Central sleep apnea leads to a disorganized, interrupted sleep. Patients report a feeling of fatigue during the day, frequent arousals during the night, insomnia and sleepiness during daytime [11]. Even though the patients themselves may be unaware of the apneic event, as it occurs during their sleep, partners often observe the incident. Some patients also experience shortness of breath and choking.

Except for the symptoms related to the apnea itself, individuals who suffer from an underlying medical condition will display the corresponding symptomatology.

• Fatigue

  Veauthier C, Paul F (2014) Sleep disorders in multiple sclerosis and their relationship to fatigue. [link.springer.com]

  The patient had a body mass index of 32.4kg/m2, and complained of fatigue, shortness of breath on exertion, excessive daytime sleepiness, and snoring. Arterial blood gas analysis showed a PaO2 and a PaCO2 of 70.9 and 31.2mmHg, respectively. [ncbi.nlm.nih.gov]

  Acetazolamide improved subjective perception of overall sleep quality (p = 0.003), feeling rested on awakening (p = 0.007), daytime fatigue (p = 0.02), and falling asleep unintentionally during daytime (p = 0.002). [doi.org]

  Some complications include: Fatigue. The repeated awakenings associated with sleep apnea make normal, restorative sleep impossible. People with central sleep apnea often experience severe fatigue, daytime drowsiness and irritability. [mayoclinic.org]

• Excessive Daytime Sleepiness

  The patient had a body mass index of 32.4kg/m2, and complained of fatigue, shortness of breath on exertion, excessive daytime sleepiness, and snoring. Arterial blood gas analysis showed a PaO2 and a PaCO2 of 70.9 and 31.2mmHg, respectively. [ncbi.nlm.nih.gov]

  Excessive daytime sleepiness is less common in children than among adults with obstructive sleep apnea. [msdmanuals.com]

• Nocturnal Awakening

  Recurrent cessation and resumption of respiration leads to sleep fragmentation, which causes excessive daytime sleepiness, frequent nocturnal awakenings, or both. [ncbi.nlm.nih.gov]

  In others, they present with symptoms of morning fatigue, daytime sleepiness, morning headache, and recurrent nocturnal awakenings. One of the common form of central apnea is known as Cheyne-stokes respiration. [queenslandsleep.com.au]

  In others, they present with symptoms of daytime sleepiness, morning tiredness, recurrent nocturnal awakenings and morning headache. Snoring does not generally occur in central sleep apnea. However, breathing patterns may be abnormal. [sleepdisordersguide.com]

• Developmental Delay

  Joubert syndrome-related disorders are autosomal-recessive disorders characterized by diffuse hypotonia, developmental delay, abnormal respiratory patterns, and the pathognomonic neuroradiologic finding of a molar tooth sign. [ncbi.nlm.nih.gov]

  She had a history of global developmental delay, seizures, bilateral cataracts, sensorineural hearing loss, biopsy-proven myopathy, and immunodeficiency with a low CD4 count complicated by recurrent respiratory infections. [pediatrics.aappublications.org]

• Epilepsy

  Here, we present a case of a 9-year-old male with Angelman syndrome, epilepsy, insomnia, and central sleep apnea. The patient was initially evaluated for nighttime awakenings and pauses in breathing. [ncbi.nlm.nih.gov]

  Drops in blood oxygen levels that are severe but not severe enough to trigger brain-cell or overall death may trigger seizures even in the absence of epilepsy. [en.wikipedia.org]

  Deppe M, Kellinghaus C, Duning T, Moddel G, Mohammadi S, et al. (2008) Nerve fiber impairment of anterior thalamocortical circuitry in juvenile myoclonic epilepsy. Neurology 71: 1981–1985. View Article Google Scholar 22. [journals.plos.org]

• Sleep Apnea

  […] breathing primary central sleep apnea central sleep apnea syndrome APNEA, CENTRAL SLEEP Sleep Apnea, Lethal Central edit English central sleep apnea sleep apnea that is characterized by a malfunction of the basic neurological controls for breathing rate [wikidata.org]

