'Nocturnal groaning': just a sound or parasomnia?
A. OLDANI, M. MANCONI, M. ZUCCONI, V. CASTRONOVO and L. FERINI-STRAMBI
Sleep Disorders Centre, Department of Neurology, HSR Turro and Università Vita-Salute San Raffaele, Milan, Italy

Summary

We describe the clinical and polysomnographic characteristics of 12 patients complaining of expiratory groaning during sleep. Groaning occurred almost exclusively during rapid eye movement sleep. We reviewed all the literature cases, obtaining a total sample of 27 patients. There is no evident association with any predisposing factors or underlying disease. The results obtained from empirical treatment, including drugs and CPAP, are unsatisfactory. The origins of nocturnal groaning, as well as the long-term prognosis, remained unexplained.

Introduction

De Roeck and Van Hoof (1983) reported the case of a young male with groaning during the rapid eye movement (REM) sleep, as a result of a forced and prolonged expiration. They suggested three possible pathogenetic mechanisms: (i) functional occlusion of the vocal chords in REM sleep and reactive forced expiration to overcome this resistance; (ii) critical narrowing of peripheral airways during expiration in REM sleep; (iii) functional and/or anatomical lesions involving neurological structures that control ventilation. Other authors (Brunner and Gonzalez, 2004; Pevernagie et al., 2001; Vetrugno et al., 2001, oral presentation) demonstrated the occurrence of groaning also during non-REM sleep, and excluded the association with identifiable neuroradiologic lesions. In all the editions of the International Classification of Sleep Disorders (1990, 1997 and 2001) proposed by the American Academy of Sleep Medicine (AASM), nocturnal groaning (NG) does not fit within any categories of sleep disorders proposed. In the latest version (International Classification of Sleep Disorders, in press) NG will be included among parasomnias. The aims of this study were to describe the clinical and polysomnographic pictures of our patients with NG and to review the literature cases.

Patients and Methods

During a 4-year period (2001–2004), we observed 21 patients with NG sound during expiration (referred by the bed partner). This patients' group represents about 0.3% of the population evaluated at the Sleep Disorders Centre during the above-mentioned period. Medical, neurological and hypnological histories (with the presence of the bed partner), and neurological examination, were assessed from all the patients. All the patients completed the Epworth Sleepiness Scale (Johns, 1991). Sixteen patients underwent a full-night 15-channel digital video-polysomnographic evaluation in the sleep laboratory. Recorded parameters were: EEG (C3-A2, O2-A1), electro-oculography (left and right outer cantus), submental, intercostalis, left and right rectus abdominis and bilateral anterior tibialis EMG activity, EKG. Oxyhemoglobin saturation (SaO2) was measured using pulse oxymetry. Oro-nasal airflow was monitored with termistors. Thoracic and abdominal respiratory movements were recorded using piezo-sensors. Data acquisition of respiratory sound was derived by a piezo-electric larynx microphone. Sleep and respiratory events were manually scored in 30-s epochs.

Sleep stages were scored according to standard criteria (Rechtschaffen and Kales, 1968).

Results

As summarized in the Table 1, the clinical data were collected from 21 patients (mean age at observation = 31.4 ±8.1 years; 13 males and 8 females). None presented neurological and/or pulmonary diseases. None had a history of psychiatric illness or use of psychotropic medication. Seven patients had a pathological score at the Epworth Sleepiness Scale. Some patients felt socially embarrassed whenever they had to sleep with other persons, but they were all unaware of this disorder, and were referred to the Sleep Centre from family members, because of the nocturnal noise. The mean age at onset of NG, referred by this group of patient, was 21.7 ± 7.0 years. Nine patients (nos 2, 4, 5, 8, 10, 11, 17, 19 and 20) reported familial cases of parasomnias (bruxism, sleepwalking; sleep talking, sleep terrors and NG).

