Diffusion-weighted imaging and diagnosis of transient ischemic attack

Brazzelli, M., Chappell, F. M., Miranda, H., Shuler, K., Dennis, M., Sandercock, P. A. G., Muir, K. and Wardlaw, J. M. (2014) Diffusion-weighted imaging and diagnosis of transient ischemic attack. Annals of Neurology, 75(1), pp. 67-76. (doi: 10.1002/ana.24026) (PMID:24085376) (PMCID:PMC4223937)

104723.pdf - Published Version
Available under License Creative Commons Attribution Non-commercial No Derivatives.



Objective Magnetic resonance (MR) diffusion-weighted imaging (DWI) is sensitive to small acute ischemic lesions and might help diagnose transient ischemic attack (TIA). Reclassification of patients with TIA and a DWI lesion as “stroke” is under consideration. We assessed DWI positivity in TIA and implications for reclassification as stroke.<p></p> Methods We searched multiple sources, without language restriction, from January 1995 to July 2012. We used PRISMA guidelines, and included studies that provided data on patients presenting with suspected TIA who underwent MR DWI and reported the proportion with an acute DWI lesion. We performed univariate random effects meta-analysis to determine DWI positive rates and influencing factors.<p></p> Results We included 47 papers and 9,078 patients (range = 18–1,693). Diagnosis was by a stroke specialist in 26 of 47 studies (55%); all studies excluded TIA mimics. The pooled proportion of TIA patients with an acute DWI lesion was 34.3% (95% confidence interval [CI] = 30.5–38.4, range = 9–67%; I2 = 89.3%). Larger studies (n > 200) had lower DWI-positive rates (29%; 95% CI = 23.2–34.6) than smaller (n < 50) studies (40.1%; 95% CI = 33.5–46.6%; p = 0.035), but no other testable factors, including clinician speciality and time to scanning, reduced or explained the 7-fold DWI-positive variation.<p></p> Interpretation The commonest DWI finding in patients with definite TIA is a negative scan. Available data do not explain why ⅔ of patients with definite specialist-confirmed TIA have negative DWI findings. Until these factors are better understood, reclassifying DWI-positive TIAs as strokes is likely to increase variance in estimates of global stroke and TIA burden of disease.<p></p>

Item Type:Articles
Glasgow Author(s) Enlighten ID:Muir, Professor Keith
Authors: Brazzelli, M., Chappell, F. M., Miranda, H., Shuler, K., Dennis, M., Sandercock, P. A. G., Muir, K., and Wardlaw, J. M.
College/School:College of Medical Veterinary and Life Sciences > School of Psychology & Neuroscience
Journal Name:Annals of Neurology
ISSN (Online):1531-8249
Copyright Holders:Copyright © 2013 The Authors
First Published:First published in Annals of Neurology 75(1):67-76
Publisher Policy:Reproduced under a Creative Commons License

University Staff: Request a correction | Enlighten Editors: Update this record

Project CodeAward NoProject NamePrincipal InvestigatorFunder's NameFunder RefLead Dept
528741An Assessment of the Cost Effectiveness of Magnetic Resonance Including Diffusion-Weighted Brain Imaging in Patients with Transient Ischaemic Attack and Minor StrokeKeith MuirNational Institute for Health Research (NIHR)09/22/169RI NEUROSCIENCE & PSYCHOLOGY