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A to Z of sleep

Is your sleep deep and delightful – or do sweet dreams elude you? Here’s everything you need to know about sleep, sleeplessness, sleeping pills and dream
Whether you live in New York or Nieu Bethesda you could be sharing a nightmare with many people around the world – sleep! Or rather the lack of it. According to experts we’re sleeping less than ever before. In fact, chronic sleep deprivation has been called ‘‘the disease of our times’’. Consider the following: 100 years ago people slept for an average of nine hours a night; today it’s closer to seven hours. With the exception of the Margaret Thatchers and Helen Zilles of this world, who claim to flourish on fewer than four hours, we simply haven’t been getting enough shut-eye since electricity was invented. But why do we HAVE to sleep?
Survival is the simple answer. Scientists today know sleep
is a complicated but necessary rest time for the body.
Glucose reserves are replenished, brain networks that
would otherwise decline are given a workout and essential
cycles, such as the secretion of growth hormones, take
place. Sleep also helps organise the memory, refresh the
mind and improve learning abilities, says Peet Vermaak,
neurophysiologist at The Pretoria Sleep Lab.
To understand just how important sleep is for survival
think about what happens when you don’t get enough:
you’re grumpy, irritable and forgetful, your moods swing,
you can’t concentrate, your memory fails and even your
speech is affected. Sleep deprivation has a serious,
negative impact on your brain.
This impact can be felt after just 17 sleepless hours: at that
point your judgment and skills are the same as someone
who has had two glasses of wine and has a blood alcohol
level of 0,05 per cent – enough to land you behind bars.
American Randy Gardner holds the record for going
without sleep. He stayed awake for 11 full days in 1965.
After four days he started hallucinating.
Then he became
delusional, believing he was a famous football player.
The National Institute of Neurological Disorders and
Strokes in the US studied rats that were deprived of sleep.
The animals survived for just three weeks even though
they have a natural lifespan of three years.
Sleep is by no means an unconscious resting time. It’s
an active, dynamic process during which the brain never
switches off , says Professor Gerhard Jordaan, Stellenbosch
University’s head of adult psychiatry. ‘‘The body uses almost
as much energy to sleep as when we’re awake.’’
Neurotransmitters that ‘‘switch off ’’ the neurons that
keep us awake, and therefore make us sleepy, control
sleeping and waking states. The chemical adenosine that
builds up in the bloodstream during the day also makes
us feel tired. At night while we’re asleep adenosine is
broken down – but only when we’re in deep sleep. If we
don’t get enough deep sleep adenosine isn’t processed
properly – and that’s why we wake up tired.
HOW MUCH SLEEP IS ENOUGH?
There’s no magic amount of sleep required for optimal health. Each individual has different sleep
needs, scientists at America’s National Sleep Foundation say. Some of us need just five hours a night; others can’t manage with fewer than 10.
The number varies with age. Babies should get about 16, teenagers up to nine and a half, and
most adults between seven and eight hours a night. Teenage sleep patterns differ from those of
adults: it’s normal for teenagers to want to go to bed late and sleep late. And while Granny sleeps
lightly and for shorter periods she still needs as much deep sleep as she used to when she was
younger. Her afternoon nap is important and she needs more sleep at night for sufficient deep rest.
Each individual has a basal sleep need, explains Dr Frans Hugo of the Panorama Psychiatry and
Memory Clinic in Cape Town. Basal sleep need is the amount of sleep you require to rise refreshed
and awake. If this isn’t satisfied a sleep debt builds up. Sleep debt is the amount of sleep you’ve
lost. You feel and show the symptoms of sleep debt and deprivation when you’re awake.
Most people fall asleep within 15 to 20 minutes of going to bed. If you fall asleep in fewer than
seven minutes you have sleep deprivation, Dr Hugo says. Overworked people with sleep debt hit
the bed like a sack of potatoes and say they went out like a light.
Adults need between six and eight hours of basal sleep a night but things get complicated
when sleep debt starts to interfere with basal sleep need. A mother with a young baby may
finally be able to sleep through several nights but the previous weeks’ lack of sleep means she
will still be tired when she wakes up because of her accumulated sleep debt. ‘‘That’s why we
have to accommodate the basal sleep need in a 24-hour cycle,’’ Dr Hugo says. The good news is
researchers believe sleep debt can be reduced – provided sleep is made as much of a priority as
eating. That’s why there’s merit in the claim a mom should sleep when her baby does.