Sixteen patients underwent video-polysomnography. Twelve of these presented episodes of NG: a sleep-related respiratory phenomenon which often began with a deep inspiration, followed by a short expiratory phase and then by a long expiratory period where the breathing signals were flat or significantly reduced (Fig. 1). These 'hypopneic' events produced a typical monotonous vocal noise. The pitch and timbre of NG appeared to vary among patients, but was fairly constant within each subject. The NG episodes were both isolated, with a duration of about 10 s, or in short sequences, lasting up to 4 min. During these noise expiratory phases, no significant EMG activity in rectus abdominis and intercostalis muscles was detected. The body position seemed to have not influence. NG occurred during expiration only, and was associated with a slight decrease in heart rate, which conversely increased in frequency at the end of the groaning episode. We observed a great prevalence for REM sleep-related episodes. In two patients polysomnography confirmed also the presence of bruxism. None of the patients showed significant obstructive sleep apneas (all had an apnea–hypopnea index <5). The SaO2 remained constantly over 90% all night long. All the patients had an index of periodic limb movements [limb movements per hour of sleep; American Sleep Disorders Association, 1993] lower than 5. Five patients with NG had a pathological score at the Epworth Sleepiness Scale (more than 10 points). The polysomnographic data of the 12 patients with NG are summarized in the Table 2. Eighty-nine percent of the total number of groaning episodes (36) occurred during REM sleep. Patient number 6 and 17 presented a reduced total sleep time and sleep efficiency; patient numbers 8 and 16 presented a reduction of slow wave sleep, while patient number 5 and 6 showed a reduction of REM sleep. Six patients (nos 2, 5, 8, 17, 19 and 20) referred that at least one of their first relatives presented a positive history of parasomnia. In the family of patient number 17 (Fig. 2a), three cases of NG, three of sleepwalking and two of bruxism were reported. In the family of patient number 20 (Fig. 2b), four cases of NG (one with coexistence of bruxism) were reported.

Five of our patients received empirical treatments: clonazepam (two patients; up to 2.0 mg at bedtime), gabapentin (up to 1600 mg at bedtime), pramipexole (0.50 mg at bedtime), and trazodone (up to 100 mg at bedtime). Only in the patient treated with gabapentin we observed a transitory disappearance of NG for 6 months. At the follow-up visit (mean duration = 18 months) NG persisted in all patients.

Review of the literature cases

The first case report of NG was from Edegem, Belgium, in 1983 (De Roeck and Van Hoof, 1983). After about 20 years of literature silence, other four patients from Bologna, Italy (Vetrugno et al., 2001), 10 from Gent, Belgium (Pevernagie et al., 2001) and eight from Zurich, Switzerland (Brunner and Gonzalez, 2004) were described. These last eight patients have been excluded from this revision because they were described only in abstract form. Including our 12 polysomnographically diagnosed patients, the overall population of NG patients in the medical literature increased up to 27 subjects.

Nocturnal groaning is certainly a rare condition: it represents <1% of the population referred to a Sleep Disorder Centre (0.54% for the Centre of Gent, Belgium and about 0.3 for our Centre; it is reasonable to suppose similar percentage for the Centre of Bologna, Italy).

Table 3 summarized the clinical data for all the 27 literature patients. Similarly to sleep breathing disorders, the NG seems to be three times more frequent in men than in women: 20 male versus 7 female. The first symptoms usually appears during adolescence or early adulthood: the mean age at onset was 19.6 years, without difference between males and females. The typical NG noise was reported to be loud and to occur on a nightly basis, or many times per night. It persists for several years: the mean interval between the NG onset and the first sleep specialist consultation is 11 years. Although patients are usually unaware of their disorder, half of them complain of daytime fatigue or somnolence. NG seems to have an inherited component: in four patients (14.8%) NG is reported in other family relatives, although polysomnographic investigations are not available. Interestingly, in two of our families (Fig. 2) the NG seems to have an autosomal dominant pattern of inheritance.

The family history for bruxism and sleep-talking seems to be inconsistent because the prevalence is similar to that in the general population (Kryger et al., 1994). The NG is a predominantly REM sleep-related phenomenon: 18 patients (66.6) show episodes exclusively during REM sleep, seven patients (25.9%) mainly during REM sleep, one patient during both NREM and REM sleep and one patient exclusively during NREM sleep. In summary, 92.6% of NG patients produce the sound exclusively or predominantly during REM sleep.

