The quantification of intracranial thrombus extent with the clot burden score predicts functional outcome, final infarct size and parenchymal hematoma risk acutely. The score needs external validation and could be useful for patient stratification in stroke trials.

Background and Purpose-The frequency of DWI negative cerebral ischemia and clinical factors associated with such a circumstance is not well understood. Methods-We performed MRI including diffusion-weighted imaging (DWI) in patients with stroke and transient ischemic attack (TIA) within 24 hours of symptom onset and again at 30 days. Results-Of 401 patients, 103 (25.6%) had an initial negative DWI study. In the DWI negative group, among the stroke patients, 6/26 (23.1%) had infarcts on follow-up MRI (4 lacunar and 2 posterior circulation syndromes) and 1 had a rMTT deficit. Among the TIA patients, 4/63 (6.3%) showed rMTT deficits and 2/63 (3.2%) had infarcts on follow-up MRI. Conclusions-Baseline perfusion weighted imaging sequences may detect ischemia in a small proportion of DWI negative cases. Only those with brain stem location or lacunar syndrome were DWI negative initially and yet had a follow-up imaging confirmation of infarct or a final clinical diagnosis of stroke. (Stroke. 2008;39:1898-1900.)

Background and Purpose-Minimal research has evaluated the renal safety of emergent computed tomography angiography (CTA) procedures, consecutive contrast medium application, and the long-term outcome in acute stroke patients. We investigated the incidence of contrast-induced renal impairment in these populations. Methods-We retrospectively reviewed patients with acute stroke syndrome who received a CTA of the brain with or without the neck within 24 hours from onset of symptoms. All creatinine results and additional conventional angiography findings were recorded. With a positive history of renal disease, contrast administration was delayed until creatinine results were available. Radiocontrast nephropathy (RCN) was defined as a Ն25% increase in serum creatinine from the baseline value up to 5 days after CTA. Results-Four hundred eighty-one patients were reviewed, and 224 met the inclusion criteria. There were 7 of 224 (3%) who fulfilled the criteria for RCN. A number of patients underwent emergent CTA without knowledge of their creatinine value; 2 of 93 (2%) developed RCN. There were 36 patients who received an additional digital subtraction angiogram, and none of these developed subsequent RCN. No patients required dialysis, and 9 of 68 (13%) had a Ͼ25% increase in their creatinine levels at a late (Ͼ30 days) follow-up. Conclusions-Overall, these results illustrate that there is a low incidence of RCN in acute stroke patients undergoing emergency CTA. Key Words: CT angiography Ⅲ digital subtraction angiography Ⅲ radiocontrast nephropathy Ⅲ renal impairment C omputed tomography (CT) bolus techniques have the advantage of minimizing treatment delays but require the use of a nonionic contrast agent. One apprehension surrounding these techniques is the concern of causing radiocontrast nephropathy (RCN). RCN is defined as an increase in the serum creatinine value by Ͼ25% occurring within 3 days after the administration of contrast medium. 1 First, the time from stroke onset to thrombolysis treatment is strongly associated with subsequent outcome in acute stroke. 2 In acute stroke when time is critical, treatment delay due to waiting for a creatinine result is not desirable. 3 Only 1 study has examined the rate of RCN in patients with unknown baseline creatinine levels. 4 Second, it is known that the risk for RCN is proportional to the dose of radiocontrast medium administered. [5][6][7] It has been suggested that multiple, consecutive procedures requiring the use of contrast medium application implies a greater risk for RCN. 8 There have been no large studies examining the safety of consecutive contrast media application in acute stroke for CT angiography (CTA) and digital subtraction angiography (DSA).Third, the long-term outcome in patients undergoing radiocontrast application is unknown. Although serum creatinine levels may return to baseline shortly after receiving contrast medium, some patients may encounter permanent renal sequelae requiring additional medical care. 9 This study sought to determine the freque...

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A majority of minor hockey coaches correctly recognized and understood issues related to sport-related concussions. Results suggested that knowledge translation through various formal and informal sources has had a positive effect. However, a majority of coaches reported having limited knowledge about concussions yet consider it an important topic.

for the VISION Study GroupBackground and Purpose-Transient ischemic attack (TIA) patients may deteriorate rapidly. MRI is being increasingly used to assess such patients. One possible mechanism of neurological worsening is the presence of perfusion abnormalities. We sought to identify what proportion of TIA patients had evidence of perfusion abnormalities on MRI. Methods-TIA patients were prospectively enrolled and had a MRI completed as soon as possible. The images were assessed for the presence of perfusion abnormalities. Results-Sixty-nine TIA patients were enrolled, and 62 had perfusion imaging. In 56 patients (81%), the symptoms had resolved before imaging. In 21 patients (33.9%), there was evidence of a perfusion abnormality defined by relative mean transit time delay. In 12 patients (19.4%), the perfusion abnormality was present despite having complete resolution of neurological symptoms. We found no relationship between the presence of a perfusion abnormality and the clinical outcome. [1][2][3][4] The assumption that TIAs are associated with complete resolution of brain ischemia leaving no permanent brain injury 5,6 is false. There is growing evidence that TIA is not a benign condition and that the risk of a subsequent stroke is high within the first 48 hours 7 of symptom onset. ConclusionsPerfusion weighted imaging (PWI) using gadoliniumbased dynamic-susceptibility contrast provides information on ischemia. In this prospective study, we sought to understand whether MRI perfusion abnormalities exist among TIA patients despite the rapid resolution of symptoms. MethodsPatients who were prospectively enrolled with hemiparesis or aphasia that resolved within 24 hours were examined within 12 hours of onset, were independent on the modified Rankin scale, and were Ն18 years of age. Images were obtained using a 3-T scanner. The PWI was acquired using dynamic susceptibility contrast imaging. Imaging was assessed by a neuroradiologist blind to clinical information except the symptom side. Images were examined for the presence of an acute DWI lesion, for an occlusion on intracranial magnetic resonance angiography (MRA), and for a perfusion delay on the mean transit time (MTT) map.Patients were assessed with the National Institutes of Health Stroke Scale at 24 hours and with the modified Rankin scale at 3 months. The potential mechanism assigned using the Trial of Org 10172 in Acute Treatment classification and any recurrent strokes were recorded.The association between the presence or absence of a relative MTT delay (PWI lesion) and baseline characteristics was assessed. Logistic regression modeling using backward elimination was used to identify the predictors of a perfusion abnormality. ResultsSixty-nine TIA patients were enrolled. The median duration of symptoms was 90 minutes (range, 5 to 1380 minutes). Twenty-seven patients were women (39%). In 56 of the patients (81%), the symptoms had resolved by the beginning of the MRI. Thirty-two patients (46.4%) had evidence of a DWI hyperintensity.In 7 patients (10.1%)...

Because the method of collecting symptoms, as well as interviewer gender, can impact test results, self-report measures may be a better way of obtaining consistent results. Clinicians and researchers should be aware that both the nature and extent of symptom reporting is greater when using questionnaires than when athletes are interviewed.

Background and Purpose-We sought to determine the frequency and clinical course of patients with acute ischemic stroke or transient ischemic attack (TIA) who had intracranial nonocclusive thrombus (iNOT) on CT angiography (CTA