  […] obstructive sleep apnea. [emedicine.medscape.com]

• Snoring

  In obstructive sleep apnea, the most common symptom is snoring, but most people who snore do not have sleep apnea. [msdmanuals.com]

  Family members may tell you that you stop breathing at night and snore excessively. If you sleep alone, you may not even know that you snore, and you may not link the possible consequences of apnea to the disorder. [healthcentral.com]

  A word about snoring Snoring by itself is not the same thing as sleep apnea. [sleepresolutions.com]

  Sleep doctors and snoring specialists I spoke with locally say they do see a higher rate of central apnea at higher altitudes like here in Colorado. Dr. [koaa.com]

  The patient had a body mass index of 32.4kg/m2, and complained of fatigue, shortness of breath on exertion, excessive daytime sleepiness, and snoring. Arterial blood gas analysis showed a PaO2 and a PaCO2 of 70.9 and 31.2mmHg, respectively. [ncbi.nlm.nih.gov]

• Loud Snoring

  Daytime sleepiness -Difficulty concentrating -Loud snoring -Witnessed apneas with resuscitative snorts -Non-restorative sleep -Morning headaches/dry mouth -Insomnia -Peds: present with over activeness instead of sleepiness What are risk factors for OSA [quizlet.com]

  Signs of Central Sleep Apnea Poor nighttime sleep, followed by daytime fatigue Shortness of breath during sleep Snoring (although the snoring might not be as loud or frequent as people who suffer from OSA) Headaches Risk Factors for Central Sleep Apnea [napervilledentistry.com]

  Associated findings of OSA include loud snoring, obesity, positive family history of apnea and snoring, daytime sleepiness and when very severe, right-sided heart failure (see Cor Pulmonale), and hypoventilation (see Underventilation ). [post-polio.org]

  After 10 to 100 seconds, the demand for oxygen grows critical, and the sleeper gasps or snores abruptly in characteristically loud, staccato bursts in the struggle to regain normal breathing. [healthcentral.com]

  Anyone who has certain symptoms -- such as loud snoring, sudden awakening and being short of breath, waking with a dry mouth or throat, waking with a headache, not being able to stay asleep or being very sleepy during the day -- may have sleep apnea and [cnn.com]

• Gagging

  He was referred for multiple tooth extractions under sedation owing to severe gag reflex and phobic anxiety disorder. The treatment was completed uneventfully under N(2)O and sevoflurane inhalation accompanied by midazolam and ketamine induction. [ncbi.nlm.nih.gov]

• Headache

  Thus, be sure to keep an eye out for particular symptoms like morning headaches, especially if you have preexisting health conditions! Featured Image Source: Rachel Tayse [morningsignout.com]

  (vs OSA which is due to upper airway obstruction) SIGNS & SYMPTOMS: chronic fatigue, daytime sleepiness, morning headaches, restless sleep but not associated with snoring. [openanesthesia.org]

  Symptoms of Obstructive Sleep Apnea Loud snoring Waking up snorting, gasping, or feeling out of breath Daytime fatigue Depression and mood swings Headaches in the morning Risk Factors for Obstructive Sleep Apnea Genetics: If your parents or grandparents [napervilledentistry.com]

  Patients with hypercapnic forms may experience daytime somnolence (sometimes called wake-time sleepiness), lethargy, and morning headache. [merckmanuals.com]

  Stopping to breathe during sleep, often with 5-30 second pauses Repeated nighttime awakenings Insomnia Periodic breathing (rapid, slows down, stops, repeats) Nighttime shortness of breath Daytime sleepiness Morning headaches Difficulty concentrating Look [chicagoent.com]

• Morning Headache

  Thus, be sure to keep an eye out for particular symptoms like morning headaches, especially if you have preexisting health conditions! Featured Image Source: Rachel Tayse [morningsignout.com]

  (vs OSA which is due to upper airway obstruction) SIGNS & SYMPTOMS: chronic fatigue, daytime sleepiness, morning headaches, restless sleep but not associated with snoring. [openanesthesia.org]

  Patients with hypercapnic forms may experience daytime somnolence (sometimes called wake-time sleepiness), lethargy, and morning headache. [merckmanuals.com]

