Catathrenia: parasomnia or uncommon feature of sleep disordered breathing?

OBJECTIVE We report a series of seven consecutive cases of catathrenia (sleep related groaning) that differ from limited previous reports in the literature with regard to sleep stage and response to treatment. BACKGROUND Catathrenia was recently defined as a parasomnia in the International Classification of Sleep Disorders Diagnostic and Coding Manual (ICSD-2), but there is debate about its classification, and its response to CPAP is unknown. METHODS We present 7 consecutive patients presenting with catathrenia over a 5-year period. They were all young women, ranging in age from 20 to 34 years with a body mass index (BMI) <25. They underwent standard clinical evaluation, questionnaires, physical exam, craniofacial evaluations, and nocturnal polysomnography. All seven were titrated on continuous passive airway pressure (CPAP) treatment for sleep disordered breathing then offered surgical treatment if unable to tolerate or adhere to CPAP recommendations. RESULTS Groaning was present throughout all stages of sleep. The mean (SD) AHI and RDI were 3.2 (0.56) and 13.1 (2.4) respectively. CPAP resolved groaning in all cases. 5 patients (71%) elected subsequent surgical intervention. Three of the 4 that followed up after surgery required adjuvant oral appliance treatment, but all four ultimately had resolution of groaning. CONCLUSIONS Catathrenia may have subtypes related to sleep stage specificity or presence of sleep disordered breathing. In our heterogeneous group of non-obese women with a normal AHI and elevated RDI, CPAP and select soft tissue surgeries of the upper airway (often augmented with an oral appliance) successfully treated nocturnal groaning.