Not getting enough sleep can affect your judgment and reflexes. Studies show medical students
who suffer from a shortage of sleep make more mistakes. American scientists warn too little sleep
has serious health implications. Obesity, diabetes, heart disease, psychiatric illness, depression,
drug abuse, learning disabilities and car accidents are all linked to sleep deprivation. On the other hand too much sleep (more than 10 hours a night) can be a strong indication of depression and other conditions.
THE IMPORTANCE OF DREAMS
Dreams occur almost exclusively during very deep sleep or REM sleep.
Scientists can still only guess why we dream. What’s clear however is we all spend about two
hours a night dreaming even though we may remember only five per cent of our dreams.
A dream’s journey through the brain begins in the midbrain – specifically the pons – and ends
in the cerebrum, the part of the brain where learning, organisation, memory and thought
processes occur. This route has caused scientists to speculate that dreams are important for the
healthy functioning of these processes. It would also explain why REM sleep is essential for the
development of the brain in children, and why babies need so much of this type of sleep.
There are several explanations for the intimate connection between dreams and memory, and
especially the question of why we find it so difficult to remember our dreams. Some biologists
say dreams are the brain’s way of sorting and deleting unimportant information so it doesn’t
become overwhelmed and stop working.
Dr Hugo emphasises research into the reasons for REM sleep and dreams hasn’t yet delivered
any hard scientific facts. ‘‘We do know REM sleep and dreams are essential for memory. Without
REM sleep the electrical currents in the brain that make up our memory literally collapse. During
dreams in REM sleep the memory currents are reactivated and more firmly fixed.’’
During dreams, Dr Hugo explains, memory networks contact other networks, starting
a chain reaction. This could explain why, during the same dream, different themes occur that are
apparently completely unrelated. Dream events also last as long as real-life ones and are experienced
in colour.
Whether you remember your dreams depends on which sleep phase you’re in when you wake
up, he adds. If you wake up during REM sleep you’ll remember your dream.
WHAT HAPPENS WHEN YOU FALL ASLEEP?
An electroencephalograph
(EEG) enables
scientists to distinguish
five phases in
each cycle. The
phases of sleep progress
in a cycle from
phase one to REM
(rapid eye movement)
sleep, after which the
cycle starts again.
PHASE ONE is light sleep, when
you’re still half awake. Your muscles
relax, your pulse slows and your
eyes move from corner to corner.
This phase lasts just a few minutes.
The slightest disturbance will wake
you and you may experience a
sensation of falling. That’s because
your muscles have started to relax.
PHASE TWO You spend almost
half of your total sleep time in
phase two, called true sleep. It
lasts for almost 20 minutes at
a time and your heartbeat,
breathing and brain waves
slow down.
PHASE THREE is the start
of deep sleep. You’re now
thoroughly relaxed. In this phase
huge, slow brain waves called
delta waves begin to occur.
Your breathing and heartbeat
decrease to their lowest possible
levels.
PHASE FOUR The brain produces
almost only delta waves and it’s
very difficult to wake you. If you’re
disturbed during deep sleep you’ll
struggle to adjust to being awake
and will feel disoriented and
groggy. Deep sleep is the phase
during which some children
experience bedwetting, night
terrors or sleepwalking.
PHASE FIVE The last phase of the cycle is REM sleep. It starts about 70 to 90 minutes after you’ve fallen asleep. Adults spend about 20 per cent of their total sleep time in this state while for babies it’s about 50 per cent. REM sleep lasts longest at night. If you doze off during the day the REM phase is longer during morning naps than in the afternoon. REM sleep may play an important role in brain development. Therefore the more REM sleep your child gets the better. As your baby grows and the brain develops less time is spent in REM sleep.
During REM sleep your brain rhythms look similar to those when you’re awake. Your eyes jerk rapidly in various directions, breathing becomes more rapid and blood pressure rises. But because messages from the brain stem to the rest of the body are ‘‘switched off ’’ your muscles become temporarily paralysed. This is essential – imagine what would happen if you acted out your dreams! Despite the temporary paralysis men may still experience erections.
It’s difficult to wake you from REM sleep and if it happened you would be disoriented and your thoughts bizarre. This is also when you’d be dreaming about that giant hairy worm chasing you and a scantily clad Angelina Jolie (or Brad Pitt) over the lip of a volcano – before you simply fly away . . .
