Catathrenia

Catathrenia also known as sleep related groaning, is an uncommon and poorly understood sleep-related breathing disorder characterized by expiratory groaning or moaning during sleep occurring in tandem with prolonged expiration ¹. The quality of groaning in catathrenia is monotone, and often presents with a morose or sexual connotation, causing a significant social problem for patients ². Catathrenia is not usually noticed by the person producing the sound and there is no association with risk of physical harm. However, catathrenia does present a significant disturbance to the bed partner and has been associated with subjective impairments to sleep quality, including unrefreshing sleep and fatigue. Bed partners generally report hearing the person take a deep breath, hold it, then slowly exhale; often with a high-pitched squeak or groaning sound. Once aware of it, people with catathrenia tend to be awakened by their own groaning as well ³.

Catathrenia (sleep related groaning) is a long-lasting disorder that often occurs nightly ⁴. The groaning sound is usually quite loud. Your breathing becomes unusually slow during a groaning episode. You take in a slow, deep breath. Then you make a long exhale that includes the moaning sound. The sound can last from only a few moments to more than 40 seconds. It always ends with a sigh or a grunt. Groans often repeat in clusters for two minutes to one hour. These clusters of groaning may recur many times per night.

Facial expressions are calm and do not reflect anguish. Despite the moaning sound, the groans do not seem to be related to any emotional feelings. Groaning can occur when lying in any position. But it tends to stop when you change positions in bed. Then it may resume again later in the night.

The person who groans is usually unaware of the sounds. It is much more disturbing to the bed partner, roommate or family member who hears it. Other descriptions of the groaning sound include the following:

• High-pitched or cracking sounds
• Loud humming
• Loud roaring

You may need to see a sleep specialist if catathrenia or sleep related groaning severely disrupts your bed partner’s sleep. You should also see a sleep specialist if you can’t sleep well or are very tired during the day.

Your sleep doctor will need to know when the groaning began. He or she will want to know how often it occurs and how long it lasts. The sleep specialist will need to know your complete medical history. Be sure to inform him or her of any past or present drug and medication use.

There is no specific treatment for groaning. A study in the journal SLEEP ⁵ finds that catathrenia can be successfully treated with continuous positive airway pressure (CPAP). CPAP provides a steady stream of pressurized air to patients through a mask that they wear during sleep. This airflow keeps the airway open, preventing the pauses in breathing that characterize sleep apnea and restoring normal oxygen levels. Although the mechanism of action of CPAP treatment in patients with catathrenia is not well understood, Ott et al. ⁶ demonstrated reductions in nocturnal groaning and improved daytime well-being following CPAP possibly from a reduction in active adduction during expiration. Pharmacotherapy and cognitive behavioral therapy (CBT) are other modalities others have used to manage catathrenia, though with varied results ⁷.

Catathrenia derived from the Greek Kata (to bellow) and Threnia (to lament) was initially described by De Roeck and van Hoof in 1983 ⁸, less than 100 cases of catathrenia have been reported in the published literature to date ⁹. Partially as a result of this, its classification, pathogenesis and clinical relevance remain debated, at least partially due to the low number of cases in the reported literature. Catathrenia was classified as a parasomnia in the International Classification of Sleep Disorders, 2005 Second Edition, a diagnostic and coding manual developed by the American Academy of Sleep Medicine ¹⁰, but has more recently been classified among sleep-related breathing disorders in the third edition ¹.

Catathrenia is sufficiently rare that many otolaryngologists and even sleep specialists remain unfamiliar with this atypical breathing pattern. In a series by Jaar et al. in 2009 ¹¹, the incidence of catathrenia was identified as 25 of 15,052 patients (0.17%) who presented with sleep and/or wake problems at a sleep center over a 10-year period in Japan. Overland et al. ¹² stated that the incidence of catathrenia was 4 of 1,004 patients (0.4%) undergoing polysomnography over a 1-year period at their institution in Norway. Okura and Muraki ¹³ explain, the polysomnographic pattern of catathrenia so closely resembles that of central sleep apnea that catathrenia may be erroneously scored as central sleep apnea unless a detailed analysis of video and audio recordings is performed by properly trained technicians.

Catathrenia causes

The cause of sleep related groaning is not known. It is not related to any problem with breathing. There is also no abnormal brain activity involved. A physical exam tends to show no related medical cause. There also does not appear to be any link to mental disorders.

