Changes in Language Function and Recovery-Related Prognostic Factors in First-Ever Left Hemispheric Ischemic Stroke

Abstract

Objective To investigate longitudinal changes in language function in left-hemispheric ischemic stroke patients as well as factors that influence language recovery until 1 year after stroke onset. Methods We analyzed data from 235 patients with first-ever left-hemispheric ischemic stroke. All patients completed the Korean version of the Frenchay Aphasia Screening Test (K-FAST) at 7 days (T1), 3 months (T2), 6 months (T3), and 1 year (T4) after stroke onset. Repeated measures analysis of variance (ANOVA) was used to investigate changes in language function between time points. Subgroup analysis was performed according to the K-FAST scores at T1. Stroke lesion volume was assessed using diffusion tensor images, and involvement of language-related brain regions was examined. Multiple regression analysis was used to analyze factors influencing improvement of K-FAST score. Results The K-FAST scores at T1, T2, T3, and T4 differed significantly (p<0.05). In the subgroup analysis, only the severe group showed continuous significant improvement by 1 year. Factors that negatively influenced improvement of language function were the age at onset, initial National Institutes of Health Stroke Scale (NIHSS) score, and initial K-FAST score, whereas education level and stroke lesion volume positively affected recovery. Involvement of language-related brain regions did not significantly influence long-term language recovery after ischemic stroke. Conclusion Recovery of language function varied according to the severity of the initial language deficit. The age at stroke onset, education level, initial severity of aphasia, initial NIHSS score, and total stroke lesion volume were found to be important factors for recovery of language function.

The Effectiveness of Transcranial Magnetic Stimulation (TMS) Paradigms as Treatment Options for Recovery of Language Deficits in Chronic Poststroke Aphasia

“…Regarding lesion location, some studies suggest that lesions involving the left STG (superior temporal gyrus) and Wernicke's area are associated with poor aphasia improvement [ 70 ]. With regard to lesion magnitude, even though large left hemisphere lesions are typically associated with poorer recovery [ 71 ], in a recent study, patients with larger stroke volumes showed greater aphasia improvements regardless of the involvement of the language areas [ 72 ]. This could explain the findings from the current study in which the only participant who showed statistically significant improvements had diffuse and large brain lesions in the left hemisphere.…”

“…Research on the role of BDNF (brain-derived neurotrophic factor) variants on language recovery poststroke is emerging, and several studies have demonstrated that it influences recovery [ 75 , 76 ]. Also, through univariate analysis, it has been shown that total lean body mass—not adipose tissue—may be a positive factor for predicting aphasia improvement [ 72 ]. Lastly, evidence in relation to the impact of sex [ 77 ], handedness, and educational background [ 78 ] on language recovery is controversial.…”

Predictors of functional communication in people with aphasia after stroke

“…19 An individual's level of schooling is known to affect both recovery and language performance poststroke. 37,38 Individuals with low levels of schooling employ simpler grammar structures and use more oral than written language, and they do not engage as much in social reading and writing activities. 38,39 The results obtained herein may be associated with the level of schooling of the sample; indeed, in Brazil, much of the population suffers from limited access to formal education.…”

Therapies and Challenges in the Post-Stroke Aphasia Rehabilitation Arena: Current and Future Prospects

“…Even though it is reasonable to assume that larger lesions may affect language network hubs and consequently confer a greater negative impact on language recovery, findings regarding lesion magnitude are controversial. While it has been shown that larger lesions are associated with poorer recovery e.g., [ 120 ], there is evidence that this is not always the case [ 121 ]. Considering the existing evidence connecting the location and size of lesions, it is important to understand their combined impact on aphasia recovery.…”