Central hypoventilation syndrome | |
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Other names | Ondine's curse, primary alveolar hypoventilation, alveolar hypoventilation secondary to neurologic disease, idiopathic acquired central hypoventilation syndrome |
Ondine by John William Waterhouse (1849–1917) | |
Specialty | Neurology |
Central hypoventilation syndrome (CHS) is a sleep-related breathing disorder that causes ineffective breathing, apnea, or respiratory arrest during sleep (and during wakefulness in severe cases). CHS can either be congenital (CCHS) or acquired (ACHS) later in life. The condition can be fatal if untreated. CCHS was once known as Ondine's curse.
ACHS can develop as a result of severe injury or trauma to the brain or brainstem. [1] Congenital cases are very rare and involve a failure of autonomic control of breathing. In 2006, there were only about 200 known cases worldwide. As of 2008, only 1000 total cases were known. [2] The diagnosis may be delayed because of variations in the severity of the manifestations or lack of awareness in the medical community, particularly in milder cases. [3] However, as there have been cases where asymptomatic family members also were found to have CCHS, it may be that these figures only reflect those found to require mechanical ventilation. In all cases, episodes of apnea occur in sleep, but in a few patients, at the most severe end of the spectrum, apnea also occurs while awake.
Although rare, cases of long-term untreated CCHS have been reported and are termed late onset CCHS (LO-CCHS). [4] There have, however, even been cases of LO-CCHS where family members found to have it have been asymptomatic. [5] Again, lack of awareness in the medical community may cause such a delay. [6] CCHS susceptibility is not known to be affected by sex or race. [3]
CHS is associated with respiratory arrests during sleep and, in some cases, to neuroblastoma (tumors of the sympathetic ganglia), Hirschsprung disease (partial agenesis of the enteric nervous system), [7] dysphagia (difficulty swallowing) and anomalies of the pupilla. Other symptoms include darkening of skin color from inadequate amounts of oxygen, drowsiness, fatigue, headaches, and an inability to sleep at night. Patients with CHS also have a sensitivity to sedatives and narcotics, which makes respiration even more difficult. A low concentration of oxygen in the red blood cells also may cause hypoxia-induced pulmonary vasoconstriction and pulmonary hypertension, culminating in cor pulmonale or a failure of the right side of the heart. [8] Associated complications may also include gastro-esophageal reflux, ophthalmologic issues, seizures, recurrent pneumonia, developmental delays, learning disabilities, episodes of fainting, and temperature disregulation. [9]
CHS is exhibited typically as a congenital disorder, but in rare circumstances, can also result from severe brain or spinal trauma or injury (such as after an automobile accident, stroke, asphyxiation, brain tumor, encephalitis, poisoning, as a complication of neurosurgery) or due to particular neurodegenerative conditions such as Parkinson's disease, multiple system atrophy, or multiple sclerosis. Long and Allen (1984) were the first to report the abnormal brainstem auditory-evoked responses in an alcoholic woman who recovered from Ondine's curse. These investigators hypothesized that their patient's brainstem was poisoned—not destroyed—by her chronic alcoholism. [10]
Medical investigation of patients with this syndrome has led to a deeper understanding of how the body and brain regulate breathing on a molecular level. PHOX2B, a transcription factor involved in the development of neurons, [11] can be associated with this condition. [12] [13] [14] [15] This homeobox gene is important for the normal development of the autonomic nervous system. [16]
The disease used to be classified as a "neurocristopathy", [17] [18] or disease of the neural crest because part of the autonomic nervous system (such as sympathetic ganglia) derives from the neural crest. However, this denomination is no longer favored because essential neurons of the autonomic nervous system, including those that underlie the defining symptom of the disease (respiratory arrests), are derived from the neural tube (the medulla), not from the neural crest, which may be the case in other mixed embryological origins and neurocristopathies. [19]
Children with CCHS develop life-threatening episodes of apnea with cyanosis, usually in the first months of life. Medical evaluation excludes lesions of the brain, heart, and lungs but demonstrates impaired responses to build-up of carbon dioxide (hypercapnia) and decreases of oxygen in the circulation (hypoxia), the two strongest stimuli to increase breathing rate.[ citation needed ]
Polysomnography shows that hypoventilation is most marked during slow-wave sleep. Specifically, infants with CCHS usually display lower tidal volumes during sleep, meaning they inhale less air during a normal breath [20] . In the most severe cases, hypoventilation is present during other nonrapid eye movement sleep stages and even wakefulness. A subset of CCHS patients are at very high risk for developing malignant neural crest-derived tumors, such as neuroblastoma.
