In Vivo Assessment of Astrocyte Reactivity in Patients with Progressive Supranuclear Palsy.

OBJECTIVE: Although astrocytic pathology is a pathological hallmark of progressive supranuclear palsy (PSP), its pathophysiological role remains unclear. This study aimed to assess astrocyte reactivity in vivo in patients with PSP. Furthermore, we investigated alterations in brain lactate levels and their relationship with astrocyte reactivity. METHODS: We included 30 patients with PSP-Richardson syndrome and 30 healthy controls; in patients, tau deposition was confirmed through 18F-florzolotau positron emission tomography. Myo-inositol, an astroglial marker, and lactate were quantified in the anterior cingulate cortex through magnetic resonance spectroscopy. We measured plasma biomarkers, including glial fibrillary acidic protein as another astrocytic marker. The anterior cingulate cortex was histologically assessed in postmortem samples of another 3 patients with PSP with comparable disease durations. RESULTS: The levels of myo-inositol and plasma glial fibrillary acidic protein were significantly higher in patients than those in healthy controls (p < 0.05); these increases were significantly associated with PSP rating scale and cognitive function scores (p < 0.05). The lactate level was high in patients, and correlated significantly with high myo-inositol levels. Histological analysis of the anterior cingulate cortex in patients revealed reactive astrocytes, despite mild tau deposition, and no marked synaptic loss. INTERPRETATION: We discovered high levels of astrocyte biomarkers in patients with PSP, suggesting astrocyte reactivity. The association between myo-inositol and lactate levels suggests a link between reactive astrocytes and brain energy metabolism changes. Our results indicate that astrocyte reactivity in the anterior cingulate cortex precedes pronounced tau pathology and neurodegenerative processes in that region, and affects brain function in PSP. ANN NEUROL 2024.

Plasma biomarkers for predicting the development of dementia in a community-dwelling older Japanese population.

AIM: To assess the association between plasma amyloid ß (Aß) 42/40, phosphorylated tau (p-τ)181, glial fibrillary acidic protein (GFAP), or neurofilament light chain (NfL) and the risk of dementia and to determine whether these plasma biomarkers could improve the ability to predict incident dementia in a general older population. METHODS: A total of 1346 Japanese community-dwelling individuals aged ≥65 years without dementia were followed prospectively for 5.0 years. Plasma biomarkers were quantified using a Simoa HD-X analyzer. A Cox proportional hazards model was used to estimate the hazard ratios of each plasma biomarker level for the risk of dementia. RESULTS: During the follow-up, 151 participants developed dementia, of whom 108 had Alzheimer disease (AD) and 43 non-Alzheimer dementia (non-AD). Lower plasma Aß42/40 levels and higher plasma p-τ181 levels were significantly associated with developing AD but not non-AD, whereas significant associations were observed between higher plasma levels of GFAP and NfL and risk of both AD and non-AD (all P for trend <0.05). In addition, adding these four plasma biomarkers into a model consisting of the total score of the dementia risk model significantly improved the predictive ability for incident dementia. CONCLUSION: Our findings suggest that plasma Aß42/40 and p-τ181 are specific markers of AD, and plasma GFAP and NfL are potential biomarkers for all-cause dementia in the general Japanese older population. In addition, the measurement of these plasma biomarkers may be a useful and relatively low-invasive procedure for identifying individuals at high risk for developing dementia in clinical practice.

Validation of a newly developed immunoassay for TDP-43 in human plasma.

