Figure 12 The syndrome of wall-eyed bilateral internuclear ophthalmoparesis (INO) in an patient with multiple sclerosis with progressive disease and a history of a severe inflammatory demyelinating syndrome involving the tegmentum of the ponto-mesencephalic junction, which affected the medial longitudinal fasciculus (MLF) bilaterally

Note the exotropic appearance of both eyes (i.e., wall-eyed). Attempted gaze to the right or left revealed adduction slowing and limitation consistent with bilateral INO. There was also reduced vertical smooth pursuit and vertical vestibulo-ocular reflexes (both pathways course through the MLF).