NEUROPLASTICITY OF THE LANGUAGE NETWORK POST-STROKE: A FUNCTIONAL MAGNETIC RESONANCE IMAGING ANALYSIS

Abstract

The involvement of left and right hemispheric brain regions in the recovery of linguistic abilities following post-stroke aphasia remains an ongoing subject of debate. This review focuses on the contributions of functional magnetic resonance imaging (fMRI) studies in elucidating the functional interactions, neural reorganization, and dynamics of neuroplasticity within language networks of aphasia. It delineates the temporal dynamics of language recovery, mainly focusing on the longitudinal analysis from acute to chronic phases post-stroke, noting diverse linguistic processing patterns and recuperation in individuals with aphasia at various stages of rehabilitation. During acute phase, there is significant neural disruption with decreased activity in language regions and increased activity in left perilesional areas. In subacute phase, activation expands to bilateral domain-general and right homologous areas. In chronic phase, reactivation is predominantly   in left perilesional and adjacent language areas, demonstrating the  brain's  dynamic  response  to  ischemic  injury.  The functional contributions to language recovery from the perilesional and spared left hemisphere language areas, right hemisphere homologous area, and bilateral general regions change over time. Subsequently, the review explores how an integrated approach combining fMRI with non-invasive brain stimulation can reveal the neuroplasticity and neural reorganization within language  network. These interdisciplinary approaches have unveiled novel insights into the mechanisms of neural plasticity, potentially augment rehabilitative strategies during speech and language therapy.