The Value of a Well-Trained Ear: Incidental Detection of Catathrenia on Home Sleep Apnea Tests in Patients With Low Probability for Obstructive Sleep Apnea.

Catathrenia is a rare sleep-related breathing disorder marked by nocturnal groaning during prolonged exhalation. Home sleep apnea tests are growing in popularity, but no prior case reports exist documenting catathrenia detected by a home sleep apnea test. We report two cases of catathrenia incidentally detected in patients with low to intermediate risk of obstructive sleep apnea, in which diagnostic polysomnography was recommended but denied by insurers. Events were automatically scored as central apneas, leading to diagnostic uncertainty. The key to identification of catathrenia in both patients was combination of audio review of events, pattern of expiratory air trapping, and mismatch between central apnea flow signal attenuation and increased sound noted on audio amplitude signal. Diagnostic polysomnography was ordered in both cases for confirmation of diagnosis, leading to increased care costs.