Catathrenia (sleep-related groaning)

History and terminology Sleep-related groaning was first reported in the medical literature in 1983 when De Roeck and Van Hoof described, in abstract form, the case of a young male with groaning during REM sleep as the result of forced and prolonged expiration. In 2001, Vetrugno et al. described four additional patients (three males, one female) between 15 and 25 years of age and introduced the term catathrenia (from the Greek κατά = like, and θρήνος = groan) to discriminate this unusual sleep-related behavior from other respiratory and non-respiratory disturbances during sleep. In the same year, Pevernagie et al. reported 10 patients (7 males, 3 females), aged between 20 and 49 years, who had sleep-related respiratory dysrhythmia characterized by clusters of bradypneic events associated with prolonged expiration and expiratory sound production consistent with monotonous vocalization and occurring predominantly during REM sleep. In 2004, Brunner and Gonzalez reported, in abstract form, eight other patients (six males, two females) who had prolonged groaning-like vocalization during sleep and, in 2005, Oldani et al. described 21 patients (13 males and 8 females) between 18 and 43 years of age, highlighting that no effective treatment was available to solve nocturnal groaning.In 2005, catathrenia was included by the American Academy of Sleep Medicine into The International Classifications of Sleep Disorders Diagnostic and Coding Manual (ICSD-2) as a parasomnia.