Catathrenia is distinct from both sleep talking (a parasomnia with loud talking during sleep) and snoring (noise due to vibration of upper airway soft tissues related to variations in airway resistance) ². It has been emphasized that catathrenia cannot be considered as expiratory snoring ¹⁴. Acoustic analysis shows that the origins of the sounds in catathrenia and snoring and clearly different: catathrenia is laryngeal, whereas snoring is guttural. Iriarte et al. ¹⁵ demonstrated the ability to calculate a main frequency, presence of harmonics, and a greater relative decibel intensity as features characteristic of catathrenia compared to the absence of these during snoring. The presence of harmonics supports sound of vocal origin—as this is distinct from the chaotic sound produced during snoring. In addition, Ott et al. ⁶ identified active adduction and vibration of the vocal cords during expiration via laryngoscopy in a sedated patient with catathrenia, thus providing similarities between groaning and phonation. The duration of the noise and the absence of any concomitant abnormal motor phenomena distinguish this expiratory sound from the moaning that occurs during epileptic seizures ¹⁶. Interestingly, however, the rapid-eye-movement (REM) predominance of catathrenia and the increased laryngeal motor activity seems to suggest that catathrenia has features of both a sleep-related breathing disorder and parasomnia (ie, REM Sleep Behavior Disorder).

Catathrenia symptoms

Catathrenia or sleep related groaning causes you to make loud, vocal groaning noises as you sleep ¹⁷. Your breathing may become unusually slow while you groan. You may take a slow deep breath in, followed by a long moaning exhale, ending with a sigh or a grunt. The sound can last up to 40 seconds and often repeats in clusters for two minutes to one hour.

A mild case of restless sleep or daytime fatigue may be a result. Otherwise, there is usually no major sleep complaint. The groaning is more likely to disturb the sleep of the bed partner or others in the household. A hoarse voice or sore throat might appear in the morning.

The groaning appears more often during the stage of rapid-eye-movement (REM) sleep. There are five stages of sleep that make up one sleep cycle. You normally complete four to six sleep cycles in one night. The fifth stage of each cycle is called REM sleep. It usually begins about 90 minutes after you fall asleep. REM sleep makes up about 20 percent to 25 percent of your total sleep time.

The first REM period tends to last for only a few minutes. The REM stage gets longer during each sleep cycle. Your last period of REM sleep may last as long as an hour. These latter periods of REM sleep include most episodes of groaning. Groaning may occur from time to time during non-REM sleep.

A moaning sound can also occur during an epileptic seizure. This sound would not occur on a regular basis like groaning does. A moaning type of sound can also be made by snoring. But the primary sound of snoring occurs when you inhale. Groaning occurs when you exhale. Some people can make a harsh, shrill, creaking sound when they breathe. This is called stridor. It may occur mainly when they sleep. But stridor happens with almost every breath. Unlike groaning, it does not appear in blocks of time in the night.

Catathrenia diagnosis

Tests are not normally needed for someone who has catathrenia or sleep related groaning. Your doctor may have you do an overnight sleep study if your problem is severely disturbing your sleep. This study is called a polysomnogram. It charts your brain waves, heart beat, and breathing as you sleep. It also records how your arms and legs move. Polysomnogram study will help reveal if your nightmares are related to any other sleep disorder. The classic polysomnographic description of catathrenia is a deep inhalation followed by a protracted exhalation during which moaning or groaning sounds are produced, usually lasting between 2 and 49 seconds ¹⁵. Catathrenia occurs predominantly during REM sleep ⁶, but has also been identified in non-REM sleep ⁷; these episodes occur without observed respiratory distress and the arterial oxygen saturation remains normal ¹⁸.

A patient will usually be referred to an ENT (ear, nose, and throat) specialist for a thorough exam. The doctor will make sure that other conditions are not the cause of the groaning.

Catathrenia treatment

A study in the journal SLEEP ⁵ finds that catathrenia can be successfully treated with continuous positive airway pressure (CPAP). CPAP provides a steady stream of pressurized air to patients through a mask that they wear during sleep. This airflow keeps the airway open, preventing the pauses in breathing that characterize sleep apnea and restoring normal oxygen levels. Although the mechanism of action of CPAP treatment in patients with catathrenia is not well understood, Ott et al. ⁶ demonstrated reductions in nocturnal groaning and improved daytime well-being following CPAP possibly from a reduction in active adduction during expiration. Pharmacotherapy and cognitive behavioral therapy (CBT) are other modalities others have used to manage catathrenia, though with varied results ⁷.

References

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