Triaging transient ischemic attack and minor stroke patients using acute magnetic resonance imaging

Abstract

We examined whether the presence of diffusion-weighted imaging (DWI) lesions and vessel occlusion on acute brain magnetic resonance images of minor stroke and transient ischemic attack patients predicted the occurrence of subsequent stroke and functional outcome. 120 transient ischemic attack or minor stroke (National Institutes of Health Stroke Scale < or = 3) patients were prospectively enrolled. All were examined within 12 hours and had a magnetic resonance scan within 24 hours. Overall, the 90-day risk for recurrent stroke was 11.7%. Patients with a DWI lesion were at greater risk for having a subsequent stroke than patients without and risk was greatest in the presence of vessel occlusion and a DWI lesion. The 90-day risk rates, adjusted for baseline characteristics, were 4.3% (no DWI lesion), 10.8% (DWI lesion but no vessel occlusion), and 32.6% (DWI lesion and vessel occlusion) (p = 0.02). The percentages of patients who were functionally dependent at 90 days in the three groups were 1.9%, 6.2%, and 21.0%, respectively (p = 0.04). The presence of a DWI lesion and a vessel occlusion on a magnetic resonance image among patients presenting acutely with a transient ischemic attack or minor stroke is predictive of an increased risk for future stroke and functional dependence.

DWI Reversal Is Associated with Small Infarct Volume in Patients with TIA and Minor Stroke

“…[1][2][3] The presence and the volume of DWI lesions carry a negative prognostic value in this population. [4][5][6] The DWI-restricted lesions are thought to represent the irreversibly damaged ischemic core. 7 This premise was recently brought into question by studies suggesting a high rate of DWI lesion reversal in patients with stroke who had undergone thrombolytic therapy.…”

Comparison of Optimized and Standard Diffusion-Weighted Imaging at 1.5T for the Detection of Acute Lesions in Patients with Transient Ischemic Attack

“…Indeed, the presence of a DWI lesion confirms the vascular origin of the deficit and is associated with a greater risk for future stroke and functional dependence. 5 We extend to TIAs the results obtained by others in acute stroke patients, with a slightly different optimized DWI sequence on a 1.5T unit. 3 Although these authors did not report any stroke patient with bright dots exclusively visible on optimized DWI and normal standard DWI, optimized DWI showed twice as many lesions as standard DWI.…”

An urgent access neurovascular clinic

“…Clinicians may not be as good as they think they are in correctly determining the vascular distribution 3 • a positive diffusion-weighted imaging (DWI) may also provide prognostic information in its own right 4 • the pattern of infarction on DWI can provide clues to the cause of the event 5 • MR angiography (MRA) can detect vascular disease at sites other than the carotid bifurcation eg vertebral and intracranial stenosis.…”