Internuclear Ophthalmoplegia (MLF syndrome)
- * In an internuclear ophthalmoplegia, upon contralateral gaze, the unaffected eye abducts but the ipsilateral eye is unable to adduct.
- In this example, upon right gaze, the right eye abducts (goes outward) but the left eye is unable to adduct (cross midline).
- The unaffected eye is not totally unaffected, it actually has horizontal nystagmus upon abduction, presumably because of the divergence that occurs from the left eye adduction failure. (In the video, we see this horizontal nystagmus of the right eye upon abduction).
- Internuclear ophthalmoplegia commonly occurs from demyelinating plaques in multiple sclerosis.
- In this video, it occurs from a very small, stroke localized to the MLF tract.
- For the full anatomy of this disorder, see the Final Common Pathway (for Horizontal Eye Movements).
Video
- Demonstration of abnormal eye movements in a gentleman with a focal stroke in a restricted region involving the left MLF tract.