There were no specific modification of the sleep structure and architecture: they were normal in about half of the patients; in the others different findings were reported: reduced total sleep time and sleep efficiency (26%); reduction of slow wave sleep (14.8%); reduction (14.8%) or increase (14.8%) of REM sleep. Four patients also showed concomitant bruxism. No other motor and/or behavioral abnormalities were founded. None presented obstructive sleep apneas.

Notwithstanding the origin of NG is unclear, few bedtime treatments have been administered in empirical way: clonazepam (0.5–2.0 mg), gabapentin (up to 1600 mg), pramipexole (0.50 mg), carbamazepine (600 mg), trazodone (up to 100 mg), paroxetine (20 mg) and dosulepine (75 mg) did not show a sustained effect on the groaning noise. Only in two patients a transitory effect was reported: in patient G8 (Pevernagie et al., 2001) the NG disappeared for 1 month with dosulepine, in patient M2 for 6 months with gabapentin. Inconsistent effects on NG have been reported with nasal CPAP (up to 8 cmH2O) (Pevernagie et al., 2001). At the follow-up visit (available for eight of our patients; mean duration of the follow-up =18 months) NG persisted in all patients.

Discussion

Up to now, 35 patients (eight of them in abstract form) have been described in the medical literature with the term of NG. For this reason, groaning during sleep was not included within the current categories of sleep disorders proposed by the AASM (1990, 1997 and 2001). On the basis of the two papers published in 2001 (Vetrugno et al., 2001; Pevernagie et al., 2001), in the latest International Classification of Sleep Disorders (in press), NG will be included among parasomnias. The clinical hallmark of the disorder is the change in respiration, with sound production, during (REM) sleep. Wakefulness, non-rapid eye movement (NREM), and REM sleep all lead to changes in respiration. Changes in the upper airway pressure flow characteristics during sleep are crucial in the pathophysiology of sleep-disordered breathing. About half of the total airflow resistance in breathing is placed in the upper airway. This resistance, minimal during wakefulness, increases twofold during sleep, in particular during REM sleep (Mathew and Remmers, 1984). The respiration usually does not produce any vibration or sound during wakefulness. The sleep-related increase of upper airway resistance is often responsible for the turbulence, vibration and sound tipically observed in a lot of respiratory disorders during sleep. This could also be responsible for the well-known 'ZZZZZ' sound, which is universal in cartoons. The 'ZZZZZ' sound, often considered, at least in cartoons, as a sign of good sleep, probably represents the early stage of the snoring. Anyway, the various form of sleep-disordered breathing (snoring, obstructive, central and mixed apneoas) consists of a mainly inspiratory phenomenon. The sound, particularly loud in snoring and obstructive apneas, is produced during the inspiratory phase and decreases during expiration. The sound of the expiratory phase in these diseases often resembles the 'ZZZZZ'. Expiratory apnea, which has received little attention in the medical literature, is defined as absence of polysomnographically recorded nasal and oral airflow in the presence of continued expiratory effort against an occluded or partially obstructed upper airway. Almost all expiratory apneas, most frequent in children, are preceded by an augmented breath or sigh (Sheldon et al., 1993). There is some evidence that the central component of a mixed apnea is either prolonged expiration or an expiratory apnea (Sanders et al., 1985). The sound of the expiratory phase in snoring and obstructive sleep apneas, as well as in the expiratory apneas is typically unremarkable. For this reason, the monitoring of respiratory sound signals could be important for the identification of 'expiratory diseases during sleep'. The presence of clustered bradypneic events associated with prolonged expiration and expiratory sound production is the common finding in all the patients described up to now, under the term of NG, in the literature (De Roeck and Van Hoof, 1983; Pevernagie et al., 2001; Vetrugno et al., 2001). The differential diagnosis among the various conditions producing vocalization during sleep includes moaning occurring during sleep-related seizures, snoring, stridor and some parasomnias (sleepwalking, pavor nocturnus and REM sleep behavior disorder). Although the anamnestic data are often suggestive, the polysomnography with monitoring of sound signals is fundamental for the identification of vocalization episodes during sleep. In absence of sound monitoring the polysomnographic pattern of patients with NG could be misinterpreted as central apneas–hypopneas. Once recorded, the episodes of groaning have peculiar characteristics: bradypneic episodes consisting of deep inspiration followed by protracted expiration and irregular sound production during the expiratory phase. These are often in clusters and occur almost exclusively during REM sleep. Anyway, the more specific finding is the typical sound production. Patients are usually unaware of their disorder, but some of them show social and familial problems. The groaning recurs every night, but apparently is not associated with relevant sleep problems. The daytime fatigue or somnolence reported by half of the patients is a non-specific symptom and is not associated with the duration or intensity of the groaning episodes. In our sample, the only patient with the most severe daytime somnolence (i.e. score at the Epworth Sleepiness Scale = 18) did not show NG during polysomnography. Patients do not show medical and or psychiatric disturbances (in particular, no sign of respiratory diseases). In summary, at present, there is no evident association of NG with any predisposing factors or underlying disease. Often the patients decline any treatment. However, the results obtained from empirical treatment, including drugs and CPAP, are unsatisfactory. The origins of NG, as well as the long-term prognosis, remained unexplained. A possible mechanism of pathogenesis could be a functional REM sleep-related narrowing of upper airways during expiration. This produces the groaning sound. If this 'ZZZZZ' represents only an 'unusual sound', the early stage of the snoring (presnoring), a specific 'expiratory disease during sleep' or a new type of parasomnia needs to be further investigated and discussed.

