Dynamic functional reorganization in post-stroke aphasia: a state-of-the-art fMRI review from disease evolution to...

Post-stroke aphasia (PSA) is a common and disabling consequence of stroke, characterized by substantial heterogeneity in language impairment and recovery trajectories. In recent years, functional magnetic resonance imaging (fMRI) has markedly advanced our understanding of the neural mechanisms underlying PSA recovery by revealing dynamic changes in regional activation, functional connectivity, and large-scale network coordination. This review provides a state-of-the-art synthesis of fMRI studies on functional reorganization in PSA across two intersecting dimensions: the temporal evolution of the disease course (acute, subacute, and chronic stages) and the major categories of rehabilitation intervention, including behavioral therapies, neuromodulation, and combined treatment approaches. Current evidence suggests that PSA recovery is a stage-dependent and network-based neuroplastic process. In the early phase after stroke, recovery is strongly influenced by the rapid recruitment of domain-general cognitive control systems, whereas later recovery is increasingly shaped by the reorganization of residual left-hemisphere language networks, with contralesional and cerebellar contributions becoming more prominent in patients with extensive left-hemisphere damage. However, important controversies remain regarding the functional role of right-hemisphere activation and the relative significance of perilesional restoration versus compensatory recruitment. Furthermore, the field is limited by substantial heterogeneity in patient characteristics, lesion profiles, study design, and imaging methodology, which constrains comparability across studies and hinders clinical translation. By integrating current evidence, unresolved debates, and emerging trends, this review highlights key research gaps and outlines future directions for biomarker-guided, stage-adapted, and individualized rehabilitation strategies in PSA.