Bringing light to the sirens of night: laryngoscopy in catathrenia during sleep

To the Editors: Catathrenia is a rare sleep disorder characterised by groaning and prolonged expiration confined to sleep alternating with normal breathing that may occur at all sleep stages. After its first description in 1983 1, catathrenia was recently introduced into the International Classification of Sleep Disorders 2. Although the exact pathogenesis remains unknown, catathrenia has been considered a parasomnia. Important differential diagnoses include moaning during epileptic seizures, central sleep apnoea, sleep-related laryngospasm, expiratory snoring and stridor. Most patients complain about social distress in their partnership, and only a minority suffers from excessive daytime sleepiness (EDS). Continuous positive airway pressure (CPAP) treatment has shown to be effective in some patients 3. Several postulated theories exist on the underlying mechanism. Ortega-Albas et al. 4 assumed the underlying mechanism was …