The level of TAR DNA-binding protein 43 (TDP-43) in human blood was reported to have potential for use as a specific fluid biomarker, which represents disease-specific pathologies, for TDP-43 proteinopathies, including amyotrophic lateral sclerosis (ALS) and frontotemporal lobar degeneration (FTLD), which involves the aggregation and deposition of TDP-43 in the nervous system. However, at present, no reliable immunoassay can precisely quantify TDP-43 in human plasma and detect the difference in plasma TDP-43 levels between patients with ALS and controls. We recently developed a novel ultrasensitive immunoassay to quantify TDP-43 in human plasma, and in this study, we analytically validated this assay for application as a diagnostic biomarker for TDP-43 proteinopathies. The novel TDP-43 assay was assessed for the limit of detection, lower limit of quantification, intra- and interassay variation, linearity, parallelism, and analytical spike recoveries. Additionally, 17 pilot plasma samples obtained from patients with ALS and age-matched controls were analyzed using the assay. Our novel TDP-43 assay showed sufficient analytical performance to quantify TDP-43 in human plasma, with high sensitivity (LOD and LLOQ of 0.109 and 0.759 pg/mL, respectively) and high intra- and interassay precision (%CV) below 15 %. The experimental results for spike recovery, parallelism, and dilution linearity were also acceptable. In addition, despite a small sample size, significant differences in the plasma levels of TDP-43 were found between patients with ALS and controls (ALS, 66.63 ± 20.52 pg/mL; control, 42.70 ± 23.06 pg/mL, p = 0.0330). These results support that our novel TDP-43 assay is a reliable and innovative method for the quantification of TDP-43 in human plasma and can be a potential blood-based biomarker for the diagnosis of TDP-43 proteinopathies. Further large-scale studies are warranted to validate its usefulness.

Investigating neural dysfunction with abnormal protein deposition in Alzheimer's disease through magnetic resonance spectroscopic imaging, plasma biomarkers, and positron emission tomography.

In Alzheimer's disease (AD), aggregated abnormal proteins induce neuronal dysfunction. Despite the evidence supporting the association between tau proteins and brain atrophy, further studies are needed to explore their link to neuronal dysfunction in the human brain. To clarify the relationship between neuronal dysfunction and abnormal proteins in AD-affected brains, we conducted magnetic resonance spectroscopic imaging (MRSI) and assessed the neurofilament light chain plasma levels (NfL). We evaluated tau and amyloid-ß depositions using standardized uptake value ratios (SUVRs) of florzolotau (18F) for tau and 11C-PiB for amyloid-ß positron emission tomography in the same patients. Heatmaps were generated to visualize Z scores of glutamate to creatine (Glu/Cr) and N-acetylaspartate to creatine (NAA/Cr) ratios using data from healthy controls. In AD brains, Z score maps revealed reduced Glu/Cr and NAA/Cr ratios in the gray matter, particularly in the right dorsolateral prefrontal cortex (rDLPFC) and posterior cingulate cortex (PCC). Glu/Cr ratios were negatively correlated with florzolotau (18F) SUVRs in the PCC, and plasma NfL levels were elevated and negatively correlated with Glu/Cr (P = 0.040, r = -0.50) and NAA/Cr ratios (P = 0.003, r = -0.68) in the rDLPFC. This suggests that the abnormal tau proteins in AD-affected brains play a role in diminishing glutamate levels. Furthermore, neuronal dysfunction markers including Glu/tCr and NAA/tCr could potentially indicate favorable clinical outcomes. Using MRSI provided spatial information about neural dysfunction in AD, enabling the identification of vulnerabilities in the rDLPFC and PCC within the AD's pathological context.

Altered Brain Energy Metabolism Related to Astrocytes in Alzheimer's Disease.

