Abstract
• A patient with Shy-Drager syndrome exhibited a partial defect in antidiuretic hormone (ADH) release, and cluster breathing, an indication of pontomedullary respiratory center damage, with a normal CO2 response curve. This extends the spectrum of abnormalities associated with this degenerative disease of the central nervous system. The presence of a pontomedullary respiratory pattern without an impaired CO2 response curve suggests that neurons that determine respiratory rhythm function independently from those that function as chemoreceptors.