduced recurrent hemorrhage, and associated aneurysm was related to recurrent hemorrhage. Even in multivariate analysis, the endovascular treatment reduced (hazard ratio, 0.027; P < .0001) and associated aneurysm increased (hazard ratio, 3.4; P = .044) the risk of recurrent hemorrhage.

CONCLUSIONS

Endovascular embolization is the first choice of treatment for spinal cord AVMs and is effective in preventing recurrent hemorrhage.

Quasiparticle-mediated spin Hall effect in a superconductor

In some materials the competition between superconductivity and magnetism brings about a variety of unique phenomena such as the coexistence of superconductivity and magnetism in heavy-fermion superconductors or spin-triplet supercurrent in ferromagnetic Josephson junctions. Recent observations of spin-charge separation in a lateral spin valve with a superconductor evidence that these remarkable properties are applicable to spintronics, although there are still few works exploring this possibility. Here, we report the experimental observation of the quasiparticle-mediated spin Hall effect in a superconductor, NbN. This compound exhibits the inverse spin Hall (ISH) effect even below the superconducting transition temperature. Surprisingly, the ISH signal increases by more than 2,000 times compared with that in the normal state with a decrease of the injected spin current. The effect disappears when the distance between the voltage probes becomes larger than the charge imbalance length, corroborating that the huge ISH signals measured are mediated by quasiparticles.

Pathology of embolic debris in carotid artery stenting

BACKGROUND

The relationship between magnetic resonance (MR) plaque imaging and the pathology of distal embolic debris is unknown. We aimed to evaluate the relationship between the pathology of embolic debris in the embolic filter during carotid artery stenting (CAS), MR plaque imaging, and new ischemic lesions on diffusion-weighted imaging (DWI).

METHOD

We prospectively reviewed the 36 patients who underwent CAS using a filter-type embolic protection device. Pathology of debris was categorized into thrombosis, inflammatory cells, elastic fiber, and calcification. We compared the clinical parameters, MR plaque imaging, and pathological characteristics of the embolic debris retained in the filter during CAS on univariate analysis.

RESULTS

Eleven patients had and 25 patients did not have new lesion on DWI. All of DWI-high lesions were identified in affected side middle cerebral artery territory. Embolic debris was microscopically confirmed in 28 patients (78%); thrombosis in 11 (31%), inflammatory cells in 13 (36%), elastic fiber in 12 (33%), and calcification in 9 (25%). Proportion of asymptomatic carotid stenosis, intra-operative bradycardia/hypotension, and inflammatory cells of debris were significantly higher in patients with new DWI-high lesions. There was no significant relationship between the pathological characteristics and MR plaque imaging of distal embolic debris.

CONCLUSIONS

Our study showed that new DWI-high lesions might be influenced by types of debris in the filter. The need for future studies specifically examine the association of pathology of debris and findings of MR plaque imaging with new DWI-high lesions during CAS is emphasized.

Arterial stiffness as a risk factor for cerebral aneurysm

OBJECTIVES

A low ankle-brachial index (ABI) is associated with increased mortality and risk of myocardial infarction and stroke in the general population. Arterial stiffness can be assessed non-invasively by the measurement of brachial-ankle pulse wave velocity (PWV), a simple and reproducible method. Because the importance of ABI and baPWV in the pathogenesis of cerebral aneurysms remains uncertain, we aimed to measure ABI and baPWV in patients with intracranial saccular and dissecting aneurysms to clarify whether these aneurysms are associated with arterial stiffness and atherosclerosis.

MATERIALS AND METHODS

We prospectively investigated 78 patients diagnosed with intracranial saccular (n = 66) and dissecting (n = 12) aneurysms. The control group consisted of an age- and gender-matched normal population. We compared the clinical characteristics in patients with intracranial saccular aneurysms and controls, those with intracranial dissecting aneurysms and controls, and those who had cerebral aneurysms with and without subarachnoid hemorrhage. We also compared ABI and baPWV among saccular aneurysm locations and evaluated the correlation between the number of saccular aneurysms and ABI and baPWV.

RESULTS

Multivariate logistic regression analysis shows that hypertension and higher baPWV (>1400 cm/s) are significantly associated with saccular aneurysms. Simple regression analysis revealed no correlation between the number of saccular aneurysms and ABI (r = -0.064, P = 0.611), and baPWV (r = 0.007, P = 0.956).

CONCLUSIONS

The baPWV was associated with intracranial saccular aneurysms even after adjustment of hypertension and smoking. Assessment of the baPWV may aid the evaluation of the intracranial saccular aneurysm and the development of strategies for screening patients with intracranial saccular aneurysms.