OBJECTIVE: Increasing evidence suggests that reactive astrocytes are associated with Alzheimer's disease (AD). However, its underlying pathogenesis remains unknown. Given the role of astrocytes in energy metabolism, reactive astrocytes may contribute to altered brain energy metabolism. Astrocytes are primarily considered glycolytic cells, suggesting a preference for lactate production. This study aimed to examine alterations in astrocytic activities and their association with brain lactate levels in AD. METHODS: The study included 30 AD and 30 cognitively unimpaired participants. For AD participants, amyloid and tau depositions were confirmed by positron emission tomography using [11 C]PiB and [18 F]florzolotau, respectively. Myo-inositol, an astroglial marker, and lactate in the posterior cingulate cortex were quantified by magnetic resonance spectroscopy. These magnetic resonance spectroscopy metabolites were compared with plasma biomarkers, including glial fibrillary acidic protein as another astrocytic marker, and amyloid and tau positron emission tomography. RESULTS: Myo-inositol and lactate levels were higher in AD patients than in cognitively unimpaired participants (p < 0.05). Myo-inositol levels correlated with lactate levels (r = 0.272, p = 0.047). Myo-inositol and lactate levels were positively associated with the Clinical Dementia Rating sum-of-boxes scores (p < 0.05). Significant correlations were noted between myo-inositol levels and plasma glial fibrillary acidic protein, tau phosphorylated at threonine 181 levels, and amyloid and tau positron emission tomography accumulation in the posterior cingulate cortex (p < 0.05). INTERPRETATION: We found high myo-inositol levels accompanied by increased lactate levels in the posterior cingulate cortex in AD patients, indicating a link between reactive astrocytes and altered brain energy metabolism. Myo-inositol and plasma glial fibrillary acidic protein may reflect similar astrocytic changes as biomarkers of AD. ANN NEUROL 2023.

[How Helpful are Blood and Cerebrospinal Fluid Biomarkers for the Early Diagnosis of Alzheimer's Disease?]

Early diagnosis of Alzheimer's disease (AD) relies on imaging and fluid biomarkers to objectively detect and quantitatively evaluate brain AD pathologies. Amyloid- and tau-PET scans recently enabled clinicians to make definitive diagnoses based on abnormal amyloid/tau deposition in the human brain. Since PET scans and blood-based biomarkers are mutually complementary, the identification of suitable blood-based biomarkers is essential for screening brain AD pathologies. According to the National Institute on Aging and Alzheimer's Association (NIA-AA) Research Framework published in 2018, AD is defined by its underlying pathologic processes, which can be diagnosed in vivo using suitable biomarkers. These biomarkers are categorized under the ATN classification system, including ß amyloid deposition (A), pathologic tau (T), and neurodegeneration (N). Originally, all the ATN fluid biomarkers were assessed using cerebrospinal fluid, but currently these biomarkers can be quantified using blood samples. Among those blood-based ATN biomarkers, the plasma levels of Aß42/40 ratio, p-tau, and neurofilament light chain (NfL) representing "A," "T," and "N" biomarkers, respectively, are useful in the early diagnosis of AD. However, further studies and additional data are required before utilizing these blood-based biomarkers as stand-alone diagnostic markers for AD.

IgG index of cerebrospinal fluid can reflect pathophysiology associated with Lewy bodies in Parkinson's disease.

BACKGROUND: Neuroinflammation is one of the pathophysiologies of Parkinson's disease (PD). Lewy bodies, the pathological hallmark of PD, emerge as a consequence of α-synuclein aggregation, and neuroinflammation is induced concurrently with this aggregation. Imaging and cerebrospinal fluid (CSF) biomarkers that reflect PD pathophysiology have been developed or are under investigation. The IgG index of CSF is a marker of inflammation, and may also reflect the pathophysiology of PD. AIM: We examined if the IgG index reflects the pathophysiology of PD in drug-naïve PD patients. METHOD: The subjects were 20 consecutive PD patients who underwent 123I-MIBG scintigraphy for assessment of the heart to mediastinum (H/M) ratio and wash out rate, 123I-Ioflupane SPECT for examination of the specific binding ratio in the striatum, and lumbar puncture before treatment. The CSF IgG index and levels of pathogenic proteins (total α-synuclein, oligomeric α-synuclein, total tau, phosphorylated tau and amyloid Aß1-42) were determined. The IgG index was compared with the other parameters using Spearman correlation analysis. RESULTS: The IgG index showed a significant correlation with the H/M ratio in early (r = -0.563, p = 0.010) and delayed (r = -0.466, p = 0.038) images in 123I-MIBG scintigraphy and with the CSF total tau level (r = -0.513, p = 0.021). CONCLUSION: Neuroinflammation is involved in PD pathophysiology in some patients, and a higher IgG index indicates the presence of neuroinflammation accompanied by emergence of Lewy bodies.

