Presence of Acute Ischaemic Lesions on Diffusion-Weighted Imaging Is Associated with Clinical Predictors of Early Risk of Stroke after Transient Ischaemic Attack

Abstract

Background: Early risk of stroke after a transient ischaemic attack (TIA) can be reliably predicted with risk scores based on clinical features of the patient and the event, but it is unclear how these features correlate with findings on brain imaging and few studies have investigated this in the subacute phase. Methods: Two hundred consecutive patients attending a specialist clinic underwent diffusion-weighted brain imaging (DWI) on the day of the clinic (≧3 days after a TIA) and the presence of recent lesions (positive DWI) was related to the presence of clinical features associated with a high stroke risk and to 2 validated risk scores (ABCD and California). Results: Thirty-one patients (16%) had positive DWI. Increasing ABCD and California scores were associated with positive DWI (p = 0.02 for both) independent of the delay from TIA to scan. Conclusion: Presence of recent ischaemic lesions on DWI correlates with validated clinical scores for risk of stroke after TIA in patients scanned subacutely. Future prognostic studies of DWI after TIA should adjust for the risk scores to determine the independent predictive value of DWI and hence the likely role of DWI in refinements of the scores.

An assessment of the cost-effectiveness of magnetic resonance, including diffusion-weighted imaging, in patients with transient ischaemic attack and minor stroke: a systematic review, meta-analysis and economic evaluation

“…DWI was positive for ischaemic change in 37% (mean ± 12% SD, range 16-67%). 47,48,87,137,215 Having an acute ischaemic lesion on DWI (compared with not having a lesion) may predict increased risk of subsequent stroke, 87,92,93 but the effect of a DWI ischaemic lesion on stroke prediction independent of clinical scoring 47,94 was unclear. 87,[92][93][94] Clinical features and carotid stenosis may be a stronger predictor of recurrent stroke risk.…”

“…47,48,87,137,215 Having an acute ischaemic lesion on DWI (compared with not having a lesion) may predict increased risk of subsequent stroke, 87,92,93 but the effect of a DWI ischaemic lesion on stroke prediction independent of clinical scoring 47,94 was unclear. 87,[92][93][94] Clinical features and carotid stenosis may be a stronger predictor of recurrent stroke risk. 93,137 Given the uncertainty around the accuracy of the widely publicised ABCD and ABCD2 clinical scores 62 in predicting stroke risk, 71,144,168 DWI could add prognostic as well as diagnostic value.…”

The California, ABCD, and Unified ABCD2 Risk Scores and the Presence of Acute Ischemic Lesions on Diffusion-Weighted Imaging in TIA Patients

“…13 In their study, patients were scanned later (median interval of 15 days), and they did not find an association between motor weakness and positive DWI whereas they found an association with dysarthria.…”

Diagnostic Usefulness of the ABCD 2 Score to Distinguish Transient Ischemic Attack and Minor Ischemic Stroke From Noncerebrovascular Events

“…Our findings are further supported by MRI studies reporting associations among individual ABCD 2 items, higher ABCD 2 scores, and diffusion-weighted imaging evidence of minor ischemic injury in patients with symptoms fulfilling the clinical definition of TIA. 22,23 The diagnosis of TIA may prove difficult in practice for several reasons. Older patients may have difficulty recalling or describing resolved symptoms, particularly if a prolonged delay to medical assessment occurs.…”