The University at Buffalo Center for Sleep Disorders Research (CSDR) consists of basic scientists and clinicians (Neurologists and Pulmonologists) who are interested primarily in mechanisms of neurological dysfunction which results as a consequence of respiratory disturbances which occur in sleep. These disturbances generally fall in the categories of obstructive sleep apnea (OSA) or central sleep apnea. Respiratory sleep disorders are common and affect more than five percent of the US population and they are associated with significant morbidity and mortality. Most of the clinicians in our group are board certified in Sleep Medicine. Inasmuch as sleep-associated respiratory disturbances are associated with periodic oxygen lack or hypoxia, the effects of hypoxia on the central nervous system are a major focus of the Group. Therefore, in addition to sleep disturbances the Group has interests in the central nervous system damage which occurs in acute altitude illness and high altitude cerebral edema and in chronic obstructive pulmonary disease.