REM sleep is an extremely sensitive state, affected by food and drink (particularly caffeine), medication (asthma treatments, for example), alcohol, diet pills (which contain stimulants), diuretics, cigarettes and extreme cold or hot environments.
If REM sleep is interrupted just once during the night your body doesn’t return to the normal sleep cycle when you go back to sleep – it goes directly back into REM sleep to try to catch up. Mothers of young children spend more time in REM sleep than in any other phase because of the constant interruptions of their sleep cycle. After REM sleep the entire sleep cycle starts again.
Sleep has recurring cycles – between
three and five a night – of 90 to 110 minutes
each. The cycles of sleep become more
shallow as the night progresses.
DEEP SLEEP Is also the phase when hormones such as testosterone and growth hormones are secreted. In adults growth hormones ensure cells, skin, bone tissue and muscles remain healthy – your proverbial beauty sleep. In babies and children they facilitate growth and trigger puberty.
HOW DANGEROUS ARE SLEEPING PILLS?
Doctors generally try to treat sleep
disorders without resorting to medication,
and especially without the use of
benzodiazepam sleeping pills. Not all
sleeping pills are the same – some are
definitely more addictive and dangerous
than others.
Sleeping pills can be fatal in large doses
and particularly if they’re taken with
alcohol or anything else that can make you
drowsy. Benzodiazepams are extremely
addictive and potentially dangerous
– they can cause birth defects in fetuses
and leave newborns with respiratory
problems, among other things, if a mother
takes them during pregnancy. Children
shouldn’t use them since it may delay
physical and mental development.
Because benzodiazepam has a depressant
effect it can be dangerous to people
with respiratory illnesses, depression,
psychiatric conditions, muscle disease,
porphyria, sleep apnoea, epilepsy,
glaucoma, kidney or liver trouble or
alcohol or drug problems.
Under no circumstances should you
take sleeping pills not prescribed specifically for you. You must also follow the
recommended dosage exactly.
Types of sleeping pills
There are mainly two groups of sleeping
pills: the benzodiazepams (such as
Halcion, Normison, Loramet, Dormicum,
Dormonoct and Hypnor) and the new
generation of non-benzo diazepams (such
as Stilnox and Imovane).
Benzodiazepams help with anxiety and
insomnia but they’re also used as a sleeping
pill before anaesthetic, as a light
anaesthetic, in the treatment of alcohol
abuse and as a muscle relaxant.
Some benzodiazepams induce sleep
almost immediately but their effect lasts
just a few hours. Others work for more
than 12 hours. The faster they take effect
the more addictive they are.
Dormicum, Dormonoct and Halcion
work so fast you could fall asleep before
you have time to get into bed. Within a
few weeks of using these fast-acting drugs
– or any fast-acting sleeping pill – you
could become addicted and experience
severe withdrawal symptoms when you
stop taking them.
Certain sleeping pills, such as Rohypnol
and Dormicum, cause such severe memory
loss they’re abused as date rape drugs.
If you’ve been using sleeping tablets for
weeks you shouldn’t go cold turkey if you
want to stop. Wean yourself off the tablets
gradually with your doctor’s help.
Sleeping tablets such as Stilnox, which
are not benzodiazepams, are used just to
help you fall asleep. You’re less likely to
become dependent on this type.
DO ANY OTHER PRODUCTS WORK? The popular herbal remedy Valerian has a calming effect but its side effects aren’t well researched. Pregnant women, children and people with liver problems should preferably avoid it. It should
also not be used in combination with other medications that make you drowsy. There is anecdotal evidence that avenasativa
(wild oats), lavender and chamomile also help. Nytol contains an antihistamine that relaxes you. It shouldn’t be given to
babies, children or pregnant women or be taken in combination with other medications that make you drowsy.
SLEEP AND YOUR BODY’S INTERNAL CLOCK
The secret of your unique sleep needs can be
revealed by considering your body’s internal
clock, also called the circadian clock (circadian
comes from a Latin word meaning ‘‘around the day’’). It
refers to the body’s response to external things – sunlight,
for example – during a 24-hour cycle.
Your circadian clock is in the hypothalamus. It’s a structure the size of a
pinhead; it responds to light received by the eye and regulates the secretion
of melatonin, the sleep hormone. In all people, with the exception of teenagers,
the amount of melatonin secreted increases from sunset onwards
– it’s literally the body’s Mr Sandman!
This part of the brain also synchronises other functions linked to going
to sleep and waking up, including body temperature, hormone secretion,
urination and blood pressure.