Enzymatic properties and clinical associations of serum alpha-galactosidase A in Parkinson's disease.

OBJECTIVE: Recent studies have revealed an association between Parkinson's disease (PD) and Fabry disease, a lysosomal storage disorder; however, the underlying mechanisms remain to be elucidated. This study aimed to investigate the enzymatic properties of serum alpha-galactosidase A (GLA) and compared them with the clinical parameters of PD. METHODS: The study participants consisted of 66 sporadic PD patients and 52 controls. We measured serum GLA activity and calculated the apparent Michaelis constant (Km ) and maximal velocity (Vmax ) by Lineweaver-Burk plot analysis. Serum GLA protein concentration was measured by enzyme-linked immunosorbent assay. We examined the potential correlations between serum GLA activity and GLA protein concentration and clinical features and the plasma neurofilament light chain (NfL) level. RESULTS: Compared to controls, PD patients showed significantly lower serum GLA activity (P < 0.0001) and apparent Vmax (P = 0.0131), but no change in the apparent Km value. Serum GLA protein concentration was lower in the PD group (P = 0.0168) and was positively associated with GLA activity. Serum GLA activity and GLA protein concentration in the PD group showed a negative correlation with age. Additionally, serum GLA activity was negatively correlated with the motor severity score and the level of plasma NfL, and was positively correlated with the score of frontal assessment battery. INTERPRETATION: This study highlights that the lower serum GLA activity in PD is the result of a quantitative decrement of GLA protein in the serum and that it may serve as a biomarker of disease severity.

Associations of Alzheimer's-related plasma biomarkers with cognitive decline in Parkinson's disease.

BACKGROUND: Parkinson's disease (PD) is associated with cognitive decline through multiple mechanisms, including Alzheimer's disease (AD) pathology and cortical Lewy body involvement. However, its underlying mechanisms remain unclear. Recently, AD-related plasma biomarkers have emerged as potential tools for predicting abnormal pathological protein accumulation. We aimed to investigate the association between AD-related plasma biomarkers and cognitive decline in PD patients. METHODS: Plasma biomarkers were measured in 70 PD patients (49 with nondemented Parkinson's disease (PDND) and 21 with Parkinson's disease dementia (PDD)) and 38 healthy controls (HCs) using a single-molecule array. The study evaluated (1) the correlation between plasma biomarkers and clinical parameters, (2) receiver operating characteristic curves and areas under the curve to evaluate the discrimination capacity of plasma biomarkers among groups, and (3) a generalized linear model to analyze associations with Addenbrooke's Cognitive Examination-Revised and Montreal Cognitive Assessment-Japanese version scores. RESULTS: Plasma glial fibrillary acidic protein significantly correlated with cognitive function tests, including all subdomains, with a notable increase in the PDD group compared with the HC and PDND groups, while plasma neurofilament light chain captured both cognitive decline and disease severity in the PDND and PDD groups. Plasma beta-amyloid 42/40 and pholphorylated-tau181 indicated AD pathology in the PDD group, but plasma beta-amyloid 42/40 was increased in the PDND group compared with HCs and decreased in the PDD group compared with the PDND group. CONCLUSIONS: AD-related plasma biomarkers may predict cognitive decline in PD and uncover underlying mechanisms suggesting astrocytic pathologies related to cognitive decline in PD.

Safety and tolerability of bosutinib in patients with amyotrophic lateral sclerosis (iDReAM study): A multicentre, open-label, dose-escalation phase 1 trial.

