Motor neurone disease

Motor neurone disease is the name for a rare condition where parts of the nervous system become damaged. This causes progressive weakness, usually with muscle wasting.

Motor neurone disease occurs when specialist nerve cells in the brain and spinal cord called motor neurones stop working properly. Motor neurones control important muscle activity, such as:

gripping
walking
speaking
swallowing
breathing

As the condition progresses, people with motor neurone disease will find these activities increasingly difficult – and eventually impossible – to do.

Exactly what causes motor neurones to stop working properly is unclear, but there is not currently thought to be a link with factors such as race, diet and lifestyle.

In about 5% of cases there is a family history of either motor neurone disease or a related condition called frontotemporal dementia. In most of these cases faulty genes have been identified as contributing to the condition.

There is no single test to diagnose motor neurone disease and diagnosis is based mainly on the opinion of a neurologist. Sometimes specialised tests are needed to rule out other possible conditions.

Progression of symptoms

The symptoms of motor neurone disease begin gradually over weeks and months, usually only on one side of the body initially, and get progressively worse. Common early symptoms are:

a weakened grip, which can cause difficulty picking up or holding objects
weakness at the shoulder that makes lifting the arm difficult
a "foot drop" caused by weak ankle muscles
dragging of the leg
slurred speech (dysarthria)

The condition is not usually painful.

As damage progresses, symptoms spread to other parts of the body and the condition becomes more debilitating.

Eventually, a person with motor neurone disease may be unable to move. They may also find communicating, swallowing and breathing very difficult.

In 10-15% of cases, motor neurone disease is associated with a type of dementia that can affect things such as personality and behaviour. This is called frontotemporal dementia.

Read more about symptoms of motor neurone disease.

Treating motor neurone disease

There's currently no cure for motor neurone disease. Treatment therefore aims to:

make the person feel comfortable and have the best quality of life possible
compensate for the progressive loss of bodily functions such as mobility, communication, swallowing and breathing

For example, a breathing mask can help reduce shortness of breath, and the insertion of a small feeding tube (called a gastrostomy) helps maintain nutrition and overall comfort. Medication is used to help control oral secretions if necessary.

A medication called riluzole has shown a very small improvement in patients' overall survival, but it is not a cure and does not stop the progression of the disease.

Read more about treating motor neurone disease.

Survival rates

Motor neurone disease is a severely life-shortening condition for most people. Life expectancy for about half of those with the condition is three to four years from the start of symptoms. However, some people may live for up to 10 years, and others even longer.

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 strong community and specialist support, many people lead a relatively independent lifestyle and enjoy a quality of life they may not have imagined was possible at the time of their diagnosis.

In most cases, motor neurone disease is fatal because of the eventual involvement of the breathing muscles, which typically makes someone with the condition gradually more drowsy and more susceptible to chest infections.

The end of life in someone with motor neurone disease is not usually distressing and is most often in their own home. In a few cases, a person with motor neurone disease may die suddenly but painlessly during their sleep.