Biomarkers.

Background: The performance of blood-based phosphorylated tau (pTau) immunoassays to detect asymptomatic Alzheimer's disease (AD) has important implications for therapeutic trials. pTau217 is often recommended as the preferred epitope due to its high fold changes in AD. The current study investigates the ability of a novel pTau217 assay to predict the dynamic phase of amyloid-β (Aβ) accumulation in comparison to the best-performing pTau181 assay.

Biomarkers.

Background: In Alzheimer disease (AD) changes in the small world network have been described, which can be considered as the balance between local connectivity, exhibited with the "clustering coefficient", and global integration, investigated by "characteristic path length". With high-density EEG, we examined the effect of early spread of tau aggregates on these global graph measures.

Method: This study includes 47 participants who underwent a 100-minute dynamic F-MK6240 PET-scan and a five-minutes eyes closed 128-channel resting-state EEG.

Biomarkers.

Background: Synaptic loss is a critical early pathological hallmark of neurodegeneration, in particular in Alzheimer's disease (AD), as evidenced by in vitro as well as in vivo PET studies. To date, it is not clear how blood-based synaptic and AD biomarkers relate to synaptic density in the brains of non-demented elderly, including those diagnosed with depression.

Method: This cross-sectional study included 61 older adults with no history of dementia (age [mean±SD] = 71±6 years, MMSE (median[IQR] = 28[3], 64% female, 38% late-life depression) from the Leuven late-life depression (L3D) study.

Ictal SPECT Imaging Findings in Parkinson's Disease with Rapid Eye Movement Sleep Behavior Disorder.

Background: Rapid eye movement sleep behavior disorder (RBD) is an established prodrome and symptom of synucleinopathies. The pathophysiology of this disorder has been well studied but there is a lack of functional imaging data to illustrate the dysfunction in vivo.

Objectives: We aimed to investigate the functional changes of RBD, by performing ictal REM sleep SPECT, comparing subjects with Parkinson's Disease (PD) and evidence of RBD to subjects with PD and no RBD.

Comparison of Classical, Neural Network and Hybrid Models for Hysteretic Single-tendon Catheter Kinematics.

While robotic control of catheter motion can improve tip positioning accuracy, hysteresis arising from tendon friction and flexural deformation degrades kinematic modeling accuracy. In this paper, we compare the capabilities of three types of models for representing the forward and inverse kinematic maps of a clinical single-tendon cardiac catheter. Classical hysteresis models, neural networks and hybrid combinations of the two are included.