EYELID LAG WITHOUT EYELID RETRACTION IN PRETECTAL DISEASE

We report a patient with prerectal eyelid lag without retraction. MRI showed high signal abnormality dorsal to the right red nucleus in a re gion thought responsible for premotor eyelid control. The dissociation of eyelid lag from eyelid retraction in this patient would suggest th at 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.