Cognitive and neural correlates of prospective memory in acute to early sub-acute stroke

Abstract

Prospective memory (PM) refers to the ability to form an intention and remember to execute it in the future. Previous research suggests that chronic stroke patients display PM deficits, but this has not been investigated in acute patients using standardised clinical measures. We assessed PM performance in acute and early sub-acute stroke patients using a short form of the Memory for Intentions Screening Test (MIST-SF). We investigated relationships between lesion characteristics and acute PM deficits, changes in PM performance between acute and follow-up assessment, and whether PM predicts long-term cognitive and clinical outcomes. Fifty-eight stroke patients and 47 controls completed the MIST-SF and standard cognitive and clinical measures, and patients' brain scans were obtained for lesion and network-level subtraction analysis. The same test battery was administered to 33 stroke patients 6–12 months after acute testing. PM deficits were observed in acute patients on seven of eleven MIST-SF outcome measures. Better overall PM performance and time-based PM performance was associated with better performance on executive functioning measures, while higher event-based PM scores only correlated with faster processing speed. Stroke patients’ PM performance did not significantly differ between acute testing and follow-up. Acute PM performance was a strong predictor of long-term PM but did not predict long-term cognitive and clinical outcomes. Limited conclusions could be drawn regarding lesion anatomy and PM impairment due to insufficient lesion overlap. These findings provide insight into PM function in acute and early sub-acute stroke patients and may inform future cognitive rehabilitation and intervention.