In contrast to bilateral internuclear ophthalmoplegia, which is usually due to multiple sclerosis, unilateral internuclear ophthalmoplegia is nearly always attributable to vascular occlusion.1,2 The responsible vessel is presumably one of the perforating branches of the basilar artery. Several clinical series have been reported, but to our knowledge only four autopsy studies of unilateral internuclear ophthalmoplegia have been previously recorded. All of these showed a lesion of the medical longitudinal fasciculus on the side of the affected medial rectus muscle, but other lesions in the brain stem were also present. The purpose of the present report is to document the clinical and pathologic changes in a fifth case, one which is of unusual interest in that the lesion was confined to the median longitudinal fasciculus and had been present for nine years prior to death.
The first two pathologic studies1,3 were done on patients who had been examined clinically
KUPFER C, COGAN DG. Unilateral Internuclear OphthalmoplegiaA Clinicopathological Case Report. Arch Ophthalmol. 1966;75(4):484-489. doi:10.1001/archopht.1966.00970050486008