"We don't know what causes Central Apnea."

A sleep doctor recently told me that the medical community really doesn't know what causes Central Apnea.
I understand that an ASV machine is the likely solution to treat Centrals. My Doctor stated that a pattern of events suggests either a mask leak or a full face issue. One week ago he increased my pressure from 8 to 10 and wants to see what happens to the index. It appears that I'll need to be retested, since the Centrals are persisting at 10.

Clear Airways on recent nights: 8.41 / 7.22 / 4.82 / 3.27 / 2.72 / 5.76 / 7.40

I was able to find some possible causes of central apnea (listed below), but none of those conditions seem to apply to me, or at least I don't think any of them apply.

I'd be interested in learning from others who have really studied Central Apnea to find out more.

Thank you.

-Chuck-


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http://www.nlm.nih.gov/medlineplus/ency ... 003997.htm

Central sleep apnea often occurs in people who have certain medical conditions. For example, it can develop in persons who have life-threatening problems with the brainstem, which controls breathing.
Conditions that can cause or lead to central sleep apnea include:
Arthritis and degenerative changes in the cervical spine or the base of the skull
Bulbar poliomyelitis
Complications of cervical spine surgery
Encephalitis affecting the brainstem
Neurodegenerative illnesses such as Parkinson's disease
Obesity
Radiation of the cervical spine
Stroke affecting the brainstem
Primary hypoventilation syndrome
Use of certain medications such as narcotic-containing painkillers
A form of central sleep apnea commonly occurs in people with congestive heart failure.
If the apnea is not associated with another disease, it is called idiopathic central sleep apnea.
Central sleep apnea is not the same as obstructive sleep apnea, which is due to a blockage in the airway.
A condition called Cheyne-Stokes respiration can mimic central sleep apnea. This involves breathing to a variable depth, usually while sleeping.

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OTHER CAUSES OF CENTRAL SLEEP APNEAS.
--There are many other causes of central apneas that are less common--many of which can also cause inadequate depth of breathing (hypoventilation) during sleep. The following examples arise from damage to either the nervous system's breathing control mechanisms or inadequate function of the muscles used for breathing. A number of these disorders may involve elevations in blood carbon dioxide tensions with failure of the patient's breathing drive to respond normally to such build-ups in carbon dioxide levels.
Brainstem tumors, strokes, encephalitis and malformations such as Arnold-Chiari syndrome, Leigh's syndrome, multiple sclerosis.
Autonomic ("automatic") nervous system dysfunction--for example, in Shy Drager syndrome, Riley-Day syndrome and diabetic autonomic neuropathy.
Phrenic nerve palsies (damage to the nerves that activate the diaphragms).
Post-polio syndrome, amyotrophic lateral sclerosis (ALS), myasthenia gravis and Duchenne's muscular dystrophy.
--Treatment of these other causes must be tailored to the individual patient.

Central apneas occur for a variety of reasons. Some central-apnea types are fairly well understood by medicine, but others are not. Idiopathic central apneas are generally of unknown origins. CompSAS, as a central-apnea type, is not completely understood.

See the sections called VENTILATORY CONTROL STABILITY as well as CENTRAL SLEEP APNEA PATHOGENESIS in this document to help formulate an idea of what can happen in physiology to cause central apneas:
http://ajrccm.atsjournals.org/content/172/11/1363.full

Bear in mind central apneas in low numbers are innocuous and occur in the "normal" population (non-SDB population).

How low would those low numbers need to be?

I started to get diabetes so I wonder if it is related- I've had some tingling/pain in the feet. I've also read that GERD or gastro esophogeal reflux disease may be a cause so I've been trying nexium/zantac but I'm still having problems using the ASV. the resmed model seems to be too sensitive for me, the pressure keeps shooting up to 20cm so I think I'm going to try a max PS setting that puts the IPAP at 16cm instead.
I slept 9 hours finally on the ASV at max IPAP 20cm and still don't feel well with the mirage quattro mask- I think the fit life mask may be better
I don't really understand isn't even 12cm enough to open your airway and give your body oxygen, why would I need 20cm?

chunkyfrog wrote:How low would those low numbers need to be?

-SWS may not have seen your question. Or JohnBFisher. So I'll give my take, for what it is worth. (Certainly not worth as much as their takes, either of them; but I'll throw in another link to try to make up for that. )

My answer would be: Depends. Does the person have symptoms indicating sleep is being affected? Is O2 saturation affected for long periods? Is the person's AHI over 5? Are 50% of the events centrals? Etc.

Some people just "naturally" tend to have unstable breathing at sleep onset or in conjunction with arousals or at shifts in their sleep stages. A person like that who has to take a breathing-affecting medication or who has a particularly bad set of nights of restless sleep or who sleeps at a higher-than-usual-for-him altitude may see a lot of "centrals" (or, technically, open-airway apneas) show up on a home machine's estimates for a few nights, for example. That may not likely mean the person needs a special machine. On the other hand, if a person suddenly has a noticeable increase in central apneas for no apparent reason and that increase persists, it is certainly worth mentioning to a doc, in my opinion, just like any other unexplained change in an important body function.

