Figure 8 One of our patients with multiple sclerosis had a dorsal midbrain syndrome that included a left hyperdeviation consistent with skew deviation and a left internuclear ophthalmoparesis (on attempted right gaze as seen in the lower figure)

The lesion was at the level of the left midbrain (after the decussation of the rightward originating otolith pathways) and involved the medial longitudinal fasciculus. Also note the enlarged left pupil, which exhibited the characteristics of near-light dissociation.