Lesions on DWI and the Outcome in Hyperacute Posterior Circulation Stroke

Background: Few studies have addressed the association between the characteristics of ischemic lesions detected by diffusion-weighted imaging (DWI) and the clinical outcome in patients with hyperacute posterior circulation ischemic stroke. This study demonstrates a relationship between the findings assessed by DWI and the outcome in patients with hyperacute posterior circulation ischemic stroke. Methods: We reviewed data from 118 patients who had posterior circulation ischemic stroke within six hours from the onset of their symptoms. The clinical outcome included early neurological deterioration (END) and a favorable outcome at three months after the onset of symptoms. Using DWI, the lesion volume and the number and location of injured anatomical regions were analyzed to evaluate whether the results correlated with the clinical outcome measures. Results: The number of injured anatomical regions assessed by DWI was associated with the initial and delayed neurological status. Both the total volume and the number of injured anatomical regions associated with END and a favorable outcome. Analysis of the location of the injured regions determined that only a pontine lesion independently associated with END. Interestingly, four out of five patients who underwent decompressive craniectomy exhibited a large infarction volume but minor symptoms. Conclusions: In patients with hyperacute posterior circulation ischemic strokes, the lesions assessed by DWI were associated with the clinical outcome, regardless of the initial neurological status. DWI is an effective initial imaging tool for assessing the extent of lesions and clinical outcomes in patients with hyperacute posterior circulation ischemic stroke.