  Stopping to breathe during sleep, often with 5-30 second pauses Repeated nighttime awakenings Insomnia Periodic breathing (rapid, slows down, stops, repeats) Nighttime shortness of breath Daytime sleepiness Morning headaches Difficulty concentrating Look [chicagoent.com]

  headaches Restless sleep But a person with CSA may also have: Difficulty swallowing Voice changes Sense of weakness and numbness Diagnosis A thorough sleep study with polysomnography (PSG) will show whether the lapses in breathing result from airway [uofmhealth.org]

• Difficulty Concentrating

  Do you have difficulty concentrating and/or find it hard to recall your memory? Are you constantly tired for no particular reason? If you answered yes to these three questions, you might want to check if you have sleep apnea. [morningsignout.com]

  Stopping to breathe during sleep, often with 5-30 second pauses Repeated nighttime awakenings Insomnia Periodic breathing (rapid, slows down, stops, repeats) Nighttime shortness of breath Daytime sleepiness Morning headaches Difficulty concentrating Look [chicagoent.com]

  You may have difficulty concentrating and find yourself falling asleep at work, while watching television or even when driving. Cardiovascular problems. [mayoclinic.org]

  concentrating Been diagnosed with ADHD (in children and adults) – sometimes OSA is misdiagnosed as ADHD [renewsleep.com]

• Somnolence

  Patients with hypercapnic forms may experience daytime somnolence (sometimes called wake-time sleepiness), lethargy, and morning headache. [merckmanuals.com]

  Historical note and terminology The term "central sleep apnea" was coined by Gastaut and his collaborators in their report on the abnormal breathing patterns observed in a subtype of so-called "Pickwickian patients," morbidly obese subjects with somnolence [medlink.com]

  Morbidly obese with right heart failure and somnolence - Those on chronic opioids or with neuromuscular disease - Chronic heart failure and low EF -Refer to sleep specialist for management as it is more difficult as well [quizlet.com]

  Patients afflicted with this condition exhibit daytime somnolence and disturbed sleep patterns. Central sleep apnea leads to a disorganized, interrupted sleep. [symptoma.com]

  CSA is present when a patient has greater than five central apneas per hour of sleep with associated symptoms of disrupted sleep (such as excessive daytime somnolence). [acc.org]

• Sleep Disturbance

  On evaluation, a history of severe sleep disturbed breathing was elicited. Anticipating obstructive sleep apnea (OSA), polysomnography was performed, detecting severe central sleep apnea (CSA) without OSA. [ncbi.nlm.nih.gov]

  Kaynak H, Altintas A, Kaynak D, Uyanik O, Saip S, Agaoglu J, Onder G, Siva A (2006) Fatigue and sleep disturbance in multiple sclerosis. Eur J Neurol 13:1333–1339 CrossRef PubMed Google Scholar 4. [link.springer.com]

  Other information is also obtained from the sleep study including limb movements, snoring, oxygen saturation, total sleep time, and sleep disturbances. [emedicinehealth.com]

Laboratory examinations are of little diagnostic value in cases of people with a suspected sleep disorder. Decreased levels of arterial blood oxygen may be detected in individuals with an underlying heart failure or apnea related to an ascent to a high altitude.

Polysomnography, a type of sleep study, is the most useful diagnostic tool. Findings are categorized depending on the type of apnea:

• Primary central sleep apnea: Features more than 5 central apneic incidences per hour, with a minimum 10-second duration. They are observed during the first and second sleep stage and the patient may be prevented from reaching the stage of delta sleep. The periodic circle of apneic events is lasts no longer than 45 seconds.
• CSB-CSA: PaCO2 values tend to reach levels near the apneic threshold and the cycle of apnea and hyperpnea has a duration greater than 45 seconds.
• High-altitude central sleep apnea: The apneic cycle length lasts for 12-34 seconds. The first and second sleep stages last for a longer period of time than in healthy individuals and delta sleep is of decreased duration.
• Central sleep apnea related to drug abuse: More commonly observed during NREM sleep.The patterns of breathing-apneas may have a periodic nature but this is not always necessary.

