Lecture 17: Sleep/EEG Flashcards
Why do we need sleep?
1) Shrinkage- synaptic shrinkage during sleep to make room for new connections the following day (most ‘hot’ topic at the moment)
2) Body repair?
3) Predator avoidance?
4) Energy replenishment?
What do the recent research on sleep and the brain suggest? (3 things)
1) Sleep improves procedural memory
2) Problem solving skills
3) Pruning and strengthening of circuits that promotes learning new things and reinforcing old ones.
True or False?
1) All of us need 8 hours.
2) Snoring is common and harmless.
3) If you are always tired, you are not sleeping enough.
4) You can catch up on sleep deficits during the weekend.
1) All of us need 8 hours.
Majority of adults need 8 hours.
2) Snoring is common and harmless.
Snoring can possibly be harmful, e.g. sleep apnoea if it is severe.
3) If you are always tired, you are not sleeping enough.
It might be true, but not all the time. Lack of sleep might not be the cause of tiredness.
4) You can catch up on sleep deficits during the weekend.
It does not work like that. Sleep deficit can carry on for a long time.
True or False?
5) Alcohol helps you sleep
6) Students who fall asleep in class are lazy*
7) If you are tired and driving, roll a window down or turn up the radio*
5) Alcohol helps you sleep
Alcohol would help you initiate sleeping, but poor quality of sleep.
6) Students who fall asleep in class are lazy*
Students are usually hard-working, and they fall asleep in class mainly because you are sleep deprived.
7) If you are tired and driving, roll a window down or turn up the radio*
This only helps to a small extent.
How do you diagnose sleep disorders?
1) Sleep history
2) Sleep diary (~ 2 weeks)
3) Actigraph
4) Polysomnogram
What are the 2 types of sleep?
REM (rapid eye movement sleep)
Non-REM
Describe the stages of sleep
Stage 1 and 2 (bad sleeping) are in light sleep, and it can be awakened easily.
• In stage 1, eyes move slowly and muscle activity slows, and many people experience sudden muscle contractions preceded by falling sensation (hypnic jerk).
• In stage 2, eye movement stops and brain waves become slower with occasional burst of rapid brain waves.
Stages 3 and 4 (good sleeping) are referred to as deep sleep or delta sleep, and it is very difficult to wake someone. There is no eye movement or muscle activity.
• In stage 3, extremely slow brain waves called delta waves are interspersed with smaller, faster waves.
• In stage 4, brain produces delta waves almost exclusively.
REM sleep occurs after resurfacing from stage 3 and 4. This occurs ~5 times a night, totalling ~2 hours. This is the time when most dreams occur.
• In REM period, breathing becomes more rapid, irregular and shallow, eyes jerk rapidly and limb muscles are temporarily paralyzed. Also, heart rate increases, blood pressure rises, males develop erections and the body loses some of the ability to regulate its temperature.
• Brain waves during this stage increase to levels experienced when a person is awake.
Waking may occur after REM. If awoken during REM sleep while dreaming, a person can remember the dreams.
We remember less than 5% of dreams.
What sort of questions come up in Sleep History taking?
1) Sleep onset
2) Sleep latency (abnormal if longer than ½ to 1 hour or shorter than 5 minutes)
3) Interruptions (normal if there is 1 or 2 brief interruptions then go back to sleep)
4) Total sleep time (hugely varied)
5) Quality of sleep (good with deep sleep)
6) Long term pattern (abnormal if free runner clock with shifting pattern)
7) Sleep attacks/narcolepsy (suddenly fall asleep anywhere anytime)
8) Sleepiness during the day
9) Sleep walking, talking, eating, sex, snoring, violent activities.
What happens during a polysommogram?
Physiologic sensor leads are placed on the patient in order to record:
- Brain electrical activity (sleep EEG)
- Eye and jaw muscle movement
- Leg muscle movement
- Airflow
- Respiratory effort (chest and abdominal excursion)
- EKG
- Oxygen saturation
What are the 3 Major groups of Sleep Symptoms?
1) Sleep symptoms
2a) Insomnia
2b) Excessive daytime sleepiness
2c) Parasomnias (sleep talking, walking, sex etc.)
Describe Insomnias
Poor quality of sleep due to:
• Primary insomnia (everything is normal except sleep)
- Secondary insomnias (due to substances, psychiatric**, medical, neurological condition with 50% depression and anxiety)
- Circadian rhythm problems (e.g. night owls)
- Jet lag
- Shift work
- Sleep disorder
- Thinking style (e.g. tense, neurotic, anxious, perfectionistic style can predispose you to insomnia)
Describe Excessive Daytime Sleepiness Conditions
2) Excessive Daytime Sleepiness
Difficulty in maintaining desired wakefulness, falling asleep at inappropriate times, excessive amount of sleep due to:
- Sleep apnoea (loud snoring and lack of oxygen supply)
- Idiopathic hypersomnia (no known causes)
- Substances
- Circadian rhythm disorder
- Sleep deprivation
- Narcolepsy/sleep attacks (accompany with change in emotion tones)
Describe Parasomnias
Various sleep conditions such as:
- Sleep walking/ somnambulism
- Sleep sex
- Sleep eating
- Sleep talking (somniloquy)
- Sleep screaming
- REM behaviour disorders
- Periodic limb movements (PLM’s)
- Restless legs
- Bruxism
How do you manage sleep disorders?
1) Need to have correct diagnosis first
2) Multi-modal approach (psychological, behavioural, biological)
o Cognitive Behavioural Treatment for Insomnia – Bed Restriction Programme!!!
o Light Treatment!! (Bright light Exposure)
o Melatonin
o Continuous Positive Airway Pressure (CPAP)
o Medications
What are some countermeasures for sleep deprivation, fatigue and sleepiness? **
Sleep is important!!!
1) Sleep
• 2-8 hours nap prior to a 24 hour sleep loss (shiftwork)
• 15 minute naps every 2-3 hour intervals
• Sometimes, more than 2 hour naps can worsen sleep inertia
2) Medications for staying awake:
• Caffeine (10-15min wakefulness)? Methamphetamine (very effective for wakefulness)? Cocaine (very effective)?
3) Modafinil
• Modafinil (wakefulness at a safe level without much side effects, prescription medicine for narcolepsy)
