When “looks” can be deceiving – Internuclear ophthalmoplegia after mild traumatic brain injury: Case report and literature review

INTRODUCTION: Walled-eyed monocular internuclear ophthalmoplegia (WEMINO) syndrome is a sub-variant of internuclear ophthalmoplegia (INO) and involves the same clinical findings with the addition of exotropia of the ipsilateral eye. Causes typically include multiple sclerosis (MS) and ischemia (hemorrhagic or embolic) but can be secondary to blunt trauma as seen in our presented case. PRESENTATION OF CASE: A 27-year-old man presented with new-onset visual changes, diplopia, and strabismus following a motor vehicle collision. Physical exam showed left ocular exotropia and slight hypertropia on forward gaze with deficiency of left convergence and disconjugate eye movements on horizontal gaze with right nystagmus on rightward gaze. Imaging showed hyperintensities in the right middle cerebellar peduncle and left temporal-occipital white matter likely consistent with diffuse axonal injury but otherwise nonspecific. The patient was treated conservatively with left eyepatch and exhibited improvement of exotropia and diplopia at 1 week follow up. DISCUSSION: Common causes of WEMINO syndrome include MS and ischemia with no prior reports, to our knowledge, being secondary to the blunt trauma seen in our case. Patients with WEMINO present with the typical signs of failure of ipsilateral adductive movement during lateral along with ipsilateral exotropia. Management involves treating the underlying disorder, if possible, with conservative measures with traumatic origins. CONCLUSION: Until now, WEMINO syndrome secondary to trauma has not been previously documented. Our patient was effectively treated with conservative measures alone.