Multifactorial interplay on language recovery following left-hemispheric stroke: A retrospective study

Understanding the relative contribution of various factors influencing initial severity of aphasia and recovery after a stroke is essential for optimising neurorehabilitation programmes. We investigated how various significant sociodemographic, cognitive, clinical, stroke-related and rehabilitation-related factors modulate aphasia severity and language recovery following left-hemispheric stroke. Employing an innovative method, we conducted a retrospective analysis of 96 stroke participants to explore the combined impact of these factors. The initial severity of aphasia was categorised into severe, mild/moderate and no aphasia based on the severity of their language deficits in the subacute phase (Aphasia Severity Rating Scale, ASRS). To assess speech-and-language recovery, we classified 53/96 patients with aphasia into high and poor recovery categories using a gain score formula (ASRS_discharge-ASRS_admission)/ASRS_admission. Subsequently, we performed statistical analyses (univariate analyses and forward stepwise logistic regression combined with bootstrap) to identify the determinants of the initial severity of aphasia and the degree of recovery. Our analyses unveiled that more severe aphasia initially was correlated with a more severe stroke (Odds Ratio, OR = .90, p = .041), moderate/severe executive dysfunction (OR = .068, p < .001) and larger lesion size (OR = .068, p < .001). Furthermore, the degree of recovery was associated with the intensity of speech-and-language therapy (OR = 1.47, p = .043). These findings enrich our understanding of the determinants of aphasia severity and language recovery, employing an original methodology to scrutinise the collective effect of multiple variables in a retrospective analysis of stroke participants. A better knowledge of these factors may help implement personalised language rehabilitation programmes to maximise speech-and-language recovery.