Most people have heard of narcolepsy, but few really know what it is and how it affects sufferers. The brain disorder disrupts sleeping patterns and tends to cause excessive daytime sleepiness, which can sometimes result in sufferers falling asleep at inappropriate times. It affects around 25,000 people in the United Kingdom.
What are the symptoms?
As well as the nodding off bit, which most people are aware of anyway, the long-term condition also causes difficulty concentrating for many sufferers. The condition can often be misinterpreted as laziness or rudeness by those unaware of it. Cataplexy – or loss of muscle control – is a less well-known symptom – and it often follows strong emotions like laughter or anger.
Sleep paralysis is also frequently reported, with sufferers having difficulty moving as they fall asleep or wake up. While the condition does not cause serious health problems, it can have a severe impact on everyday life and restrict what sufferers are able or allowed to do. If you are diagnosed with the condition you should stop driving immediately and inform the DVLA.
Research has indicated that narcolepsy is caused by a lack of the brain chemical orexin, which has the role of regulating sleep. It has been suggested that some people's immune systems attack the chemical mistakenly, however this is not always the cause.
Aside from the cause, a number of triggers have been identified. These include inherited genetic fault and hormonal changes – such as those which accompany puberty or the menopause. Other triggers are serious psychological stress, a sudden change in sleep patterns, an infection such as flu or having the flu vaccine Pandemrix.
Narcolepsy can also sometimes develop as a secondary illness, when somebody is suffering from a brain tumour, a head injury, multiple schlerosis or encephalitis. It appears to affect men and women equally, and often emerges during adolescence. It is usually diagnosed between the ages of 20 and 40.
How is it diagnosed?
Narcolepsy is one of those illnesses which is identified by ruling out other possibilities – and once that has been done sufferers will usually be asked to keep a sleep diary and fill out a questionnaire on their sleeping habits. Care has to be taken in the diagnosis, as it shares some symptoms with other conditions such as sleep apnoea, epilepsy, depression and an underactive thyroid gland. A physical examination, blood pressure test and blood test could also follow – and if your doctor believes you may have the condition you will be referred to a sleep specialist.
More questions will follow and you may be asked to visit a sleep centre where you will stay over for the night with electrodes attached to your body and sensors monitoring your sleep activity. Other diagnostic tools include a sleep latency test – basically checking how quickly you fall into REM sleep during a daytime nap – and measuring the level of orexin in your brain using a lumbar puncture procedure.
Is there a cure or treatment?
The bad news is that there is currently no cure. The good news is that the condition can be managed to a certain extent so that it has less impact on sufferers' daily lives. Establishing good sleeping habits is the first step for most patients – and this can include taking frequent short naps throughout the day, sticking to a strict routine at bedtime, relaxing before hitting the sack and avoiding caffeine in the later part of the day.
Exercise is encouraged, but don't work out too close to bedtime. Medication can also be prescribed in more serious cases – with stimulants to help sufferers stay awake, sodium oxybate to relieve cataplexy and anti-depressants to treat cataplexy, hallucinations and sleep paralysis.
Check out the NHS Choices website and Narcolepsy UK for more information and support. There is more information about narcolepsy and driving on the gov.uk website.