It is a nebulous area, I think. But I like this overview from a few years back almost as much as I like -SWS' link that he gave above:

http://chestjournal.chestpubs.org/conte ... 2/595.full

Seeing as many of the potential causes being with 'cervical', and seeing as probably the majority of us are .. seniors, would it be that unlikely if there was a connection to regular old degenerative discs and/or spinal cord issues?

Ah, Jeff... I did miss chunkyfrog's post. Thanks for chiming in!

-SWS wrote:Ah, Jeff... I did miss chunkyfrog's post. Thanks for chiming in!

I figured.

Feel free to correct or redirect my answer.

As SWS noted, in some instances doctors added researchers well understand the cause of central apnea. in my own instance the cause is well understood .. I have a neuro degenerative disorder. That is, over time something unknown is causing me to loose neurons in my cerebellum and brainstem area. They do not know the cause of the degeneration but the process has been observed by the impact to many "automatic" neurological functions, such as swallowing or my eyes tracking moving objects or my eyes at rest out my eyes looking upward or my central apnea. In my specific case, it is as if there was aasky scraper that was slowly but surely losing rivers and sometimes even girders from its structure. While the process might last aalong time, eventually the building will be compromised. complete collapse is then possible unless as part of the process other structural members can be made too pick up the load. This neuro plasticity (the ability to repurpose neurons) is just one of the reasons researchers shop not fully understand the full process. even with neuron loss, the system continues to function.

By the way, the original poster would do well to search for Rested Gal's "Links to Central Apnea". That post provides aagreat deal of background information.

JohnBFisher wrote: . . . Rested Gal's "Links to Central Apnea". . . .

viewtopic.php?p=22702

I think the O2 sat number may be the most important and anything below 92 may be bad

wow that is terrible to have a degenerative disease. I hope that you can see many specialists with your insurance Mr. Fisher.
I've been reading some articles that say that GERD can cause apneas and that you can treat it by elevating the head and taking meds like nexium/zantac or gaviscon. I take klonopin and there are some smaller studies that say it reduces central apnea. I also take HC suppositories and it seems to improve my breathing at 25mg. I am trying taking zantac right before bed with nexium. I also have started to have swallowing problems.

You should get an MRI and a full check up by a neurologist.

Thank you for all of the great information provided. -Chuck-

Julie wrote:Seeing as many of the potential causes being with 'cervical', and seeing as probably the majority of us are .. seniors, would it be that unlikely if there was a connection to regular old degenerative discs and/or spinal cord issues?

In my non-pro opinion as your average youngish patient, I would think degenerative-disc conditions would be more likely to cause pain issues that would create breathing pauses than it would be for any wear-and-tear-type skeletal problems to create the sort of nerve-communication disruptions that would "cause" true central apnea. I think that something severe enough to create spinal-cord issues of that nature, even from cervical trauma, would tend to have multiple manifestations, not just central apneas.

Little more than a guess on my part, though.

-SWS? John? Uncle Dave?

(Actually I have NO idea what I'm talking about. I'm just trying to lure the knowledgeable posters back in . . . )

It is good to see the scientists using the term "idiopathic" when they just don't know.
It beats blaming the syndrome on old age, menopause, or a personality defect.
More research is definitely indicated--to assign causes (and hopefully, solutions) to more of these cases.

chunkyfrog wrote:How low would those low numbers need to be?

Generally subclinical is an overall AHI under 5. However, there are still reputable sleep doctors and researchers who think an AHI between say 5 and 10 (the "grey zone") can be unassociated with both symptoms and pathology. So I think the answer "it depends" is probably right.

However, I think it's worth noting that those AHI cutoffs for clinical versus subclinical are PSG scores rather than home xPAP machine scores. Our home machines can prolifically score apneas and hypopneas that are related to awakenings and arousals---many of which would not qualify as apneas, hypopneas, or sleep-disordered breathing. The first thing any CPAP user should do when they see a smattering of central apneas in their CPAP data, is question whether the data reflects true central apneas or just poor quality of sleep----with the latter often entailing false-positive central apnea scores on home machines. Home machines lack multiple PSG data channels for proper scoring. They cannot measure EEG-scored wake versus sleep, for instance. Nor can they measure lacking respiratory effort.

Julie wrote: Seeing as many of the potential causes being with 'cervical', and seeing as probably the majority of us are .. seniors, would it be that unlikely if there was a connection to regular old degenerative discs and/or spinal cord issues?

Apparently your take is true, Julie:

Conditions that can cause or lead to central sleep apnea include:
• Arthritis and degenerative changes in the cervical spine or the base of the skull
•Bulbar poliomyelitis
•Complications of cervical spine surgery
•Encephalitis affecting the brainstem
•Neurodegenerative illnesses such as Parkinson's disease
•Obesity
•Radiation of the cervical spine
•Stroke affecting the brainstem
•Primary hypoventilation syndrome
•Use of certain medications such as narcotic-containing painkillers

http://www.nlm.nih.gov/medlineplus/ency ... 003997.htm

I didn't know that! And I have arthritis in my neck. Good to know!!