Bilateral internuclear ophthalmoplegia--an unusual initial presenting sign of giant cell arteritis.

A 63-year-old man presented six days after the sudden onset of horizontal double vision. His left eye became divergent two days later. On initial examination he had bilateral internuclear ophthalmoplegia with weakness of adduction and abducting nystagmus. Convergence was weak but there were no other neuro-ophthalmic signs. Constitutional signs included confusion and unsteadiness on his feet. A provisional diagnosis of arteritis was made. His ESR was 92 mm/h and a superficial temporal artery biopsy confirmed the diagnosis of giant cell arteritis. After two weeks or oral prednisolone his eye movements returned to normal. There have been no further relapses. This would appear to be a unique presentation of giant cell arteritis. The causes of internuclear ophthalmoplegia are discussed along with a review of the ocular and neuro-ophthalmic signs of giant cell arteritis.