Tags: Chronobiology, Circadian rhythm, Diagnosis, Sleep disorder, Sleep research
Funding of sleep research by the National Institutes of Health (NIH) is prioritized according to the National Sleep Disorders Research Plan. The plan resulted from 1993 legislation establishing the National Center on Sleep Disorders Research with the mandate, in part, to:
- Conduct and support research, training, health information dissemination, and other activities with respect to a basic understanding of sleep and sleep disorders, including research on biological and circadian rhythms, chronobiology, and other sleep-related topics.
The first such plan was dated 1996. The second and current one is from 2003: http://www.nhlbi.nih.gov/health/prof/sleep/res_plan/sleep-rplan.pdf
The present Sleep Disorders Research Advisory Board, chaired by Charles A. Czeisler and with Michael Twery as Executive Director, has been working for a year or so on a revision. The 2011 research plan will provide a guide for future scientific sleep and circadian research, both basic and clinical.
While the 2003 plan is organized under such headings as Basic sleep science, Enabling technology, and Pediatrics, the 2011 plan will be organized around research goals.
The draft of April 2011 contains five goals. They are concerned with, in short version:
- Sleep and circadian functions and mechanisms
- Factors contributing to sleep and circadian disorders and disturbances
- Prevention, diagnosis and treatment of sleep and circadian disorders and circadian disruption
- Dissemination of sleep and circadian research findings
- Sleep and circadian research training, to accelerate the pace of discovery
There appears to be a greatly increased emphasis on circadian disorders and research in this draft. The word ‘sleep’ appears seldom alone; it’s always ‘sleep and circadian’.
Those of us with circadian abnormalities are perhaps most happy with goal 4. Health care professionals, educators, policy makers and the general public are at present largely unaware of the results of research to date, and the resulting ignorance leads to misdiagnosis of most of us. The research community knows a great deal more than the medical community does, and dissemination of that knowledge should have high priority.
Next post: 64. Circadian Sleep Disorders Network
Tags: Chronobiology, Non-24, Sleep research
The Physiological Society is an venerable British scientific society dating from the time of Darwin. Articles in their journal, Proceedings of the Physiological Society, normally have rather obscure titles like “Synaptic connexions of serotonin-containing neurons in Planorbis Corneus.” But in 1970 a paper from three scientists at the University of Manchester appeared with a title that reads more like that of a science fiction story: “A Man with Too Long a Day”. The man who was the subject of the paper claimed that he was unable to live on a 24-hour day. Instead his sleep wake cycle followed a 26-hour pattern. While humans in isolation experiments sometimes followed non-24 hour schedules, this was the first report of someone who followed such a pattern in normal life, and, more importantly to him, he was unable to live on 24 hours however hard he tried. The scientists were able to confirm the reality of his complaint by a clever experiment.
He was then confined in an isolation unit, without a timepiece, and his
habits were recorded by a remote signalling device; he there followed an
activity cycle of 26 hr. After 5 days a clock, which he knew could be
adjusted to gain or lose several hours a day, was started, and he was asked
to try to conform his habits to the time recorded on the clock; unknown
to the subject, this clock was running at a normal rate, though its absolute
time was in error since it was started at the time which he believed it to be.
He was still unable to conform his habits to a 24 hr cycle, just as when
living in nychthemeral surroundings.
This was the first report of what is now known as Non-24 Hour Sleep Wake Cycle Disorder, more concisely N24. The authors did not report any attempt to treat his condition.
Eight years later, doctors at the Albert Einstein College of Medicine reported another case of what they called “hypernychthemeral syndrome” after the Greek hyper (over) + nychthemeron (24-hour period of night and day). Long-term temperature monitoring recorded his rhythms for several months. In 1980 a third case was reported, this time of a man “John” and his partner “Mary”. John had N24 while Mary’s sleep had previously been normal but at times followed Johns N24 schedule. Charts of their sleep show a kind of circadian dance as their rhythms would coincide for a while and then diverge.
None of these early cases were successfully treated. In 1983 the Clinical Psychobiology Branch at the US National Institutes of Health reported the first successful treatment of N24, by using vitamin B-12. Subsequent cases have reported N24s who respond to B-12 although many do not. (It makes me much worse!)
The next known case, in 1985, responded to clonazepam but the subject reported he felt worse on the drug despite his normalized schedule and chose to stop the drug and resume an N24 schedule. This was a pattern often found in later N24 cases — sometimes the cure is worse than the disease.
Three reports in the late 80s studied the effects of light, with differing results. Light successfully treated one person. Another N24 was initially able to entrain with light, but a later Internet report seems to say she (by the way the first woman with true N24) had to stop it due to migraines. But a Japanese study found that an N24 person was resistant to the normal phase shifting effects of light, suggesting that some N24s develop the condition due to insensitivity to light.
A few more reports appeared in the early 1990s. The NIH published a detailed study of a second patient, showing endocrine abnormalities, some of which were corrected by light treatment while others were not. And researchers in Japan published a growing number of case reports and pioneering studies.