References

•American Sleep Disorders Association. Recording and scoring leg movements. The Atlas Task Force. Sleep, 1993, 16: 748–759.
Medline, CSA
•Brunner D. P. and Gonzalez H. L. Catathrenia: a rare parasomnia with prolonged groaning during clusters of central or mixed apneas. J. Sleep Res., 2004, 13 (Suppl. 1): 107.
•De Roeck J. and Van Hoof E. Sleep-related expiratory groaning: a case report. Sleep Res., 1983, 12: 377.
•Johns M. W. A new method for measuring daytime sleepiness: the Epworth Sleepiness Scale. Sleep, 1991, 14: 540–545.
Medline, ISI
•Kryger M. H., Roth T. and Dement W. C. (eds). Principles and Practice of Sleep Medicine. W.B. Saunders, Philadelphia, PA, 1994: 693–786.
•Mathew O. P. and Remmers J. E. Respiratory function of the upper airway. In: N. A. Saunders and C. E. Sullivan (Eds) Sleep and Breathing. Marcel Dekker, New York, 1984: 163–200.
•Pevernagie D. A., Boon P. A., Mariman A.N.N., Verhaeghen D. B. and Pauwels R. A. Vocalization during episodes of prolonged expiration: a parasomnia related to REM sleep. Sleep Med., 2001, 2: 19–30.
CrossRef, Medline
•Rechtschaffen A. and Kales A. A Manual of Standardized Terminology, Techniques and Scoring System for Sleep Stages of Human Subjects. US Government Printing Office, Washington DC, 1968.
•Sanders M. H., Rogers R. M. and Pennock B. E. Prolonged expiratory phase in sleep apnea: a unifying hypothesis. Am. Rev. Respir. Dis., 1985, 131: 401–408.
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•Sheldon S. H., Oenal E., Lillie J. and Spire J. P. Sleep-related post-inspiratory upper airway obstruction in children. Sleep Res., 1993, 22: 270.
•American Academy of Sleep Medicine; ICSD, International Classification of Sleep Disorders; Diagnostic and Coding Manual: American Academy of Sleep Medicine; 1990, 1997 and 2001.
•American Academy of Sleep Medicine; ICSD, International Classification of Sleep Disorders 2; Diagnostic and Coding Manual; American Academy of Sleep Medicine; 2005 (in press) (Presented at the APSS 18th Annual meeting, June 5–10, 2004, Philadelphia, PA, USA).
•Vetrugno R., Provini F., Plazzi G., Vignatelli L., Lugaresi E. and Montagna P. Catathrenia (nocturnal groaning): a new type of parasomnia. Neurology, 2001, 56: 681–683.
Medline, ISI, CSA

http://www.blackwell-synergy.com/doi/full/10.1111/j.1365-2869.2005.00460.x

http://www.aasmnet.org/jcsm/AcceptedPapers/ACryInTheNight.pdf

just spelling my name correctly this time!

