This is a central nervous system disorder, associated with sleep problems. These include tiredness, excessive sleeping or sleepiness in daylight hours, hallucinations, sleep paralysis, (being unable to move when either waking up or going to sleep), sleep attack (falling asleep instantaneously and without warning) and sometimes partial or total loss of muscle control can occur (e.g. emotional stimulus can lead to a person from down with laughter!- this is called cataplexy.) Barring injury when sleep suddenly occurs, it is not thought to reduce life expectancy but can be socially, educationally and occupationally very disabling.
It occurs equally in the sexes, in about 30 000 people in the UK, with the onset often being in late childhood or adolescence. There are probably a large number of people who go unrecognized with this condition.
It is thought to be due to decreased/absent production of a chemical called hypocretin, a peptide, which regulates sleep in the area of the brain called the hypothalamus, meaning that sleep regulation is disturbed. The group of cells that produce hypocretin may be completely or partially destroyed, hence there may be degrees of severity of how a patient may be affected. The exact mechanism is unclear; it is proposed that this is an auto-immune process, i.e. the body attacking itself, although other factors such as hormone alterations in puberty or infections have been implicated too in its development.
Making the diagnosis
The diagnosis may be suspected on the basis of the history, but an examination is required to rule out other possibilities (with relevant blood tests) such as sleep apnoea (obstruction of the upper airway passages at nighttime), or an under-active thyroid gland.
A sleep diary and completing an Epworth Sleepiness questionnaire (see appendix 1) are often used as the first steps towards making a diagnosis of narcolepsy. A score of 10 or fewer is ‘normal’ whilst 18 + means specialist help may be required.
Sleep centre studies
Referral to a sleep studies centre often occurs to confirm the suspected diagnosis. Investigations that can be carried out in this setting includes
- Polysomnographic studies – which monitors muscle, eye and brain activity during sleep
- Measurement of how fast you fall asleep- nacroleptics tend to fall asleep very quickly, and many enter straight into rapid eye movement (REM) unlike most people for whom this may take 40-1 hour plus from initially falling asleep
There is no cure but behavioural modification techniques and medications are used to help affected individuals and minimize the impact of narcolepsy on day to day life. Steps such as taking regular naps lasting 5-10 minutes at spaced out intervals may overcome daytime tiredness, and adhering to a regimented bedtime may also help. There are support groups such as narcolepsy XXX which may be of use, as the impact on lifestyle can be considerable for the condition and for tis treatment, hence advice and help can be sought from these patient groups.
Financial benefits may be available to sufferers, e.g.
Personal Independence Payments, Employment and Support Allowances. Permissible benefits do vary in the devolved nations and guidance should be sought (e.g. Citizen’s advice bureau).
There may be risk to the person with narcolepsy and to other road users from this condition and the DVLA must be notified when this diagnosis is made by completion of a form otherwise there is a fine payable up to 1000 pounds. www.gov.uk/nacrolepsy
If the patient’s doctor does not state otherwise, the patient must cease driving when the diagnosis is made. Any accidents or incidents that occur may invalidate insurance cover and the patient may face a fine or custodial sentence depending on the nature of the event.
Information, advice and support may be obtained from:
FUTURE LEGAL CASES
There may be legal cases relating to swine flu vaccination. Studies have found an increased incidence among a vaccinated population.