title: Validating a threshold of ocular gaze deviation for the prediction of acute ischaemic stroke.
abstract: OBJECTIVE
  To determine a threshold at which the degree of ocular gaze deviation (OGD) on axial imaging is highly specific for the prediction of acute ischaemic stroke.
  
  
  METHODS
  A retrospective analysis of 517 patients who had received MRI with diffusion-weighted imaging (DWI) for suspected acute stroke was performed. The degree of OGD was measured in all patients and the presence and location of infarction determined. The difference in OGD between groups was compared using the independent t-test for normally distributed data and the Mann-Whitney test for non-normal data. The sensitivity and specificity for degrees of OGD in the prediction of acute infarction was calculated using a receiver operating curve (ROC) analysis.
  
  
  RESULTS
  The imaging of 448 patients meeting the inclusion criteria was reviewed. Acute infarct was demonstrated in 34.8% (n=156). There was a significant difference in the degree of OGD between patients with an acute infarct and those without evidence of acute ischaemia (p<0.001). ROC curve analysis for OGD demonstrated area under the curve (AUC) = 0.619 with increasing degrees of OGD more specific for acute infarct. OGD >11.95° had a sensitivity of 17% and specificity of 95.9% in predicting acute infarction.
  
  
  CONCLUSIONS
  Significant OGD>11.95° has a high specificity for acute infarct. This threshold may provide a helpful additional sign in the detection of subtle acute infarct, particularly on axial CT brain imaging.
authors.affiliation: Oxford University Hospitals National Health Service Trust, Radiology Department, John Radcliffe Hospital, Headley Way, Oxford, UK. Electronic address: DavidMcKean@doctors.org.uk.
authors.forename: D
authors.initials: D
authors.lastname: McKean
authors.affiliation: Oxford University Hospitals National Health Service Trust, Radiology Department, John Radcliffe Hospital, Headley Way, Oxford, UK.
authors.forename: M
authors.initials: M
authors.lastname: Kudari
authors.affiliation: New College, University of Oxford, Holywell St, Oxford OX1 3BN, UK.
authors.forename: M
authors.initials: M
authors.lastname: Landells
authors.affiliation: Oxford University Hospitals National Health Service Trust, Radiology Department, John Radcliffe Hospital, Headley Way, Oxford, UK.
authors.forename: D
authors.initials: D
authors.lastname: Grant
authors.affiliation: Oxford University Hospitals National Health Service Trust, Radiology Department, John Radcliffe Hospital, Headley Way, Oxford, UK.
authors.forename: S
authors.initials: S
authors.lastname: Johnson
authors.affiliation: Buckinghamshire Healthcare National Health Service Trust, Radiology Department, Aylesbury, UK.
authors.forename: L
authors.initials: L
authors.lastname: López de Heredia
authors.affiliation: Buckinghamshire Healthcare National Health Service Trust, Radiology Department, Aylesbury, UK.
authors.forename: S
authors.initials: S
authors.lastname: Yanny
authors.affiliation: Buckinghamshire Healthcare National Health Service Trust, Radiology Department, Aylesbury, UK.
authors.forename: E K
authors.initials: EK
authors.lastname: Woo
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001921:Brain / Q000473:pathology; D002545:Brain Ischemia / Q000150:complications / Q000175:diagnosis* / Q000503:physiopathology*; D004056:Differential Threshold; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods; D017352:Echo-Planar Imaging / Q000379:methods / Q000592:standards; D005260:Female; D005403:Fixation, Ocular / Q000502:physiology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D015835:Ocular Motility Disorders / Q000150:complications / Q000175:diagnosis* / Q000503:physiopathology*; D011237:Predictive Value of Tests; D012372:ROC Curve; D015203:Reproducibility of Results; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D020521:Stroke / Q000150:complications / Q000175:diagnosis* / Q000503:physiopathology*; D055815:Young Adult