Sleep Disorders Starter questions - PowerPoint Presentation

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Sleep Disorders

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Starter questions

What is a sleep disorder?Can you name any?

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Answers

What is a sleep disorder?Problems falling asleep, staying asleep, or staying awake during the day.Can you name any?There are 100s!

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The disruption of biological rhythms can have negative physiological and psychological effects as the internal biological clock attempts to readjustThings that disrupt our biological rhythms are:Jet lagShift work (this is relevant to your assessment)

Circadian Rhythms Sleep Disorders

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Circadian Sleep Disorders

Circadian rhythm sleep disorders all involve a problem in the timing of sleep - when the person is awake and when they are asleep The circadian clock is set by exogenous zeitgebers e.g. light/dark. This keeps us synchronized to the 24/h dayJet lag and Shift work can lead to Circadian rhythm sleep disorder involves at least one of the following problems: You have a hard time initiating sleep, You struggle to maintain sleep, waking up frequently during the night Wake up too early and are unable to go back to sleepSleep is non-restorative or of poor quality

You can use the sheet provided to take notes

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Jet Lag….The Facts.

Symptoms

TirednessIrritabilityConcentration problemsAnxiety

Jet Lag only occurs when flying from East-West or from West to East.in other words when we change time zones. Jet Lag does not occur form North-South and vice versa!!

ExampleYou fly from Scotland –Boston (USA). You leave at 11am arrive 5pm British time actually it is 12pm in Boston...by 8pm Boston time you’ll be tired as it is 1am to you normally!!

Your body is preparing for sleep but the external time givers tell you it’s only early evening.

Your biological clock has become desynchronised from external

zeitgebers

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Disruption of biological rhythms: Jet Lag…..

Travelling from East to West means your body clock is ahead of local time. e.g. we feel like it’s 1am but local time is 8pm This is an example of phase delay (local time behind us)Travelling from West to East means your body clock is behind local time and you are not ready to sleep yet e.g. our body clock thinks it 7pm but local time is midnight. This is an example of phase advance (local time ahead of us)By delaying/advancing our rhythms we are compromising our ability to cope in the short term.ResynchronisationEvening when there is radical resynchronisation from Jet Lag the SCN (master clock) will gradually adjust to the changed time of dayThis takes time however and the symptoms of jet lag can last several days

C

ircadian

sleep

disorders

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Research into Jet Lag

Recht

et al (1995) Baseball teams travelling to games

Waterhouse et al (2007) Cabin Crew & cognitive performance

What can you find out about these studies?

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Research into Jet Lag

Recht et al (1995) Baseball / Travelling to games (3 year study)Travelling West to East, American Baseball teams won 37% of gamesTravelling from East to West, they won 44% of gamesRecht et al concluded that jet lag affected the players’ performance – they effects were worse after phase advanceEvaluation? Too many uncontrolled variables e.g. ability of other team

Waterhouse et al (2007) reviewed 500 articles on aviation & health

Found that disrupted sleep patterns led to cabin crew experiencing decreased cognitive performance (e.g. memory)

Also found a link with

Mental health problems and Menstrual cycle problems

Confirmed that jet lag can lead to problems with cognitive process, and directly affect brain function & physiological processes e.g. stress

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Jet Lag…How can we reduce the impact/effects of Jet Lag? Any ideas?

Use melatonin to reset the body clock..As we know Melatonin plays a crucial role in the SCN that controls biological rhythmsMelatonin has been shown to reduce the effects of jet lagShould not be used unless intending to stay in new time zone over 3 days.Timing is important too...individuals should be allowed to sleep after the melatonin…. If not they are prolonging their circadian rhythm. There is little scientific evidence on flying performance and melatonin however….cabin crew who have ingested melatonin are not allowed to fly within 36 hrOther ideas… Adopt local eating times etc to help reset the biological clock as soon as possible.