Background: Amyotrophic lateral sclerosis (ALS) is a progressive neurodegenerative disease caused by the loss of motor neurons, and development of effective medicines is urgently required. Induced pluripotent stem cell (iPSC)-based drug repurposing identified the Src/c-Abl inhibitor bosutinib, which is approved for the treatment of chronic myelogenous leukemia (CML), as a candidate for the molecular targeted therapy of ALS. Methods: An open-label, multicentre, dose-escalation phase 1 study using a 3 + 3 design was conducted in 4 hospitals in Japan to evaluate the safety and tolerability of bosutinib in patients with ALS. Furthermore, the exploratory efficacy was evaluated using Revised ALS Functional Rating Scale (ALSFRS-R), predictive biomarkers including plasma neurofilament light chain (NFL) were explored, and single-cell RNA sequencing of iPSC-derived motor neurons was conducted. Patients, whose total ALSFRS-R scores decreased by 1-3 points during the 12-week, received escalating doses starting from 100 mg quaque die (QD) up to 400 mg QD based on dose-limiting toxicity (DLT) occurrence, and all participants who received one dose of the study drug were included in the primary analysis. This trial is registered with ClinicalTrials.gov, NCT04744532, as Induced pluripotent stem cell-based Drug Repurposing for Amyotrophic Lateral Sclerosis Medicine (iDReAM) study. Findings: Between March 29, 2019 and May 7, 2021, 20 patients were enrolled, 13 of whom received bosutinib treatment and 12 were included in the safety and efficacy analyses. No DLTs were observed up to 300 mg QD, but DLTs were observed in 3/3 patients of the 400 mg QD cohort. In all patients receiving 100 mg-400 mg, the prevalent adverse events (AEs) were gastrointestinal AEs in 12 patients (92.3%), liver function related AEs in 7 patients (53.8%), and rash in 3 patients (23.1%). The safety profile was consistent with that known for CML treatment, and ALS-specific AEs were not observed. A subset of patients (5/9 patients) was found to respond well to bosutinib treatment over the 12-week treatment period. It was found that the treatment-responsive patients could be distinguished by their lower levels of plasma NFL. Furthermore, single-cell RNA sequencing of iPSC-derived motor neurons revealed the pathogenesis related molecular signature in patients with ALS showing responsiveness to bosutinib. Interpretation: This is the first trial of a Src/c-Abl inhibitor, bosutinib, for patients with ALS. The safety and tolerability of bosutinib up to 300 mg, not 400 mg, in ALS were described, and responsiveness of patients on motor function was observed. Since this was an open-label trial within a short period with a limited number of patients, further clinical trials will be required. Funding: AMED and iPS Cell Research Fund.

Soluble TREM2 and Alzheimer-related biomarker trajectories in the blood of patients with diabetes based on their cognitive status.

AIM: We aimed to elucidate the dynamics of blood biomarkers according to the severity of cognitive impairment in patients with type 2 diabetes mellitus (DM) and to identify useful biomarkers for diabetes-related dementia. METHODS: This was a cross-sectional, nested case-control study of 121 Japanese DM and non-DM patients with different levels of cognitive functioning. We evaluated participants' cognitive functions, blood biomarkers related to Alzheimer's disease, and soluble triggering receptors expressed on myeloid cells 2 (sTREM2). We then compared these biomarkers between the DM and non-DM and across the different cognitive strata. RESULTS: In all cognitive strata, significantly lower levels of serum sTREM2 were observed in the DM than in the non-DM. We also found that plasma levels of phosphorylated tau (p-tau) increased with increasing levels of cognitive decline in both the DM and non-DM. However, this was accompanied by a decrease in plasma amyloid-ß(Aß42/Aß40 ratios in non-DM only. CONCLUSION: This study revealed novel characteristic trajectories of dementia-related blood biomarkers in diabetes-related dementia, suggesting the pathological involvement of molecular cascades initiated by impaired microglial activation. This results in decreased serum sTREM2, followed by tauopathy without substantial amyloid plaques, reflected by plasma p-tau elevation with no decrease in the Aß42/Aß40 ratio. Clinical trials (the unique trial number and the name of the registry): UMIN000048032, https://www.umin.ac.jp.

