Edinburgh Imaging

14 Apr 20. Featured Paper

Improving clinical detection of acute lacunar stroke: analysis from the IST-3.

Link to paper on AHA Journals, Stroke



Francesco Arba, Grant Mair, Stephen Phillips, Peter Sandercock, Joanna M. Wardlaw, & on behalf of the Third International Stroke Trial Collaborators



Background & purpose: We aim to identify factors associated with imaging-confirmed lacunar strokes & improve their rapid clinical identification early after symptom onset using data from the IST-3 (Third International Stroke Trial).

Methods: We selected patients likely to have lacunar infarcts as those presenting with: Oxfordshire Community Stroke Project lacunar syndrome; a random sample with National Institutes of Health Stroke Scale (NIHSS) score <7; & recent lacunar infarct identified on imaging by IST-3 central blinded expert panel.

An independent reviewer rated brain scans of this sample & classified visible infarcts according to type, size, & location.

We investigated factors associated with presence of lacunar infarct on a 24 to 48 hour follow-up scan using multivariable logistic regression & calculated sensitivity & specificity of Oxfordshire Community Stroke Project alone & in combination with NIHSS score <7.

Results: We included 568 patients (330 lacunar syndrome; 147 with NIHSS score <7; 91 with lacunar infarct on baseline imaging, numbers exclude overlaps between groups), mean (±SD) age, 73.2 (±13.6) years, 316 (56%) males, & median NIHSS score 5 (IQR, 4–8).

On 24 to 48 hour scan, 138 (24%) patients had lacunar infarcts, 176 (31%) other infarct subtypes, 254 (45%) no visible infarct.

Higher baseline systolic blood pressure (odds ratio, 1.01 [95% CI, 1.01–1.02]) & preexisting lacunes (odds ratio, 2.29 [95% CI, 1.47–3.57) were associated with recent lacunar infarcts.

Sensitivity & specificity of lacunar syndrome was modest (58% & 45%, respectively), but adding NIHSS score <7 increased specificity (99%), positive & negative predictive values (97% & 87%, respectively).

Conclusions: In patients presenting within 6 hours of stroke onset, adding NIHSS score <7 to Oxfordshire Community Stroke Project lacunar syndrome classification may increase specificity for identifying lacunar stroke early after stroke onset.

Our findings may help selection of patients for clinical trials of lacunar stroke & should be validated externally.