Who Falls After Stroke? Evidence From a Prospective Stroke Cohort

BackgroundFalls are a frequent and serious complication after stroke, affecting more than 30% of survivors within the first year. While age and comorbidities are established risk factors for falls, stroke-specific contributors--particularly lesion-related impairments in mobility and gait--are less well understood and may inform targeted secondary prevention. MethodsWe analyzed data from 94 patients with disabling subacute ischemic stroke enrolled in the prospective BAPTISe cohort, a predefined imaging and biomarker sub-cohort of the multicenter PHYS-STROKE trial. Detailed gait and mobility assessments were performed at baseline. Principal component (PC) analysis reduced seven mobility-related and four gait-related variables into two composite scores: PC1-Mobility and PC1-Gait, explaining 56% and 82% of variance, respectively. PC1-Mobility reflected global disability and functional mobility in daily life, whereas PC1-Gait captured spatiotemporal walking capacity and efficiency. Lesion network mapping (LNM) using a normative connectome identified functional networks associated with each domain. Patient-reported falls up to six months post-enrollment were the primary endpoint. ResultsLNM of PC1-Mobility revealed a predominantly cortical network involving pre- and postcentral gyri, superior and middle frontal gyri, and sensorimotor integration areas. In contrast, PC1-Gait was associated with subcortical and infratentorial connectivity, including bilateral thalamus, brainstem, and cerebellum. In multivariable regression, network similarity scores were not independently associated with falls; only older age was significant (adjusted OR1.08, 95%CI1.02-1.15,p=0.013). LNM of fall occurrence showed a cortical network with significant spatial overlap with the PC1-Mobility network(p<0.001). ConclusionThis exploratory, hypothesis-generating study identified distinct lesion-derived functional networks associated with post-stroke mobility and gait impairment. Our findings suggest that falls may be more closely linked to disruptions in cortical networks involved in voluntary motor control and whole-body coordination, rather than subcortical structures primarily modulating gait. These results provide a foundation for future research aimed at improving fall risk stratification and targeted prevention strategies in stroke survivors.