Intracranial artery stenosis or occlusion predicts ischemic recurrence after transient ischemic attack

Abstract

Background and purpose: Patterns of DWI findings that predict recurrent ischemic events after TIA are well-established, but similar assessments of intracranial MRA findings are not available. We sought to determine the imaging characteristics of MRA that are predictive of early recurrent stroke/TIA in patients with TIA.

Materials and methods: We performed a retrospective analysis of 129 consecutive patients with a clinical diagnosis of TIA in whom MR imaging was done within 24 hours of symptom onset. We calculated the sensitivity, specificity, positive predictive value, and negative predictive value of >50% stenosis or occlusion of symptomatic intracranial arteries for recurrent stroke/TIA at 7 days after TIA. We used logistic regression analysis to adjust for the clinical ABCD(2) score. We performed this analysis for symptomatic steno-occlusive lesions at any site and symptomatic steno-occlusive lesions on proximal large intracranial arteries (internal carotid artery, vertebral artery, basilar artery, and circle of Willis).

Results: Forty-two (32.5%) patients had acute ischemic lesions on DWI; 16 (12.4%) had significant MRA lesions, of which 11 (8.5%) were on proximal vessels. Nine patients had early recurrence (TIA, 7; minor stroke, 2). Only patients with proximal MRA lesions were at higher risk of early recurrence independent of the ABCD(2) score (adjusted odds ratio, 5.5; 95% confidence interval, 1.1-27.8; P = .04).

Conclusions: Proximal lesions of cerebral arteries seen on MRA were predictive of recurrent stroke/TIA at 7 days. These findings suggest that MRA could be used to improve the selection of patients with TIA at high risk of early recurrent stroke/TIA.

Fig 1.

A 57-year-old woman with right transient hemiparesis (clinical duration = 2 minutes, delay since the first clinical symptom = 12 hours). ABCD² score = 4. A, DWI shows some foci of high signal intensity in the left frontal lobe with a decrease of ADC on the ADC map (B). C, 3D TOF reveals a significant proximal stenosis of the left M1 segment (arrow). The patient had another right transient impairment in the subsequent 48 hours.

Fig 2.

A 59-year-old man with left regressive hemiparesis (clinical duration = 3 minutes, delay since the first clinical symptom = 3 hours). ABCD² score = 4. A, DWI demonstrates a subtle hyperintensity in the right subinsular region with corresponding decrease of ADC on the ADC map (B). C, 3D TOF depicts right M1 segment grade 2 occlusion (arrow), responsible for the acute ischemic lesion in the insular lobe. The patient had another left transient hemiparesis in the subsequent 48 hours.