Diagnostic Impact of Intracranial Vessel Wall MRI in 205 Patients with Ischemic Stroke or TIA.

BACKGROUND AND PURPOSE: Secondary prevention of ischemic stroke depends on determining the cause of the initial ischemic event, but standard investigations often fail to identify a cause or identify multiple potential causes. The purpose of this study was to characterize the impact of intracranial vessel wall MR imaging on the etiologic classification of ischemic stroke. MATERIALS AND METHODS: This was a single-center, retrospective study of 205 consecutive patients who were referred for vessel wall MR imaging to clarify the etiology of an ischemic stroke or TIA. An expert panel classified stroke etiology before and after incorporating vessel wall MR imaging results using a modified Trial of Org 10172 in Acute Stroke Treatment system. We measured the proportion of patients with an altered etiologic classification after vessel wall MR imaging. RESULTS: The median age was 56 years (interquartile range = 44-67 years), and 51% (106/205) of patients were men. Vessel wall MR imaging altered the etiologic classification in 55% (112/205) of patients. The proportion of patients classified as having intracranial arteriopathy not otherwise specified decreased from 31% to 4% (64/205 versus 9/205; P < .001) and the proportion classified as having intracranial atherosclerotic disease increased from 23% to 57% (48/205 versus 116/205; P < .001). Conventional work-up classification as intracranial arteriopathy not otherwise specified was an independent predictor of vessel wall MR imaging impact (OR = 8.9; 95% CI, 3.0-27.2). The time between symptom onset and vessel wall MR imaging was not a predictor of impact. CONCLUSIONS: When vessel wall MR imaging is performed to clarify the etiology of a stroke or TIA, it frequently alters the etiologic classification. This is important because the etiologic classification is the basis for therapeutic decision-making.

Evidence-based guideline: The role of diffusion and perfusion MRI for the diagnosis of acute ischemic stroke: report of the Therapeutics and Technology Assessment Subcommittee of the American Academy of Neurology.

OBJECTIVE: To assess the evidence for the use of diffusion-weighted imaging (DWI) and perfusion-weighted imaging (PWI) in the diagnosis of patients with acute ischemic stroke. METHODS: We systematically analyzed the literature from 1966 to January 2008 to address the diagnostic and prognostic value of DWI and PWI. RESULTS AND RECOMMENDATIONS: DWI is established as useful and should be considered more useful than noncontrast CT for the diagnosis of acute ischemic stroke within 12 hours of symptom onset. DWI should be performed for the most accurate diagnosis of acute ischemic stroke (Level A); however, the sensitivity of DWI for the diagnosis of ischemic stroke in a general sample of patients with possible acute stroke is not perfect. The diagnostic accuracy of DWI in evaluating cerebral hemorrhage is outside the scope of this guideline. On the basis of Class II and III evidence, baseline DWI volumes probably predict baseline stroke severity in anterior territory stroke (Level B) but possibly do not in vertebrobasilar artery territory stroke (Level C). Baseline DWI lesion volumes probably predict (final) infarct volumes (Level B) and possibly predict early and late clinical outcome measures (Level C). Baseline PWI volumes predict to a lesser degree the baseline stroke severity compared with DWI (Level C). There is insufficient evidence to support or refute the value of PWI in diagnosing acute ischemic stroke (Level U).

Stroke and pregnancy.

BACKGROUND AND PURPOSE: We sought to characterize the subtypes of stroke associated with pregnancy and the puerperium, with emphasis on timing, etiology, risk factors, and outcome. METHODS: We conducted a retrospective analysis of patients admitted to the Toronto Hospital between January 1, 1980, and June 30, 1997, with a diagnosis of stroke during pregnancy or within 6 weeks postpartum. Strokes were classified as ischemic (arterial or venous) or hemorrhagic (subarachnoid or intracerebral). All patients were investigated with at least a CT scan of the head, and most had MRI and/or cerebral angiography. RESULTS: Of approximately 50 700 admissions for delivery, 34 patients with a diagnosis of stroke were identified (21 infarctions and 13 hemorrhages). Of patients with infarction, 13 were arterial and 8 were venous. Nine of 13 arterial events occurred in the third trimester or puerperium. Seven of 8 venous occlusions occurred postpartum. An etiologic diagnosis was made in 7 of 13 patients with arterial territory infarction, including cardiac emboli, coagulopathies, and carotid artery dissection. Of patients with hemorrhage, 7 were subarachnoid and 6 were intracerebral. The etiology was identified in 10 patients: 3 were due to ruptured aneurysms, 5 were associated with arteriovenous malformations, and 2 were associated with disseminated intravascular coagulation. All patients with infarction survived, but 3 patients with hemorrhage died. CONCLUSIONS: The majority of strokes associated with pregnancy were arterial occlusions. Most presented during the third trimester and puerperium.

Carotid artery stenosis. Selecting candidates for surgical management.

Many patients with significant carotid artery stenosis are candidates for endarterectomy, a procedure now proved to reduce the incidence of future stroke and death. In this article, Drs Jaigobin and Perry describe an approach to patients with both symptomatic and asymptomatic carotid stenosis and review current indications for surgical referral. They also emphasize the importance of recognizing and managing concurrent coronary artery disease.