Motor Neurone Disease (MND) is a condition that can affect many parts of the body, by damaging the neurones (another term for nerves).
It is relatively rare, with up to 5,000 adults in the UK being affected by MND at any one time. Most people are over 40 when they are diagnosed with this condition.
What is Motor Neurone Disease?
Whether we want to walk, pick up a pen, speak or swallow, our motor neurones are involved. They deliver the messages from our brain and spinal cord, to the muscles we need to use.
MND is a progressive neurodegenerative disease, which means that the symptoms don’t stay as they are – they are likely to become progressively worse, and continue to damage motor neurones.
MND tends to affect the muscles in the hands, feet or mouth first. People who have MND may notice that as the disease continues they may start to lose mobility in their arms and legs. However people with this condition are unlikely to all have the same symptoms.
As the disease progresses it is likely to affect many muscles in the body, including those in the face and neck. This may eventually make it difficult for people with MND to speak, swallow and breathe.
Upper motor neurones travel from the brain to the spinal cord, and take instructions to the lower motor neurones. Lower motor neurones start off in the spinal cord and use the instructions delivered by the upper motor neurones to control our muscles.
Because the upper and lower motor neurones have different jobs, when they are damaged it can cause different symptoms.
Weakened and stiff muscles are a symptom of damage to the upper motor neurones, while damage to lower motor neurones is more likely to cause muscles to become floppy and weak.
As the motor neurones become progressively more damaged, the muscles become weaker and waste away. In the early stages of MND, early symptoms may include “foot drop” where the front of the foot doesn’t lift off the ground as it used to. However, this may be caused by a compressed nerve, or a pinched nerve, so isn’t always a sign of MND.
MND is caused by the malfunction of motor neurones in the brain and spinal cord. What we don’t yet know is what causes this malfunction. Once this problem has started, it continues, with the result that the symptoms become progressively worse.
Motor Neurone Disease is not just one disease, but a small group of diseases.
MND conditions include:
- Amyotrophic lateral sclerosis ALS is the most common form, and affects about eight out of 10 people with MND.
- Progressive bulbar palsy (PBP). In this condition difficulty with both speaking and swallowing can be a common symptom.
- Progressive muscular atrophy (PMA). In this condition the muscles in the hands and feet are often the first to be affected.
- Primary lateral sclerosis (PLS) is quite a rare form of MND. The main symptom is weak leg muscles.
Causes of motor neurone disease
There isn’t a clear cause of MND yet. Many experts in this field think that this condition is probably caused by a combination of genetic and environmental factors. This combination of factors is likely to be different for every person, so finding out exactly what triggers the onset of MND is a problem.
Symptoms of motor neurone disease
Because MND can affect people in different ways, the symptoms can be different for each person with this condition. Someone with MND may not have all the symptoms mentioned here, and their symptoms are unlikely to come in any particular order.
It’s also important to bear in mind that other health issues may develop that are unrelated to MND, but which may need expert assessment by a GP or specialist.
Physical symptoms of motor neurone disease can include:
This can affect balance and posture and may increase the risk of falls.
GPs or health and social care team can refer patients to a physiotherapist who can recommend exercises to help with this problem.
A dietitian may also be able to help by giving advice on how to keep body weight steady.
Related: The health benefits of seeing a physiotherapist
Twitching and rippling sensations under the skin (fasciculations)
The twitching and feelings of rippling under your skin (known as fasciculations), are often some of the first symptoms (and some of the most irritating) that develop in MND.
Medication may help ease these symptoms, so talk to your GP, specialist nurse, or consultant about ways to ease the problem.
These can happen when the muscles used in the voluntary control of breathing are affected by MND, and don’t work as effectively as they should.
To help with this you may be referred to a respiratory consultant. The treatment may involve physiotherapy, breathing exercises, advice on effective coughing, specialist equipment to help with breathing, and ventilation.
(In rare cases respiratory-onset MND starts by affecting the lungs.)
This can happen if the muscles in the face, mouth and throat (known as the bulbar muscles) become weak. This is known as dysphagia, and may cause difficulties with swallowing. It may also interfere with being able to eat and swallow normally. This can cause problems with eating and drinking, and can mean that it’s more difficult to take in enough food and liquid.
A speech and language therapist and a dietitian may be able to help with some symptoms. They can look at how well someone with MND can swallow, and give advice on how to cope with any choking episodes.
The dietitian may also suggest how to increase the amount of calories and proteins you take in. Having a tube inserted into the abdomen (a gastrostomy) may help to keep weight steady, and prevent any more weight loss.
Related: Could I benefit from seeing a dietitian?
Fatigue can be another symptom. An occupational therapist should be able to give advice on how to combat this.
Pain can come with MND, although this condition doesn’t usually cause this directly. The discomfort may come from stiff joints, or sitting in an uncomfortable position.
A health and social care team should be able to help with advice on avoiding or relieving pain.
Ibuprofen and similar non-steroidal anti-inflammatory drugs may also help. If you are taking other medication, check with your doctor that it’s safe to take these pain-relieving drugs as well.
Emotional lability is the term doctors use when someone has difficulty controlling their emotions. People with MND can have this, with symptoms of sudden outbursts of crying or laughing, that they find hard to control.
About 35% of those with MND also have cognitive changes – which in most cases are mild. This means that they have problems with their ability to make decisions, to carry out tasks that involve planning ahead, and some problems with language.
Cognitive symptoms can include:
- lack of insight
- difficulty concentrating, taking in and processing information
- inappropriate behaviour, such as aggression
- repetitive/compulsive behaviour
- binge-eating and craving sweet or fatty foods
Up to 15% of those with MND show signs of the condition frontotemporal dementia.These people often have more noticeable personality and cognitive changes.
Related: What is dementia?