Perpetual, Shifting Jet Lag: Non-24-Hour Sleep-Wake Syndrome and Corollary Discharge
Submitted by AnnaM on Tue, 04/17/2007 - 1:58am.
The United States (and much of the rest of the world) times work and school days in relation to the 24 hour solar day. In order to be awake at socially acceptable times for work and school, then, a person's internal clock, or circadian rhythm, must also conform to the 24-hour day. Common thinking holds that cycles may vary considerably within that 24 hour framework- hence "night owls" and "morning people"- but no one can completely diverge from the 24 hour pattern.
Or can they? Today, psychiatrists and sleep specialists have identified many types of circadian rhythm disturbances and disorders. Some are relatively mild- jet lag following travel across time zones, for instance- and generally remedy themselves within a few days <a href="http://serendip.brynmawr.edu/exchange/#4">(4)</a> Others, however, are more debilitating. Possibly the most debilitating of all is non-24-hour sleep-wake syndrome. People with this disorder, instead of having a 24-hour circadian rhythm, have an internal clock that runs in cycles of 25 hours or more, which may or may not begin in alignment with the 24-hour day. The result (if the condition is left untreated) is a pattern known as free-running, where a person's sleep cycle shifts a few hours later each day, never settling consistently; this pattern makes school, regularly scheduled work, and other daily routines generally taken for granted very difficult <a href="http://serendip.brynmawr.edu/exchange/#4">(4)</a>. One source describes the pattern as "a state of perpetual, shifting jet lag" <a href="http://serendip.brynmawr.edu/exchange/#3">(3)</a>
People could easily question why this disorder is often so devastating. Maybe the concepts of 24 hour days and sleep disorders are purely socially constructed, they might say; why not simply allow for more flexible work and school schedules to reflect a diversity of circadian rhythm patterns? But while such changes could certainly be useful to non-24-hour sleep-wake syndrome patients, long-established social patterns are incredibly hard to deconstruct. So long as most of the world adheres to the 24-hour clock, and so long as the non-24-hour sleep-wake syndrome patient needs to interact with others not on their sleep cycle, all the flexible scheduling in the world cannot solve the problem. I became especially interested in non-24-hour sleep-wake syndrome after letting a friend of mine, who has the syndrome, stay with me on a night when he felt he was too impaired from sleeplessness to navigate public transit home. At roughly 8 PM, a time that should be early for most twenty-somethings, he could not walk twenty feet to my doorway without staggering. "I fail the sobriety test," he joked as he settled in for the night, but I thought his offhand remark was a striking analogy; he had consumed no alcohol that night, but an outside observer noting his age, his gait, and the time of night might automatically assume drunkenness rather than sleep deprivation.
It's also tempting to label non-24-hour sleep wake syndrome as an entirely biological disorder. Indeed, neurologists can now name many of the areas of the brain responsible for regulating circadian rhythms, and provide some explanations as to how those areas might be disrupted in those with non-24-hour sleep-wake syndrome. The most important area in these explanations is a pair of small cell clusters in the hypothalamus known as the superchiasmatic nucleus, or SCN. Photoreceptors in the retina receive sensory input of light and transmit this input through the optic nerve to the SCN, which uses the light cues to entrain, or "set," the person's biological clock <a href="http://serendip.brynmawr.edu/exchange/#2">(2)</a>. Since light comes and goes in 24 hour cycles as per the rotation of the Earth, it follows that human sleep-wake cycles, which depend on light cues, should also be roughly 24 hours long. The SCN also uses these light cues to regulate cycles of melatonin, a hormone produced in the pineal gland. In a person with normal sleep cycles, melatonin levels peak in the middle of the night, lowering throughout the day and rising as darkness begins again; shifting levels of melatonin are associated with overall shifts in sleep patterns <a href="http://serendip.brynmawr.edu/exchange/#2">(2)</a>. Using this model, one could interpret non-24-hour sleep-wake syndrome as an inability to process these light cues "normally," or as a reduced sensitivity to light cues. This inability or reduced sensitivit, then, encourages underproduction of melatonin at night and over-production during the day, resulting in unusually timed sleep cycles. However, there are undoubtedly institutions in society that encourage abnormal sleep patterns on some level, in addition to physical factors like melatonin problems. Consider American high schools which start at 7 or 7:30 in the morning, forcing students to wake up at 5 or 6. For much of the academic year, there is little natural light at 5 or 6 in the morning. This discrepancy between sensory input and alertness is hard enough on teenagers with normal circadian rhythms<a href="http://serendip.brynmawr.edu/exchange/#1">(1)</a>; for those with non-24-hour sleep-wake syndrome, it must be especially difficult to adjust to.