• Hypercapnia

  […] therapy, hypoxic responsiveness was restored and the ventilatory response to hypercapnia doubled. [ncbi.nlm.nih.gov]

  Hypercapnia with decreased ventilatory drive Eucapnia or hypocapnia with increased ventilatory drive but with episodes of apnea, periodic breathing, or both Causes of hypercapnia with decreased ventilatory drive include hypothyroidism and central lesions [merckmanuals.com]

• Hyperprolactinemia

  […] referred at the age of 4 years because of obesity and under observation for 16 years, was found to be suffering from a hypothalamic syndrome of unknown origin characterized by progressive obesity, polyphagia, deficiency of growth and thyroid hormone, hyperprolactinemia [ncbi.nlm.nih.gov]

If the central sleep apnea incidents lead to no profound symptomatology and do not cause discomfort or decreased functionality during the day, simple monitoring may suffice. Individuals who are suitable candidates for monitoring are those who experience apneic events during sleep-wake transition, those who do not display considerably decreased oxygen levels in their blood or those whose apnea occurs while using a CPAP breathing machine. It should be noted that 1 out of 5 cases of central sleep apnea resolve without any intervention.

As far as therapeutic options are concerned, both medications and breathing enhancement devices are available to treat cases of central sleep apnea

Breathing assistance devices

Patients with CSB-CSA can significantly benefit from the use of continuous positive airway pressure devices (CPAP). Apneic syndromes induced by hypoventilation can be treated with the use of a bilevel positive airway pressure device (BIPAP). Another therapeutic option involves the addition of dead space, by means of attaching a plastic cylinder of 400 to 800 mL to a mask; this can help to increase carbon dioxide reserve over the apneic threshold and reduce the occurrence of sleep apneas. This method has been attempted in cases of primary sleep apnea and CSB-CSA.

Central sleep apnea due to Cheyne-Stokes breathing can also be treated with the use of adapted servo-ventilation (ASV), as well as with the administration of oxygen, if the patient suffers from heart failure as well [12]. Oxygen is also an option for sleep apneas due to high altitude, or apneas accompanied by very low levels of circulating oxygen.

Medications

Patients affected by CSB-CSA or sleep apneas caused by high altitude can benefit from the administration of acetazolamide, a drug that induces bicarbaturia, lowering the apneic threshold. Theophylline can also be employed in patients with heart failure causing central sleep apnea [13]. Lastly, sedatives such as zolpidem and temazepam can be used to relieve apneic events that are not accompanied by high levels of CO2 in the blood. They are believed to lead to a stabilize sleep pattern, with a more progressive and delayed transition from sleep to wakefulness.

Prognosis depends on the underlying condition and is especially positive from patients displaying idiopathic (primary) sleep apnea.

Central sleep apnea due to Cheyne-Stokes breathing pattern (CSB-CSA)

CSB-CSA is frequently associated with an underlying condition such as a cerebrovascular event, heart failure or kidney failure. The sleep pattern is usually disorganized and interrupted. The intermittent breathing occurs every 45 seconds or more and follows a typical crescendo-decrescendo pattern.

Central sleep apnea due to a condition, unrelated to Cheyne-Stokes breathing

This type of apnea is linked to an underlying disorder other than heart or kidney failure. It is not characterized by a crescendo-decrescendo pattern.

Central sleep apnea due to high altitude

Occurs when the patient has recently been in surroundings of high altitude (5000m or more).

Central sleep apnea due to narcotic use

It is primarily caused by the abuse of substances such as opiates or depressants of the central nervous system.

Primary central sleep apnea

This type of central sleep apnea syndrome is not associated with an underlying pathology, does not feature the crescendo-decrescendo pattern of breathing and does not lead to hypoxia. Patients usually experience 5 or more apneic events per hour that lasts for at least 10 seconds.

Complex sleep apnea

It can develop during titration of CPAP or after a tracheostomy, in cases of patients who are affected by obstructive sleep apnea [3].