Sequencing of the gene PHOX2B revealed mutations in 91% of the cases within a French cohort. [7]
Physicians unable to recognize the disorder should seek help from a neurologist and a pulmonologist. In some locations, such as France, optimal management of patients, once identified, has been aided by the creation of a national registry and the formation of a network of centers.[ citation needed ]
People generally require tracheostomy and lifetime mechanical ventilation on a ventilator in order to survive. However, it has now been shown that biphasic cuirass ventilation can effectively be used without the need for a tracheotomy. Other potential treatments for CCHS include oxygen therapy and medicine for stimulating the respiratory system. Currently, problems arise with the extended use of ventilators, including fatal infections and pneumonia. [21]
There are two primary organisations focused on delivering new treatments for CCHS. These are Keep Me Breathing, a UK based research charity which focuses solely on CCHS and The CCHS Network, a US based research charity which focuses the vast majority of its funding on CCHS scientific research.
Most people with CCHS (unless they have the Late Onset form) do not survive infancy, unless they receive ventilatory assistance during sleep. An alternative to a mechanical ventilator is diaphragm pacing. [22]
CCHS was first described in 1962 by Severinghaus and Mitchell in three patients following surgery to the upper cervical spinal cord and brainstem. [23]
Its name is a reference to the story of Ondine and Hans, characters in Ondine, a 1938 play by Jean Giraudoux based on traditions tracing back through Undine (a novella of 1811) to earlier European folk tales. The water-spirit Ondine tells her future husband Hans, whom she had just met, that "I shall be the shoes of your feet ... I shall be the breath of your lungs". Ondine reluctantly makes a pact with her uncle the King of the Ondines that if Hans ever deceives her he will die. After their honeymoon, Hans is reunited with his first love Princess Bertha. Ondine leaves Hans in an attempt to protect him, but she is recaptured by a fisherman and Hans is stricken by the King's curse. On meeting Ondine again, Hans tells her that "all the things my body once did by itself, it does now only by special order ... A single moment of inattention and I forget to breathe". Hans and Ondine kiss, after which he dies.
Since being coined in 1962 the name has become controversial in medical literature, as later summaries frequently misunderstood the plot of Ondine and its connection to the diagnosis. Most frequently, Ondine was inaccurately blamed for cursing Hans, but other mistakes sometimes changed the nature of the curse itself. Such errors led to confusion in defining the medical condition. [24]
Sleep apnea is a sleep-related breathing disorder in which repetitive pauses in breathing, periods of shallow breathing, or collapse of the upper airway during sleep results in poor ventilation and sleep disruption. Each pause in breathing can last for a few seconds to a few minutes and occurs many times a night. A choking or snorting sound may occur as breathing resumes. Common symptoms include daytime sleepiness, snoring, and non restorative sleep despite adequate sleep time. Because the disorder disrupts normal sleep, those affected may experience sleepiness or feel tired during the day. It is often a chronic condition.
In neurology, the Chiari malformation is a structural defect in the cerebellum, characterized by a downward displacement of one or both cerebellar tonsils through the foramen magnum.
Obesity hypoventilation syndrome (OHS) is a condition in which severely overweight people fail to breathe rapidly or deeply enough, resulting in low oxygen levels and high blood carbon dioxide (CO2) levels. The syndrome is often associated with obstructive sleep apnea (OSA), which causes periods of absent or reduced breathing in sleep, resulting in many partial awakenings during the night and sleepiness during the day. The disease puts strain on the heart, which may lead to heart failure and leg swelling.
Hypoventilation occurs when ventilation is inadequate to perform needed respiratory gas exchange. By definition it causes an increased concentration of carbon dioxide (hypercapnia) and respiratory acidosis. Hypoventilation is not synonymous with respiratory arrest, in which breathing ceases entirely and death occurs within minutes due to hypoxia and leads rapidly into complete anoxia, although both are medical emergencies. Hypoventilation can be considered a precursor to hypoxia and its lethality is attributed to hypoxia with carbon dioxide toxicity.
Macroglossia is the medical term for an unusually large tongue. Severe enlargement of the tongue can cause cosmetic and functional difficulties in speaking, eating, swallowing and sleeping. Macroglossia is uncommon, and usually occurs in children. There are many causes. Treatment depends upon the exact cause.
Obstructive sleep apnea (OSA) is the most common sleep-related breathing disorder and is characterized by recurrent episodes of complete or partial obstruction of the upper airway leading to reduced or absent breathing during sleep. These episodes are termed "apneas" with complete or near-complete cessation of breathing, or "hypopneas" when the reduction in breathing is partial. In either case, a fall in blood oxygen saturation, a disruption in sleep, or both, may result. A high frequency of apneas or hypopneas during sleep may interfere with the quality of sleep, which – in combination with disturbances in blood oxygenation – is thought to contribute to negative consequences to health and quality of life. The terms obstructive sleep apnea syndrome (OSAS) or obstructive sleep apnea–hypopnea syndrome (OSAHS) may be used to refer to OSA when it is associated with symptoms during the daytime.
Agonal respiration, gasping respiration, or agonal breathing is a distinct and abnormal pattern of breathing and brainstem reflex characterized by gasping, labored breathing, and is accompanied by strange vocalizations and myoclonus. Possible causes include cerebral ischemia, hypoxia, or anoxia. Agonal breathing is an extremely serious medical sign requiring immediate medical attention, as the condition generally progresses to complete apnea and heralds death. The duration of agonal respiration can range from two breaths up to several hours of labored breathing.