The best model for explaining non-24-hour sleep-wake syndrome then, I believe, is one based on the principle of corollary discharge. Corollary discharge, as we discussed in class, is a mechanism that allows humans to distinguish between internal and external sensorimotor input; discrepancies between sensory and motor inputs lead to various forms of discomfort. Explaining non-24-hour sleep wake syndrome in terms of corollary discharge problems emphasizes the complex relationships between biological and societal factors in the disorder. On one level, the discrepancy between non-24-hour sleep-wake syndrome sufferers' internal melatonin levels and outside light cues surely plays a role in creating their irregular sleep patterns. This biological explanation also explains why blind people tend to have non-24-hour sleep-wake syndrome at far higher rates than sighted people; since they take in no light through the retina, the SCN cannot register light cues, which in turn inhibits its ability to regulate the pineal gland's melatonin release cycles <a href="http://serendip.brynmawr.edu/exchange/#3">(3)</a>. But institutions with rigid, early start times, like some jobs or schools, also create corollary discharge problems, since they force people to be awake at times when light cues and melatonin cycles would otherwise indicate the need for sleep <a href="http://serendip.brynmawr.edu/exchange/#1">(1)</a>. This discharge explains why shift workers, who may alternate between very early and very late work hours, often have disrupted sleep patterns (although they will rarely have true non-24-hour sleep-wake syndrome, which is a very rare condition.)
Non-24-hour sleep wake syndrome cannot be cured, only controlled. It's interesting to note, though, that common methods of controlling the condition attack both the biological and the social underpinnings. To regulate internal circadian rhythms, non-24-hour sleep-wake syndrome patients can take melatonin supplements before bed, bringing their nighttime melatonin levels up to "normal" and, hopefully, encouraging sleep at socially acceptable hours. In addition, sighted patients may use light therapy: exposure to a bright, full-spectrum light early in the day, in an attempt to mimic the bright light of the afternoon hours when the person might naturally wake up <a href="http://serendip.brynmawr.edu/exchange/#4">(4)</a>. But social factors, like career choice, can also help in the management of the disorder; having a job where one can work from home and choose one's own hours makes the erratic sleep schedule a bit less problematic.
This disorder is a perfect illustration of why it is problematic to claim that disabilities are entirely biologically based or entirely socially constructed. Claiming biological basis alone completely ignores the fact that institutions like high school may aggravate existing disorders. But claiming only social construction leaves little room for interventions based in biology, such as attempts to alter melatonin cycles in non-24-hour sleep-wake patients; while fighting to change the social bases of the disorder is certainly admirable, there's no denying that it cannot produce the immediate effects of melatonin or light therapy. Balance between these two aspects of the disorder seems to be the key; hopefully, medical professionals and social scientists working together can help to shed more light on this condition, as it were.
Web Sources
1. "High School Start Times Deprive Teens of Sleep, Affect Academic Performance"
http://www.medicalnewstoday.com/medicalnews.php?newsid=2568
2. "Information About Sleep."
http://science.education.nih.gov/supplements/nih3/sleep/guide/info-sleep.htm
3. "Pathophysiology and Treatment of Circadian Rhythm Sleep Disorders"
http://www.medscape.com/viewarticle/465494_30
4. Sleep Disorder Primer
http://health.discovery.com/centers/sleepdreams/sleepdisorders/sleepdisorders.html#3
I saw the information about
I saw the information about this on wikipedia accidentally the other day and I noticed this is exactly the problem I’m facing. It has brought great problems to my life in the past few years cause I keep having sleeping time that delays every night and wake up later and later everyday. It gave me great trouble for going to school everyday on time.
I don’t really know if I should go for a doctor cause it’s such a rare condition that probably no one is gonna believe me... I tried to explain this to my family but they don’t seem to take it at all…
Anyway, thanks for posting this article, it explains many things in details. :)
you know, of all the stuff
you know, of all the stuff on n-24 on the internet I have read, this paper is by far the most accurate as far as capturing what n-24 is like and how devastating it is. Just to say "I dont have a 24 hour schedule" doesnt capture it at all... but you seem to know that and your paper reflects it. People think sleep problems are minor, or that it just takes willpower and scheduling manipulation (i.e. of work or school) to live a normal life... maybe that is true with other sleep disorders, I really dont know, but with n-24 no one can really understand how life-altering and devastating it can be. Willpower can't do it. Medication can't do it. And no one who is on a normal schedule naturally understands how set in stone the 24hour day is... if you deviate, you're basically s.o.l.
