Recovery of language function and prognostic factors during the first year after ischemic stroke

Abstract

In this study, we investigated the language function recovery and influencing factors at 1 year after their first-ever ischemic stroke in patients with language disorders. We analyzed the data of 235 patients with first-ever acute ischemic stroke in the left-hemisphere who completed Korean version of Frenchay Aphasia Screening Test (K-FAST) at 7 days, 3 months, 6 months, and 1 year after stroke onset. Repeated measures Anova was used to investigate changes of language function among each time points. Subgroup analysis was performed according to the K-FAST score category at 7 days after onset. The Broca's area, Heschl's gyrus, and Wernicke's area were selected as the regions of interests (ROIs). Using the MRIcro ® software, each patient's lesion volume and involvement of ROIs were examined in their diffusion-weighted images. Improvement of language function was assessed by a shifting of the K-FAST score category and the K-FAST score changes (delta K-FAST) from 7days to 1 year after stroke onset. Multiple logistic regression analysis and multiple regression analysis were performed to investigate influencing factors for category shift and delta K-FAST, respectively. Significant differences were noticed in mean K-FAST scores between each assessment time points, however, secondary analysis revealed that these differences were contributed by initially severe K-FAST subgroup ( P < 0.05). Positive factors for the K-FAST category shift over time were female, alcohol consumption, and involvement of Heschl's gyrus, whereas negative factors were involvement of Wernicke's area and old age. Obesity and stroke lesion volume were positively related to higher delta K-FAST from 7 days to 1 year. These results demonstrated that recovery of language function differently occurred according to the initial severity of language dysfunction. Patients who initially suffered from larger stroke lesion or patients who had involvement of Heschl's gyrus demonstrated better catch-up of language function over 1 year after their stroke onset.