Circadian rhythm disorder

PowerPoint PresentationSleep Well Clinic
12:05 - 13:00 WS #125: Circadian Sleep Disorders (Repeated)
The Structure of Sleep
Overview
REM - Rapid Eye Movement NREM - Non-Rapid Eye Movement
Stages 1 and 2 light sleep Stages 3 and 4 deep sleep
90 -100 Minute sleep cycles. 4 – 5 cycles per night to feel refreshed
25% REM, 50% Stage 2 and 25% stages 3 and 4
Circadian Rhythms
Controlled by
External environment cues – Zeitgebers (Time keepers)
Circadian Rhythms
Controls sleep architecture
Varies with age
1 : 2 ratio
o Melatonin
o Light
o Exercise
Association with melatonin secretion
Circadian Rhythms
Testosterone
Circadian Rhythms
exogenous (tablets)
Tablets (0.5mg) are most effective at altering the
sleep phase when taken 4 – 6hrs before sleep
Circadian Rhythms
The most alerting
Exercise - Alerting
light
used to enhance or inhibit sleep
Feeding - Affects Gastric acid
by:
- Physiological delay (in Adolescents)
- Both sleep onset and morning waking are delayed
Prevalence:
Delayed Sleep Phase Syndrome
Treatment:-
(See Adolescent sleep)
and evening darkness
Circadian Sleep/Wake Disorders
- Slowly advancing sleep phase with age (and work)
- Excessive evening sleepiness
- “Sleep Maintenance insomnia”
Circadian Sleep/Wake Disorders
Treatment :-
- Reassurance.
- Evening exercise
- More common with
- No defined Sleep/Wake cycle
Total sleep time is not affected
- Poor consolidation of sleep
light
schedule
- Associated with
- Developmental / intellectual disability
Circadian Sleep/Wake Disorders
- Day and Night Routine,
Adolescent Sleep
How much sleep do they need? 8½– 9¼ hrs
How much sleep do they get?
Only 15% reported getting 8½hrs sleep on
week nights
o Construct a schedule
Best for those with very severe DSP (>4am)
o Delay bed time and wake time by 3 hours every night
until target sleep time is reached
o Allow no more than 8 hours ‘sleep opportunity’
ie 4am ------------------ 12midday
Circadian Rhythms
o Go to bed when sleepy
o Advance bed time and wake time by 15 minutes every
night until target sleep time is reached
o Allow no more than 8 hours ‘sleep opportunity’
ie 2:00am ------------------ 10:00am
Circadian Rhythms
o Timing – after lowest core body temperature
o Intensity – the brighter the light the more rapid the effect
(outside is ideal)
(longer in dim light)
o Dim the lights in the evening
o Avoid electronic media for at least two hours before bed
o Use ‘blue blocking’ glasses in the evening
o Avoid caffeine in the afternoon and evening
o Avoid vigorous exercise within 4 hours of bedtime
Circadian Rhythms
o Has a number of physiological functions
o Responsible for peripheral vasodilation
(consequent fall in core body temperature)
From: The journal of clinical endocrinology & metabolism; Salti,R; 85(6):2137-2144 (2000)
Circadian Rhythms
o Large doses (3mg – 5mg) tend to be sedative
o Small doses (0.3mg – 0.5mg) given 5-6 hours before
target sleep onset is effective
o Most effective when endogenous melatonin is not present
e.g. shiftwork / jet lag
o Results in peripheral vasodilation and fall in core body
temperature
Circadian Rhythms
Important considerations:
• Relaxation of the process will result in a rapid return to
the DSP
Late nights to bed on Friday and Saturday nights will result in difficulty
sleeping on Sunday night and difficulty getting up on Monday morning.
• Moving West will have immediate benefit but it won’t
last!
this regime is begun the better, especially in pre-teen years.
• Blue-blocking sunglasses in the evening
• No sunglasses in the morning
• Ensure morning light exposure is after the calculated lowest
core body temperature
Sleepiness in 8 situations)
covers many aspects of sleep)
- Morningness-Eveningness Questionnaire
The Epworth Sleepiness Scale
How likely are you to doze off or fall asleep in the following situations, in contrast to just
feeling tired?
This refers to your usual way of life in recent times.
Even if you have not done some of these things recently, try to work out how they
would have affected you.
Use the following scale to choose the most appropriate number for each situation:
0 = would never doze
1 = slight chance of dozing
2 = moderate chance of dozing
3 = high chance of dozing
It is important that you put a number (0 to 3) in each of the eight boxes.
Brief questions:
(19 Questions)
1. What time would you get up if you were entirely free to
plan your day?
2 What time would you go to bed if you were entirely free to
plan your day?
7. During the first half-hour after you wake up in the morning,
how tired do you feel?
12. If you got into bed at 11:00 PM, how tired would you be?
Thank You