Executive Impairment Is Associated with Impaired Memory Performance in Working-Aged Stroke Patients.

Abstract

Executive dysfunction is associated with impaired memory performance, but controversies remain about which aspects of memory are involved and how general intelligence influences these connections. We aimed to clarify these connections in stroke patients by comparing various memory measures in patients with and without executive impairment. Our consecutive cohort included patients with a first-ever ischemic stroke. Neuropsychological assessments were completed 6 months and 2 years after stroke. We classified patients as executively impaired, when at least two of five executive measures were defective at 6 months. At both 6 months and 2 years, we compared list learning of unrelated words, story recall, and recall of geometric figures in patients with and without executive impairment, while controlling for general intelligence. Patients with executive impairment (n=66; 37%) performed worse in list learning (p=.001; partial η2=.058) and immediate recall of a logical passage (p=.010; partial η2=.037) 6 months after stroke compared to executively intact patients (n=113). At the end of the 2-year follow-up period, the patients who were executively impaired at 6 months (n=53; 37%) still performed worse than executively intact patients (n=92) in list learning (p<.001; partial η2=.096), and additionally in delayed recall of the list (p=.006; partial η2=.052) and immediate recall of geometric figures (p=.007; partial η2=.050). In our working-aged stroke patients, executive impairment was common. Executive impairment was associated with memory tasks that provided less inherent structure and required the use of active memory strategies. Clinicians should remember this role of executive dysfunction when interpreting memory performance.