Many of the studies I've come across list cpap as the treatment of choice for idiopathic central sleep apnea although they really don't know why such as this review in Chest:

Chest wrote:

Nasal CPAP has been shown to be effective in some patients with ICSA.[98] [99] The mechanism for improvement in these patients is not clear but may relate to prevention of inhibitory reflex mechanisms that arise during airway closure and potentially CPAP-induced increases in lung volume/O2 stores.

Another review of current treatments (O2, acetazolimide, theophylline, cpap, bipap) finds research supporting adaptive pressure support servo-ventilation (ASV) as having better clinical results and compliance for CSA than bipap:

Sleep Medicine Clinics wrote:

Overall compliance was significantly better with ASV than with CPAP, which decreased over time to less than 4 hours per night. Improved adherence to ASV may be attributed to the bilevel effect of pressure adjustments during respiratory cycles, but it also may reflect the overall effectiveness of treatment [60]. ASV also resulted in a statistically significant increase of 7% in LVEF; no such benefit was observed with CPAP. This lack of cardiovascular improvement with CPAP is in contrast to findings of multiple other studies reviewed earlier in this paper and may be explained by the lower overall airway pressure achieved.

Yes, cpap is used as a treatment of central apneas (more of a prevention than a cure).  However, the technology I referred to is considered an "appropriate response" to central apnea and not a treatment considering the limitations of cpap.

References:

Eckert, D.J. Central sleep apnea: Pathophysiology and treatment. Chest - 01-FEB-2007; 131(2): 595-607

Connolly, T.A. Sleep-Related Breathing Disorder and Heart Disease--Central Sleep Apnea. Sleep Medicine Clin - March 2007; 2(1); 107-117


_________________
my cpap: resmed s8 autoset vantage
my mask: resmed mirage quattro

manuel,

I basically agree with everything you say/quote.

For our purposed here there are basically two types of central apnea (CA), primary central apnea where the only cause of loss of breathing is because the brain is not telling the body to breath, and as secondary central apnea where CA is not the primary cause of loss of breathing, but idiopathic (cause unknown) and secondary to other sleep disturbances - obstructive apneas, hypopneas, etc.

With primary CA standard CPAPs/BiPAPs are relatively useless because primary CA cannot be treated by increasing therapy pressure, it must be treated by rhythmic stimulation.  

With idiopathic CA the cause needs to be determined and treated.

I use myself as an example. Whether this applies to others with the same problem, I don't know but I would guess it probably does to some degree.

On standard CPAP at my titrated pressure I experience central apneas. Even during my last sleep study, under direct monitoring, I experienced central apneas. The CAs are induced by too much pressure, but not by the pressure alone, but as a result of constant pressure for an extended period of time. After a while at the constant pressure the body's tissues become saturated with oxygen, causing CO2 to decrease and initiating central apneas.

Because my main sleep disturbance is obstructive apneas and hypopneas, I have solved this problem by using an APAP. By providing only the pressure necessary to suppress these disturbances as required, my tissues don't become saturated with O2 so no central apneas.

Since I started on APAP therapy over three months ago, I have not had a single central apnea. How do I know this since I'm using an APAP, which I stated in previous posts, couldn't handle central apneas? These machines CAN DETECT central apneas because an apnea is an apnea, but CAN'T DISTINGUISH between an obstructive and a central apnea. Because it can't distinguish between apneas, and can't handle CAs, whenever a CA happens it shows up as an "unresponsive" apnea. I have experienced no unresponsive apneas, therefore no CAs.

Basically this is what the study you’re referencing says.

Runningbare


_________________
I am an engineer not a doctor. All of my suggestions are from my own experience and not medical advice. All information should be discussed with your doctor before implementation.

Respironics M Series APAP w/C-Flex & heated humidifier & Optilife Mask

runningbare wrote:

These machines CAN DETECT central apneas because an apnea is an apnea, but CAN'T DISTINGUISH between an obstructive and a central apnea. Because it can't distinguish between apneas, and can't handle CAs, whenever a CA happens it shows up as an "unresponsive" apnea.

There's a commercially available (not sure about the US) cpap machine called the SOMNOsmart.  It utilizes a technology called FOT.  What does FOT do?  It sends a vibration through the cpap air flow which tells it whether the airway is closed (OSA) or if the airway is open (CSA).  The machine can take 2 courses of action depending of the state of the airway.  If the airway is closed and an apnea is detected, the machine will increase pressure to alleviate the obstruction.  If the airway is open and an apnea is detected it will do nothing.  A product brochure on the manufacturer's Web site describes the SOMNOsmart 2 as "for optimum differentiation of obstructive and central events."

Respiratory & Critical Care Medicine wrote:

During conventional CPAP titration, it may be difficult in some cases, particularly at intermediate and higher CPAP levels, to distinguish central events from those caused by residual obstruction. One advantage associated with the use of FOT is that it provides a clear distinction between obstructive and central events. In our patients there were relatively few central apneas observed during CPAP. However, in all cases central apneas occurred without increases in |Z|[|Z|=respiratory impedance]. The behavior of respiratory impedance was particularly interesting during the onset of REM sleep. Central hypopneas are common in this situation and may be misleading during the titration procedure. The |Z| tracing demonstrated that the majority of these nonapneic events during REM onset occurred without upper airway obstruction, indicating that CPAP would not need to be increased.

I'm afraid 10 years from now, after all cpaps on the market have this technology, cpaps will still have the notorious distinction for their inability to distinguish obstructive and central apneas.


References:

Badia, J.R. et al. Clinical Application of the Forced Oscillation Technique for CPAP Titration in the Sleep Apnea/Hypopnea Syndrome. Am. J. Respir. Crit. Care Med., Volume 160, Number 5, November 1999, 1550-1554

Randerath, W.J. et al. Autoadjusting CPAP Therapy Based on Impedance Efficacy, Compliance and Acceptance. Am. J. Respir. Crit. Care Med., Volume 163, Number 3, March 2001, 652-657


_________________
my cpap: resmed s8 autoset vantage
my mask: resmed mirage quattro