Sleep disorders: When going to bed is a nightmare

If you think that the worst that can happen at night is insomnia, think again. A range of little known, but relatively common, sleep disorders can cause fatal injury, disrupt personal and working life, or lead to dangerous misdiagnoses. Sleep medicine is still a young science – but effective methods of diagnosis and treatment are finally making night-time safer. Here are seven of the most problematic.

REM Sleep Behaviour Disorder

What is it?

Brain activity during Rapid Eye Movement (REM) sleep, the crucial 25 per cent of slumber when we dream, is pretty much the same as when we're awake. The big difference, however, is that our muscles become so relaxed during this time that we are effectively paralysed – almost certainly a protective mechanism to prevent people acting out dangerous dreams. When this mechanism doesn't work during REM sleep, it results in REM Sleep Behaviour Disorder (RBD) – where sufferers are able to act out dreams that can often be "vivid, action-filled and antagonistic", according to RBD expert, Dr Carlos Schenk of the Sleep Disorder Centre at the University of Minnesota.

Three in 100 people, mainly men over 50, suffer from RBD, sometimes with devastating consequences; some self-harm and many assault their partners. Typically, an RBD sufferer yells out, punches or kicks in response to a dream, and court cases involving RBD show that choking and headlocks are common.

Retired steelworker, Brian Thomas spent 10 months in prison after he got his wife in a headlock and then strangled her while in the throes of a nightmare during a romantic weekend away. Thomas, 59, from Neath, near Swansea, was only freed in November when the prosecution acknowledged that the cause of his behaviour was RBD rather than malice.

What causes it?

Scientists don't yet know what causes RBD, though around 40 per cent of sufferers go on to develop Parkinson's disease.

What's the treatment?

Getting the disorder diagnosed in a sleep clinic is an essential first step. Sleeping alone, preferably on a mattress, is advisable. Some sufferers tether themselves to the bed or use pillow barricades. "It is now standard practice to treat RBD with clonazepam, a non-addictive benzodiazepine, though it is not yet licensed for this purpose in the UK," says Dr Chris Idzikowski, Edinburgh Sleep Centre director ( www.edinburghsleepcentre.com ).

Restless Legs Syndrome

What is it?

One in 10 of the population experience an irresistible urge to move their legs as a result of an itching, burning, or otherwise uncomfortable feeling in the legs when they are sleeping. Eight out of 10 RLS sufferers also experiencing involuntary leg twitching during sleep. Until recently it was frequently misdiagnosed as a brain or muscle disorder, or sufferers were thought to be depressed. Now, however, doctors have started to recognise that RLS is a serious health problem, disrupting sleep and having an adverse effect on quality of life.

What causes it?

Recent research at John Hopkins University suggests that an iron deficiency in the brain is a major cause of RLS. Scientists are optimistic that on-going research funded by the pharmaceutical industry will soon produce a drug that cures RLS by targeting the way the body regulates iron intake.

What's the treatment?

Get a diagnosis at a sleep clinic. There is no licensed treatment for RLS, but specialists in the UK will try a range of medications to treat the disorder, including anti-epileptic drugs, opiates to induce relaxation and sleeping pills. Practise Pilates, yoga or other stretching exercises late in the day.

Bruxism

What is it?

Eight out of 100 people grind their teeth at night, disrupting sleep, damaging teeth and causing facial pain.

What causes it?

A typical sufferer is a young, educated adult who smokes, drinks lots of coffee and alcohol, and may be suffering from anxiety. People with obstructive sleep apnoea are also at higher risk.

What's the treatment?

Wearing a plastic gum shield prevents the noisiest grinding as well as wear and tear of teeth. Hypnotherapy can also help.

Sleep walking

What is it?

Nearly one in five children are somnambulists – which involves getting out of bed and walking around the room or house in a confused state while deeply asleep. It's most common between the ages of three and five. But it can persist into, or even begin in, adulthood.

What causes it?

Obstructive sleep apnoea (see below) is one of a number of sleep disorders that can trigger sleep walking, as is bed-wetting in children. Adults start sleep walking usually as a result of sleep deprivation or of being under the influence of sedatives, including alcohol.

What's the treatment?

