Mechanisms of how sarcopenia affects functional outcomes in acute ischaemic stroke.

Sarcopenia, a common geriatric condition characterized by the loss of skeletal muscle mass and function, can negatively affect functional outcomes in acute ischaemic stroke; however, the underlying mechanisms remain unclear. We hypothesized that sarcopenia affects post-stroke outcomes, mediated through its impact on dysphagia, early neurological deterioration, or post-stroke recovery, particularly in patients with motor deficits. To explore this hypothesis, we included 600 consecutive elderly (≥65 years) patients with acute (<1 week) ischaemic stroke and assessed: (i) the relationships sarcopenia has with dysphagia, early neurological deterioration and various phases of recovery after stroke (in-hospital, post-discharge [up to 3 months], and chronic [3 months to 1 year]) and (ii) whether either presenting symptoms or lesion locations modify the impact of sarcopenia on stroke outcomes. Temporal muscle thickness, a marker of sarcopenia, was measured by brain magnetic resonance imaging and dichotomized into low versus high temporal muscle thickness at the 25th percentile cut-off point. Logistic regression analysis, mediation analysis and statistical brain mapping were conducted. Mean age was 75.3 ± 6.1 years and 303 (50.5%) were male. Low temporal muscle thickness (<5.1 mm) was independently associated with dysphagia (adjusted odds ratio 1.89 [95% confidence interval 1.06-3.37],