68. Non-24 — Not Just a Disorder of the Blind, a guest post

24 July 2014 at 03:12 | Posted in Circadian rhythm | 3 Comments
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Perhaps I’ve “arrived”, when Healthline.com approaches me with an offer of a guest post?  I said yes, please.  So here is the article by their health-and-fitness writer Adrienne:

Adrienne

Thank you Healthline and Adrienne, for the timely article!    –D

 

 Non-24 — Not Just a Disorder of the Blind

Non-24-Hour Sleep-Wake Disorder is not a condition that a lot of people were aware of, at least until the first medication for it was approved by the U.S. Food and Drug Administration earlier this year.  The advertising for Vanda Pharmaceuticals’ new drug has brought some attention to the disorder, but since the drug is aimed at (and only approved for) those who are blind, few realize that the disorder can and does affect sighted people as well.

Non-24 in Layman’s Terms

Non-24 is a circadian rhythm sleep disorder that causes people to be unable to adjust their sleep-wake cycles to a 24 hour day.  This causes their sleep time to progress around the clock.  To put it more simply:  Each night people who have Non-24 go to sleep later than the night before, each time sleeping in the next day in accordance with the time they went to bed.  They go to bed later and later every day, eventually ending back at the same bedtime and starting the cycle all over again.  As you can imagine, this doesn’t only interfere with day-to-day responsibilities, but it can also lead to daytime sleepiness, memory issues, depression and more.

Non-24 in the Sighted 

In a majority of totally blind people, Non-24 is the result of their inability to perceive light; the lack of  light interferes with synchronization of their internal clocks to the day/night cycle in nature.  Even though the disorder goes by the same name for the sighted as it does for the blind, the causes are entirely different.  Though it’s not currently known just how many sighted people have Non-24, there are several known causes of it.

Here are some of them:

  • Changes in light sensitivity. In some sighted people, even though they are able to see well and appear to have great vision, daily light signals may not get through properly, leading to disrupted circadian rhythms.
  • Melatonin imbalance. Melatonin, a hormone, plays a part in linking sleep to the day-night cycle.  Some sighted people with Non-24 have been found to produce less melatonin than normal while others produce too much.  Problems with metabolizing melatonin properly can also impair circadian rhythm and cause Non-24.
  • Trauma and physical damage to the brain. Healthy people who suffer head injury can develop Non-24 when the injury damages the circadian and sleep centers of the brain.  This can also be the case with brain tumors, such as craniopharyngiomas.  For some it’s the brain tumor itself that causes the damage while for others it can be the effect of treatment, such as radiation.
  • Environmental factors. Sometimes it’s a sighted person’s exposure to light, or the lack of it, that can interfere with the ability to maintain a 24-hour sleep-wake cycle.  An example of this, in scientific studies in the laboratory, is being in an isolated environment without access any clues as to what time of the day it is, and not being allowed to turn lights on or off as desired.  In such studies healthy people will temporarily acquire a non-24 sleep pattern, though, of course, not the disorder.
  • Individual sleep patterns.  According to The National Organization for Rare Disorders  (NORD), a person’s need for sleep could lead to a Non-24 sleep cycle.  They give the example of a healthy person who may sleep 8 hours and stay awake for 16 while another person may need 12 hours of sleep but still be awake for the normal 16 hours, leading to a 28-hour day.  The same can happen for a person who sleeps the normal 8 hours but then requires 20 hours of awake time before sleep again is possible, also leading to a 28-hour day.

These are just some of the known or suspected causes of Non-24 in the sighted.

References

 

Adrienne is a freelance writer and author who has written extensively on all things health and fitness for more than a decade.  You can connect with Adrienne on Facebook here.

Healthline.com is funded, apparently exclusively, by advertising and they own, are owned by or are affiliated with Healthline Networks, Inc., Healthline Corp and YourDoctor.com

Their goal is to educate and empower users with relevant and responsible information in order to foster better communication between doctors and patients.

You can go to http://www.healthline.com for more information on sleep disorders and other related conditions.