Sleep walkers may become angry if woken – but it's far more dangerous not to wake them. Making the bedroom safe by locking doors and windows, and removing sharp objects around the (non-bunk) bed, is an obvious strategy. Hypnotherapy can help. Dr Idzikowski recommends paroxetine and clonazepam for adult sleep walkers – as well as cutting back on caffeine, cigarettes and alcohol, and going to bed at regular hours.

Sleep paralysis

What is it?

The brain signals that inhibit muscle movement during REM sleep may not stop immediately on waking. Four out of 10 people experience this phenomenon at least once in their lives. They feel paralysed, and and one in five of this group also experience bizarre and often terrifyingly realistic visual and auditory hallucinations. Most frequently they report seeing or feeling a ghostly, devil-like or human presence in the room. The disorder used to be explained as the work of witches or nocturnal attacks by devils or evil spirits, according to Chris French, Professor of Psychology at Goldsmiths University, London. But today, he says, it's more likely to explain the relatively widespread belief in alien abduction,

"People need a logical explanation to reassure themselves that they are not losing their sanity. They read about sightings of UFOs and the endorsement of alien abduction by a handful of maverick scientists. And then they discover that other people have had the same experience, and as an explanation, it becomes almost comforting," says Professor French. "What clinches the conviction is the widely held belief that aliens routinely wipe all memories of the actual kidnap, so that just because you can't remember being abducted doesn't mean it didn't happen."

The widely quoted statistic that 3.7 million Americans believe they have been abducted by aliens is actually based on a questionnaire which listed the symptoms of sleep paralysis. "The research assumed that anyone who had a memory of being unable to move while feeling the presence of frightening creatures or humanoids had actually been abducted," says French.

What causes it?

It's probably an hereditary disorder and often happens to people with narcolepsy (below), occurring most frequently as a result of sleep deprivation or stress.

What's the treatment?

Avoid getting overtired, sleep at regular hours, and reduce stress as far as possible. Be aware that disruption to the sleep cycle such as jet lag or shift work raises the risk. Most people need only reassurance – and many can learn

to enjoy, or at least tolerate, an occasional episode. But for those severely affected, anti-depressant drugs that suppress REM sleep may be necessary.

Narcolepsy

What is it?

This condition, affecting one in 2,500 men, women and children, is experienced as an irresistible need to sleep for up to an hour during the day. This excessive day-time sleepiness can be triggered by laughter, anger, surprise or sexual arousal, and causes havoc if it occurs while eating a meal, driving a car, bathing a baby or cooking food. Relationships, both personal and at work, also suffer, and people with narcolepsy frequently develop low self-esteem, depression and a terror of falling asleep at an inappropriate time.

What causes it?

Recent research suggests that narcolepsy is the result of the body's failure to produce a brain chemical called orexin, which may be genetic. It may be associated with other sleep disorders, including obstructive sleep apnoea and and restless legs syndrome.

What's the treatment?

Counselling, lifestyle, advice on exercise, scheduling sleep and mealtimes, and cognitive behavioural therapy help to come to terms with the disorder and control the unplanned naps. Stimulants including amphetamine can be prescribed to increase alertness.

Obstructive sleep apnoea

What is it?

This major cause of road traffic accidents due to day-time sleepiness is caused by the muscles in the back of the throat failing to keep the airway open, despite efforts to breathe. In severe OSA, the sufferer doesn't breathe for up to one minute, sometimes as many as 400 times a night. It's not a killer – at least not directly. The body has a self-preservation mechanism where the brain wakes you up in order to make you breathe. But up to one in 10 of the population, mostly middle-aged men, have their sleep seriously disrupted by OSA, with partners suffering from the noisy snoring that goes with it.

A recent Israeli study suggests that far from being dangerous, OSA actually extends your lifespan, possibly because the constant breaks in oxygen and blood supply to the heart and brain, caused by the pauses in the breathing, somehow strengthen these organs and make them better able to cope if a heart attack or stroke occurs. Most experts, however, insist that treatment is essential, and the Department of Health is now funding treatment and research to what is seen as a major social and clinical problem.

What causes it?

Obesity, a double chin, smoking and drinking are all thought to contribute.

What's the treatment?

The most effective method, using a Continuous Positive Airway Pressure device, is usually prescribed only after diagnosis in a sleep clinic. This nasal gadget keeps the airways inflated so that the lungs receive oxygen throughout the night. Those with milder symptoms can wear a plastic gum shield (a Mandibular Advancement Device), which forces the lower jaw forward and stops the tongue from blocking off the airway to your throat.