Catathrenia, a REM predominant disorder of arousal?

The clinical characteristic of catathrenia: a new look at an old issue-a systematic review of existing literature

STUDY OBJECTIVES

The International Classification of Sleep Disorders categorized catathrenia as a respiratory disorder, but there are doubts whether episodes appear during rapid eye movement (REM) sleep or the non-rapid eye movement (NREM), their duration, and symptoms. The main objectives were to identify the most common features and relations of catathrenia.

METHODS

PubMed, Embase, and Web of Science were searched according to the PRISMA 2020 guidelines. The Joanna Briggs Institute and the ROBINS-I tools were chosen to assess the risk of bias.

RESULTS

A total of 288 records were identified, 31 articles were included. The majority of the studies had a moderate risk of bias. 49.57% of episodes occurred during the NREM sleep, while 46% took place during REM. In 60.34% females, catathrenia was more common in the NREM, while in 59.26% of males was in REM sleep (p < 0.05). Females and obese individuals were found to have shorter episodes (p < 0.05). Age was inversely correlated with minimal episodes duration (r =  - 0.34). The continuous positive airway pressure (CPAP) therapy was inversely correlated with the maximal episode duration (r =  - 0.48).

CONCLUSIONS

Catathrenia occurs with similar frequency in both genders. The most frequent symptoms embraced groaning, awareness of disturbing bedpartners, and daytime somnolence-not confirmed by the Epworth Sleepiness Scale. The episodes occur more frequently in NREM than in REM sleep. Catathrenia may be considered as a sex-specific condition. The effects of CPAP treatment leading to shortening episodes duration, which may indicate the respiratory origin of catathrenia.

Lamentations in the night: A systematic review on catathrenia

Catathrenia is a loud expiratory moan during sleep that is a social embarrassment and is sometimes confused with central apnea on polysomnography. It affects about 4% of adults, but cases are rarely referred to sleep centers. Catathrenia affects males and females, children and adults, who are usually young and thin. A "typical" catathrenia begins with a deep inhalation, followed by a long, noisy exhalation, then a short, more pronounced exhalation, followed by another deep inhalation, often accompanied by arousal. The many harmonics of the sound indicate that it is produced by the vocal cords. It is often repeated in clusters, especially during REM sleep and at the end of the night. It does not disturb the sleepers, but their neighbors, and is associated with excessive daytime sleepiness in one-third of cases. The pathophysiology and treatment of typical catathrenia are still unknown. Later, a more atypical catathrenia was described, consisting of episodes of short (2 s), regular, semi-continuous expiratory moans during NREM sleep (mainly in stages N1 and N2) and REM sleep, often in people with mild upper airway obstruction. This atypical catathrenia is more commonly reduced by positive airway pressure and mandibular advancement devices that promote vertical opening.

Differences in Polysomnographic and Craniofacial Characteristics of Catathrenia Phenotypes: A Cluster Analysis

Purpose

Catathrenia is a rare sleeping disorder characterized by repetitive nocturnal groaning during prolonged expirations. Patients with catathrenia had heterogeneous polysomnographic, comorbidity, craniofacial characteristics, and responses to treatment. Identifying phenotypes of catathrenia might benefit the exploration of etiology and personalized therapy.

Patients and Methods

Sixty-six patients diagnosed with catathrenia by full-night audio/video polysomnography seeking treatment with mandibular advancement devices (MAD) or continuous positive airway pressure (CPAP) were included in the cohort. Polysomnographic characteristics including sleep architecture, respiratory, groaning, and arousal events were analyzed. Three-dimensional (3D) and 2D craniofacial hard tissue and upper airway structures were evaluated with cone-beam computed tomography and lateral cephalometry. Phenotypes of catathrenia were identified by K-mean cluster analysis, and inter-group comparisons were assessed.