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69.  Next post: –another guest post–

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67. N24 Awareness Day

24 November 2013 at 22:43 | Posted in Circadian rhythm | 6 Comments
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The online N24 community has decided to name November 24 as N24 Awareness Day.  We are encouraging bloggers and tweeters and anyone else with a platform to help spread awareness and knowledge of Non-24-Hour Sleep-Wake Disorder (N24).

The web page which links to these efforts is here (click on the N24 Day Logo):

N24 Awarenes Day Icon
This would be an appropriate time to review some events in 2013 relevant to N24.

One important advance was a paper by Kitamura et al. which measured the intrinsic circadian period in 6 patients with N24.  They compared it with two groups of individuals without a circadian disorder.  One group had an intermediate circadian preference.  The other group had an evening preference. The latter group however did not have DSPS, only a preference for being active later in the day.

Kitmura et al. found that the intrinsic period of the N24s was 24.5 hours, which was significantly longer than that of the intermediate types, but not significantly longer than that of the evening types.  The average period of the N24s was longer than that of the evening types but because of the great degree of overlap between those groups the difference was not significant.  The longest period found in an evening type subject was nearly identical to the longest period among the N24 subjects (around 24.7 hours).

These results suggest that a longer-than-average intrinsic period is a component of N24, but it is not the only causative factor.  Other factors, such as differences in phase angle between sleep and temperature rhythms, as found in several studies, may play a role.

Another paper, by An et al.  did not discuss N24 explicitly, but the results may have import for those with the condition.  They studied the effect of Vasoactive Intestinal Peptide (VIP) on shifting of circadian rhythms in mice and in cell cultures from the SCN.  They found that VIP depending on time and dose could either enhance or reduce the mutual synchronization of SCN cells.  Further, when SCN cells were less tightly synchronized together, they adapted more quickly to phase changes.  This suggests that by manipulation of VIP levels it may be possible to increase the adaptability of the SCN to phase changes.  Since N24s with a longer period need to change phase every day if they are trying to maintain a normal schedule, this approach might be of help.   It might also help people with DSPS when trying to shift to an earlier sleep phase.

–posted by LivingwithN24

REFERENCES

Kitamura S, Hida A, Enomoto M, Watanabe M, Katayose Y, Nozaki K, Aritake S, Higuchi S, Moriguchi Y, Kamei Y, Mishima K. Intrinsic circadian period of sighted patients with circadian rhythm sleep disorder, free-running type.Biol Psychiatry. 2013 Jan 1;73(1):63-9.

An S, Harang R, Meeker K, Granados-Fuentes D, Tsai CA, Mazuski C, Kim J, Doyle FJ 3rd, Petzold LR, Herzog ED. A neuropeptide speeds circadian entrainment by reducing intercellular synchrony. Proc Natl Acad Sci U S A. 2013 Nov 12;110(46):E4355-61.

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Next post:  68.  Guest post: Non-24 — Not Just a Disorder of the Blind

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66. Blogathon: “Dear Diagnosis”

7 November 2013 at 23:34 | Posted in Circadian rhythm | 5 Comments
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Julie Flygare, the author of  Wide Awake and Dreaming: A Memoir of Narcolepsy, is hosting «Dear Diagnosis»,  a blogathon where she invites «all narcolepsy and chronic disease bloggers to write a letter to yourself on your diagnosis day.”  To date, all responses are from narcolepsy bloggers.  She needs one from another chronic disease blogger, I think. 

Dear me in April 2004,

Elation!  Finally a doctor who recognizes that you are not (just) lazy and inconsiderate.  He understands so well that he asks about things you never realized were connected to your sleep problems.  He asserts that you have a valid condition and even has a name for it:  Delayed Sleep Phase Syndrome, which in years to come will be “uprated” to Delayed Sleep Phase Disorder.

Yes, you are on a high which will last several months, in spite of the fact that the treatment he recommends doesn’t really work.  Thanking the heavens for the Internett, you will research DSPS and discover that its been known (but only to  chronobiologists, apparently) for over 20 years.  You will fill a couple of ring binders with scientific studies, learning to read and understand them along the way.

