title: Catathrenia, a REM predominant disorder of arousal?
abstract: OBJECTIVE
  Catathrenia is an uncommon and poorly understood disorder, characterized by groaning during sleep occurring in tandem with prolonged expiration. Its classification, pathogenesis, and clinical relevance remain debated, substantially due to the limited number of cases reported to date. We report a series of consecutive cases of catathrenia, their clinical and polysomnographic characteristics, and their subsequent management.
  
  
  METHODS
  Consecutive patients with catathrenia who had undergone full polysomnography in our institution over a 5.5-year period were included. Catathrenia events (CEs) were examined in clusters, which formulated catathrenia periods (CPs). The relationships between CPs, sleep stage distribution, electroencephalogram (EEG) arousals, and other sleep parameters were assessed, along with the clinical presentation and management of catathrenic patients.
  
  
  RESULTS
  A total of 427 CPs were identified in 38 patients, 81% arising from rapid eye movement (REM) sleep. EEG arousals preceded or coincided with the onset of 84% of CPs, which were of longer duration than those not associated with an arousal (57.3 ± 56.8 vs. 32.2 ± 29.4 s, p < 0.001). Each CE had a characteristic airflow signal, with inspiration preceding a protracted expiration and a brief more rapid exhalation, followed by deep inspiration. Although the majority of patients were referred on the basis of bed partner complaints, 44.7% complained of daytime sleepiness. Continuous positive airway pressure therapy and sleep-consolidating pharmacotherapy led to subjective improvement, but were limited by poor long-term adherence.
  
  
  CONCLUSIONS
  In the largest series of catathrenia patients reported to date, we found that this rare disorder is characterized by a distinct breathing pattern and arises predominantly from REM sleep, with arousals almost uniformly preceding or coinciding with the onset of CPs.
authors.affiliation: Sleep Disorders Centre, Guy's and St Thomas' Hospitals, London, United Kingdom.
authors.forename: Panagis
authors.initials: P
authors.lastname: Drakatos
authors.affiliation: Sleep Disorders Centre, Guy's and St Thomas' Hospitals, London, United Kingdom.
authors.forename: Sean
authors.initials: S
authors.lastname: Higgins
authors.affiliation: Sleep Disorders Centre, Guy's and St Thomas' Hospitals, London, United Kingdom.
authors.forename: Iain
authors.initials: I
authors.lastname: Duncan
authors.affiliation: Sleep Disorders Centre, Guy's and St Thomas' Hospitals, London, United Kingdom.
authors.forename: Sara
authors.initials: S
authors.lastname: Stevens
authors.affiliation: Sleep Disorders Centre, Guy's and St Thomas' Hospitals, London, United Kingdom.
authors.forename: Sakina
authors.initials: S
authors.lastname: Dastagir
authors.affiliation: Sleep Disorders Centre, Guy's and St Thomas' Hospitals, London, United Kingdom.
authors.forename: Adam
authors.initials: A
authors.lastname: Birdseye
authors.affiliation: Sleep Disorders Centre, Guy's and St Thomas' Hospitals, London, United Kingdom.
authors.forename: Dimosthenis
authors.initials: D
authors.lastname: Lykouras
authors.affiliation: Sleep Disorders Centre, Guy's and St Thomas' Hospitals, London, United Kingdom.
authors.forename: Rexford
authors.initials: R
authors.lastname: Muza
authors.affiliation: Sleep Disorders Centre, Guy's and St Thomas' Hospitals, London, United Kingdom.
authors.forename: Nadia
authors.initials: N
authors.lastname: Gildeh
authors.affiliation: Sleep Disorders Centre, Guy's and St Thomas' Hospitals, London, United Kingdom; King's College London, London, United Kingdom.
authors.forename: Ivana
authors.initials: I
authors.lastname: Rosenzweig
authors.affiliation: Sleep Disorders Centre, Guy's and St Thomas' Hospitals, London, United Kingdom; King's College London, London, United Kingdom.
authors.forename: Adrian J
authors.initials: AJ
authors.lastname: Williams
authors.affiliation: Sleep Disorders Centre, Guy's and St Thomas' Hospitals, London, United Kingdom; King's College London, London, United Kingdom.
authors.forename: Guy D
authors.initials: GD
authors.lastname: Leschziner
authors.affiliation: Sleep Disorders Centre, Guy's and St Thomas' Hospitals, London, United Kingdom. Electronic address: brian.kent@gstt.nhs.uk.
authors.forename: Brian D
authors.initials: BD
authors.lastname: Kent
mesh_terms: D000328:Adult; D001143:Arousal / Q000502:physiology; D015928:Cognitive Behavioral Therapy; D045422:Continuous Positive Airway Pressure; D004569:Electroencephalography; D005260:Female; D006801:Humans; D006993:Hypnotics and Sedatives / Q000627:therapeutic use; D008297:Male; D020447:Parasomnias / Q000503:physiopathology* / Q000628:therapy; D017286:Polysomnography; D012895:Sleep, REM / Q000502:physiology
chemical_list: D006993:Hypnotics and Sedatives
keywords: Arousal disorders; Catathrenia; Parasomnia; Sleep disordered breathing