Isolated abducens nerve palsy caused by vascular compression

Causes of isolated abducens nerve palsy include aneurysms of the vertebral artery (VA), tumor, diabetes mellitus, and meningitis.1 Elongation of arteries of the vertebral basilar system occasionally causes facial nerve palsy or trigeminal nerve disturbance by compression. We describe a patient with isolated right abducens nerve palsy due to vascular compression of the elongated left VA. A 47-year-old man had a 2-year history of horizontal diplopia without other symptoms. Mild hypertension (149/97 mm Hg) was the only notable feature of his medical history. He complained of horizontal diplopia during rightward gaze and diplopia of primary position after drinking too much. Rightward saccades were hypometric. Edrophonium test was …