Abnormal orbicularis oculi reflex response in sleep apnea secondary to acromegaly. Evidence of pontomedullary dysfunction in sleep apnea syndrome.

Severe sleep apnea was present in a patient with upper airway obstruction due to acromegaly. The study of orbicularis oculi reflex responses (OORR) disclosed a marked prolongation of the late response prior to tracheostomy. Following the surgical relief of upper airway obstruction, sleep apnea disappeared, and the latency of the late response of the OORR was dramatically reduced but failed to normalize. The OORR and especially its late response were normal in a patient with acromegaly who did not experience sleep apnea. In two patients with sleep apnea, but without acromegaly, the late responses of the OORR were abnormal. It is suggested that the presence of abnormal OORR in sleep apnea may reflect a basic defect in pontomedullary control of respiration during sleep.