Isolated Abducens Nerve Palsy Due to Anterolateral Pontomedullary Infarction in a Young Adult

A 24-year-old woman suffered from headache for several days, and then binocular diplopia occurred. On examination, she demonstrated signs of right abducens nerve palsy. General examination was unremarkable. A detailed neurological examination was normal, revealing no evidence of brain stem dysfunction. Brain magnetic resonance imaging (MRI) demonstrated hyperintensities in the right upper anterolateral medulla on T2weighted images and diffusion-weighted images. Her diplopia resolved in 2 months. Ophthalmological examination revealed complete recovery. Follow-up MRI revealed hyperintensities in the right anterolateral lower pons and upper medulla. A complete MRI study should be considered in nontraumatic isolated abducens palsy, which includes thin sections through the nucleus and fascicle of the abducens nerve.