Ocular Lateral Deviation as a Vestibular Sign to Improve Detection of Posterior Circulation Strokes: A Review of the Literature

Background Posterior circulation stroke can present with dizziness/vertigo without other general neurological symptoms or signs, making it difficult to detect, and missed stroke can deteriorate. Therefore, a sign that can be easily identified during an examination would be helpful to improve the detection of this type of stroke. Objective The objective of this review is to highlight an ocular sign that is seen in posterior circulation strokes called ocular lateral deviation (OLD). OLD is mostly seen in dorsolateral medullary strokes, and it is also seen in pontine and cerebellar strokes. OLD is detected by asking a patient to look straight ahead and then briefly close their eyes. Upon re-opening their eyes, the examiner will see that the eyes have deviated to one side; the patient's eyes will then make corrective saccade(s) to return to looking straight ahead. Complete eye deviation is a central sign of posterior circulation stroke. Discussion OLD is an under-recognized vestibular ocular sign of central vestibulopathies including posterior circulation stroke. The most common location is in the dorsolateral medulla, where one-third of such strokes have complete OLD. Eye deviation can also be appreciated on computed tomography or magnetic resonance imaging. OLD can be detected up to 6 months after a posterior circulation stroke. Conclusions Checking for the sign of complete eye deviation in patients with dizziness/vertigo could be a simple, quick method for detecting posterior circulation stroke, and a means to improving the patients’ outcome.