Motor neurone disease is a rare condition that progressively damages the nervous system, causing the muscles to waste away.
Motor neurone disease occurs when specialist nerve cells, called motor neurones, stop working properly. Motor neurones control important muscle activity such as:
- walking
- speaking
- breathing
- swallowing
As the condition progresses, people with motor neurone disease will find these activities increasingly difficult, and eventually impossible, to do.
Exactly what causes the motor neurones to stop working properly is unclear, but several theories have been suggested.
Find out about the possible causes of motor neurone disease.
In its early stages, motor neurone disease causes symptoms such as:
- a weakened grip, which can cause difficulty picking up or holding objects
- a general feeling of tiredness
- muscle pains and cramps
As the damage progresses, the symptoms become more debilitating. In the final stages, a person with the condition will be unable to move their body (the medical name for this is total body paralysis) and their breathing difficulties will get worse.
Read more about the symptoms of motor neurone disease.
Treating motor neurone disease
There's currently no cure for motor neurone disease. Treatment aims to:
- make the person feel as comfortable and have the best quality of life as possible
- compensate for the progressive loss of bodily functions such as swallowing and breathing
For example, breathing masks and feeding tubes can help with breathing and swallowing difficulties, at least in the short to medium term.
A medication called riluzole can extend the lifespan of some people with motor neurone disease, but it's only moderately effective. Most people being treated would only live 3–6 months longer than otherwise expected.
Read more about the treatment of motor neurone disease.
Who is affected by motor neurone disease?
Motor neurone disease is a rare condition that affects around 2 in every 100,000 people each year in England.
Most cases first develop in people in their late 50s or early 60s. Motor neurone disease is slightly more common in men than women.
In around 10% of cases, the person has a family history of motor neurone disease. This is known as familial motor neurone disease.
This type of motor neurone disease usually develops earlier when a person is in their late 40s or early 50s.
Types of motor neurone disease
There are three main types of motor neurone disease, which have similar symptoms but progress in different ways:
- Limb-onset disease begins with symptoms that affect the arms and legs, such as muscle weakness and loss of function. This is the most common type and accounts for 70% of cases.
- Bulbar-onset disease begins with symptoms that affect the mouth and throat, such as difficulties swallowing and slurred speech. This accounts for around 25% of cases.
- Respiratory-onset disease begins with symptoms that affect the lungs, such as shortness of breath. This accounts for around 5% of cases.
Survival rates
The outlook for motor neurone disease is very poor:
- People with limb-onset motor neurone disease will live for 3–5 years after their symptoms start.
- People with bulbar-onset and respiratory-onset motor neurone disease will live for 2–3 years after their symptoms appear.
People with some other less common types of motor neurone disease would be expected to live for up to 10 years. Some people have lived for several decades. The most famous example is the British physicist Stephen Hawking, who was diagnosed with motor neurone disease over 40 years ago.
Living with motor neurone disease can be frustrating, challenging and sometimes a terrifying possibility, but it's not necessarily as bleak as many people imagine. With treatment and support, many people lead a relatively independent lifestyle and enjoy a reasonably good quality of life.
However, once the breathing difficulties reach a certain stage, the body becomes starved of oxygen and the person with motor neurone disease will die.
Contrary to some reports, most people with motor neurone disease die painlessly and comfortably in their sleep.