A Machine Learning-Based Approach to Discrimination of Tauopathies Using [18 F]PM-PBB3 PET Images.

BACKGROUND: We recently developed a positron emission tomography (PET) probe, [18 F]PM-PBB3, to detect tau lesions in diverse tauopathies, including mixed three-repeat and four-repeat (3R + 4R) tau fibrils in Alzheimer's disease (AD) and 4R tau aggregates in progressive supranuclear palsy (PSP). For wider availability of this technology for clinical settings, bias-free quantitative evaluation of tau images without a priori disease information is needed. OBJECTIVE: We aimed to establish tau PET pathology indices to characterize PSP and AD using a machine learning approach and test their validity and tracer capabilities. METHODS: Data were obtained from 50 healthy control subjects, 46 patients with PSP Richardson syndrome, and 37 patients on the AD continuum. Tau PET data from 114 regions of interest were subjected to Elastic Net cross-validation linear classification analysis with a one-versus-the-rest multiclass strategy to obtain a linear function that discriminates diseases by maximizing the area under the receiver operating characteristic curve. We defined PSP- and AD-tau scores for each participant as values of the functions optimized for differentiating PSP (4R) and AD (3R + 4R), respectively, from others. RESULTS: The discriminatory ability of PSP- and AD-tau scores assessed as the area under the receiver operating characteristic curve was 0.98 and 1.00, respectively. PSP-tau scores correlated with the PSP rating scale in patients with PSP, and AD-tau scores correlated with Mini-Mental State Examination scores in healthy control-AD continuum patients. The globus pallidus and amygdala were highlighted as regions with high weight coefficients for determining PSP- and AD-tau scores, respectively. CONCLUSIONS: These findings highlight our technology's unbiased capability to identify topologies of 3R + 4R versus 4R tau deposits. © 2022 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.

[Recommendations (Proposal) for promoting research for overcoming neurological diseases 2020].

The Japanese Society of Neurology discusses research, education, and medical care in the field of neurology and makes recommendations to the national government. Dr. Mizusawa, the former representative director of the Japanese Society of Neurology, selected committee members and made "Recommendations for Promotion of Research for Overcoming Neurological Diseases" in 2013. After that, the Future Vision Committee was established in 2014, and these recommendations have been revised once every few years by the committee. This time, the Future Vision Committee made the latest recommendations from 2020 to 2021. In this section I, we will discuss clinical and research topics of neurology categorized by the methodology, including genetic research, translational research, nucleic acid therapies, iPS research, and nursing/welfare.

[Recommendations (Proposal) for promoting research for overcoming neurological diseases 2020].

The Japanese Society of Neurology discusses research, education, and medical care in the field of neurology and makes recommendations to the national government. Dr. Mizusawa, the former representative director of the Japanese Society of Neurology, selected committee members and made "Recommendations for Promotion of Research for Overcoming Neurological Diseases" in 2013. After that, the Future Vision Committee was established in 2014, and these recommendations have been revised once every few years by the committee. This time, the Future Vision Committee made the latest recommendations from 2020 to 2021. In this section II, we will discuss clinical and research topics of neurology categorized by the diseases. In each field, the hot topic of the disease was described by the expert.

[Idiopathic Normal Pressure Hydrocephalus and Neurodegenerative Diseases: a Short Review of Differential Diagnosis].

There are a variety of neurodegenerative diseases that require differentiation from idiopathic normal pressure hydrocephalus(iNPH), including Alzheimer's disease, Parkinson's disease, dementia with Lewy bodies, frontotemporal dementia, progressive supranuclear palsy, and corticobasal degeneration. As the clinical features and structural imaging findings of these diseases may overlap with iNPH, biomarkers reflecting disease-specific pathology are necessary for differential diagnosis. In addition, these diseases often coexist with iNPH in elderly patients, and it is important to confirm the coexistence of their pathology even in cases clinically diagnosed as iNPH. This review provides an overview of established and emerging biomarkers for neurodegenerative diseases.