To the commenter above... Rita, good luck. You very well might have a problem finding a good doctor if you really do have n-24 (pray you dont!) because almost none of them seem to know about this disease. I have had a hell of a time even getting them to really understand what my symptoms are, they are so unused to seeing this.
Why should I be forced to
Why should I be forced to take personality-changing medication just to fit in with a socially imposed expectation of how I should fit in with the rest of society. The stopped "medicating" gay people decades ago in most countries. You wouldn't medicate somebody who didn't have blue eyes just to force them to fit the norm. I've been through two breakdowns medicating my body trying to force it to follow a 24-hour clock. I have been healthy and happy for the last three years since I just followed my normal body clock, but now am having my social security removed from me because I "refuse" to turn up at their god-ordained times for interview.
what a relief
I've been fighting this my whole life. Choosing to take temporary jobs and often struggling to pull off all-nighters just to try to skip the part of the cycle that would make me sleep through normal work hours.
I've never been able to keep a regular job and have been forced to miss countless important social events simply because my clock is off.
Many times over the years I have made the off handed comment to friends: 'It's weird, I sleep 8 hours like anyone else but my body thinks there is 26 hours in a day... so every day I go to bed just a little bit later. next thing I know I'm sleeping form 9 am to 5 pm'
I accidentally happened across this site (and others) while doing a search on 'exhaustion' trying to figure out some things. I can't put into words what a huge relief to know this is a documented and un-curable disorder and to know that I can finally give up my 15+ year struggle and focus on changing my lifestyle rather than continuing to try to change myself.
I'm not terribly excited by the idea that I'll be limited to 'work from home' jobs but it's not far off from what I've already been doing all these years and my sanity is well worth it.
Thank you very much for the article. this revelation is certainly one of the life-changing variety.
Circadian rhythm disorder
Anna,
I am 35 years old and my day is about 30 Hours. I must wait until I feel sleepy before going to bed or I will not sleep at all. If I allow myself to go approximately twenty hours and then sleep ten I stay rested and have no problems. My sleeping area must be completely blacked out as any light will bring me to an awakened state. I have gone as long as 4 to 6 days with Insomnia when I have tried to hold myself to a 24 hour clock. My sleeping only becomes a problem when I have to do something that requires me to not hold to this approximately 30 Hr day. When my 30 Hour day gets messed up it takes me 2-3 days to get it back in sequence. If I fight it I can get to a 26-27 hour day for awhile but it really messes me up and I become sleep deprived and almost schizophrenic in behavior. In fact my psychiatrist calls me borderline schizo affective. However if I keep to my personal bilogical clock, get my 10 hours sleep, I have no problems with my thinking. Needless to say, no one has an answer on how to put me in line with society. No medication has really changed my clock other than flat knocking me out. I am constantly seeking to understand this "disorder". Your Blog has been the closest to describing me that I have run into except that my 2-3 days a week of being awake during normal daylight hours don't seem to make a difference in light getting to my SCN. The bottom line is what you stated. It is very difficult for me to hold a job. It is also difficult to make and keep friends.
Thanks for trying to find an answer for us. If you want to know anything else just drop me a line.
Sincerely,
David
I am 55 years old and have
I am 55 years old and have been planning to go to a 30 hour day as soon as I retire. I do not believe I could make this schedule work while employed. I am so happy to know that I am not the only person that suffers from this. About 4 years ago, I started having "spells" were I would completely space out. I could not make my mouth work to say what I was thinking. But it would be extremely difficult to stay aware of what was going on around me. I could come back for a few seconds and then I would be gone again. After 2 years of testing. and repeat testing and repeat again testing. The thought was that I must be having a seizure of some kind. I'm now taking medication for seizures and have not had a complete spell since. At the time the doctor said that sleep depravation can cause seizures. My husband died 6 months ago. Since then I have been having a lot of trouble getting to bed. When I get to bed I can sleep. I just cannot get to bed.
And Now I see again how easy it would be to slip into a 30 hour cycle. What I do not understand from the explanation above is Why do we have to treat this? Not everyone is the same every one is different. Not every one has a normal temperature of 98.6. We do not treat people whose normal is lower or higher that 98.6. We do not make their bodies stay at 98.6. Why are people talking about treating this? If this is our normal why cannot we just keep it that way. It seems to me by making me conform to a 24 hour day is what has caused my health problems.
