The concepts of brain reserve and cognitive reserve were recently suggested as valuable predictors of stroke outcome. To test this hypothesis, we used age, years of education and lesion size as clinically feasible coarse proxies of brain reserve, cognitive reserve, and the extent of stroke pathology correspondingly. Linear and logistic regression models were used to predict cognitive outcome (Montreal Cognitive Assessment) and stroke-induced impairment and disability (NIH Stroke Scale; modified Rankin Score) in a sample of 104 chronic stroke patients carefully controlled for potential confounds. Results revealed 46% of explained variance for cognitive outcome (p < 0.001) and yielded a significant three-way interaction: Larger lesions did not lead to cognitive impairment in younger patients with higher education, but did so in younger patients with lower education. Conversely, even small lesions led to poor cognitive outcome in older patients with lower education, but didn’t in older patients with higher education. We observed comparable three-way interactions for clinical scores of stroke-induced impairment and disability both in the acute and chronic stroke phase. In line with the hypothesis, years of education conjointly with age moderated effects of lesion on stroke outcome. This non-additive effect of cognitive reserve suggests its post-stroke protective impact on stroke outcome.

Working memory (WM) represents the capacity to store and process a limited amount of information. Better understanding developmental changes of WM forms a key topic in research on neuropsychology of aging. Previous studies reveal age-differences in WM and in executive functions (EFs). Although EFs are seen as essential mechanisms in WM, the specific relation between the two cognitive constructs so far remains unclear. The present study set out to investigate the unique roles of the three main facets of EFs (i.e., updating, inhibition, and shifting) in accounting for age-related variability in WM. Therefore, onehundred seventy-five younger and 107 older adults performed a battery of cognitive tests including measures of WM, EFs, and processing speed. A set of statistical approaches including regression analyses and path models was used to examine the cognitive correlates that could explain individual and age-related variance in WM. Significant age-differences were found on WM and on EF measures. Regression analyses and path models showed that updating and inhibition but not shifting played a major role in explaining age-related variance in WM. In sum, findings suggest that updating and inhibition are most influential for agedifferences in WM. They further show that age and processing speed do not significantly contribute to variability in WM performance beyond executive resource. The present findings have implications for conceptual and developmental theories of WM and may further offer an initial empirical basis for developing possible trainings to improve older adults' WM performance by strengthening the efficiency of updating and inhibitory processes.

Purpose To evaluate a MRI postprocessing tool for the enhanced and rapid detection of focal cortical dysplasia (FCD). Methods MP2RAGE sequences of 40 consecutive, so far MRI-negative patients and of 32 healthy controls were morphometrically analyzed to highlight typical FCD features. The resulting morphometric maps served as input for an artificial neural network generating a FCD probability map. The FCD probability map was inversely normalized, co-registered to the MPRAGE2 sequence, and re-transferred into the PACS system. Co-registered images were scrolled through “within a minute” to determine whether a FCD was present or not. Results Fifteen FCD, three subcortical band heterotopias (SBH), and one periventricular nodular heterotopia were identified. Of those, four FCD and one SBH were only detected by MRI postprocessing while one FCD and one focal polymicrogryia were missed, respectively. False-positive results occurred in 21 patients and 22 healthy controls. However, true positive cluster volumes were significantly larger than volumes of false-positive clusters (p < 0.001). The area under the curve of the receiver operating curve was 0.851 with a cut-off volume of 0.05 ml best indicating a FCD. Conclusion Automated MRI postprocessing and presentation of co-registered output maps in the PACS allowed for rapid (i.e., “within a minute”) identification of FCDs in our clinical setting. The presence of false-positive findings currently requires a careful comparison of postprocessing results with conventional MR images but may be reduced in the future using a neural network better adapted to MP2RAGE images.