Results

Two distinct clusters of catathrenia were identified: cluster 1 (n=17) was characterized to have more males (71%), a longer average duration of groaning events (18.5±4.8 and 12.8±5.7s, p=0.005), and broader upper airway (volume 41,386±10,543 and 26,661±6700 mm3, p<0.001); cluster 2 (n=49) was characterized to have more females (73%), higher respiratory disturbance index (RDI) (median 1.0 [0.3, 2.0] and 5.2 [1.2, 13.3]/h, p=0.009), more respiratory effort-related arousals (RERA)(1 [1, 109] and 32 [13, 57)], p=0.005), smaller upper airway (cross-sectional area of velopharynx 512±87 and 339±84 mm2, p<0.001) and better response to treatment (41.2% and 82.6%, p=0.004).

Conclusion

Two distinct phenotypes were identified in patients with catathrenia, primary catathrenia, and catathrenia associated with upper airway obstruction, suggesting respiratory events and upper airway structures might be related to the etiology of catathrenia, with implications for its treatment.

Catathrenia in severe obstructive sleep apnea: A novel entity never described before

STUDY OBJECTIVES

Catathrenia, derived from the Greek κατά (kata) meaning below and θρηνώ (threnia) to lament, is characterized by expiratory groaning episodes during sleep. In a case series of nine patients with severe obstructive sleep apnea, we observed a peculiar groaning entity that has not been described before.

METHODS

We described and illustrated the cases with polysomnographic tracings and additional audio recordings.

RESULTS

All patients were men, obese (body mass index 39 ± 6 kg/m2) with an apnea-hypopnea index ranging from 47 to 125/h. In addition, we identified groaning events that were consistently preceded by a cortical arousal associated with a "rescue" respiration after an obstructive hypopnea or apnea. These events exhibited characteristics of "mixed apnea's", but the "central apnea-like part" was a prolonged expiratory groaning phase, with immediately after the terminal expiratory snort appearance of an obstructive apnea. In case the duration of this expiration was at least 10 s we calculated these events separately and the index was 8.4 ± 7.7/h. More rarely (index 0.6 ± 0.5/h) a "central apnea mimicking event" with groaning not followed by an obstruction, was observed. We also observed groaning episodes during expiration with a shorter duration (less than 10 s), not calculated separately. Positive airway pressure, which was well tolerated, eliminated these events.

CONCLUSIONS

This novel catathrenia entity preceded by a cortical arousal and "rescue" respiration in response to obstructive events is intriguing. Possible explanations for these observations are further discussed in this article.

Catathrenia in children: clinical presentation, polysomnographic features, natural history, and response to therapy

STUDY OBJECTIVES

To determine the clinical presentation, polysomnographic appearance, and the response to therapy of catathrenia in children.

METHODS

A retrospective analysis was performed in children referred or evaluated at the Boston Children's Hospital Sleep Center between 1998 and 2021 who were documented to have catathrenia either as a chief complaint or an incidental finding.

RESULTS

Catathrenia was identified in 21 children. The age of onset by parent report was 6.4 ± 4.4 years (range: birth-14 years), but the diagnosis was at 8.3 ± 3.8 years (range: 1.5-14 years). Catathrenia was the chief complaint for 24% of patients and was incidentally identified in 76% referred for breathing concerns. Bruxism was observed in 62% of patients. Catathrenia events most often occur following an electrocortical arousal (79%) and are most common in the second half of the night (73%). Catathrenia was observed exclusively in rapid eye movement (REM) sleep (16%), exclusively in non-REM sleep (32%), and in both sleep states (52%). Treatment of obstructive sleep apnea resulted in resolution or improvement in the obstructive sleep apnea in all patients, but the catathrenia persisted at a reduced level.

CONCLUSIONS

Most catathrenia in children is diagnosed incidentally during evaluation for sleep-disordered breathing, although the groaning often started many years earlier. Catathrenia events decreased considerably after treatment of obstructive sleep apnea, but persisted in all patients. Catathrenia was also observed in children without signs or symptoms of sleep-disordered breathing, indicating that these are distinct conditions. The majority of children with catathrenia had no sleepiness or behavioral concerns.

CITATION

Katz ES, D'Ambrosio C. Catathrenia in children: clinical presentation, polysomnographic features, natural history, and response to therapy. J Clin Sleep Med. 2023;19(8):1505-1511.

