Neuroplasticity in Speech and Language Recovery Following Stroke or Traumatic Brain Injury

Background: Stroke and traumatic brain injury (TBI) frequently lead to acquired communication disorders (e.g., aphasia, dysarthria, cognitive‑communication deficits). Recovery of speech and language functions in these populations depends on neuroplasticity—the brain’s ability to reorganise neural networks in response to injury and therapeutic intervention. Objective: To review mechanisms of neuroplasticity underlying speech and language recovery after stroke and TBI, summarise current evidence from neuroimaging and behavioural studies, discuss clinical implications for speech‑language therapy and audiological rehabilitation, and propose future research directions. Methods: A narrative review of literature published 2018–2025 was conducted via PubMed, Scopus, and ScienceDirect using keywords 'neuroplasticity', 'aphasia recovery', 'TBI language', 'speech therapy', 'stroke', 'traumatic brain injury', 'brain reorganisation'. Studies focusing on neural mechanisms, therapy‑induced plasticity, and rehabilitation outcomes were included. Results: Evidence identifies three major neuroplastic processes: (1) perilesional reorganisation within the dominant hemisphere, (2) recruitment of contralesional (non‑dominant hemisphere) homologous regions and domain‑general networks, and (3) restoration and remodelling of network connectivity (white matter tracts, functional networks). Intensive behavioural therapy (e.g., constraint‑induced language therapy, melodic intonation therapy), neuromodulatory techniques (e.g., transcranial magnetic stimulation, tDCS), and auditory/motor‑based interventions enhance plasticity and improve outcomes. Conclusions: Neuroplasticity is fundamental to speech and language recovery after stroke or TBI. Therapeutic strategies that are intensive, targeted, and multimodal can optimise cortical and network‑level reorganisation.