BACKGROUND AND PURPOSE:The regional leptomeningeal score is a strong and reliable imaging predictor of good clinical outcomes in acute anterior circulation ischemic strokes and can therefore be used for imaging based patient selection. Efforts to determine biological determinants of collateral status are needed if techniques to alter collateral behavior and extend time windows are to succeed.

Background and Purpose-Transient ischemic attack and minor stroke portend a substantial risk of recurrent stroke. MRI can identify patients at high risk for a recurrent stroke. However, MRI is not commonly available as an emergency. If similarly clinically predictive, a CT/CT angiographic (CTA) imaging strategy would be more widely applicable. Methods-Five hundred ten patients with consecutive transient ischemic attack and minor stroke underwent CT/CTA and subsequent MRI. We assessed the risk of recurrent stroke within 90 days using standard clinical variables and predefined abnormalities on the CT/CTA (acute ischemia on CT and/or intracranial or extracranial occlusion or stenosis Ն50%) and MRI (diffusion-weighted imaging-positive). Results-There were 36 recurrent strokes (7.1%; 95% CI, 5.0 -9.6). Median time to the event was 1 day (interquartile range, 7.5). Median time from onset to CTA was 5.5 hours (interquartile range, 6.4 hours) and to MRI was 17.5 hours (interquartile range, 12 hours). Symptoms ongoing at first assessment (hazard ratio, 2.2; 95% CI, 1.02-4.9), CT/CTA abnormalities (hazard ratio, 4.0; 95% CI, 2.0 -8.5), and diffusion-weighted imaging positivity (hazard ratio, 2.2; 95% CI, 1.05-4.7) predicted recurrent stroke. In the multivariable analysis, only CT/CTA abnormalities predicted recurrent stroke. In a secondary analysis, CT/CTA and MRI were not significantly different in their discriminative value in predicting recurrent stroke (0.67; (95% CI, 0.59 -0.76 versus 0.59; 95% CI, 0.52-0.67; Pϭ0.09). Conclusions-Early assessment of the intracranial and extracranial vasculature using CT/CTA predicts recurrent stroke and clinical outcome in patients with transient ischemic attack and minor stroke. In many institutions, CTA is more readily available than MRI and physicians should access whichever technique is more quickly available at their institution.

Background and Purpose-Definitions for chronic lacunar infarcts vary. Recent retrospective studies suggest that many acute lacunar strokes do not develop a cavitated appearance. We determined the characteristics of acute lacunar infarcts on follow-up MRI in consecutive patients participating in prospective research studies. Methods-Patients with acute lacunar infarction on diffusion-weighted imaging were selected from 3 prospective cohort studies of minor stroke imaged within Ͻ24 hours of onset. ). Evidence of cavitation on MRI was rated separately on fluid-attenuated inversion recovery, T1, and T2 sequences by 2 independent study physicians; discrepant readings were resolved by consensus. Results-Probable or definite cavitation on any sequence was more common at 90 days compared with 30 days (PՅ0.001 for all sequences). At 90 days, evidence of cavitation was seen on at least 1 sequence in 33 of 34 patients (97%). The T1-weighted sequence was most sensitive to the presence of cavitation (94% at 90 days). By contrast, the fluid-attenuated inversion recovery sequence frequently failed to show evidence of cavitation in the brain stem or thalamus (only 10 of 18 [56%] showed cavitation). Conclusions-MRI scanning at 90 days with T1-weighted imaging reveals evidence of cavitation in nearly all cases of acute lacunar infarction. By contrast, reliance on fluid-attenuated inversion recovery alone will miss many cavitated lesions in the thalamus and brain stem. These factors should be taken into account in the development of standardized criteria for lacunar infarction on MRI. (Stroke. 2012;43:1837-1842.)

Background and Purpose— Minor stroke and transient ischemic attack portend a significant risk of disability. Three possible mechanisms for this include disability not captured by the National Institutes of Health Stroke Scale, symptom progression, or recurrent stroke. We sought to assess the relative impact of these mechanisms on disability in a population of patients with transient ischemic attack and minor stroke. Methods— Five hundred ten consecutive minor stroke (National Institutes of Health Stroke Scale <4) or patients with transient ischemic attack who were previously not disabled and had a CT/CT angiography completed within 24 hours of symptom onset were prospectively enrolled. Disability was assessed at 90 days using the modified Rankin Scale. Predictors of disability (modified Rankin Scale ≥2) and the relative impact of the initial event versus recurrent events were assessed. Results— Seventy-four of 499 (15%; 95% CI, 12%–18%) patients had a disabled outcome. Baseline factors predicting disability were: age ≥60 years, diabetes mellitus, premorbid modified Rankin Scale 1, ongoing symptoms, baseline National Institutes of Health Stroke Scale, CT/CT angiography-positive metric, and diffusion-weighted imaging positivity. In the multivariable analysis ongoing symptoms (OR, 2.4; 95% CI, 1.3–4.4; P =0.004), diabetes mellitus (OR, 2.3; 95% CI, 1.2–4.3; P =0.009), female sex (OR, 1.8; 95% CI, 1.1–3; P =0.025), and CT/CT angiography-positive metric (OR, 2.4; 95% CI, 1.4–4; P =0.001) predicted disability. Of the 463 patients who did not have a recurrent event, 55 were disabled (12%). By contrast 19 of 36 (53%) patients were disabled after a recurrent event (risk ratio, 4.4; 95% CI, 3–6.6; P <0.0001). Conclusions— We found that a substantial proportion of patients with transient ischemic attack and minor stroke become disabled. In terms of absolute numbers, most patients have disability as a result of their presenting event; however, recurrent events have the largest relative impact on outcome.

Background and Purpose-Few studies have examined predictors of cognitive impairment after minor ischemic stroke and transient ischemic attack (TIA). We examined clinical and imaging features associated with worse cognitive performance at 90 days. Methods-TIA or patients with minor stroke underwent neuropsychological testing 90 days post event. Z scores were calculated for cognitive tests, and then grouped into domains of executive function (EF), psychomotor processing speed (PS), and memory. White matter hyperintensity and diffusion-weighted imaging volumes were measured on baseline magnetic resonance imaging. Ninety-day outcomes included modified Rankin Scale (mRS) and Centre for Epidemiological Studies Depression Scale (CES-D) score. Results-Ninety-two patients were included, 76% male, 54% TIA, and mean age 65.