Associations Between Language and Cognition After Stroke: Longitudinal Observational Study

Abstract

Poststroke language impairment, including aphasia, often co-occurs with cognitive and emotional symptoms, complicating recovery. Understanding these combined impairments and their neural bases is critical for effective rehabilitation. This study examined associations between aphasia severity, language-mediated cognitive deficits, and lesion patterns at acute and subacute stages. We analyzed data from 100 stroke patients, assessing language and cognitive performance at the acute stage (1-week poststroke) and 3 months poststroke. Acute stage lesion data were used to examine distributed lesion patterns and anatomical overlap between poststroke language impairment severity, based on Boston Diagnostic Aphasia Examination Aphasia Severity Rating Scale (BDAE-ASRS), and related neuropsychological impairments. Among the 100 stroke patients, 48 exhibited at least mild aphasia based on the BDAE-ASRS. Spearman rank correlations revealed that greater language impairment severity was linked to poor performance in memory recall, executive functioning, verbal fluency, naming, and comprehension at both time points. However, it was not associated with reduced mood, depressive symptoms, or quality of life. Lesion–behavior correlations were strongest at the acute stage, particularly in the left frontal, insular, and temporal regions, indicating a left-lateralized structure–function relationship. This pattern weakened but remained evident for verbal memory and naming at 3 months. Correlation stability over time was moderate (r_s = 0.432), with strong associations between acute language impairment severity and neuropsychological deficits (r_s = 0.700–0.895). These findings highlight the broader cognitive impact of poststroke language impairment and its shared neuroanatomical substrates, emphasizing the importance of early lesion patterns in shaping recovery. Future research should continue to explore the neural mechanisms of aphasia to inform targeted and effective therapeutic interventions.