If you visit someone in Australia you fl y from west to east and cross
several time zones. This interferes with your circadian rhythms in the worst
possible way and results in jet lag. Crossing time zones in the other direction
– from east to west (from Australia to South Africa, for example) also causes
jet lag but not to the same degree.
Today artificial melatonin supplements and light therapy (doctors apply
bright lights during sleep to restore normal biorhythms) are used to combat
the effects of jet lag. Melatonin should however be used only under medical
supervision. It builds up in the body and its side-effects haven’t yet been
thoroughly researched.
Jan Top of the Panorama Sleep Clinic says shift workers suffer from a
similar type of exhaustion because their bodies’ normal exposure to light
is disturbed. Fatigue among shift workers has resulted in serious industrial
disasters. The nuclear accidents at Chernobyl and Three Mile Island, the Exxon oil spill and most of the motor vehicle accidents on the road between Laingsburg and Beaufort West have been linked to sleep deprivation. Shifts should be limited to eight hours and the body must be allowed a rest period before shifts change, Top says.
DID YOU KNOW?
Because of the body’s circadian
clock there’s a greater risk of dying
between 4-6 am. Most heart
attacks occur in the early hours of the
morning. Your body weight is at its
lowest between 9 am and noon while
reaction time peaks at about 4 pm.
Asthma attacks typically happen
between midnight and 6 am and
most women give birth
naturally around 1 am.
SLEEPING DISORDERS
It’s estimated one in four people suffer
from some form of sleeping disorder
– and it affects both their productivity
and quality of life
Sleeplessness
Sleeplessness (insomnia) is the most common
sleeping disorder and most people suffer from it at
some point in their lives, says Dr Frans Hugo of the
Panorama Psychiatry and Memory Clinic.
Stress, poor diet, hormonal changes, underlying
illness or jet lag are the most common causes. Age
also plays a role and more women than men struggle
with sleeplessness after middle age.
According to Dr Hugo 90 per cent of sleeplessness
can be treated without medication. ‘‘I always
tell my patients Randy Gardner’s record is 11 days,
so you know you’re going to sleep after two weeks
because at some stage your sleep debt will be so
huge you’ll simply drift off .’’
Good sleep habits are as good as any pill when it
comes to conquering insomnia,
he says. Sleeping pills are a temporary solution at
best because within a few days the brain ‘‘unlearns’’
how to sleep. ‘‘When you’re on medication your
sleep ‘architecture’ is different. You have less REM
sleep and your memory patterns are less firmly
fixed,’’ Dr Hugo says. Before popping a sleeping pill
ask yourself how long you’re planning to take them
because some medications – especially benzodiazepam
sleeping pills such as Valium – are addictive.
Sleep apnoea
If you believe snoring isn’t dangerous, think again.
In some cases it’s a symptom of sleep apnoea, which
can be life-threatening.
Sleep apnoea (when you stop breathing for
short periods while sleeping) is one of the most
undiagnosed medical conditions, Jan Top of the
Panorama Sleep Clinic says. ‘‘If you sleep badly,
snore heavily and are overweight you should
consult your doctor.’’
Sleep apnoea occurs when fat accumulated
around the neck, such as a double chin or
slackened muscle tissue, flattens the oesophagus
during sleep and blocks the flow of air for 10 to
60 seconds. The brain registers a shortage of
oxygen, you gasp for air and start breathing again
normally. This can happen up to 100 times a night,
leaving you tired, irritable and unhappy the next day. You also get headaches because of oxygen deprivation.
‘‘People joke about being woken by their partner’s snoring
but sleep apnoea can be lethal,’’ Top says. ‘‘It can cause
serious diseases such as diabetes, heart attacks, kidney
damage and depression. When you read about people dying
peacefully in their sleep it’s often as a result of sleep apnoea.’’
New research shows a second type of sleep apnoea which
has nothing to do with obesity and obstruction but is caused
by a fault in the breathing control centre of the brain.
Although it can be dangerous it can be treated effectively.
Some people stop breathing at night because signals from
this centre in the brain don’t reach the muscles used to
breathe, Pretoria East Sleep Clinic neurophysiologist Bernard
Tjallinks says.
Sleep clinic experts are able to diagnose both types of
sleep apnoea and treat them with an apparatus that blows
air into the mouth, ensuring continuous oxygen intake.