Well, I've continued to keep up over time and am amazed at all the great info now..no solutions but at least there's a bunch of us with the same issue!  I'd like to go back to a question I asked a long time ago of Daniela  .... I'm a firm believer that this issue has to do with stress and/or a traumatic event that has been suppressed and is being relived at some level while sleeping...breath holding to me seems to be a very human reaction to something that we worry about .. and, yes it could be subconscious...so, am i on to something here...do any of you feel that there may be either an abundance of stress or fear in your lives (job, health, other?) or about a traumatic event that happened when you were younger?  I know it's hard to discuss but i'd like to know if i'm even luke-warm on this one....my wife swears that i breath hold less when i'm less stressed...and i did have a severe traumatic event occur at 7 years old

...and you?

I definately do it MUCH less when I am not stressed.  Whenever something is bothering me it gets noticeably worse.  No traumatic events in my childhood.

I am not sure if it is sleep apnea that I have or not. I will be in almost a dreamy state right as I am awaking with an "apnea attack". It is very scary as I cannot breath, and in my dreamy state it feels as if I am suffocating. I do suffer from anxiety, however have not sought treatment. I really would like to know if this disorder really scares those who have it, as it feels like I am going to suffocate to death quite often. It feels like I "kick" myself out of sleep. Let me know if this is similar to anyone else.

All of this sounds very familiar.  I'm 35, female, normal weight, and have been holding my breath while sleeping for at least 10 years--probably more.  I had a sleep study about 4 years ago, and the doctor said I did not have apnea.  I realize I am still doing this and would like to know how to stop.  I'm not sure if this is related, but I have extremely vivid dreams every night--at least 2 or 3 that I remember.  I feel fairly rested during the day, but always have a very difficult time waking up.

Another post--I've had the same dreams of suffocating since I was a little girl. It only happens once or twice a year, and hasn't happened recently, but it always very scary, and I had the same feeling that I had to force myself to wake up and force myself to take a breath, which was always very difficult.  Yes, a horrible, scary thing.

Anyone have any new info for treating this?  Why hasnt someone gone to professionals for this.  I am sick and tired of people telling me i groan in my sleep.

Well, I thought I didn't have apnea because I hold my breath, not fail to take one, but OSA was my diagnosis, and CPAP has helped with it. It does seem that the sleep clinic should have been able to address the issue, whatever the cause. Perhaps you need to visit a better clinic? They aren't all equal.

BreatheHolder wrote:

I hold my breath at night - I take a breath, hold it for a while, then exhale very slowly making annoying "leaky beach ball" sounds until I do it again...I've done this for the past 10 years.  I'm 45 and in good health not overweight...when i started doing this I was in even better shape than now running 5 miles a day.

I know this is not apnea but I can't find any information on this problem even though a few others have written about this issue....I'm very tired during the day and it's getting old.  I did a sleep study about 5 years ago and they found no indications of apnea.  I've had regular physicals every year with nothing unusual and did an EKG about 3 years ago with no negative results.

My friend was taking a training class and was told by the instructor that breath holding was a sign of cardiac problems...any one know more about this? Any one know of any other possible causes???

Any help at all would be appreciated.  Thanks.

This looks like what I suffer from , it is called Catathrenia, or nocturnal groaning. I've been searching for the last 9 years, and was just told about it 2 days ago. Unfortunately, it seems there is no solution for that yet. You can find more information describing it exactely on the web.

Sleep Disorders Centre, Department of Neurology, HSR Turro and Universita Vita-Salute San Raffaele, Milan, Italy. wrote:

Four patients between 15 and 25 years of age presented with exclusively expiratory groaning during sleep. Groaning usually occurred during the second part of the night, beginning at age 5 to 16 years. Patients were unaware of the nocturnal noise, but it alarmed others. Results of otorhinolaryngologic and neurologic examinations were normal. Expiratory groaning arose during REM and non-REM sleep stage 2, and was repeated in clusters. Nocturnal groaning, which the authors term catathrenia, represents a distinctive parasomnia.

