Abstract
Purpose :
The debate over the need for MRI neuroimaging in the initial workup of acute oculomotor mononeuropathies is ongoing. While most cases are due to microvascular ischemia, studies have demonstrated that 1-15% are due to intracranial neoplasm, stroke, aneurysm, inflammation, and infection. This study seeks to analyze the etiology of acute isolated mononeuropathies of cranial nerves III, IV, and VI based on neuroimaging to help determine the benefit of early MRI neuroimaging.
Methods :
This study is a retrospective chart review. Patients were screened using ICD-9 codes for diplopia and cranial nerve II, IV, & VI palsies in the billing database at MedStar Washington Hospital Center from April 2000 to April 2015. Patients selected were 50 years of age and older, presented within 1 month of onset of symptoms, and obtained CT/MRI/MRA brain scans at time of presentation or up to 6 months following. Exclusion criteria: history of strabismus, orbital disease, head trauma, prior neurosurgical intervention, prior lumbar puncture, neurological symptoms indicating additional neurologic dysfunction, and artifact affecting radiology read. Data collected included age, race, gender, duration of symptoms, type of diplopia, cranial nerve affected, cause of mononeuropathy (if known), history of trauma, MRI finding(s), vascular risk factors, and findings of other results, if known, to include erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), lumbar puncture (LP), acetylcholine receptor antibody, and temporal artery (TA) biopsy.
Results :
Of the 81 patients recruited, 30 qualified for selection. Patient demographics: 16 (55%) female, 17 (59%) African American, 3 (10%) Hispanic, 5 (17%) Asian, 3 (10%) declined to identify, 1 (3%) Caucasian. All patients had 1 or more vascular risk factors. Palsies identified: 3rd 6 (21%), 4th 9 (31%), 6th 7 (24%), combination 7 (24%). Patients with symptoms of headache on presenation: 11 (38%). Palsy etiology: 13 (45%) microvascular ischemia, 5 (17%) neoplasm, 3 (10%) cerebrovascular accident, 2 (7%) infection, 1 (3%) inflammation, 5 (17%) undetermined.
Conclusions :
While most oculomotor palsies were due to microvascular ischemia, a substantial 37% were due to other potentially serious and treatable conditions warranting early MRI neuroimaging.
This is an abstract that was submitted for the 2016 ARVO Annual Meeting, held in Seattle, Wash., May 1-5, 2016.