Role of Early Neuroimaging in Managing Acute Isolated Ocular Motor Nerve Palsies

Abstract

Background: The role of early neuroimaging in older vasculopathic patients presenting with acute isolated ocular motor nerve palsy is still being debated. We wanted to demonstrate the approach differences between neurologists and ophthalmologists, and examine the role of early neuroimaging in managing acute ocular motor mononeuropathies. Methods: Retrospective chart review. Patients ≥ 50 years with vasculopathic risk factors, presenting with acute isolated third, fourth or sixth cranial nerve palsies. We compared the rate of early neuroimaging referral between neurologists and ophthalmologists at initial presentation, and assessed the proportion of cases in which the final diagnosis has changed after early neuroimaging, in a single medical center. Results: 54 patients were included. After excluding patients with third nerve palsy, the rate of patients referred to early neuroimaging was significantly greater when initially presented to a neurologist compared with an ophthalmologist (29/38 patients were referred to early neuroimaging, of whom twenty by a neurologist and nine by an ophthalmologist, p<0.001). Out of 38 patients presented with fourth or sixth nerve palsies, only 4/38 (10%) were found to have a cause other than presumed microvascular ischemia, and only 2/29 (7%) patients referred to neuroimaging were found to have a causative lesion. Conclusions: The decision to perform early neuroimaging in older patients with acute isolated 4th or 6th nerve palsies and vasculopathic risk factors could be weighed against observation alone. Thorough history taking and prudent physical examination are important for identifying patients with greater risks, therefore needing early neuroimaging.