Sleep-induced ventilatory dysfunction in Down's syndrome.

Three patients with Down's syndrome demonstrated severe sleep-induced ventilatory failure characterized by Cheyne-Stokes respiration with superimposed obstruction of the upper airway. Anatomic otolaryngologic factors were present in two of the three patients, implicating both mechanical and CNS factors in the pathogenesis of this phenomenon. Administration of protriptyline hydrochloride elicited considerable improvement in one case. Occult sleep-related ventilatory failure may account for the previously unexplained tendency for pulmonary hypertension to develop in patients with Down's syndrome.