Quantification of monoamine oxidase B expression with C-SL25.1188 for imaging reactive astrocytes in patients with Alzheimer's disease.

Purpose: Astrocyte reactivation can be assessed using positron emission tomography (PET) ligands targeting monoamine oxidase B (MAO-B). C-SL25.1188 binds reversibly to MAO-B, allowing precise density measurements, but requires invasive arterial sampling.

Neural Basis of Anxiety in Dementia With Lewy Bodies.

Objective: The association between core clinical features and anxiety and the neural basis of anxiety in patients with dementia with Lewy bodies (DLB) are unknown. Therefore, this study examined the core clinical features associated with anxiety in DLB and identified the brain regions associated with anxiety using statistical imaging analysis.

Methods: This study was conducted using a part of the data from "The Japan multicenter study: Behavioral and psychological symptoms Integrated Research in Dementia-Retrospective Neuroimaging part".

Advances in PET imaging of protein aggregates associated with neurodegenerative disease.

Neurodegenerative diseases such as Alzheimer disease (AD), Parkinson disease, frontotemporal lobar degeneration and multiple system atrophy (MSA) are characterized pathologically by deposition of specific proteins in the brain. Five major neurodegenerative disease-associated proteins - amyloid-β (Aβ), tau, α-synuclein, TAR DNA-binding protein 43 (TDP43) and fused in sarcoma (FUS) - are commonly encountered, and the disease specificity and neurotoxicity of the fibrillar protein assemblies are determined by factors such as the protein type, fibril structure, degree of multimerization and post-translational modifications. This article reviews the latest advances in PET technologies aimed at visualizing neurodegenerative proteinopathies, and highlights the importance of these technologies for emerging diagnostic and therapeutic approaches.

Neuropathological correlations of F-florzolotau PET in a case with pick's disease.

Background: Pick's disease (PiD) is classified as frontotemporal lobar degeneration with pathological tau aggregates. Positron emission tomography (PET) with F-florzolotau provides high-contrast imaging of diverse tau fibrils. While our previous work demonstrated the detectability of three repeat (3R) tau pathology by F-florzolotau PET in an autopsy-confirmed PiD patient, its potential for quantitative assessment of 3R tau aggregates in living individuals remains unclear.

Concurrent Alzheimer's disease pathologies in Lewy body diseases affect cognition and glucose metabolism in the posterior cingulate gyrus: A multimodal PET study.

BackgroundLewy body disease (LBD) is a neurodegenerative disease characterized by Lewy bodies, and it clinically presents dementia with Lewy bodies (DLB) and Parkinson's disease (PD). Alzheimer's disease (AD) pathologies frequently coexist with LBD, complicating the clinical manifestation.ObjectiveWe evaluated the impact of AD pathologies, including amyloid-β and tau depositions, on cognitive dysfunction and glucose metabolism in LBD using multiple positron emission tomography scans.

Diverse tau pathologies in late-life mood disorders revealed by PET and autopsy assays.

Introduction: Late-life mood disorders (LLMDs) may represent prodromal manifestations of neurodegenerative dementia; however, the neuropathological basis of LLMDs, including depression and bipolar disorder, remains unclear. We aimed to investigate the involvement of Alzheimer's disease (AD) and non-AD tau pathologies in LLMD participants.

Methods: Fifty-two LLMD participants and 47 age- and sex-matched healthy controls (HCs) underwent tau and amyloid beta (Aβ) positron emission tomography (PET) imaging using F-florzolotau and C-Pittsburgh compound B.

Diffusion Tensor Image Analysis Along the Perivascular Space in Former Professional Athletes with Repetitive Mild Traumatic Brain Injury History.

Rationale And Objectives: The long-term changes in the glymphatic system of former professional athletes exposed to repetitive mild traumatic brain injuries remain poorly understood. This study aimed to use diffusion tensor image analysis along the perivascular space (DTI-ALPS) to evaluate the glymphatic system activity and correlate the ALPS index with neuropsychiatric symptoms in former professional athletes.

Materials And Methods: 30 former professional athletes and 24 age- and sex-matched controls underwent DTI with 3 T magnetic resonance imaging, and neuropsychiatric tests were performed in the athlete group.

Neuroimaging of psychosis, agitation, and affective disturbance in Alzheimer's disease, dementia with Lewy bodies, and mild cognitive impairment.

Objectives: This study identifies neuropsychiatric syndromes and investigates their relationship with neuroimaging in Alzheimer's disease dementia (AD), dementia with Lewy bodies (DLB), and mild cognitive impairment (MCI).

Methods: Magnetic resonance imaging and perfusion single-photon emission computed tomography data were collected for 281, 68, and 180 patients with AD, DLB, and MCI, respectively, from three Japanese institutions. Neuropsychiatric Inventory was used for exploratory factor analysis in each group.

Human biodistribution and radiation dosimetry of two novel α-synuclein PET tracers, F-SPAL-T-06 and F-C05-05.

F-SPAL-T-06 and F-C05-05 are two novel positron emission tomography (PET) radioligands targeting α-synuclein fibrils. Our study aimed to evaluate the biodistribution, safety, and radiation dosimetry of each tracer in humans. Biodistribution and radiation dosimetry studies were carried out with two healthy volunteers for each tracer, F-SPAL-T-06 (one female and one male volunteer, both aged 63 years) and F-C05-05 (one female and one male volunteer, aged 63 and 73 years, respectively).

Neuropsychiatric symptoms and neuroimaging-based brain age in mild cognitive impairment and early dementia: A multicenter study.