Thanks for describing the effect of N24
Most of my student-years have been affected by N24 and most of the people around me consider it as some sort of an excuse :-) .
i know for sure this is what
i know for sure this is what i have and been dealing with for years, its incredibly hard to keep a normal job that requiers you to be alert and focused ( every job that isn't done from home ) i can't explain why i'm not in sync with are solar system all i can say is i need to fix this problem or i will never have the life i want and i'm capable of living. i'm gonna go to a sleep clinic here in Vancouver Canada, and hopefully fix this or live with my parents forever broke as fuck.
if your rich its fine, but
if your rich its fine, but if you need to make money its a serious problem. and sleep deprevation can cause temporary insanity, loss of logic and common sense aswell as the ability to think clearly and protect yourself.
what about kids with this?
Our son (19 months old) is a dreadful sleeper - always has been! We've had a sleep study done and by process of emilniation our physician thinks our son has this 25-26 hour cycle. WE are beside ourselves in trying to cope as he seems to want to go to bed at 11pm! Would love to hear if anyone has any experience with managing this in kids. thanks
King Midas?
I've known about N-24 for years before finding that the disease was known to medicine. I am 25 years old, and I have had a "circadian" rhythm of well over 24 hours since I was approximately 12 years old. I have been homeschooled following sixth grade (and I've never regretted it for an instant). I haven't been Non-24 diagnosed yet, due to fear of a misdiagnosis (stemming in part from a recent diagnosis and prescription for attention defecit disorder).
Extending my sleep schedule to 48 hours by means of meditative "reduced energy states" allowed me to hold a daily job for one year, but the necessity of medication breaks in the ADD prescription (to avoid tolerance build-up and exhaustion) meant frequent problems.
Without the medication I have very limited control (or close to none at all) over a 36 hour sleep schedule. I've attempted light and melatonin therapies on my own, and had distressingly unpleasant results.
I'm still hopeful that I will find a career in which the ability (and necessity) of working an extremely long shift will be beneficial rather than abysmal.
To other N-24 sufferers: Don't give up on turning your curse into a blessing. If the world can't find a use for you, find a use for the world.
N-24: A mind is a terrible thing to waste
finally...i think n-24 describes the symptoms i've been having for the last 10 years or so. if left alone for an extended period of a week or more, i will sleep for 12-18 hours and then be awake for 24-30 hours. during november 2007 i kept a detailed sleep log and found that i averaged 37 hours awake, then 19 hours asleep. despite seeing sleep doctors, i never got a diagnosis that fit these symptoms. as a result of all this i have lost my 30-year career as a scientist, despite having an extremely flexible schedule allowed to me(it was ok to work anytime in the 24-hour day,but i could not work at home), because,after many years of doing so, i suddenly could no longer manage to work 40 hours during a 168-hour week since October 2006. the symptoms have basically ruined my life, despite a very understanding family. now i must hope for a new career that can be done at home. also i'm very skeptical that light therapy or melatonin treatment can even make a dent in my totally erratic schedule.
Me too!!!
I've had this condition since I was around twelve and only found out it's name now.
My (probably worthless) advice to all the other non-24ers is either work from home, or find a job with very flexible hours. It is so nice, not having to pull those all-nighters just to get to work on time.
Oh, and if you're in school - my condolences.
Been n24 all my life, time to wake society up to it perhaps?
I've had this all my life, I'm nearly forty, and it caused me SO much grief throughout school.... finally managed to work from home and I agree with the topmost anonymous poster, why should we be drugged with mind-altering stuff just because of the way we are?
Left alone to live my life to my internal clock, I'm perfectly healthy and as mentally and emotionally balanced as anyone - hell, more than plenty of folks I can think of!
No-one expects society to change to accomodate us, but a wider understanding that this exists, it's real, and we're not just LAZY would be good.
People still tell me I need to just "force myself" out of bed at the same time each day: albeit, 3 hours before I'm ready to wake up, because my days are 26, now pushing 27, hours long. And sure, I can do that for an important meeting, or two, but every day for the rest of my life?! Give me a break - sleep deprivation's a form of torture, and I'm damned if I'm going to torment myself into an early grave for no good reason.
Sorry for the rant, one thing I must say is it's good to read so many comments, though I'm sorry it has to happen to anyone, because I know it's a hard journey before the truth becomes apparent.
We really need to unite on this one because even Wikipedia's entry is still making it seem like it only happens as a rare pathology, whereas the reality is, whatever the cause, someone out there is suffering right now because they don't know this exists.
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