Find out more about the most common sleep disorders.
Sleep apnoea is a common condition which is characterised by periodic cessations or reductions in breathing during the night. A common feature of sleep apnoea is snoring, although snoring does not necessarily occur in all sleep apnoea patients.
In people who have sleep apnoea, during the night the walls of their throat come together and partially or fully obstruct the airway.
Breathing stops for a period until a drop in blood oxygen levels triggers the brain to begin waking up. As the brain begins to wake up, muscle tone returns to the throat. Normal breathing resumes and the sleeper falls back to sleep.
In most cases the sleeper is not aware of waking. This pattern can repeat throughout the night, interrupting normal sleep patterns and putting extra strain on the heart.
Symptoms of sleep apnoea are:
- daytime sleepiness, fatigue and tiredness
- poor concentration
- irritability and mood changes
- impotence and reduced sex drive
- need to frequently urinate during the night
- witnessed apnoeas or periods of
Treatment can involve making lifestyle changes such as:
- weight reduction
- reducing alcohol intake
- improving cardiovascular health
Continuous positive airway pressure (CPAP) is the most effective treatment for obstructive sleep apnoea. The sleeper wears a mask which transmits increased air pressure into the airway, preventing the walls of the throat from collapsing during the night. The key to successful CPAP therapy is finding the right mask and air pressure for the patient.
Mandibular advancement splint (MAS) devices are mouth guards that hold the bottom jaw forward during sleep. They can be effective for less severe forms of sleep apnoea.
Although not always effective, surgery to the palate and base of tongue may be useful when other therapies fail.
Restless leg syndrome (RLS) is a nervous system condition characterised by unpleasant sensations in the legs and the uncontrollable urge to move them. Patients often describe a tingling, itching or crawling sensation in their legs.
Symptoms occur primarily at night when a person is relaxing and can range in severity from uncomfortable to painful.
Most people will experience the symptoms of restless legs at some point in their life. Precipitating factors include pregnancy, iron deficiency, antidepressant use and kidney failure.
The cause of RLS is unknown, although there appears to be a genetic link, with the condition occurring more frequently in families.
Periodic limb moments (PLMs) occur during sleep, can be severe enough to wake the sleeper and can result in poor sleep and daytime fatigue.
An assessment of RLS usually includes a comprehensive clinical evaluation. Iron levels will be checked and the patient will usually undergo a sleep study to look for co-existing sleep issues, such as sleep apnoea.
RLS can often be treated with iron supplements if iron levels are low. Measures such as pacing or walking can provide short term relief. For more severe cases, medication can be prescribed that can lessen the symptoms of RLS.
Difficulty falling asleep or staying asleep is a very common problem. In any one year 30% of the Australian population have difficulty sleeping.
There are many reasons why people have difficulty falling asleep so it’s important to be carefully evaluated by your doctor to ensure there are no other contributing factors. Insomnia is usually a symptom of something, rather than a disease. If insomnia persists over a month or more, it is called ‘persistent insomnia” or 'chronic insomnia'.
People who suffer from insomnia often become frustrated or anxious about their sleeplessness, which contributes to their insomnia. It can help to stop expecting to sleep all night. Having less sleep may cause tiredness but will not cause harm.
Sleep hygiene refers to the behaviours we have around sleep. Some habits, such as watching television in bed or napping during the day can negatively affect our ability to get a good night’s sleep.
Treatment for insomnia usually combines changing behaviours and thoughts around sleep. Pharmaceutical intervention is sometimes employed but is rarely successful in the long term unless behaviour and thoughts are addressed.
Narcolepsy is a rare condition, affecting 1 in every 2,000 people.
It affects both genders and is usually first observed between the ages of 10 and 30. It is a chronic neurological disorder that results in excessive daytime sleepiness. It may occur in conjunction with other symptoms such as cataplexy, sleep paralysis and hallucinations.
In people with narcolepsy, the part of the brain that controls falling asleep functions abnormally. During the day while they are awake, they may fall asleep with minimal warning, often going straight into a stage of sleep called Rapid Eye Movement (REM) sleep.
REM sleep is associated with dreaming and a loss of muscle tone which is why people with Narcolepsy sometimes experience hallucinations and cataplexy.
If your sleep physician suspects narcolepsy, they may refer you for a Multiple Sleep Latency Test (MSLT). You will have a normal overnight sleep study in a sleep laboratory and then stay the next day for a series of naps at two hour intervals.
During each nap you will be encouraged to try to sleep and two parameters will be assessed:
- How long it takes you to fall asleep
- Whether you have REM sleep
Falling asleep quickly and having multiple episodes of REM sleep tend to indicate narcolepsy.
There is no cure for narcolepsy but symptoms can be controlled with medication. Antidepressant medication can help with cataplexy and stimulants can alleviate symptoms of sleepiness. Planned napping can also help to lessen symptoms.
Disorders of arousal from sleep are known as parasomnias. They usually occur during arousal from Non-Rapid Eye Movement (NREM) sleep when sleep and wake overlap.
Common parasomnias include:
- Somniloquy (sleep talking)
- Somnambulism (sleepwalking)
- Pavor nocturnus (night terrors)
Parasomnias can occur for a range of reasons and it’s important to determine if the events occur spontaneously or are triggered by other sleep disorders. It is for that reason that a sleep study is usually recommended when evaluating the disorder.
If parasomnias occur during NREM sleep, they usually begin in childhood and lessen in frequency with age. These parasomnias can often be effectively managed by avoiding alcohol and ensuring adequate sleep but they can be treated with medication if required.
Other parasomnias that occur on arousal from REM sleep (REM behaviour disorder or RBD) tend to occur in men over the age of 50 and can manifest as dramatic or violent outbursts during sleep.
In the diagnosis of RBD other neurological disorders must be ruled out. An overnight sleep study is used in the diagnosis of this disorder and treatment often involves medication.