Journal Article

Associations of Clinical Stroke Misclassification (‘Clinical-Imaging Dissociation’) in Acute Ischemic Stroke

Potter, Gillian, Sudlow, Cathie, Doubal, Fergus, Jackson, Caroline, Dennis, Martin, Wardlaw, Joanna

2010

Overview

Background: Up to 20% of lacunar infarcts are clinically misdiagnosed as cortical infarcts and vice versa. The reasons for this discrepancy are unclear. We assessed clinical and imaging features which might explain this ‘clinical-imaging dissociation’ (C-ID). Methods: Patients with an acute stroke syndrome (cortical or lacunar) underwent magnetic resonance imaging including diffusion-weighted imaging (DWI). We recorded DWI-positive infarcts and proximity to cortex for small subcortical infarcts. We examined factors associated with C-ID. Results: 137 patients with a mild cortical or lacunar syndrome had an acute ischemic lesion on DWI. Of these, 21/93 (23%) with a cortical syndrome had an acute lacunar infarct and 7/44 (16%) with a lacunar syndrome had an acute cortical infarct. From 72 patients with an acute lacunar infarct on DWI, lesion proximity to cortex (odds ratio (OR) 14.5, 95% confidence interval (CI) 1.61–130.1), left hemisphere location (OR 8.95, 95% CI 1.23–64.99) and diabetes (OR 17.1, 95% CI 1.49–196.16) predicted C-ID. On multivariate analysis of all 137 patients, C-ID was associated with diabetes (OR 7.12, 95% CI 1.86–27.2). Conclusions: C-ID occurs in a fifth of patients with mild stroke. Lacunar infarcts lying close to cortex are more likely to cause cortical symptoms. Diabetes is associated with any clinical-imaging mismatch. Stroke misclassification which can arise with clinical classification alone should be minimized in research by verification with high-sensitivity imaging.

• Publisher: S. Karger AG
• Subject: Acute Disease / Aged / Aged, 80 and over / Basal Ganglia - blood supply / Basal Ganglia - diagnostic imaging / Brain Infarction - classification / Brain Infarction - complications / Brain Infarction - diagnosis / Brain Infarction - diagnostic imaging / Brain Ischemia - diagnosis / Brain Ischemia - diagnostic imaging / Brain Stem - blood supply / Brain Stem - diagnostic imaging / Cerebral Cortex - blood supply / Cerebral Cortex - diagnostic imaging / Cerebral Infarction - diagnosis / Cerebral Infarction - diagnostic imaging / Diabetes Complications - diagnosis / Diabetes Complications - diagnostic imaging / Diagnosis, Differential / Diagnostic Errors / Diffusion Magnetic Resonance Imaging / Female / Humans / Infarction, Anterior Cerebral Artery - diagnosis / Infarction, Anterior Cerebral Artery - diagnostic imaging / Infarction, Posterior Cerebral Artery - diagnosis / Infarction, Posterior Cerebral Artery - diagnostic imaging / Male / Middle Aged / Movement Disorders - etiology / Original Paper / Prospective Studies / Sensation Disorders - etiology / Sensitivity and Specificity / Single-Blind Method / Tomography, X-Ray Computed