That overnight sleep study at the hospital in the early ‘90s that came up with “not narcolepsy” as a diagnosis should have rung a bell for that neurologist!  Curses on him.

It will, unfortunately, take years for you to stop blaming it all on your own lack of self-discipline and to (re)gain some self-esteem.  You will still have to make sincere apologies when you are late for work and miss appointments.

You will foolishly refuse to accept 100% disability when it is offered, going along with your GP who feels you should at least keep working part-time for social reasons.  So you’ll be 40% disabled for a while, then 60%.  Retirement age comes as a great relief.

You will actually start a blog about DSPS, partly for yourself but also in hopes of helping anyone who stumbles upon it.  You’ll hear from thankful people; it’s great to be appreciated!  You’ll find a wonderful support group, “niteowl”, online where intelligent and helpful people help each other learn.  You’ll find other fora where you can help people.  You’ll eventually start a wiki, then be a part of starting a non-profit, Circadian Sleep Disorders Network, to provide support, inform and try to spread awareness.

Your sleep specialist (yes, the same one as today)  will tell you: “Now you can hang out a sign and start taking patients.”  He’s joking, of course, but it’s a nice compliment.

In sum, your life will continue to center in large part around your sleep problems, as it always has, but increasingly in a positive way!

Best wishes,

Me in 2013

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Next post:  67.  ~coming soon~

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65. Sleep inertia

18 March 2012 at 06:54 | Posted in Circadian rhythm | 8 Comments
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Sleep inertia refers to temporary cognitive problems, low levels of alertness and vigilance, and impaired motor dexterity immediately upon awakening from an episode of sleep.  The ability to perform mental and/or physical tasks including learning is deficient for a period of time.  Executive functioning may be especially impaired; decision-making can be impaired by 50%.  Sleep inertia has been shown to be a robust, quantifiable process.

That’s the fancy way of saying that one feels groggy, slow, disoriented and a bit stupid for a while after getting up.

Normal people experience sleep inertia on abrupt awakening from a nap of more than 30 minutes and on abrupt awakening in the middle of the night.  It may last from 5 minutes to an hour or more.  The stage of sleep may be of some importance for the degree of impairment and how long it lasts.   Some degree of sleep inertia is possible even when the sleep from which a person has awoken may have fully dissipated their sleep need

“Circadian misalignment is the basis for all circadian rhythm sleep disorders. These disorders are often associated with impairments of cognitive performance that can have adverse effects on school and work performance, overall quality of life, and safety.”  [Reid et al]  Sleep inertia is common in circadian rhythm disorders and it seems to be more severe and long-lasting here than in normal people.  On top of this, people going to work or school by 9 a.m. are getting up in the middle of their biological night where sleep inertia has been shown to be 3.6 times worse than in “daytime”.

A few recent quotes from people in our support group

show that we find sleep inertia to be a major problem:

–The people I was traveling with even thought I was dead on one occasion because of my usual “coma” type sleep/difficulty waking.

–My son does that comatose thing when he is sleeping too.  NOTHING will wake him.  SO the sleep doc’s office calls and says to be sure and wake him on schedule.  I just said “Huh? That’s supposed to be funny, isn’t it?”

–I have the very deep sleep characteristic as well…  I’ve slept through fire alarms, even a jackhammer tearing up the street literally right outside my window.  […]  I’ll also apparently have limited conversations with people while still asleep, though I’ll have no recollection.  My college roommate told me I would crawl halfway down the ladder from my bunk and turn off my alarm clock with my foot, still dead asleep.

–Of course it doesn’t help that I won’t be anywhere close to alert for at least an hour after waking up if it’s morning…

–No one could understand how I could always be late for work; my bosses said “please just call and let us know if u will be late.”. What the?  There was never any recollection of turning off multiple alarms (if I did–maybe they ran out–I could never figure it out).  How could I call in my sleep? ;).  No options, if you are deaf, you can’t hear, and it’s like I was deaf or in a coma.

–I too have slept through fire alarms, normal alarms, building work in my room at one point etc.  My parents always said I could sleep through a nuclear blast :P  And I also talk in my sleep when someone’s trying to wake me up — not much though, just enough to reply “yes, I’m getting up” or something similar.