What’s striking about these early cases of N24 is how few of them there were: eight years between the first and second cases! N24 appeared to be a very rare disorder, and it’s probable no N24 ever met anyone else with N24.
Then came the Internet.
As with many conditions, the Internet has broken the isolation of N24s. It’s still a rare condition by any measure, but not as rare as once thought. On Internet sites and mailing lists such as the NiteOwl list for DSPS and N24, more and more N24 people are popping up to say “I’m here” and the talk about the difficulties of living with and/or trying to treat their condition. And that’s why I’m here on this blog, to talk about N24, what N24 folks say, what the science says. This post has been about the past of N24, but we are here to make a better future for those whose sleep follows a “different drummer”. Great thanks to delayed2sleep for inviting me on this blog. Let’s see what we can do!
I classified “A Man with Too Long a Day” as the first medical report of a person with N24, and that is accurate and how it is generally cited in the medical literature. However a few years ago I was reading Sylvia Nasar’s biography of John Nash, A Beautiful Mind. She devotes a chapter to Nash’s friend, the brilliant mathematician and game theorist Lloyd Shapley. Shapley and Nash met at Princeton in 1950 when both were graduate students. In describing Shapley, Nasar says this:
Shapley’s greatest eccentricity at the time was his claim that he was on a
twenty-five-hour sleep cycle. He worked and slept at extremely odd hours, often
transposing night and day. “Every once in a while he’d disappear from sight.”
another student recalled. “That’s what he said. We accepted anything.”
It’s not clear if Shapley’s schedule was voluntary or involuntary. The latter would make him the first known N24.
Posted by LivingwithN24 (aka “L”).
Next post: 51. Melatonin: Less Is (Sometimes) More
Tags: ASPS, Body clock, Chronobiology, Chronotype, Disability, DSPS, Eveningness, Genetic mutation, Japanese study, Light therapy, Morningness, Non-24, Prevalence, SAD, Sleep architecture, Sleep disorder
There are a great many sleep disorders. I read recently that an official list of them had been pared down to about 70. Many have to do with not getting enough sleep, or getting sleep of poor quality by several criteria. Some have obvious causes, such as chronic pain, frequent stops in breathing etc.
My interest is in the timing of sleep as my sleep seems otherwise normal. As the experts put it, I have normal “sleep architecture”. (For a good, short explanation of sleep architecture — stages and brain waves — see this page from Feinberg School of Medicine at Northwestern University in the USA.)
Nearly all of us can reset our clocks daily, adjusting the various rhythms to 24 hours. As much as I’ve read about it, I’ve not found a good enough explanation for being able to adjust to 24 hours while not being able to adjust to sleeping midnight to eight or so.
I’m not immune to the light/dark cycle. I need to get up at noon. I fly 8 hours east or west, go through jet lag like anyone else and within days I need to get up at noon in the new location. This is built in. I’m not the only one. I’d just like to understand it better.
A Japanese paper (2004) suggests these possible mechanisms:
- reduced sensitivity of the oscillator to photic entrainment,
- an intrinsic period beyond the range of entrainment to the 24 hour day, and
- abnormal coupling of the sleep/wake cycle to the circadian rhythm.
One of the most rare disorders which occurs naturally is called Non-24. Sufferers simply(?) live on a 23, 25 or 26 hour cycle, getting up one hour later each day for example, thus coming in sync with the earth’s rotation every few weeks. Their rhythms are in sync internally, just not with the light/dark cycle outside. Most, but not all, of these people are blind.
ASPS, Advanced Sleep-Phase Syndrome, is also rare. These people fall asleep and awaken much earlier than normal. The disorder runs in families, and an American family has been studied intensively the last few years. Research on their genetic mutation was published in 2001. “Detailed sequence studies of the candidate human gene, hPer2, in the affected family members, revealed a key change in a single amino acid — from serine to glycine — at position 662 in the hPer2 protein.” The alteration “occurred in the portion of the hPer2 protein that governed binding to an enzyme called casein kinase one-epsilon (CK1e ).” In animal models, this enzyme regulates “proteins involved in controlling the length of circadian rhythms.”
Now this is beyond me, but it would appear that these disorders may be genetically programmed. Though ASPS is rare, it seems reasonable that researchers start there, since one can compare the DNA of people who are related to one other.
Another disorder which may be related to the others is Seasonal Affective Disorder, SAD. Sufferers are normal in summer, have problems of mood, weight gain etc. when days get shorter and can often be treated successfully by bright light therapy. It seems likely that they may have a mild form of ASPS or DSPS which is “treated” by morning/evening daylight when days are long.
Diurnal preference, spoken of as “morningness”, larks, and “eveningness”, owls, is also a subject of study, the field of chronobiology. This is, reasonably enough, connected to one’s circadian rhythms. However, it does not appear that ASPS is an extreme morningness chronotype nor DSPS an extreme eveningness chronotype. The internal relationships among the various rhythms do not place these conditions on a simple continuum.