Premorbid antiplatelet use and ischemic stroke outcomes.

OBJECTIVE: To evaluate the independent effect of premorbid antiplatelet use on incident ischemic stroke severity and outcome at discharge. METHODS: The authors studied consecutive patients presenting within 24 hours of ischemic stroke over a 1-year period. National Institutes of Health Stroke Scale (NIHSS) score at presentation was used as index of stroke severity and a modified Rankin scale of 0 to 1 at discharge as index of good functional outcome. Patients were categorized according to their premorbid antiplatelet use as antiplatelet-inclusive (AI) and no antiplatelet (NA). Demographic data, risk factors, pertinent laboratory tests, other medications, and stroke mechanisms were controlled for across the two groups using multivariate logistic regression. RESULTS: A total of 260 individuals met study criteria: 92 patients were on antiplatelet agents prior to admission, 168 were on no antiplatelets. Pretreatment with antiplatelet was associated with lower presenting median NIHSS (4.5 vs 7, p = 0.005). Antiplatelet use was associated with less severe stroke at presentation in those having no history of stroke or TIA (4.8 vs 8.0, p = 0.03) but not in those with a prior history of stroke or TIA (4.9 vs 4.9, p = 0.987). The likelihood of a good outcome was increased in those on antiplatelets after adjusting for other variables (OR 2.105, p = 0.0073). CONCLUSIONS: Prestroke use of antiplatelet may be associated with reduced severity of incident ischemic strokes in those with no prior history of stroke or TIA, and with an increased likelihood of a good discharge outcome regardless of prior cerebrovascular event history.

Angiotensin 2 type 2 receptor activity and ischemic stroke severity.

BACKGROUND: Drugs that increase angiotensin 2 formation, including thiazides, calcium channel blockers, and angiotensin 2 type 1 (AT1) receptor blockers, may be more effective in stroke prevention than angiotensin 2 suppressive drugs such as angiotensin-converting enzyme inhibitors and beta-blockers. OBJECTIVE: To assess whether angiotensin 2 formation increasing drugs reduce incident stroke severity compared with angiotensin 2 formation suppressive drugs. METHODS: Consecutive patients presenting within 24 hours of first-ever ischemic stroke over an 18-month period were studied. Subjects were only included if they were on only angiotensin 2 formation increasers, only angiotensin 2 formation suppressors, or no antihypertensive agents. NIH Stroke Scale (NIHSS) score at presentation was used as the index of stroke severity. Demographic data, risk factors, admission blood pressures, other medications, and stroke mechanisms were controlled for across the three groups using least absolute deviation linear regression. RESULTS: One hundred seventy-five individuals met study criteria. Mean age was 67.4 years; 45% were women. Forty-nine patients were on angiotensin 2 formation suppressors and 16 on angiotensin 2 formation increasers. Age at admission, atrial fibrillation, previous antithrombotic use, cardioembolic and large-vessel atherosclerotic mechanisms, and mean systolic and diastolic blood pressure were significant univariate predictors of presenting median NIHSS score. On multivariate analysis, the adjusted median NIHSS score was lower in the angiotensin 2 increasers (median = 2.2; p = 0.005) and trended lower for angiotensin 2 suppressors (median = 4.4; p = 0.054) compared with the no-antihypertensive group (median = 6.0). There was no difference in stroke severity between angiotensin 2 increasers compared with angiotensin 2 suppressors (p = 0.123). CONCLUSIONS: Angiotensin 2 formation increasing agents did not reduce ischemic stroke severity more than angiotensin 2 formation suppressing agents. However, the prestroke use of antihypertensives was associated with reduced severity of incident ischemic strokes.

The relationship between skill learning and repetition priming: experimental and computational analyses.

Skill learning and repetition priming are considered by some to be supported by separate memory systems. The authors examined the relationship between skill learning and priming in 3 experiments using a digit entering task, in which participants were presented with unique and repeated 5-digit strings with controlled sequential structure. Both skill learning and priming were observed across a wide range of skill levels. Performance reflected the effects of learning at 3 different levels of stimulus structure, calling into question a binary dichotomy between item-specific priming and general skill learning. Two computational models were developed which demonstrated that previous dissociations between skill learning and priming can occur within a single memory system. The experimental and computational results are interpreted as suggesting that skill learning and priming should be viewed as 2 aspects of a single incremental learning mechanism.