–The last time I was working regularly I had to budget at least an hour to get dressed because I could count on “losing” about 30 minutes every morning.  Just standing in the middle of the kitchen or in the shower asleep.

–Similarly, I set an alarm for three hours before class starts (takes 10-20 minutes to walk to class) because I seriously lose time when I wake up, especially if I wake up after fewer than an optimal number of hours of sleep. I don’t know if I sleep standing or not, but I definitely haze out and lose time.

–My boss can’t understand my DSPS.  And now I have an accommodation so I can work noon to 8:30 pm and still I don’t hear the alarms and often wake up half an hour before I need to be at work, thus I am often (OK, almost always) a little bit late even at noon.  I was told at work that since my supervisor was going to be on vacation, I’d need to come in to work at 8am for that week.  (I have a medical disability accommodation).  I explained it to them like this….if I was in a wheelchair, and my boss normally did something like climbing a ladder to replace lightbulbs, would you expect me to figure out a way to do that in her absence?  Would you remove a wheelchair ramp for a week for someone and expect them to crawl up a few steps for a week?

–I do wanna point out, my partner is the least DSPS person I know, he’s very average, sleeps 8 hours if allowed, but does very well on 6, works full time 9-5 without a problem. My point is, he’s normal :P  And if you set an alarm for his middle of the night, he will also be comatose-like and a total zombie even if he does manage to hear it and get up. And he’s actually fallen asleep in the shower/kitchen while getting ready for work before, when he’s had to get up at hours like 3-4am (which is very rare). So I don’t think that this type of sleep is DSPS or N24 specific .

 REFERENCES:

 Bruck D, Pisani DL.  The effects of sleep inertia on decision‐making performance.  Journal  of Sleep Research.  1999; 8: 95–103.

Matchock RL.  Circadian and sleep episode duration influences on cognitive performance following the process of awakening.  International Review of Neurobiology. 2010;93:129-51.

Achermann P, Werth E, Dijk DJ, Borbely AA.  Time course of sleep inertia after nighttime and daytime sleep episodes.  Archives italiennes de biologie. 1995 Dec;134(1):109-19.

Groeger JA, Lo JC, Burns CG, Dijk DJ.  Effects of sleep inertia after daytime naps vary with executive load and time of day.  Behavioral Neuroscience.  2011 Apr;125(2):252-60.

Reid KJ, McGee-Koch LL, Zee PC.  Cognition in circadian rhythm sleep disorders.  Progress in Brain Research. 2011;190:3-20.

Scheer FA, Shea TJ, Hilton MF, Shea SA.  An endogenous circadian rhythm in sleep inertia results in greatest cognitive impairment upon awakening during the biological night.  Journal of Biological Rhythms.  2008 Aug;23(4):353-61.

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66.  Next post:  67.  Blogathon:  “Dear Diagnosis”

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64. Circadian Sleep Disorders Network

28 November 2011 at 22:00 | Posted in Circadian rhythm | 4 Comments
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UPDATE:

CSD-N is now set up to accept paying members.  Charter membership (before 31 March 2012) is just US$25.  The organization needs many members to increase its clout in working for its goals.  See the “Join us” page on the website. 

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There’s a new organization for us:  Circadian Sleep Disorders Network – advocating for people with misaligned body clocks.  It’s incorporated as a non-profit in the USA and very soon will be accepting paying members.

Its mission statement:

  • Circadian Sleep Disorders Network is a non-profit organization dedicated to improving the lives of people with chronic circadian rhythm disorders.
  • We aim to increase awareness within the medical community and among the general public, to provide emotional support and practical ideas for people living with these disorders, to encourage research into circadian rhythms, and to advocate for accommodations in education and employment for people with circadian rhythm sleep disorders.

The website, under construction, is at CSD-N.org.  There you’ll find a two-sided brochure which may be downloaded and freely distributed; it is available in both A4 format and 8.5×11 letter size.

Here’s wishing the new organization a long and useful life.

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Next post:  65.  Sleep inertia

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