Mandibular advancement device as treatment trial for catathrenia (nocturnal groaning)

STUDY OBJECTIVES

Catathrenia is a rare disease, classified as isolated symptoms and normal variants under sleep-related breathing disorders in the International Classification of Sleep Disorders, third edition. Because of its rarity, the research on its pathogenesis and treatment is insufficient. This study aimed to evaluate whether the mandibular advancement device (MAD) could be considered an alternative treatment trial and if so, to explore factors predicting its effectiveness.

METHODS

Thirty patients (12 males and 18 females, aged 16 to 67 years) with catathrenia participated in the study. They underwent standard clinical evaluation, questionnaires, physical examinations, craniofacial evaluations, video-polysomnography, and imaging of the upper airway before and after the insertion of the MAD. Groaning index (GI, groaning episodes per hour of sleep) and apnea-hypopnea index (AHI) were evaluated and anatomic factors predicting effectiveness were explored.

RESULTS

The sleep efficiency of most patients was higher than 80% and groaning was present throughout all stages of sleep. With the insertion of MAD, GI decreased significantly from 5.8 (2.7, 14.3) to 2.8 (1.3, 12.2) events/h (P = 0.014). Age had a negative effect on efficacy. Mandibular repositioning of MAD, especially the amount of vertical opening and changes of cross-sectional area of hypopharynx, was positively related with efficacy.

CONCLUSIONS

The MAD could be considered a possible treatment trial for those seeking treatment for groaning.

CLINICAL TRIAL REGISTRATION

Registry: Chinese Clinical Trial Registry; Identifier: ChiCTR-COC-17013239; URL: http://www.chictr.org.cn/showproj.aspx?proj=22286.

The importance of audio-video documentation during polysomnography for diagnosis of catathrenia in a 6-year-old child: case report

Catathrenia is a rare disorder classified as a respiratory one and characterized by expiratory groans during sleep. We report a case of catathrenia in a 6-year-old male patient, with documented video and audio polysomnography. The diagnosis of catathrenia is made through a detailed analysis of video and audio recordings during the examination. Although there is no association with the risk of physical damage known today, catathrenia presents itself as a source of anxiety among patients and their families. The differentiation of catathrenia with central apnea, obstructive apnea, primary snoring, and parasomnias will influence both the prognosis and the diagnosis and treatment of the patient.

Polysomnographic characteristics and acoustic analysis of catathrenia (nocturnal groaning)

OBJECTIVE

Catathrenia is a sleep disorder characterized by nocturnal groaning sounds emitted during prolonged expiration. As a rare condition, its polysomnographic findings were inconsistent. We aimed to present polysomnographic characteristics of catathrenia patients and perform acoustic analysis of groaning sounds.

APPROACH

Twenty-three patients (eight males and 15 females) diagnosed with catathrenia by video-polysomnography were included. They underwent clinical evaluation and physical examination, and answered a questionnaire. Acoustic analyses (oscillograms and spectrograms) of catathrenia and snoring signals were performed by Praat 6.1.09. Sounds were classified according to Yanagihara criteria.

MAIN RESULTS

The average age of catathrenia patients was 29.6 ± 10.0 years, with a body mass index of 22.3 ± 5.1 kg m^-2. A total of 3728 groaning episodes were documented. Catathrenia events of 16 patients (70%) were rapid eye movement (REM)-predominant. The average duration of groaning was 11.4 ± 4.6 s, ranging from 1.3 to 74.9 s. All signals of groaning were rhythmic or semi-rhythmic, classified as type I and type II, respectively, with formants and harmonics. Snoring events were observed in nine patients. Snoring mainly occurred in the non-REM stage, with a duration of less than 1.5 s. Signals of snoring were chaotic, classified as type III, without harmonics.

SIGNIFICANCE

Catathrenia occurred in all sleep stages but mainly in REM. Durations of groaning varied greatly across patients. Acoustic characteristics of catathrenia were typical. Groaning had rhythmic or semi-rhythmic waveform, formants and harmonics, indicating vocal origin, while snoring had chaotic waveform.