Serum asymmetric dimethylarginine level correlates with the progression and prognosis of amyotrophic lateral sclerosis.

BACKGROUND AND PURPOSE: The aim was to investigate the association between serum asymmetric dimethylarginine (ADMA) levels and the progression and prognosis of amyotrophic lateral sclerosis (ALS), and to compare cerebrospinal fluid (CSF) and serum ADMA levels with other biomarkers of ALS. METHODS: Serum ADMA levels of sporadic ALS patients (n = 68), disease control patients (n = 54) and healthy controls (n = 20) were measured using liquid chromatography tandem mass spectrometry. Correlations of the ADMA level and other markers (nitric oxide and neurofilament light chain levels) were analyzed. Changes in the ALS Functional Rating Scale Revised (ALSFRS-R) score from the onset of disease (ALSFRS-R pre-slope) was used to assess disease progression. Survival was evaluated using the Cox proportional hazards model and Kaplan-Meier analysis. RESULTS: The serum ADMA level was substantially higher in patients with ALS than in healthy controls and disease controls. Serum ADMA level correlated with CSF ADMA level (r = 0.591, p < 0.0001) and was independently associated with the ALSFRS-R pre-slope (r = 0.505, p < 0.0001). Patients with higher serum ADMA levels had less favorable prognoses. CSF ADMA level significantly correlated with CSF neurofilament light chain level (r = 0.456, p = 0.0002) but not with nitric oxide level (r = 0.194, p = 0.219). CONCLUSION: Serum ADMA level is an independent biomarker of ALS disease progression and prognosis and reflects the degree of motor neuron degeneration.

Amyotrophic lateral sclerosis: Correlations between fluid biomarkers of NfL, TDP-43, and tau, and clinical characteristics.

OBJECTIVES: We previously reported the diagnostic and prognostic performance of neurofilament light chain (NfL), TAR DNA-binding protein 43 (TDP-43), and total tau (t-tau) in cerebrospinal fluid (CSF) and plasma as amyotrophic lateral sclerosis (ALS) biomarkers. The present study aimed to elucidate associations between clinical characteristics and the markers as well as mutual associations of the markers in ALS patients using the same dataset. METHODS: NfL, TDP-43, and t-tau levels in CSF and plasma in 75 ALS patients were analyzed. The associations between those markers and clinical details were investigated by uni- and multivariate analyses. Correlations between the markers were analyzed univariately. RESULTS: In multivariate analysis of CSF proteins, the disease progression rate (DPR) was positively correlated with NfL (ß: 0.51, p = 0.007) and t-tau (ß: 0.37, p = 0.03). Plasma NfL was correlated with age (ß: 0.53, p = 0.005) and diagnostic grade (ß: -0.42, p = 0.02) in multivariate analysis. Plasma TDP-43 was correlated negatively with split hand index (ß: -0.48, p = 0.04) and positively with % vital capacity (ß: 0.64, p = 0.03) in multivariate analysis. Regarding mutual biomarker analysis, a negative correlation between CSF-NfL and TDP-43 was identified (r: -0.36, p = 0.002). CONCLUSIONS: Elevated NfL and t-tau levels in CSF may be biomarkers to predict rapid DPR from onset to sample collection. The negative relationship between CSF NfL and TDP-43 suggests that elevation of CSF TDP-43 in ALS is not a simple consequence of its release into CSF during neurodegeneration. The negative correlation between plasma TDP-43 and split hand index may support the pathophysiological association between plasma TDP-43 and ALS.

[Recommendations (Proposal) for promoting research for overcoming neurological diseases 2020].

