A clinically contextualized, hands-on biostatistics workshop for rheumatology fellows-in-training: a quasi-experimental pre-post educational intervention study.

Stroke in young adults, aged 18–50 years, constitutes approximately 10% of all stroke cases and shows an increasing incidence. While these patients often show good motor recovery, one-third of young stroke patients experience mild vascular cognitive impairment, and another third experiences major vascular cognitive impairment up to 6 months post-stroke. Notably, during the chronic phase, post-stroke cognitive impairment (PSCI) is present in up to 40%, which may persists even decades after the initial event. These young individuals require robust cognitive abilities to establish families, advance their careers, and maintain active social lives. Consequently, PSCI may significantly impact their quality of life. Several studies have examined the mechanisms underlying PSCI and found associations with stroke severity, stroke recurrence and lesion characteristics (e.g. volume and location). However, these relationships do not entirely account for the variation in cognitive outcomes observed among stroke patients. Increasing evidence suggests that the impact of the stroke lesion on a certain location of the brain network may explain the disproportional effects on PSCI, especially when the hub regions, highly connected to other brain regions, are damaged. The brain’s network can be characterized through graph theory, a mathematical framework reliant upon delineating edges (connections) between nodes (brain regions) predicated on structural associations. Focal lesions can disrupt the intricate brain circuits, consequently impairing the brain’s capacity to efficiently integrate neural processes. Strategically located stroke lesions may diminish the overall network efficiency by disrupting the connectivity of regions linked to the lesion. The hub regions play a pivotal role in the integration of information across different brain networks, which is an important prerequisite for optimal cognitive function. Accumulating evidence suggests that a less efficient brain network is linked with cognitive impairment across various neurological diseases and has the capacity to predict cognitive performance longitudinally. Furthermore, several studies have shown that stroke patients with a less efficient brain network have lower chance of cognitive recovery. Moreover, various studies focused particularly on specific brain networks (i.e. default mode network), while others analyzed overall brain connectivity or measures involving ipsilesional, contralesional, or interhemispheric connections. Specifically, hub regions appear to play a critical role in cognitive recovery, examined through various approaches, including evaluating the effect of the degree of affected hub regions (lesion impact score) and assessing the influence of rich-club regions on cognitive function. However, the majority of these studies have been conducted on stroke patients aged over 50, many of whom have concurrent comorbidities, including neurodegenerative diseases and prestroke brain lesions. Furthermore, limited information is available regarding the relation between brain network metrics and cognitive performance in younger stroke patients.