Neurophysiological basis of manual force asymmetries in young and senior adults.

In this study, we investigated age differences in manual force production to explore their neurophysiological basis. Manual pinching and gripping forces were first measured during unilateral and bilateral efforts in two groups of right-handed adults (young, n = 12, senior, n = 11). Then, transcranial magnetic stimulation (TMS) was applied to each hemisphere to assess central motor inhibition via the contralateral and ipsilateral silent period (cSP, iSP). Laterality quotients (LQs) were computed to determine asymmetries for unimanual strength tests and hemispheric asymmetries in TMS measures. Bilateral indices (BLI) were computed to assess the bilateral force deficit (BFD). During unilateral efforts, both young and senior participants exhibited similar degrees of asymmetry. Similarly, no age difference was detected when comparing LQs derived from TMS measures. During bilateral efforts, although BLI tended to be lower in seniors, no age difference was detected. Asymmetry in strength and BLI showed no association with hemispheric asymmetry in TMS measures, except for the asymmetry in pinch strength, which was associated with asymmetry in the iSP duration. These observations confirm that asymmetries in manual strength and BFD are little affected by age. Also, our results show that hemispheric asymmetries in transcallosal inhibition are associated with pinch strength asymmetry.

Are Socioeconomic Factors Associated With Atrial Fibrillation Sex-Dependent? A Narrative Review.

Atrial fibrillation (AF), the most prevalent cardiac arrhythmia, poses a significant public health and economic burden. Although socioeconomic factors such as income and education have been implicated in AF incidence and outcomes, the potential sex-specific associations remained underexplored. This narrative review aimed to fill this gap by synthesizing existing literature on the sex-specific impact of socioeconomic factors on AF incidence, treatment, and outcome. Among these socioeconomic factors, we identified income and education as the most frequently cited determinants. Nevertheless, the magnitude and direction of these sex differences remained inconsistent across studies. The review uncovered that many studies did not include sex in the analysis when assessing the impact of socioeconomic factors on AF. We highlighted that there is a paucity of studies employing sex-stratified reporting and sex interaction analyses, thereby hindering a deeper understanding of these relationships.