Cross-sectional studies of normal aging indicate an association between memory and hippocampal volume, and between executive functioning and subcortical-frontal circuits. Much less is known, however, about the relationship between longitudinal MRI changes and cognitive decline. The authors hypothesized that longitudinal change in memory would be best predicted by change in hippocampal volumes, whereas change in executive functioning would be best predicted by cortical atrophy and progression of MRI markers of cerebrovascular disease. For this study, 50 healthy elderly subjects underwent structural MRI and cognitive testing at baseline and again at follow-up, with a mean follow-up interval of 45 months. Volumetric MRI measures were hippocampus, cortical gray matter, white matter signal hyperintensity (WMSH), and lacunae. Neuropsychological measures were psychometrically robust composite scores of episodic memory (MEM) and executive functioning (EXEC). Hierarchical multiple regression indicated that a decrease in hippocampus was associated with a decline in MEM, whereas decreased cortical gray matter and increased WMSH were independently associated with a decline in EXEC. Results suggest that in normal aging, cognitive functioning declines as cortical gray matter and hippocampus decrease, and WMSH increases. The association between WMSH and EXEC further highlights the cognitive sequealae associated with cerebrovascular disease in normal elderly.Correspondence concerning this article should be addressed to Joel H. Kramer , 1997). There are also age-related increases in subcortical ischemic vascular disease that can independently contribute to cognitive decline and dementia (Román, Erkinjuntti, Wallin, Pantoni, & Chui, 2002). Population-based studies have reported "silent" (i.e., asymptomatic) lacunae in 11%-28% of clinically asymptomatic elderly (Longstreth et al., 1998;Price et al., 1997;Vermeer et al., 2003), whereas the prevalence of white matter signal hyperintensities on MRI has ranged from 30% to 100% across studies of healthy elderly samples (Breteler et al., 1994;Longstreth et al., 1998;Ylikoski et al., 2000). Diffusion tensor MRIs have shown a progressive reduction in fractional anisotropy and an increase in diffusivity with age (Charlton et al., 2006).Despite the co-occurrence of age-related cognitive decline and brain changes, associations between brain volume and cognitive ability in healthy subjects have been difficult to establish. Although several studies have reported that hippocampal atrophy is associated with poorer episodic memory performance in older subjects (De Leon et al., 1997;Golomb et al., 1996), an extensive review and meta-analysis by Van Petten (2004) noted considerable variability across studies. The common correlation between hippocampal volume and memory performance across 33 studies was statistically significant but quite low, leading to the conclusion that the evidence for a positive relationship between hippocampal volume and memory performance was weak. Divergent result...
Three experiments test whether the threat of appearing racist leads White participants to perform worse on the race Implicit Association Test (IAT) and whether self-affirmation can protect from this threat. Experiments 1 and 2 suggest that White participants show a stereotype threat effect when completing the race IAT, leading to stronger pro-White scores when the test is believed to be diagnostic of racism. This effect increases for domain-identified (highly motivated to control prejudice) participants (Experiment 2). In Experiment 3, self-affirmation inoculates participants against stereotype threat while taking the race IAT. These findings have methodological implications for use of the race IAT and theoretical implications concerning the malleability of automatic prejudice and the potential interpersonal effects of the fear of appearing racist.
Background and Purpose: Shelter-in-place (SIP) orders implemented to mitigate severe acute respiratory syndrome coronavirus 2 spread may inadvertently discourage patient care-seeking behavior for critical conditions like acute ischemic stroke. We aimed to compare temporal trends in volume of acute stroke alerts, patient characteristics, telestroke care, and short-term outcomes pre- and post-SIP orders. Methods: We conducted a cohort study in 21 stroke centers of an integrated healthcare system serving 4.4+ million members across Northern California. We included adult patients who presented with suspected acute stroke and were evaluated by telestroke between January 1, 2019, and May 9, 2020. SIP orders announced the week of March 15, 2020, created pre (January 1, 2019, to March 14, 2020) and post (March 15, 2020, to May 9, 2020) cohort for comparison. Main outcomes were stroke alert volumes and inpatient mortality for stroke. Results: Stroke alert weekly volume post-SIP (mean, 98 [95% CI, 92–104]) decreased significantly compared with pre-SIP (mean, 132 [95% CI, 130–136]; P <0.001). Stroke discharges also dropped, in concordance with acute stroke alerts decrease. In total, 9120 patients were included: 8337 in pre- and 783 in post-SIP cohorts. There were no differences in patient demographics. Compared with pre-SIP, post-SIP patients had higher National Institutes of Health Stroke Scale scores ( P =0.003), lower comorbidity score ( P <0.001), and arrived more often by ambulance ( P <0.001). Post-SIP, more patients had large vessel occlusions ( P =0.03), and there were fewer stroke mimics ( P =0.001). Discharge outcomes were similar for post-SIP and pre-SIP cohorts. Conclusions: In this cohort study, regional stroke alert and ischemic stroke discharge volumes decreased significantly in the early COVID-19 pandemic. Compared with pre-SIP, the post-SIP population showed no significant demographic differences but had lower comorbidity scores, more severe strokes, and more large vessel occlusions. The inpatient mortality was similar in both cohorts. Further studies are needed to understand the causes and implications of care avoidance to patients and healthcare systems.
Background and Purpose— Timely administration of intravenous tissue-type plasminogen activator (IV tPA) is associated with improved outcomes for acute ischemic stroke; yet, developing processes to consistently provide prompt treatment remains a challenge. We developed and evaluated a simple quality improvement intervention designed to improve door-to-needle (DTN) times for resident-led Code Stroke teams at an academic medical center. Methods— We evaluated a simple text-messaging based intervention with real-time feedback to improve DTN times for intravenous tissue-type plasminogen activator. We used the rank-sum test and linear regression to evaluate for a change in DTN times that was temporally associated with the rollout of the intervention. Results— A total of 202 patients received intravenous tissue-type plasminogen activator; 94 preintervention and 108 postintervention. The median DTN time was significantly lower in the postintervention period (56 minutes [interquartile range 44–71] versus 82 minutes [IQR 68–103], P <0.0001) and a significantly higher proportion of patients were treated within 60 minutes (61% versus 16%, P <0.001). Conclusions— A simple real-time text-messaging intervention was associated with a significant improvements in DTN times for acute ischemic stroke.
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