Internuclear Ophthalmoplegia (INO) in Multiple Sclerosis

𝗢𝗿𝗶𝗴𝗶𝗻𝗮𝗹 𝗗𝗲𝘀𝗰𝗿𝗶𝗽𝘁𝗶𝗼𝗻: This video includes 3 patients each with a known history of MS found to have unilateral or bilateral INOs on their exam. In the first 2 patients, the INOs are relatively subtle with normal adduction. However, with rapid horizontal saccades, an adduction lag is apparent which is suggestive of an INO. Occasionally a pseudo-INO can be seen in the setting of myasthenia, due to relative medial rectus weakness that exacerbates with repeated horizontal saccades (i.e., it fatigues). Because some of the fibers responsible for vertical gaze holding travel through the MLF, upbeat nystagmus in upgaze is common with bilateral MLF lesions. Number of Videos and legend for each: 1, This video shows 3 patients with MS and INOs. 𝗡𝗲𝘂𝗿𝗼-𝗼𝗽𝗵𝘁𝗵𝗮𝗹𝗺𝗼𝗹𝗼𝗴𝘆 𝗮𝗻𝗱 𝗡𝗲𝘂𝗿𝗼-𝗼𝘁𝗼𝗹𝗼𝗴𝘆 𝗧𝗲𝘅𝘁𝗯𝗼𝗼𝗸 𝗟𝗲𝗴𝗲𝗻𝗱: This video includes 3 patients each with a known history of MS found to have unilateral or bilateral INOs on their exam. In the frst 2 patients, the INOs are relatively subtle, without an adduction paresis. However, with rapid horizontal saccades, an adduction lag is apparent which is suggestive of an INO. In the 3rd patient, there were bilateral INOs with bilateral adduction paresis. https://collections.lib.utah.edu/ark:/87278/ s6tj1wb3