Editing Sleep apnea (section)

=== Central sleep apnea ===
{{Main|Central sleep apnea}}
The diagnosis of CSA syndrome is made when the presence of at least 5 central apnea events occur per hour.<ref name="Roberts-2022">{{Cite journal |last1=Roberts |first1=Erin Grattan |last2=Raphelson |first2=Janna R. |last3=Orr |first3=Jeremy E. |last4=LaBuzetta |first4=Jamie Nicole |last5=Malhotra |first5=Atul |date=2022-07-01 |title=The Pathogenesis of Central and Complex Sleep Apnea |url=https://doi.org/10.1007/s11910-022-01199-2 |journal=Current Neurology and Neuroscience Reports |language=en |volume=22 |issue=7 |pages=405–412 |doi=10.1007/s11910-022-01199-2 |issn=1534-6293 |pmc=9239939 |pmid=35588042}}</ref> There are multiple mechanisms that drive the apnea events. In individuals with heart failure with Cheyne-Stokes respiration, the brain's respiratory control centers are imbalanced during sleep.<ref>{{cite journal |vauthors=Yumino D, Bradley TD |date=February 2008 |title=Central sleep apnea and Cheyne-Stokes respiration |journal=Proceedings of the American Thoracic Society |volume=5 |issue=2 |pages=226–36 |doi=10.1513/pats.200708-129MG |pmid=18250216}}</ref> This results in ventilatory instability, caused by chemoreceptors that are hyperresponsive to CO2 fluctuations in the blood, resulting in high respiratory drive that leads to apnea.<ref name="Roberts-2022" /> Another common mechanism that causes CSA is the loss of the brain's wakefulness drive to breathe.<ref name="Roberts-2022" />
[[File:CentralApnea.png|thumb|Screenshot of a PSG system showing a central apnea]]
CSA is organized into 6 individual syndromes: Cheyne-Stokes respiration, Complex sleep apnea, Primary CSA, High altitude periodic breathing, CSA from medication, CSA from comorbidity.<ref name="Roberts-2022" /> Like in OSA, nocturnal polysomnography is the mainstay of diagnosis for CSA.<ref name="Badr-2019"/> The degree of respiratory effort, measured by esophageal pressure or displacement of the thoracic or abdominal cavity, is an important distinguishing factor between OSA and CSA.<ref name="Badr-2019"/>

====Mixed apnea====
Some people with sleep apnea have a combination of both types; its prevalence ranges from 0.56% to 18%. The condition, also called treatment-emergent central apnea, is generally detected when obstructive sleep apnea is treated with CPAP and central sleep apnea emerges.<ref name="Badr-2019"/> The exact mechanism of the loss of central respiratory drive during sleep in OSA is unknown but is most likely related to incorrect settings of the CPAP treatment and other medical conditions the person has.<ref name= ComplexRev2014>{{cite journal | vauthors = Khan MT, Franco RA | title = Complex sleep apnea syndrome | journal = Sleep Disorders | volume = 2014 | pages = 1–6 | year = 2014 | pmid = 24693440 | pmc = 3945285 | doi = 10.1155/2014/798487 | doi-access = free }}</ref>