We all need sleep, but a restful night isn't always on the cards. Let's take a look at...
- Sleepwalking, driving and even killing
- Non-24-hour sleep-wake disorder
- Narcolepsy
- Sleeping beauty syndrome
- Restless legs syndrome
- Shift work disorder
- Fatal familial insomnia
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| Sleepwalking can include other activities than just walking - like driving or murder! (Didgeman) |
Sleepwalking, Driving and even Killing
Sleepwalking or somnambulism usually happens during deep sleep. It runs in families (implying some kind of genetic link) and manifests most commonly in children. The chances of an episode seem worsened by stress, anxiety, fatigue and substance abuse. Being disturbed by sounds or having to get up to use the bathroom also seem to increase the likelihood.
Sleepwalkers typically appear awake - their eyes are usually open, though they may look right through people and give garbled responses if questioned. A walk usually lasts under 10 minutes and doesn't leave much of a memory. Usually it's best to keep an eye on the sleepwalker until they return to their bed of their own accord. If suddenly roused, the walker may lash out in confusion.
Common activities performed by a sleepwalker include sitting up in bed and looking around or going for a short wander. Rare cases include other activities, such as a woman who drove a motorbike and car in her sleep or a man that killed his wife in his sleep whilst dreaming that she was an intruder - the courts found him not guilty.
Non-24-Hour Sleep-Wake Disorder
Most people sleep in an established pattern, guided by their circadian rhythm (or body clock.) This clock isn't actually 24 hours long - the suprachiasmatic nucleus of the brain makes little adjustments from environmental cues (like how light it is) to keep the clock synchronized. Non-24-hour sleep-wake disorder is what happens when this mechanism fails.
Most commonly found in the blind (around 50% are thought to develop it since they cannot perceive light cues) the disorder can show up in the sighted as well. It is not known exactly what causes it in this situation, though being male or suffering traumatic brain injury seem to be risk factors.
Those with the condition tend to develop a 24-25 hour sleep cycle that gradually moves their "wake up" time later in the day. Eventually it loops back around and becomes "normal" again for a while, just like a clock that runs slow!
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| Narcolepsy can be found in dogs as well as humans... (Engin_Akyurt) |
Narcolepsy
You may have heard of people falling asleep in boring situations - but narcoleptics can experience the opposite problem. Bursts of strong emotion can drop them into state similar to REM sleep.
Narcolepsy seems to be the result of a number of underlying factors. Genetics, brain injury, autoimmune disease and disease in general all seem to play a role, and the condition seems more likely to develop in the Spring or early Summer. More severe cases are associated with low hypocretin (brain hormones that regulate sleep) levels.
The symptoms of narcolepsy range from excessive daytime sleepiness to "sleep-attacks" and the aforementioned cataplexy. Suddenly becoming overwhelmingly tired as a sleep-attack is bad enough, but cataplexy causes a temporary loss of muscle tone (i.e. weakness or paralysis.) Not only can this cause the sufferer to fall, they remain completely aware but unresponsive while it lasts.
Narcolepsy isn't limited to humans. The condition crops up in dogs, with similar triggers and results. Fainting goats also exist, but that's a different condition called myotonia congenita.
Sleeping Beauty Syndrome
Kleine-Levin syndrome is also known as Sleeping Beauty, as sufferers experience bouts of hypersomnia (excessive sleep) and can sleep for 20 hours at a time. Less fitting of the nickname are the other symptoms, often including enhanced appetites (both binge-eating and hyper-sexuality) along with abnormal behavior, irritability and confusion.
The syndrome is cyclic (sufferers experience episodes lasting between days and months, then long periods of normalcy) and devastating while active. Normal life is impossible during an episode - even if you're not sleeping, you're typically tired, bedridden and uncommunicative.
It is unknown what causes Kleine-Levin syndrome, but most sufferers are adolescents and episodes can occur periodically for as long as 10 years. Because the disease is so rare (and in some ways, hard to separate from other illnesses) it usually takes around 4 years before it is diagnosed.
Restless Legs Syndrome
Sometimes known as Willis-Ekbom syndrome, those afflicted with restless legs have an overwhelming urge to... move their legs. It doesn't sound like a big deal, but this desire is like an itch you can't scratch - and it tends to get worse at night. It can also cause strange feelings inside the legs or arms - imagine trying to sleep with your flesh crawling, prickling or burning beneath your skin.
To make matters worse, the condition often comes as a package with periodic leg movement disorder. This causes involuntary movements (both when asleep or awake) often resulting in kicks or flailing.
It's not actually clear what causes the syndrome. Some specialists believe that there is a link to dopamine, a naturally occurring neurotransmitter known as the "feel good" hormone. Dopamine levels in the human body start to drop towards the end of the day (perhaps explaining why it gets worse at night) and the condition can be treated by modulating dopamine levels in the patient (though not without side effects.)
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| Shift work can have serious effects on the brain... (Photographer2575) |
Shift Work Disorder
Shift work disorder occurs when an individual has difficulty adjusting to new sleep schedules, usually due to shift work. Symptoms include fatigue and sleep disturbance, as the circadian rhythm (natural sleep cycle) of the sufferer has been disrupted by the change in "bedtime."
Now this may sound like a minor thing that could be reversed by a few early nights and a couple of days to acclimatize - but a 10 year long study carried out on shift workers uncovered long-term effects. The longer someone remained in shift work, the more dramatically their cognitive abilities were impaired.
The study found that these effects took years (if not decades) to clear after ceasing shift work!
Fatal Familial Insomnia
Insomnia is bad enough - poor sleep leads to a lack of energy, impaired judgement and irritability. Now imagine that you could develop a progressive insomnia that slowly intensifies until the patient finally dies. This waking nightmare is the reality of individuals carrying a prion disease called fatal familial insomnia, a condition that lasting around two years between onset and death.
All sufferers carry an abnormal PRNP gene, whether through their heritage or via random mutation in their own DNA. This gene causes the production of toxic misfolded proteins called prions that build up in the body. Over time these prions accumulate in the thalamus, interfering with normal brain function as they kill neural tissue.
There is currently no cure for fatal familial insomnia, but scientists are developing preventative treatments for those identified as carrying the gene. Due to the nature of this condition, a long incubation period in which prions are accumulating precedes the onset of insomnia. By treating these individuals with doxycycline (an antibiotic that also has an anti-prion effect) researchers hope to "stall" the levels of these prions, keeping patients in the incubation phase rather than the insomnia phase.
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