What is motor neurone disease (MND)?
| Site: | OpenLearn Create |
| Course: | An introduction to MND for professionals |
| Book: | What is motor neurone disease (MND)? |
| Printed by: | Guest user |
| Date: | Friday, 13 February 2026, 5:57 AM |
Description
This book resource will introduce you to motor neurone disease (MND), a progressive and life-limiting neurological condition. You'll learn what MND is, who it affects, how it presents, and the different forms it can take. This foundational knowledge will support your understanding of the challenges faced by those living with the disease.
Introduction
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Motor neurone disease (MND) is a fatal, rapidly progressing neurological condition that affects up to 5,000 adults in the UK at any given time.
MND damages the motor neurones in the brain and spinal cord that control muscle movement. As these nerves stop functioning, signals no longer reach the muscles. This causes muscles to gradually weaken, stiffen, and waste away.
Over time, people with MND may become trapped in a failing body — unable to move, speak, swallow, and eventually breathe. Some individuals may also experience changes in thinking or behaviour, and a smaller proportion may develop a rare form of dementia.
There is currently no cure.
- A third of people die within a year of diagnosis.
- More than half die within two years.
- A person’s lifetime risk of developing MND is around 1 in 300.
- Each day in the UK, approximately six people are diagnosed with MND — and six people die from it.
Pause and reflect
Before continuing, take a moment to consider the following questions. When you’re ready, click the arrows below to reveal the answers.
What causes MND?
Most people diagnosed with MND have the sporadic form, which is not inherited. The causes are still being researched, but it’s believed that a combination of genetic, environmental, and lifestyle factors may be involved. A smaller proportion — about 5–10% — have inherited or familial MND, where a faulty gene is passed down through families.
Who does MND affect?
MND can affect adults of any age and from all communities. However, it is most common in people aged 55–79. Onset below age 40 is uncommon, and onset under age 30 is extremely rare. MND affects slightly more men than women.
Variants of MND
The term “motor neurone disease” refers to a group of related conditions that affect motor nerves. While they share similarities, they can present in different ways and progress differently from person to person.
You don’t need to memorise each variant, but it’s helpful to have basic awareness of how MND can vary.
Click the arrows below to reveal more information about the variants of MND.
Amyotrophic Lateral Sclerosis (ALS)
- Most common form of MND
- Involves both upper and lower motor neurones
- Can start in the limbs, bulbar region (speech/swallowing), or rarely around the shoulders
- Symptoms include muscle weakness, wasting, stiffness, and reflex changes
- Progression and survival vary — average survival is 2–5 years
- Faster progression often seen with bulbar onset or cognitive impairment
Primary Lateral Sclerosis (PLS)
- Rare form, affecting fewer than 3% of people with MND
- Affects only upper motor neurones
- Symptoms include stiffness (spasticity), usually beginning in the legs
- Often slow progression and long survival — usually not life-shortening
- May resemble hereditary spastic paraplegia (HSP)
Progressive Bulbar Palsy (PBP)
- Starts with speech and swallowing difficulties
- May also involve emotional lability (e.g. sudden laughing or crying)
- Often progresses to affect the limbs
- Can involve both upper and lower motor neurones
Progressive Muscular Atrophy (PMA)
- Accounts for 5–10% of MND cases
- Involves only lower motor neurones
- Causes muscle wasting, weakness, and visible fasciculations
- Usually begins in the limbs, especially upper limbs
- Includes “Flail Arm Syndrome” — a slower progressing form with shoulder/arm weakness
Classification of MND
How is MND classified?
MND can be grouped in two key ways. Click the arrows below to expand the content.
1. By the type of motor neurones affected
- Upper motor neurones (UMN) – originate in the brain and carry messages down the spinal cord to control voluntary movement.
- Lower motor neurones (LMN) – transmit signals from the spinal cord to the muscles to enable movement.
- Or both.
2. By the area of the body first affected
- Limb-onset MND:
- The most common form, affecting around two-thirds of people.
- Symptoms begin in the arms or legs.
- Bulbar-onset MND:
- Affects the muscles used for speech, swallowing, and the tongue.
- Accounts for most of the remaining third of cases.
- Respiratory-onset MND:
- A rare form, affecting around 3% of people.
- Begins with breathing difficulties.
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