Aim: Despite the clinical importance and significant social burden of neuropsychiatric symptoms (NPS) in dementia, the underlying neurobiological mechanism remains poorly understood. Recently, neuroimaging-derived brain-age estimation by machine-learning analysis has shown promise as an individual-level biomarker. We investigated the relationship between NPS and brain-age in amnestic mild cognitive impairment (MCI) and early dementia.

-Linked Parkinson Syndrome in Female Heterozygotes Is Associated With PET-Detectable Tau Pathology.

Background And Objectives: A previous postmortem study of men with Christianson syndrome, a disorder caused by loss-of-function mutations in the gene , reported a mechanistic link between pathologic tau accumulation and progressive symptoms such as cerebellar atrophy and cognitive decline. This study aimed to characterize the relationships between neuropathologic manifestations and tau accumulation in heterozygous women with mutation.

Methods: We conducted a multimodal neuroimaging and plasma biomarker study on 3 middle-aged heterozygous women with mutations (proband 1: mid-50s; proband 2: early 50s; proband 3: mid-40s) presenting with progressive extrapyramidal symptoms.

Alterations of striatal phosphodiesterase 10 A and their association with recurrence rate in bipolar I disorder.

Phosphodiesterase 10 A (PDE10A), a pivotal element of the second messenger signaling downstream of the dopamine receptor stimulation, is conceived to be crucially involved in the mood instability of bipolar I disorder (BD-I) as a primary causal factor or in response to dysregulated dopaminergic tone. We aimed to determine whether striatal PDE10A availability is altered in patients with BD-I and assessed its relationship with the clinical characteristics of BD-I. This case-control study used positron emission tomography (PET) with 2-(2-(3-(4-(2-[F]fluoroethoxy)phenyl)-7-methyl-4-oxo-3,4-dihydroquinazolin-2-yl)ethyl)-4-isopropoxyisoindoline-1,3-dione ([F]MNI-659), a radioligand that binds to PDE10A, to examine the alterations of the striatal PDE10A availability in the living brains of individuals with BD-I and their association with the clinical characteristics of BD-I.

Neural basis of false recognition in Alzheimer's disease and dementia with lewy bodies.

In Alzheimer's disease (AD), reports on the association between false recognition and brain structure have been inconsistent. In dementia with Lewy bodies (DLB), no such association has been reported. This study aimed to identify brain regions associated with false recognition in AD and DLB by analyzing regional gray matter volume (rGMV).

Neural Basis of Agitated Behaviors in Patients with Amnestic Mild Cognitive Impairment and Alzheimer's Disease.

Background: Aggression, a common symptom of Alzheimer's disease (AD), can impose a significant burden on caregivers, necessitating early institutionalization.

Objective: The current study examined the neural basis of aggression and its expression mechanism, to advance the development of effective treatment strategies for aggression in patients with AD.

Methods: The study sample included 257 patients; 180 were diagnosed with AD and 77 with amnestic mild cognitive impairment (aMCI).

Late-life mood disorder as the initial presentation of progressive supranuclear palsy: A case series.

Aim: Progressive supranuclear palsy (PSP) is a rapidly progressive neurodegenerative disorder characterized by Parkinsonism, supranuclear ophthalmoplegia, postural instability, and cognitive impairment.

Patients: This case series describes three patients initially diagnosed with late-life mood disorders (depression and bipolar disorder) who were later diagnosed with PSP because of the development of typical neurological symptoms.

Result: The diagnostic challenge of PSP is highlighted in this case report, particularly in the early stages, when characteristic symptoms may not be present.

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.

Association between mammillary body atrophy and memory impairment in retired athletes with a history of repetitive mild traumatic brain injury.

Cognitive dysfunction, especially memory impairment, is a typical clinical feature of long-term symptoms caused by repetitive mild traumatic brain injury (rmTBI). The current study aims to investigate the relationship between regional brain atrophy and cognitive impairments in retired athletes with a long history of rmTBI. Overall, 27 retired athletes with a history of rmTBI (18 boxers, 3 kickboxers, 2 wrestlers, and 4 others; rmTBI group) and 23 age/sex-matched healthy participants (control group) were enrolled.

PET classification of tau pathologies in patients with frontotemporal dementia.

Frontotemporal dementia refers to a group of neurodegenerative disorders with diverse clinical and neuropathological features. neuropathological assessments of frontotemporal dementia at an individual level have hitherto not been successful. In this study, we aim to classify patients with frontotemporal dementia based on topologies of tau protein aggregates captured by PET with F-florzolotau (aka F-APN-1607 and F-PM-PBB3), which allows high-contrast imaging of diverse tau fibrils in Alzheimer's disease as well as in non-Alzheimer's disease tauopathies.

Examining Frontal Lobe Asymmetry and Its Potential Role in Aggressive Behaviors in Early Alzheimer's Disease.

Background: Neuropsychiatric symptoms (NPS) in patients with dementia lead to caregiver burdens and worsen the patient's prognosis. Although many neuroimaging studies have been conducted, the etiology of NPS remains complex. We hypothesize that brain structural asymmetry could play a role in the appearance of NPS.

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).

Association of Tooth Loss with Alzheimer's Disease Tau Pathologies Assessed by Positron Emission Tomography.

Background: Deterioration of the oral environment is one of the risk factors for dementia. A previous study of an Alzheimer's disease (AD) model mouse suggests that tooth loss induces denervation of the mesencephalic trigeminal nucleus and neuroinflammation, possibly leading to accelerated tau dissemination from the nearby locus coeruleus (LC).

Objective: To elucidate the relevance of oral conditions and amyloid-β (Aβ) and tau pathologies in human participants.

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.