orofac pain. 2011 fall;25(4):291-7.
topical review: cluster headache and sleep-related breathing disorders.
bender sd.
abstract
this article reviews the existing literature of the common anatomic and physiologic aspects of cluster headache and sleep-related breathing disorders to point out evidence suggesting potential therapies beneficial for both maladies. a search of pubmed, as well as relevant textbooks, was conducted using the terms cluster, headache, sleep, apnea, pain, and chronobiology to find any previously published work that may connect the two disorders. relevant references in the literature were also investigated. as a group, cluster headache patients tend to have a higher incidence of sleep-related breathing disorders as compared to the noncluster headache population.

WHILE COMMONALITIES IN ANATOMY AND PHYSIOLOGY EXIST, ROBUST EVIDENCE LINKING THE TWO DISORDERS IS CURRENTLY LACKING. MANY PEOPLE ARE UNAWARE THAT THEY SUFFER WITH A SLEEP-RELATED BREATHING DISORDER. THE HIGH INCIDENCE OF THESE TWO DISORDERS OCCURRING TOGETHER SHOULD PROMPT THE CLINICIAN WHO TREATS CLUSTER HEADACHE PATIENTS TO BE ACUTELY AWARE THAT A YET UNDIAGNOSED SLEEP DISORDER MAY ALSO BE PRESENT.
pmid:22247924[pubmed]
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Cephalalgia. 2012 Apr;32(6):481-91.
Cluster headache and sleep, is there a connection? A review.
Barloese M, Jennum P, Knudsen S, Jensen R.
SourceDanish Headache Center, Denmark.

Abstract
PURPOSE OF REVIEW: Sleep and the chronobiological disease cluster headache are believed to be interconnected. Despite efforts, the precise nature of the relationship remains obscured. A better understanding of this relation may lead to more effective therapeutic regimes for patients suffering from this debilitating disease. This review aims to evaluate the existing literature on the subject of cluster headache and sleep. LATEST

FINDINGS: Several previous studies describe an association between episodic cluster headache and distinct macrostructural sleep phases. This association was not confirmed in a recent study of seven episodic cluster headache patients, but it was suggested that further studies into the correlation between cluster headache attacks and the microstructure of sleep are relevant. The connection between cluster headache and the hypocretins is currently under investigation.

SUMMARY: There is evidence in favour of an association between episodic cluster headache and REM sleep whereas no such relation to chronic cluster headache has been reported. Particular features in the microstructure of sleep and arousal mechanisms could play a role in the pathogenesis of cluster headache. Reports indicate that cluster headache and obstructive sleep apnoea are associated. Single cases show improvement upon treatment of sleep apnoea, but the causal relationship remains in question.

PMID:22407656[PubMed]

I truly believe that there is a greater-than-chance commonality between the two disorders, but for me, at least, successful treatment of the apnea has had no effect on the CH.

My brother just got a CPAP machine for apnoea which meant shearing off a 35yo beard.

None of us recognised him and we ignored him completely down the pub.

Well, I don't actually have sleep apnea, so my neuro said going to a sleep clinic is probably not going to be helpful as they are geared toward that issue.  I do have terrible trouble staying asleep.  I fall asleep w/ no issue, but wake several time at night.  It's been this way since I was a kid.  I've tried not eating/drinking, taking sleeping pills (knocks me out but doesn't keep me asleep) and continue to take melatonin.
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it's been an ongoing battle... still working it out!

Good question!  One I don't have a great answer for. I was under the impression that sleep apnea was the disruption of sleep due a pause in breathing or weak breathing....  and having a sudden waking episode.  From what I hear (from people who have shared my bed ) - i'm not a snorer, nor do I exhibit those "typical" sleep apnea characteristics of violent breathing and gaps in breath.

But now that you've posed the question, I can't really say unless I go to get tested.  It's on the list.

From what my sleep doctor told me, my apnea will slow the o2 flow and my brain wakes up, but my body stays asleep and I can never tell that it had happened. What this does is keep me from reaching REM sleep stage so I can sleep all night and then wake up exhausted. I was put on a CPAP over a year ago and then stopped using it because it would wake me up in the middle of the night, so I would take it off and go back to sleep. I was also diagnosed with Hypersomnia (excessive daytime sleepiness) from a daytime sleep study.

I was then diagnosed with cluster headaches and was told to start using my CPAP regularly. So I did. Then my CH got really bad. So here's my theory: As long as I wasn't using my CPAP, my CHs weren't that bad, but once I got back into the REM sleep, they got bad again. From what I understand, there's a correlation between the REM sleep and CHs. So what I'm getting at is that my apnea may actually be preventing the nighttime attacks. I'm no Dr, but that's just what I've noticed.