We describe the clinical and polysomnographic characteristics of 12 patients complaining of expiratory groaning during sleep. Groaning occurred almost exclusively during rapid eye movement sleep. We reviewed all the literature cases, obtaining a total sample of 27 patients. There is no evident association with any predisposing factors or underlying disease. The results obtained from empirical treatment, including drugs and CPAP, are unsatisfactory. The origins of nocturnal groaning, as well as the long-term prognosis, remained unexplained.

Parasomnia - Any of several disorders that frequently interfere with sleep, occurring especially among children and including sleepwalking, night terrors, and bed-wetting.


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Hello everyone!

After reading this long interesting thread I have decided to leave this link here ......where you will find all kind of information....like

    * Sleep Apnea Overview
    * Obstructive Sleep Apnea
    * Central Sleep Apnea
    * Causes of Sleep Apnea
    * Sleep Apnea Symptoms
    * Sleep Apnea Fundamentals
    * Sleep Apnea - Causes, Symptoms and Tests

          

    * Sleep Apnea Index
    * Sleep Apnea Statistics
    * Who Suffers from Sleep Apnea ?
    * Sleep Apnea - Frequently Asked Questions
    * When To Seek Medical Attention For Sleep Apnea?
    * Polysomnogram Test
    * Sleep Apnea Treatments
    * Sleep Apnea Self Care

    *  The Differences Between Obstructive Sleep Apnea And Central Sleep Apnea
    * Sleep Apnea And Snoring Differences
    * Sleep Apnea Sleep Deprivation
    * Relationship Of Sleep Apnea With Medical Problems
    * Sleep Apnoea And Impotence

        

    * Sleep Apnea Remedies
    * Sleep Apnea Prevention Tips
    * Self Help Sleep Apnea Remedy Techniques
    * Sleep Apnea Treatments For Mild, Moderate And Severe Cases
    * Central Sleep Apnea Treatment
    * Dental Devices For Sleep Apnea Treatment
    * Sleep Apnea Treatment With Tiny Implants
    * Pillar Procedure - The Latest Sleep Apnea Treatment



    * What Happens In Throat While Sleeping That Causes Sleep Apnea?
    * Ways To Minimize Discomfort Level With CPAP
    * Sleep Apnea Factors That Cannot Be Changed
    * Is It Necessary To Undergo OSA Surgery or Not?

          

    * Sleep Apnea Mask
    * CPAP Machine Information
    * CPAP Devices For Sleep Apnea -I
    * CPAP Devices For Sleep Apnea - II
    * FAQ’s Regarding CPAP Machines and Masks

         

    * What is the PITA Technique?
    * Sleep Apnea Surgery Options
    * Lower Airway Surgery
    * Tonsillectomy and Adenoidectomy
    * Nasal Surgery and Upper Airway Surgery
    * Uvulopalatopharyngoplasty
    * Tracheostomy
    * Glossectomy
    * Bariatric surgery
    * Septoplasty

You can find all the above topics here...........http://www.sleepdisordersguide.com/sleepapnea/

Marvin.


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Sleep Disorders Guide

Your Guide to A-Z Sleep Disorders.

Before my husband puts a pillow over my face!!!  I finally went to a sleep clinic 2 weeks ago.  In the a.m. the technician although cannot tell me really much, said I went from breathing down, down to a shallow breath to almost nothing.  So today I got my results and was told that I hold my breath/stop 45 times per hour.  No wonder I'm so tired all the time.  I have to go back tonight to the clinic and try the 'mask'.  They said I was in the 'severe' category.  My question to put out to you people is do any of you notice your holding your breath during the day because I do.  I feel that when I am concentrating (usually at work) I just do this weird thing where I do hold my breath until I need to take a breath and then I breathe.  I think this is becoming a habit.  I only started this whole thing in the last couple of years.

A number of people here on the forum (including me) have reported doing just that: forgetting to breathe when concentrating on something and then taking a large breath to make up for it.  I don't do this any more since being on the cpap machine.


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