Unilateral lid retraction with contralateral oculomotor paresis

A patient is presented with acute onset of partial oculomotor paresis on on e side and upper eyelid retraction on the other due to a vascular insult. A n electromyographic study revealed frontalis muscle overactivity on the sid e of lid retraction which has never been documented before, indicating that not only was the supramotor control over the central caudal nucleus affect ed as previously proposed, but the inhibition of the frontalis muscle moton eurons was also disrupted. Based on these data, a premotoneuronal system is proposed that controls upper eyelid movements by affecting the frontalis m uscle and orbicularis oculi muscle motoneurons in addition to the central c audal nucleus.