Despite the fact that the respiratory function is a continual process indispensable for the maintenance of satisfactory oxygen levels in the blood and tissues, there are two distinct circumstances, wherein an apneic event is considered normal and does not constitute a sign of ventilatory dysfunction:

• Transition from sleep to wakefulness. Apneic events during this period of time are possibly related to impaired respiratory control, caused by the resetting of chemoreceptors. It is believed that nearly half of the healthy individuals will, at some point, exhibit such an event.
• Arousal or sigh apnea: after an arousal or a sigh, the resulting hyperventilation may lead to a brief cessation of breathing.

Predominant central apnea is an uncommon medical condition, estimated to affect under 1% of the population worldwide [4]. Central sleep apnea due to Cheyne-Stokes breathing is more commonly diagnosed in male individuals older than 60 years old; women who have not yet reached menopause are unlikely to develop an apnea syndrome [5].

Mortality and morbidity have not been sufficiently studied; they are however greatly influenced by a potential underlying pathology, such as heart or renal failure, a cerebrovascular event etc.

The normal values of arterial carbon dioxide tension (PaCO2) are different during wakefulness and sleep. Depending on the normal range, values below the lowest normal limit lead to a periodic breathing cessation. The threshold for PaCO2 is higher during when an individual is asleep. Apneas are observed during the resetting of this threshold which occurs when the individual is starting to wake up.

Pathophysiologically, apneas develop either due to unstable ventilation or due to depression of the ventilatory center or chemoreceptors in the brainstem.

It is typically seen in patients suffering from CSB-CSA, primary sleep apnea and apnea related to a recent ascent to a high altitude [6]. Individuals affected by heart failure and those who have recently been to a location higher than 5000m display a lower PaCO2 baseline, which renders them susceptible to apneas. Generally a lower PaCO2 leads to an excessive response, should its value be even more diminished; this leads to a state of sleep instability and further exacerbates an existing medical condition.

On the other hand, opiates are known to suppress the ventilatory center in the brainstem, even though many individuals gradually develop tolerance to the narcotic substances [7]. Despite the tolerance effect, many individuals who engage in chronic drug abuse display a high rate of sleep apneas, hypoxia and hypercapnia [8] [9]. Even though the suppression of the respiratory function can be observed at any time during the day, sleep aggravates the phenomenon, due to an absent behavior drive. Conditions of the central nervous system, such as meningitis, cerebral hemorrhage or a tumor may also interfere with breathing, leading to an unstable breathing with a central etiology, known as Biot respiratory pattern.

Even though central sleep apnea is a different medical entity from obstructive sleep apnea, some individuals are affected by a type of mixed apnea, with both obstructive and central characteristics [10].

Central sleep apnea that is idiopathic cannot be prevented. The other types of the disease can only be prevented if the conditions that may induce the apnea are prevented. Having a healthy body weight and avoiding alcohol or drug abuse can be successful steps towards the prevention of heart failure.

The syndromes categorized under the term central sleep apnea (CSAS) include a multitude of disorders which lead to respiratory impairment during sleeping hours. Patients affected by central sleep apnea display a breathing pattern during sleep, which falls under the two following categories [1].:

• Periodic cessation of breathing during sleep
• Decreased breathing capacity during sleep

Central sleep apnea is closely linked to obstructive sleep apnea syndromes; alternative causes include a high altitude, narcotics or an underlying pathology.

The cessation of the respiratory effort, if present, is characterized by a minimum duration of 10 seconds during which no flow of air is detected in the lungs. In general, the two pathophysiological mechanisms that lead to the development of such sleep-related breathing dysfunction. This condition is either associated to hyperventilation or hypoventilation. The latter occurs in cases of people with neurological conditions that affect breathing control and the former is primarily linked to primary CSAS or high altitude.