Doctors warn sleep apnoea sufferers not to use sleeping
pills or tranquillisers because these drugs could stop them
breathing completely.
Sleepwalking
Sleepwalking (somnambulism) happens during phase four
or deep sleep. You get out of bed and do things in your sleep
that you’d normally do when you’re awake. It’s difficult to
wake you at the time and you can’t remember what happened
after the event. Sleepwalkers can injure themselves or
others. In America police pulled a driver off the road only
to discover the woman had loaded her dogs into the car and
driven 40 km – in her sleep!
Sleep terror disorder
Sleep terror disorder (night terrors) typically occur in
children and make nightmares seem tame. Parents shouldn’t
touch or pick up the child. Switch on a dim light and soothe
him in a soft voice until the episode has passed.
Restless leg syndrome
Restless leg syndrome runs in families. It’s an unpleasant
itching, prickling or tingling in your legs or feet and you
have to move around to get rid of the sensation. Older
people especially are affected. It causes sleeplessness and
is also linked to anaemia, pregnancy and diabetes. Medicine
specifically targeting the neurotransmitter dopamine
is effective.
Periodic limb movement
disorder (PLMD)
Have you ever been woken in the middle of the night because
your bedmate suddenly pulls up both legs, moves his
feet or throws his arms and legs wide? It’s telltale behaviour
of someone suffering from PLMD, Peet Vermaak says.
It’s the only movement disorder that occurs only during
sleep and can vary from repetitive cramps or jerking of the
knees, ankles and toes to large movements of all four limbs.
Many people who have PLMD don’t realise their legs and
feet move suddenly at night and disrupt their sleep; they
just feel tired the next day.
The occurrence of PLMD increases with age: almost
50 per cent of people over 65 have it. Treatment with
dopamine or sleeping pills can help.
Narcolepsy
People with narcolepsy have ‘‘nap attacks’’ during the day,
irrespective of how they sleep at night. The attacks occur suddenly
and can last from a few seconds to about 30 minutes.
Narcolepsy sufferers can also experience catalepsy (loss of
muscle control during emotional situations such as a violent
argument), hallucinations and temporary paralysis when
they wake up. The condition is serious because it can lead
to a fatal injury or accident.
Narcolepsy usually runs in families but is sometimes
linked to brain injury. It’s usually treated with stimulants or
antidepressants.
REM behaviour disorder
It sounds like something from a Halloween horror film
but REM behaviour disorder develops when the brain fails
to temporarily paralyse the muscles during REM sleep.
The result is you literally act out your dreams. Top tells of
a patient who knocked herself unconscious by running
into a wall at the sleep clinic because she was ‘‘trying to
catch a ball’’. ‘‘It’s rare but seeing it is scary and sufferers
can seriously injure themselves or others,’’ Top says.
In America there have been controversial cases in which
sufferers have committed murder or other violent acts because
of the disorder. Doctors link it with conditions such
as Parkinson’s and brain-stem damage.
Good sleeping habits
- Keep a notebook
handy and write
down anything that’s
worrying you and
may be keeping you
awake.
- Learn to fall asleep
without thinking
about it. Don’t wait to ‘‘switch
off ’’. Visualise something nice
or replay a movie you enjoyed
in your head. Dr Frans
Hugo of the Panorama
Psychiatry and Memory
Clinic says a colleague
loves Audis and every night
visualises himself walking
into a showroom, getting
into the fl ashiest car and
driving away – straight into
dreamland.
- Avoid stimulants
such as coffee,
chocolate and nicotine
after 6 pm. Alcohol
should be consumed early in
the evening and in moderate
amounts. It may relax you
at first but your brain could
switch back on in the middle
of the night after the alcohol
has been metabolised.
- Teach your brain that
bed is only for sleep and
sleep is only in bed. Don’t toss
and turn. If you’re not asleep
after 10 or 20 minutes get
up and do something boring
somewhere else – you could
even try reading the telephone
directory! Don’t watch television
or videos, read an exciting
book or try to work.
- Don’t get anxious if you can’t
sleep for a few nights. You’ll
soon catch up. ‘‘Comfort
yourself with the thought
you’ll probably sleep better
the next night or the one
after that. The worst that
can happen is you’ll be tired
and irritable the next day,’’
Dr Hugo says.
- Follow the same routine
every day. Your brain will learn
to associate it with sleep.
Exercise can help but should
be done early in the evening.
A hot bath and soothing
music can also be effective.
Try to sleep until sunrise.
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