Background and aim Ocular gaze deviation (OGD) is a well known clinical observation (Prevost's sign) in patients with acute cerebral ischemic stroke. Although OGD has been observed on CT in acute stroke, no investigation has quantified the degree of OGD in acute stroke.

Material and methods A blinded prospective comparison was performed of two groups of adult patients who underwent CT of the brain. Group 1 comprised patients with acute hemiplegia or hemiparesis due to middle cerebral artery ischemic stroke. Group 2 included ambulatory outpatients with a history of headache but no clinical neurologic signs or cerebral pathology on CT. The CT images were cropped to only show the orbital contents. A neuroradiologist, who was blinded to the clinical data, then measured the OGD for both groups. The OGD was quantified using the axial planes of the lenses relative to the nasal midline structures, and the bilateral OGD average was calculated. Both groups were also evaluated for conjugate or disconjugate gaze. Results were analyzed using Fisher's exact test.

Results 10 of 70 patients in group 1 and 15 of 46 patients in group 2 were eligible for analysis. The frequency of conjugate and disconjugate gaze was similar in the two groups (p = 0.596). An averaged OGD of >14° and an OGD >18° in either globe was predictive of the presence of acute stroke (p = 0.0166).

Conclusion Measurement of OGD is useful in predicting the presence of acute ischemic stroke.