Catathrenia, or sleep related groaning, is an uncommon feature of a sleep-related breathing disorder that can be successfully treated with continuous positive airway pressure (CPAP). The study, authored by Christian Guilleminault, MD, of Stanford University, focused on seven consecutive female patients between the ages of 20 and 34, all of whom had a chief complaint of involuntary groaning during sleep that was brought to their attention by family members. [click link for full article]