CSAS features six syndromes, each of which is caused by a distinct etiological factor [2].:

• Primary sleep apnea of infancy
• Primary central sleep apnea
• Central sleep apnea due to Cheyne-Stokes breathing pattern
• Central sleep apnea due to an underlying pathology, unrelated to Cheyne-Stokes breathing pattern
• Central sleep apnea due to high altitude
• Central sleep apnea due to illegal substance use (narcotics)

Central sleep apnea syndromes are a group of diseases which lead to interrupted breathing during a person's sleep. Central sleep apnea does not involve the loss of one's ability to breathe, but rather the absence of the necessary brain stimuli that lead to breathing.There are various types of central sleep apnea, either caused by an underlying condition or primary. Heart failure, kidney failure, having recently ascended to a high altitude, illegal substance abuse, strokes and neurological degenerative diseases may lead to apneic events.

Patients are usually unaware of the fact that they periodically stop breathing during their sleep. However, sleep is usually interrupted, an individual feels weak and sleepy during daytime accompanied by insomnia. Snoring is commonly reported by partners, as well as shortness of breath or frequent choking. Partners are usually the ones to observe that another person stops breathing during their sleep.

Central sleep apnea cannot be diagnosed with laboratory tests; these tests are likely to reveal the underlying pathology that can lead to an apneic syndrome, but not the apnea itself. A sleep study, known as a polysomnogram is conducted to diagnose the sleep disorder. In this test, the patient is monitored during their sleep and sleeping patterns in the brain are recorded together with periods when breathing temporarily stops are also tracked down.

Central sleep apnea can be treated with devices that are used during sleep and help to prevent the cessation of breathing. Nasal continuous positive airway pressure (CPAP), adaptive servo-ventilation (ASV) and bilevel positive airway pressure (BiPAP) are various options that are suggested depending on the type of apnea an individual suffers from. Oxygen may also be an option under some circumstances, alongside medications that can help to reduce the apneic events.

1. Panossian LA, Avidan AY. Review of sleep disorders. Med Clin North Am. 2009 Mar; 93(2):407-25.
2. American Academy of Sleep Medicine. International Classification of Sleep Disorders. 2nd ed. Westchester, Ill: American Academy of Sleep Medicine; 2005.
3. Guilleminault C, Simmons FB, Motta J, et al. Obstructive sleep apnea syndrome and tracheostomy. Long-term follow-up experience. Arch Intern Med. 1981 Jul; 141(8):985-8.
4. Bixler EO, Vgontzas AN, Ten Have T, et al. Effects of age on sleep apnea in men: I. Prevalence and severity. Am J Respir Crit Care Med. 1998 Jan; 157(1):144-8.
5. Johansson P, Alehagen U, Svanborg E, et al. Sleep disordered breathing in an elderly community-living population: Relationship to cardiac function, insomnia symptoms and daytime sleepiness.Sleep Med. 2009 Oct; 10(9):1005-11.
6. White DP. Pathogenesis of obstructive and central sleep apnea. Am J Respir Crit Care Med. 2005 Dec 1; 172(11):1363-70.
7. Teichtahl H, Wang D, Cunnington D, et al. Ventilatory responses to hypoxia and hypercapnia in stable methadone maintenance treatment patients. Chest. 2005 Sep; 128(3):1339-47.
8. Wang D, Teichtahl H, Drummer O, et al. Central sleep apnea in stable methadone maintenance treatment patients. Chest. 2005 Sep; 128(3):1348-56.
9. Walker JM, Farney RJ, Rhondeau SM, et al. Chronic opioid use is a risk factor for the development of central sleep apnea and ataxic breathing. J Clin Sleep Med. 2007 Aug 15; 3(5):455-61.
10. Verbraecken JA, De Backer WA. Upper airway mechanics. Respiration. 2009; 78(2):121-33.
11. Eckert DJ, Jordan AS, Merchia P, et al. Central sleep apnea: Pathophysiology and treatment. Chest. 2007 Feb; 131(2):595-607.
12. Allam JS, Olson EJ, Gay PC, et al. Efficacy of adaptive servoventilation in treatment of complex and central sleep apnea syndromes. Chest. 2007 Dec; 132(6):1839-46
13. Javaheri S, Parker TJ, Wexler L, et al. Effect of theophylline on sleep-disordered breathing in heart failure. N Engl J Med. 1996 Aug 22; 335(8):562-7