How Comorbidity Reflects on Cerebrospinal Fluid Biomarkers of Neurodegeneration in Aging

Aging, frailty, and their effects on motor performance: evidence from kinematic analysis

INTRODUCTION

Aging is commonly linked to motor impairment. However, the relationship between motor performance across age groups and frailty remains unexplored through objective analysis.

OBJECTIVE

To kinematically evaluate motor performance in older and younger adults and investigate its potential connection to frailty.

METHODS

We included 65 healthy subjects (40 females, age range 46-83 years). We used kinematic techniques to study finger-tapping and measure several movement parameters, i.e., number of movements, movement rhythm, amplitude and velocity, as well as progressive reduction in amplitude and velocity during movement repetition (sequence effect). The frailty status was evaluated using a 40-item Frailty Index (FI). We also evaluated cognitive functions, using the Mini Mental State Examination (MMSE) and the Frontal Assessment Battery (FAB). We tested possible relationships between clinical and kinematic data using Spearman's correlation.

RESULTS

A key finding was a significant difference in movement velocity between younger and older adults, with the latter exhibiting lower values (P = 0.014). Accordingly, age significantly correlated with movement velocity (ρ = -0.335, P = 0.037). Among older adults, movement velocity was also found to correlate with frailty (ρr = -0.297, P = 0.033), thus indicating that greater frailty is associated with more impaired motor performance.

CONCLUSIONS

The relationship between the age-related slowed movement execution and frailty suggests that motor performance may serve as a sensitive indicator of physical vulnerability in aging populations.

Evaluating p-tau217 and p-tau231 as Biomarkers for Early Diagnosis and Differentiation of Alzheimer's Disease: A Narrative Review

The escalating prevalence of Alzheimer's disease (AD) highlights the urgent need to develop reliable biomarkers for early diagnosis and intervention. AD is characterized by the pathological accumulation of amyloid-beta plaques and tau neurofibrillary tangles. Phosphorylated tau (p-tau) proteins, particularly p-tau217 and p-tau231, have been identified as promising biomarker candidates to differentiate the disease progression from preclinical stages. This narrative review is devoted to a critical evaluation of the diagnostic accuracy, sensitivity, and specificity of p-tau217 and p-tau231 levels in the detection of AD, measured in plasma, serum, and cerebrospinal fluid, compared to established biomarkers. Additionally, the efficacy of these markers in distinguishing AD from other neurodegenerative disorders is examined. The significant advances offered by p-tau217 and p-tau231 in AD diagnostics are highlighted, demonstrating their unique utility in early detection and differential diagnosis. This comprehensive analysis not only confirms the excellent diagnostic capabilities of these markers, but also deepens the understanding of the molecular dynamics of AD, contributing to the broader scientific discourse on neurodegenerative diseases. This review is aimed to provide key information for researchers and clinicians across disciplines, filling interdisciplinary gaps and highlighting the role of p-tau proteins in revolutionizing AD research and clinical practice.

Tau and Amyloid-β Peptides in Serum of Patients With Parkinson's Disease: Correlations With CSF Levels and Clinical Parameters

Relevance of blood-based biomarkers is increasing into the neurodegenerative diseases field, but data on Parkinson's disease (PD) remain still scarce. In this study, we used the SiMoA technique to measure serum content of total tau protein and amyloid-β peptides (Aβ-42, Aβ-40) in 22 PD patients and ten control subjects. Serum levels of each biomarker were correlated with the respective CSF levels in both the groups; in PD patients, also the correlations between serum biomarkers and main clinical parameters were tested (motor, non-motor, cognitive scores and levodopa equivalent daily dose). Serum biomarkers did not exhibit quantitative differences between patients and controls; however, only PD patients had inter-fluids (serum-CSF) associations in tau and amyloid-β-42 levels. Moreover, serum content of tau protein was inversely correlated with cognitive performances (MoCA score). These findings, albeit preliminary, indicate that brain-derived peptides may change in parallel in both peripheral blood and CSF of PD patients, eventually even in association with some clinical features. Further studies are now needed to validate the use of blood-based biomarkers in PD.