Hypoxemia is an abnormally low level of oxygen in the blood. More specifically, it is oxygen deficiency in arterial blood. Hypoxemia is usually caused by pulmonary disease. Sometimes the concentration of oxygen in the air is decreased leading to hypoxemia.
The supine position means lying horizontally with the face and torso facing up, as opposed to the prone position, which is face down. When used in surgical procedures, it grants access to the peritoneal, thoracic and pericardial regions; as well as the head, neck and extremities.
Hypopnea is overly shallow breathing or an abnormally low respiratory rate. Hypopnea is typically defined by a decreased amount of air movement into the lungs and can cause hypoxemia It commonly is due to partial obstruction of the upper airway, but can also have neurological origins in central sleep apnea.
Paired-like homeobox 2b (PHOX2B), also known as neuroblastoma Phox (NBPhox), is a protein that in humans is encoded by the PHOX2B gene located on chromosome 4.
The International Classification of Sleep Disorders (ICSD) is "a primary diagnostic, epidemiological and coding resource for clinicians and researchers in the field of sleep and sleep medicine". The ICSD was produced by the American Academy of Sleep Medicine (AASM) in association with the European Sleep Research Society, the Japanese Society of Sleep Research, and the Latin American Sleep Society. The classification was developed as a revision and update of the Diagnostic Classification of Sleep and Arousal Disorders (DCSAD) that was produced by both the Association of Sleep Disorders Centers (ASDC) and the Association for the Psychophysiological Study of Sleep and was published in the journal Sleep in 1979. A second edition, called ICSD-2, was published by the AASM in 2005. The third edition, ICSD-3, was released by the AASM in 2014. A text revision of the third edition (ICSD-3-TR) was published in 2023 by the AASM.
Diaphragm pacing is the rhythmic application of electrical impulses to the diaphragm to provide artificial ventilatory support for respiratory failure or sleep apnea. Historically, this has been accomplished through the electrical stimulation of a phrenic nerve by an implanted receiver/electrode, though today an alternative option of attaching percutaneous wires to the diaphragm exists.
Rapid-onset obesity with hypothalamic dysregulation, hypoventilation, and autonomic dysregulation (ROHHAD) is a rare condition whose etiology is currently unknown. ROHHAD mainly affects the endocrine system and autonomic nervous system, but patients can exhibit a variety of signs. Patients present with both alveolar hypoventilation along with hypothalamic dysfunction, which distinguishes ROHHAD from congenital central hypoventilation syndrome (CCHS). ROHHAD is a rare disease, with only 100 reported cases worldwide thus far.
Central sleep apnea (CSA) or central sleep apnea syndrome (CSAS) is a sleep-related disorder in which the effort to breathe is diminished or absent, typically for 10 to 30 seconds either intermittently or in cycles, and is usually associated with a reduction in blood oxygen saturation. CSA is usually due to an instability in the body's feedback mechanisms that control respiration. Central sleep apnea can also be an indicator of Arnold–Chiari malformation.
Neurocristopathy is a diverse class of pathologies that may arise from defects in the development of tissues containing cells commonly derived from the embryonic neural crest cell lineage. The term was coined by Robert P. Bolande in 1974.
A sleep-related breathing disorder is a sleep disorder in which abnormalities in breathing occur during sleep that may or may not be present while awake. According to the International Classification of Sleep Disorders, sleep-related breathing disorders are classified as follows:
Classification of sleep disorders comprises systems for classifying medical disorders associated with sleep. Systems have changed, increasingly using technological discoveries to advance the understanding of sleep and recognition of sleep disorders.
Infantile apnea is a rare disease that is characterized by cessation of breathing in an infant for at least 20 seconds or a shorter respiratory pause that is associated with a slow heart rate, bluish discolouration of the skin, extreme paleness, gagging, choking and/or decreased muscle tone. Infantile apnea occurs in children under the age of one and it is more common in premature infants. Symptoms of infantile apnea occur most frequently during the rapid eye movement (REM) stage of sleep. The nature and severity of breathing problems in patients can be detected in a sleep study called a polysomnography which measures the brain waves, heartbeat, body movements and breathing of a patient overnight. Infantile apnea can be caused by developmental problems that result in an immature brainstem or it can be caused other medical conditions. As children grow and develop, infantile apnea usually does not persist. Infantile apnea may be related to some cases of sudden infant death syndrome (SIDS) however, the relationship between infantile apnea and SIDS is not known.
Athabaskan brainstem dysgenesis syndrome (ABDS) or Athabascan brainstem dysgenesis syndrome is an extremely rare genetic condition that affects the central nervous system's brainstem. It is characterized by a variety of varied traits, such as facial paresis, sensorineural deafness, congenital horizontal gaze palsy, central hypoventilation, and developmental delay.