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Numerous biological mechanisms contribute to outcome after stroke, including brain injury, inflammation, and repair mechanisms. Clinical genetic studies have the potential to discover biological mechanisms affecting stroke recovery in humans and identify intervention targets. Large sample sizes are needed to detect commonly occurring genetic variations related to stroke brain injury and recovery. However, this usually requires combining data from multiple studies where consistent terminology, methodology, and data collection timelines are essential. Our group of expert stroke and rehabilitation clinicians and researchers with knowledge in genetics of stroke recovery here present recommendations for harmonizing phenotype data with focus on measures suitable for multicenter genetic studies of ischemic stroke brain injury and recovery. Our recommendations have been endorsed by the International Stroke Genetics Consortium.

Data on the association between air pollution and cerebrovascular disease in the United States are limited. The objective of this study was to investigate the association between short-term exposure to ambient air pollution and risk for ischemic cerebrovascular events in a US community.Daily counts of ischemic strokes/transient ischemic attacks (TIAs) (2001-2005) were obtained from the population-based Brain Attack Surveillance in Corpus Christi (BASIC) Project. Daily particulate matter less than 2.5microm in diameter (PM(2.5)), ozone (O(3)), and meteorological data were obtained from Texas Commission on Environmental Quality. To examine the association between PM(2.5) and stroke/TIA risk, we used Poisson regression. Separate models included same-day PM(2.5), PM(2.5) lagged 1 to 5 days, and an averaged lag effect. All models were adjusted for temperature, day of week, and temporal trends in stroke/TIA. The effects of O(3) were also investigated.Median PM(2.5) was 7.0microg/m(3) (interquartile range, 4.8-10.0microg/m(3)). There were borderline significant associations between same-day (relative risk [RR], 1.03; 95% confidence interval [CI], 0.99-1.07 for an interquartile range increase in PM(2.5)) and previous-day (RR, 1.03; 95% CI, 1.00-1.07) PM(2.5) and stroke/TIA risk. These associations were independent of O(3), which demonstrated similar associations with stroke/TIA risk (same-day RR, 1.02; 95% CI, 0.97-1.08; previous-day RR, 1.04; 95% CI, 0.99-1.09).We observed associations between recent PM(2.5) and O(3) exposure and ischemic stroke/TIA risk even in this community with relatively low pollutant levels. This study provides data on environmental exposures and stroke risk in the United States, and suggests future research on ambient air pollution and stroke is warranted.