Transcranial color-coded sonography to predict recurrent transient ischaemic attack/stroke

Abstract

Background and purpose: Patients with transient ischaemic attack (TIA) with a high risk of imminent stroke can be identified with the ABCD(2) score and findings on MRI and CT angiography. The predictive value of transcranial color-coded sonography (TCCS) has not been evaluated in this setting.

Methods: A retrospective analysis was conducted of patients consecutively treated for TIA or minor stroke in a TIA clinic within 24 h of symptom onset. Agreement between TCCS and MRI three-dimensional time-of-flight images for the diagnosis of proximal (internal carotid artery, vertebral artery, basilar artery, circle of Willis and main stem of the middle cerebral artery) >50% stenosis or occlusion of the intracranial symptomatic artery was evaluated. The sensitivity, specificity, predictive values and likelihood ratio of TCCS for predicting recurrent TIA/stroke at 7 days were calculated.

Results: Of 159 patients with a TIA or minor stroke within the last 24 h, 142 had a readable acoustic temporal bone window (89.3%). TCCS and MRI were performed within 4 h of each other in 116 patients. MRI showed a symptomatic proximal intracranial steno-occlusive lesion in six patients. Agreement between MRI and TCCS was perfect (κ coefficient = 1). Recurrent TIA/stroke occurred in 10 patients (eight TIA and two minor strokes). All recurrences occurred within 24 h of symptom onset. A symptomatic proximal intracranial steno-occlusive lesion was found on TCCS in 4/10 patients with recurrence and 3/132 patients without recurrence [sensitivity 40%; specificity 97.7%; likelihood ratio 18.1; odds ratio (95% CI) adjusted for ABCD(2) score 31.5 (4.5-218.6)].

Conclusion: Our study shows that TCCS can be used to guide triage of patients with TIA.

Keywords: arterial occlusion; arterial stenosis; cerebral circulation; magnetic resonance imaging; stroke; transcranial color-coded sonography; transient ischaemic attack; ultrasound/Doppler.