What is MND?
MND, which is known in the USA as Amyotrophic Lateral Sclerosis (ALS) and sometimes as Lou Gehrig’s disease, is an umbrella term for conditions that progressively damage and eventually result in the death of the nerves (motor neurones) in the brain and spinal cord that control the muscles responsible for voluntary movement. As a result the transmission of messages to muscles in the face, throat, chest and limbs are interrupted to varying extents and muscle wastage and spasticity occurs. There is no cure for MND but treatments are available which help to alleviate the symptoms.
Symptoms and types of MND
In the early stages muscle weakness might only be apparent in one limb but as the condition worsens many muscles for the important activities of walking, gripping, swallowing, speaking and breathing can be affected.
Although they are all eventually similar as they get progressively worse various subtypes of MND are recognised of which the main types are:-
- Amyotrophic lateral sclerosis (ALS). About 8 out of 10 people with MND have this type which usually starts with weakness and stiffness in the hands and feet. Life expectancy is 2 to 5 years.
- Progressive bulbar palsy (PBP). About 2 out of 10 people have this type which initially affects the muscles used for speech, chewing and swallowing. Life expectancy is 6 months to 3 years.
- Progressive muscular atrophy (PMA). Few people are affected by this type which at first causes weakness but not stiffness in the small muscles of the hands and feet. Most people live for longer than 5 years after the onset of their symptoms.
- Primary lateral sclerosis (PLS). A rare condition mainly causing weakness in the leg muscles but some people might have hand or speech problems. Life expectancy is unaffected providing ALS does not develop.
What causes MND?
It is not known what causes MND. Usually there is no family history of the condition, and it is most unlikely to develop in other family members. However, in about 10% of cases more than one member of the family has either ALS and/or frontotemporal dementia. For no obvious reasons research has revealed a higher incidence of MND amongst footballers, farmworkers and the inhabitants of Guam. Amongst the environmental factors which might be involved are exposure to chemicals, stressful lifestyles such as military service, head & leg injuries, smoking and excessive exercise.
Extensive research into MND is being carried out at many places in the USA, Europe and Australia. In the UK the Motor Neurone Disease Association is funding research at several centres relating to various aspects of MDS / ALS including:-
- Genome sequencing
- Genetic mistakes and therapy
- Stem cell technology
- Animal models
- Toxic proteins
- A gene-environment database
Research at the University of Nottingham & the Queen’s Medical Centre
Currently the Motor Neurone Disease Association is funding research at Nottingham relating to the SQSTM1 gene that governs the production of the protein p62 which has a role in in enabling cells to remove and recycle unwanted proteins. When the process breaks down the build-up of waste is thought to contribute to some forms of MND and frontotemporal dementia (FTD). The researchers are investigating the way various gene mutations associated with MND affect the p62 protein and its interactions with other proteins. This could lead to new ways of managing the symptoms of the disease.
Researchers: Professor Mark Searle, Dr Robert Layfield & Dr Marios Georgiou
Pioneering work relating to the protein waste recycling process within neurones, which impacts on other neurodegenerative diseases as well as MND, was undertaken by one of our charity’s founder members, Professor John Mayer and his colleague Professor James Lowe in the 1980s. Since 2000 Dr Lynn Bedford, who is also a member of our Management Committee, has also carried out research work relating to the 26S proteasome recycling process and the possibility of gene deletion in motor neurones.
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