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Disruption of biological rhythms: Shift Work…

Working at times when people are normally asleep, and being asleep at times when people are normally awake, causing breakdowns between internal biological clocks & external cuesRising early or retiring to bed earlier than normal is an example of phase advance.Going to bed late or getting up late is an example of phase delay.When we work at night we are going against out circadian rhythms – trying to maintain alertness when our biological clock is imposing sleep on the brain!However shifts patterns change regularly, meaning workers can be in an almost permanent state of desynchronisation On average it takes 3 days to adjust to a 12 hour shift in time. This is not long enough time for resynchronisation

C

ircadian

sleep

disorders

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We need doctors, nurses, policeman etc…so what happens to their cycle when it is disrupted by shift work? Any ideas?High illness rates, sleep disorders (insomnia) and elevated levels of stress and...accidents!Chernobyl occurred between 1am & 4am.Most lorry accidents occur between 4am & 7am.The Exxon Valdez oil tanker ran aground at 12.04am in 1989 – 10 million gallons of oil spilledEvidence: Hawkins and Armstrong-Esther (1978) studied 11 nurses during a 7 night rotation of their duty. Performance was significantly impaired on the first night but improved through the week. (Temps did not adjust until last night!)

Disruption of biological rhythms:

Shift

Work…

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Shift work & illness/sleep disorders

Czeisler et al. (1982) studied shift workers at a factory in UtahThey found high illness rates, sleep disorders and elevated levels of stress, suggesting that their internal body clocks were out of synchronisation with exogenous zeitgebersResearchers persuaded management to move to a phase-delay system of rotating shifts forward in time, to reduce negative effects. Shift rotations were adjusted to every 21 days, instead of 7 days, giving time for adjustment. Nine months later, workers appeared healthier, more content and output was up, showing how psychological research can lead to practical applications incurring positive outcomes

Evidence that 7 days is not enough time for the body to readjust

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Shifts workers tend to be awake late evening and/or early morning and sleep during the day. After a shift change people take a week to adapt to the new regime, Unless workers succeed in resetting their biological clocks they experience sleepiness at work and insomnia at home Social constraints may tempt workers to stay awake when they should be sleeping (Especially kids)People who are working shifts are often sleep deprived because they find it hard to sleep when there is light outside and its noisy

Disruption of biological rhythms:

Shift

Work…

Consequences

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Shift work & sleep disordersTreatments available?

Czeisler

et al (1990)

Bright lighting

in the work place seems to be key to helping workers to adapt to new shifts so that they are alert at work and sleep well during the

day

Light Box –

Bovin

et al (1996)

Melatonin

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Star Study: Czeisler et al (1990)

This study relates to shift work and how the use of lighting can help people adjust

Note: the measure used was body temperature

Typically the circadian body temperature is at the lowest when…. Can you remember?

When we are sleeping Approx. 04.30am

So to adapt to a nightshift, the low point of body temp would have to shift to middle of the day

Read the abstract of this research (Follow the link on Blackboard announcements) and see if you can summarise the key points -

Doing this in pairs might be useful

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Czeisler et al (1990) believes that shift work environments that are warm and dimly lit are counter productive.They believed that exposure to bright light and darkness could help shift workers resynchronise betterProcedure (10 x 2 week studies on 8 healthy men age 22-29)(None of the participants had worked regularly on night shifts before)Compared the rate of adaptation of two groups of participants to an imposed shift change by asking them to report to the lab during the night and sleep at home during the dayThe control group worked during the night in ordinary indoor lights of about 150 luxThe experimental group worked under bright illumination of 7000-12000 lux, equivalent to early morning light. The experimental group were also asked to stay in complete darkness from 9am to 5pm, whilst the controls were given no specific instructions

Star Study: Czeisler et al (1990)Exposure to Bright Light and Darkness to Treat Physiologic Maladaptation to Night Work

http://

www.nejm.org/doi/full/10.1056/NEJM199005033221801#t=articleTop

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Czeisler et al (1990)

The resetting of the biological clocks were monitored by measuring

b

ody temperature, which varies rhythmically.

