Eyelid lag without eyelid retraction in pretectal disease.

We report a patient with pretectal eyelid lag without retraction. MRI showed high signal abnormality dorsal to the right red nucleus in a region thought responsible for premotor eyelid control. The dissociation of eyelid lag from eyelid retraction in this patient would suggest that these lid signs may have separate neural mechanisms or pathways. We propose that the lesion interrupts inhibitory connections between the vertical gaze center and the central caudal nucleus.