The Japanese Society of Neurology discusses research, education, and medical care in the field of neurology and makes recommendations to the national government. Dr. Mizusawa, the former representative director of the Japanese Society of Neurology, selected committee members and made "Recommendations for Promotion of Research for Overcoming Neurological Diseases" in 2013. After that, the Future Vision Committee was established in 2014, and these recommendations have been revised once every few years by the committee. This time, the Future Vision Committee made the latest recommendations from 2020 to 2021. In this document, the general part is 1) What is neurological disease? 2) Current status of neurological disease overcoming research, 3) Significance and necessity of neurological disease overcoming research, 4) Research promotion system for overcoming neurological disease, 5) the roadmap for overcoming neuromuscular diseases, 6) a summary version of these recommendations are explained using figures that are easy for the general public to understand.

Proteomic Profiling of Extracellular Vesicles Separated from Plasma of Former National Football League Players at Risk for Chronic Traumatic Encephalopathy.

Chronic Traumatic Encephalopathy (CTE) is a tauopathy that affects individuals with a history of exposure to repetitive head impacts, including National Football League (NFL) players. Extracellular vesicles (EVs) are known to carry tau in Alzheimer's disease and other tauopathies. We examined protein profiles of EVs separated from the plasma of former NFL players at risk for CTE. EVs were separated from the plasma from former NFL players and age-matched controls using size-exclusion chromatography. Label-free quantitative proteomic analysis identified 675 proteins in plasma EVs, and 17 proteins were significantly differentially expressed between former NFL players and controls. Total tau (t-tau) and tau phosphorylated at threonie181 (p-tau181) in plasma-derived EVs were measured by ultrasensitive immunoassay. Level of t-tau and p-tau181 in EVs were significantly different, and the area under the receiver operating characteristic curve (AUC) of t-tau and p-tau181 showed 0.736 and 0.715, respectively. Machine learning analysis indicated that a combination of collagen type VI alpha 3 and 1 chain (COL6A3 and COL6A1) and reelin (RELN) can distinguish former NFL players from controls with 85% accuracy (AUC = 0.85). Based on the plasma EV proteomics, these data provide protein profiling of plasma EVs for CTE, and indicate combination of COL6A3, RELN and COL6A1 in plasma EVs may serve as the potential diagnostic biomarkers for CTE.

Cerebrospinal α-Synuclein Oligomers Reflect Disease Motor Severity in DeNoPa Longitudinal Cohort.

BACKGROUND: Tangible efforts have been made to identify biomarkers for Parkinson's disease (PD) diagnosis and progression, with α-synuclein (α-syn) related biomarkers being at the forefront. OBJECTIVES: The objectives of this study were to explore whether cerebrospinal fluid (CSF) levels of total, oligomeric, phosphorylated Ser 129 α-synuclein, along with total tau, phosphorylated tau 181, and ß-amyloid 1-42 are (1) informative as diagnostic markers for PD, (2) changed over disease progression, and/or (3) correlated with motor and cognitive indices of disease progression in the longitudinal De Novo Parkinson cohort. METHODS: A total of 94 de novo PD patients and 52 controls at baseline and 24- and 48-month follow-up were included, all of whom had longitudinal lumbar punctures and clinical assessments for both cognitive and motor functions. Using our in-house enzymelinked immunosorbent assays and commercially available assays, different forms of α-synuclein, tau, and ß-amyloid 1-42 were quantified in CSF samples from the De Novo Parkinson cohort. RESULTS: Baseline CSF total α-synuclein was significantly lower in early de novo PD compared with healthy controls, whereas the ratio of oligomeric/total and phosphorylated/total were significantly higher in the PD group. CSF oligomeric-α-synuclein longitudinally increased over the 4-year follow-up in the PD group and correlated with PD motor progression. Patients at advanced stages of PD presented with elevated CSF oligomeric-α-synuclein levels compared with healthy controls. CONCLUSIONS: Longitudinal transitions of CSF biomarkers over disease progression might not occur linearly and are susceptible to disease state. CSF oligomeric-α-synuclein levels appear to increase with diseases severity and reflect PD motor rather than cognitive trajectories. © 2021 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.