Findings:

After

6 days the experimental group had all shifted the low point of the circadian temperature rhythm by

10

hours

(

Remember

from last week that our circadian body temp is low during the night

when

we should be sleeping)?

The

controls

by just

1 hour

Therefore,

Bright lighting

in the work place seems to be key to helping workers to adapt to new shifts so that they are alert at work and sleep well during the day

Even in this situation adaptation can take up to 4 days, so workers who change shift every week would spend most of their time desynchronised

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ConclusionDemonstrated that maladaptation to night-shift work can be treated successfully with properly timed exposure to bright light during the night-shift work and darkness during daytime sleepIndividually Complete a research study sheet

Czeisler

et al (1990)

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Treatments for Jet Lag & Shift Work

Boivin

et al (1996)

put

31 male participants

on an inverted sleep pattern (so they were awake at night and slept during the day) for three days. 

Each

day when they woke they were sat in front of

dim lights for 5 hours

and then placed in one of four conditions:

1.Very

bright light

,

2.Bright

light

,3.Ordinary

room light ,

4. Continued

dim light.

Core

body temperature

was recorded and used as a measure of how well they were adapting to the new rhythm. After

three

days:

Group

1 had advanced by

five hours

(they were adapting to the new pattern best)

Group

2 had advanced by

three hours

. Group 3 had advanced by

one hour

.

Group

4 had drifted backwards by one hour (were failing to show any signs of adapting).

 

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Boivin et al (1996)

Conclusions??

Artificial

light

can help us

adapt our

biological

rhythms

to suit the environment, however,

brighter light

is even more effective.

Clearly, this useful in the workplace to help shift workers to adapt to changing sleep-wake cycles.

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Shift work can lead to other… Circadian RhythmSleep Disorders

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Activity

You

now

know

about 2 circadian sleep disorders

Jet

Lag ; Shift

work disorder

Find out about one of the following:

Primary insomnia

Secondary

insomia

Advanced

sleep phase disorder (ASP)

D

elayed

sleep phase disorder (DSP

)

Non–24-hour sleep-wake syndrome

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Insomnia

Insomnia

is the most common of the sleep

disorders

Some people have problems

sleeping, either in the quality of sleep or length of sleep.

This

means that sleep is non-restorative and leads to day time tiredness and irritability, affecting work and social functioning. It can lead to depression.

The

diagnostic criteria for insomnia are:

taking more than 30 minutes to fall asleep;

sleep efficiency (the ratio of total sleep time in bed compared with amount of actual sleep) of less than 85%;

increased number of night-time awakenings;

symptoms occurring more than three times per week.

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Activity

Using the following website, find out how chemical stimulants and depressants can affect sleep

http://

healthysleep.med.harvard.edu/healthy/science/how/external-factors

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Factors affecting Sleep: Chemical Stimulants

Many

common chemicals affect both quantity and quality of sleep.

These

include

caffeine

, alcohol, nicotine, and

as

well as prescription medications including beta

blockers and antidepressants

As

we know The longer you are awake, the stronger the sleep drive

becomes

Interestingly, caffeine, the world’s most widely used stimulant, works by temporarily blocking the

sleep drive in specific

parts of the brain (SCN

)

If sleep does occur following the intake of caffeine, the stimulant’s effects may persist for some time and can influence the patterns of

sleep – can lead to more awakenings

http

://

healthysleep.med.harvard.edu/healthy/science/how/external-factors

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Factors affecting Sleep: Depressants

Alcohol is a depressant of the Central Nervous System

Alcohol is commonly used as a sleep aid.

However

, although alcohol can help a person fall asleep more quickly, the quality of that individual's sleep under the influence of alcohol will be compromised.

Ingesting

more than one or two drinks shortly before bedtime has been shown to cause increased awakenings—and in some cases

insomnia

This is due

to the arousal effect the alcohol has as it is

metabolised

later in the

night

Alcohol can become a stimulant as our bodies process it –so you may wake up half way through the night