Authors: Daniel Lamoureux, Amer Al-Aref, Vishaal Bhambhwani. 
Northern Ontario School of Medicine.

Author Disclosure Block: D. Lamoureux: None. A. Al-Aref: None. V. Bhambhwani: None.

Title: Radiological findings in patients with isolated acute-onset ocular motility disorders (AOMD)

Abstract Body:

Purpose: To image or not to image is a critical question in the management of patients with isolated acute-onset ocular motility disorders (AOMD), without any other neurological symptoms/signs. Imaging may help in diagnosis; but is associated with risks and costs. The purpose of this study was to evaluate radiological findings in patients with isolated AOMD.
Study Design: Retrospective study
Methods: A retrospective review of patient charts with isolated AOMD (<3 months onset), who were examined by an Ophthalmologist and referred for imaging at a tertiary-care center between December 2019-May 2021, was conducted. Ophthalmology exam and diagnostic imaging findings were recorded. Radiological findings were classified as “clinically relevant”, “non-relevant”, and “normal/no positive” findings.
Results: 50 patients met inclusion criteria (3-91 years, 28M and 22F). Symptoms commonly reported were diplopia (41/50, 82%), noticeable eye drift (4/50, 8%), oscillopsia (2/50, 4%). 19 were clinically classified as nerve palsy (1 third, 10 fourth, and 8 sixth nerve), 5 acute-onset exotropia, 14 acute-onset esotropia, 7 acute-onset vertical strabismus inconsistent with nerve palsy, 2 acute-onset nystagmus, and 3 limitation of elevation/suspected dorsal midbrain syndrome. We found 9/50 (18%) with clinically relevant imaging findings; of these, 6/50 (12%) had positive neuro-imaging findings and 3/50 (6%) had positive orbital imaging findings. These included 1/8 (13%) of sixth nerve palsy (mass), 3/3 (100%) of suspected dorsal midbrain syndrome (mass/aneurysm/infarct), 2/14 (14%) of acute-onset esotropia (Chiari malformation/ischemia), and 3/7 (43%) of the acute-onset vertical strabismus (signs of thyroid ophthalmopathy). In addition, one acute-onset esotropia had elevated intracranial pressure on lumbar puncture despite normal imaging.
Conclusions: Positive neuro-imaging findings may be seen even in patients with apparently isolated ocular symptoms/signs. Certain diagnostic entities are more likely to be associated with positive imaging. This data may help clinicians and institutions with decision-making and policy formulation with respect to ordering of imaging for patients with isolated AOMD.