Effect of Cognitive Reserve on Risk of Cognitive Impairment and Recovery After Stroke

Abstract

Background and Purpose— The theory of cognitive reserve (CR) was introduced to account for individual differences in the clinical manifestation of neuropathology. This study investigated whether CR has a modulating effect on cognitive impairment and recovery after stroke. Methods— This study is an interim analysis of the Korean Stroke Cohort for Functioning and Rehabilitation. A total of 7459 patients with first-ever stroke were included for analysis. Education, occupation, and composite CR scores derived from those 2 variables were used as CR proxies. Scores from the Korean version of the Mini-Mental State Examination analyzed for 30 months after stroke onset were analyzed. Results— Lower CR increased the risk of cognitive impairment after stroke. The odds ratio was 1.89 (95% CI, 1.64–2.19) in patients with secondary education and 2.42 (95% CI, 2.03–2.90) in patients with primary education compared with patients with higher education. The odds ratio was 1.48 (95% CI, 1.23–1.98) in patients with a skilled manual occupation and 2.01 (95% CI, 1.42–2.83) in patients with a nonskilled manual occupation compared with patients with a managerial or professional occupation. In the multilevel model analysis, the Korean version of the Mini-Mental State Examination total score increased during the first 3 months (1.93 points per month) and then plateaued (0.02 point per month). The slopes were moderated by the level of education, occupation, and composite CR score: the higher the level of education, occupation, or CR score, the faster the recovery. In the older adult group, the Korean version of the Mini-Mental State Examination scores showed a long-term decline that was moderated by education level. Conclusions— Education and occupation can buffer an individual against cognitive impairment caused by stroke and promote rapid cognitive recovery early after stroke. In addition, higher education minimizes long-term cognitive decline after stroke, especially in older patients. Clinical Trial Registration— URL: https://www.clinicaltrials.gov . Unique identifier: NCT03402451.

TVA-based modeling of short-term memory capacity, speed of processing and perceptual threshold in chronic stroke patients undergoing cognitive training: case-control differences, reliability, and associations with cognitive performance

“…To test the extent that attentional abilities facilitate response to cognitive training, we tested whether higher attentional abilities as measured by the TVA at baseline were associated with larger improvement in response to cognitive training during the course of the intervention. Our results revealed a significant association between processing speed at baseline and performance improvement over the course of the intervention, indicating that patients with higher processing speed showed larger cognitive improvements, which is in line with the cognitive reserve hypothesis (Shin et al, 2020). In contrast, visual memory capacity and perceptual threshold at baseline were not significantly associated with cognitive improvement.…”

“…Given that the working memory parameter K consistently has been demonstrated to show high reliability and sensitivity to clinical conditions (Finke et al, 2005;Habekost & Bundesen, 2003;Habekost, Petersen & Vangkilde, 2014;Habekost & Rostrup, 2006), we anticipated stronger association with clinical measures for that parameter. Next, we hypothesized that (3) TVA parameters would constitute reliable and sensitive measures of specific attentional functions in chronic stroke patients in a longitudinal context, with the highest reliability found for parameter K. Further, based on the concept of cognitive reserve (Shin et al, 2020) and assuming that specific attentional abilities are beneficial for learning and cognitive plasticity, we hypothesized that (4) higher attentional abilities as measured using TVA at baseline would be associated with larger cognitive improvement during the course of the CCT, both for patients receiving active and sham tDCS as part of the intervention protocol. Lastly, we hypothesized that (5) improvement in TVA performance would be associated with improvement in CCT performance.…”

Peer Review #3 of "TVA-based modeling of short-term memory capacity, speed of processing and perceptual threshold in chronic stroke patients undergoing cognitive training: case-control differences, reliability, and associations with cognitive performance (v0.1)"

“…Our results revealed a significant association between processing speed at baseline and performance improvement over the course of the intervention, indicating that patients with higher processing speed showed larger cognitive improvements, which is in line with the cognitive reserve hypothesis (Shin et al 2020). In contrast, visual memory capacity and perceptual threshold at baseline were not significantly associated with cognitive improvement.…”

Prognostic Factors for Cognitive Recovery Beyond Early Poststroke Cognitive Impairment (PSCI): A Prospective Cohort Study of Spontaneous Intracerebral Hemorrhage

“…Long educational history has been hypothesized to protect from brain injury through promoting brain reserve capacity (29). In addition, recent evidence further supports the hypothesis that cognitive reserve affects the cognitive recovery after ischemic stroke (30). Therefore, we assumed that this hypothesis might explain the cognitive recovery of ICH survivors with higher education during follow-up.…”