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What is motor neurone disease (MND)?

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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