Biphasic sleep patterns

[Jamesmsv]

Came across an interesting fact that I've never seen mentioned in relation to cluster headaches - our apparent natural "biphasic" sleep pattern which was common up until the industrial revolution. It varied across populations but in this particular article is referred to as:

"between 9 and 10pm, slept for 3 to 3 ½ hours during their “first sleep,” awakened after midnight for an hour or so, during which individuals did practically anything and everything imaginable before taking a “second sleep,” roughly until dawn."

https://www.news-medical.net/news/20170517/History-of-sleep-what-was-normal.aspx

This just so happens to coincide with the 1am wake cycle most CH suffers experience. When at the peak of my worst cycles I also commonly get 9-10pm and 6-7am attacks, which slot in nicely to the start and end of the bi-phasic sleep period. 

It appears through a study in the 1990s that this may be the most natural sleep/wake cycle for our brains (see https://en.wikipedia.org/wiki/Thomas_Wehr)

I find it hard to believe that this is just a coincidence. Has anyone else come across this aspect of sleep behaviour in relation to CH? It may be a piece of the puzzle as it is very much governed by melatonin from what I've read so far. 

[CHfather]

Fascinating

 

[jon019]

...i find it def sleep related...but kinda opposite here....which tells me same ballpark! ungoverned would sleep 16-20 hrs straight....always a fight not to exceed 10-12 (especially escaping pain) now. CH was a literal nightmare screwing endlessly with sleep. wonky hypothalamus fer sure....

...thank you...i second "Fascinating"!

[Jamesmsv]

It's the 1am-ish part that niggles at me. As far as I'm aware ( please correct me if i'm wrong) there has been no satisfactory explanation for the 1am phenomenon which, in my opinion, is probably one of the most common symptoms of all CH sufferers. My wife is often still awake at that sort of time and is astounded when I'm in a deep, snoring sleep and go from complete stillness to suddenly sitting up at 12:58am clutching my head. 

This biphasic theory suggests there is a part of our circadian rhythm that wants us awake circa 1am. Surely there's a connection to be made; I hope there is a neurologist specialising in both sleep and cluster headaches out there who latches on to this. 

Ideally - and this is obviously a very unlikely scenario - we need to find a CH sufferer who is desperate enough and flexible enough to switch to a bi-phasic sleep pattern for a minimum of 2 years to see if it helps. Any takers?  

[CHfather]

On 1/15/2025 at 7:00 AM, Jamesmsv said:

It's the 1am-ish part that niggles at me. As far as I'm aware ( please correct me if i'm wrong) there has been no satisfactory explanation for the 1am phenomenon which, in my opinion, is probably one of the most common symptoms of all CH sufferers.

I suppose "satisfactory" is the key word in what you wrote.  Certainly there have been possible explanations offered, particularly with regard to REM sleep (Exploring the Connection Between Sleep and Cluster Headache: A Narrative Review - PMC).  

According to one study (attached here), 2am is the most common time for attacks, but midnight, 1, and 3 are right up there. (Rather than a specific time, it's probably more accurate to say ~90 minutes after falling asleep.)  (At least as far as I can tell, the attached study actually tells us almost nothing, since of course people get multiple attacks and they all are counted here.) However, as many as 25 percent of people with CH don't get nighttime attacks, and the number of reported attacks (in the study) at 2pm and 3pm (outside the time range of your theory) isn't all that much lower than the number at midnight or 1am.

On 1/15/2025 at 7:00 AM, Jamesmsv said:

This biphasic theory suggests there is a part of our circadian rhythm that wants us awake circa 1am.

Well, but why would it want people to be awake and experiencing excruciating pain, or use excruciating pain to wake them?  And why, if maybe we all, or most of us, have a biphasic instinct wired into our brains, are so few people afflicted with CH (or just generally, why do so few people wake up, with or without pain, at those early-morning hours, or ~90 minutes after falling asleep)?  And why does a daytime nap so often bring on an attack?  These questions are not to dismiss your idea, which I think could be part of the puzzle, but to say that there are surely more complex things going on and to agree with you that it would be nice if there were "a neurologist specialising in both sleep and cluster headaches out there who latches on to this."

On 1/15/2025 at 7:00 AM, Jamesmsv said:

we need to find a CH sufferer who is desperate enough and flexible enough to switch to a bi-phasic sleep pattern for a minimum of 2 years to see if it helps.

Of course, there are whole cultures that have a biphasic sleep pattern, though not exactly the kind you have been referring to. A siesta in the afternoon along with some nighttime sleep (usually less than 8 hours) is pretty common in many Latin American and European countries.  I guess someone could look at CH incidence among those populations.

 

Rozen - Cluster_Headache_in_USA-2.pdf