Motor neurone disease (MND) is the name given to a group of different conditions that cause a progressive weakening in the muscles. This weakening
eventually
leads to death although the timescale for this can be anything from a few years to several decades.
There are three main types of MND-
- Amyotrophic lateral sclerosis (ALS) affects about 50% of people with MND.With ALS both the upper and lower motor neurones are damaged Problems will
probably be first noticed in the hands - dropping things - or
tripping when walking.This mainly causes muscle stiffness and weakness as well as speech and
swallowing difficulties.Knee and ankle jerks are also a common feature. Men are more likely to be affected by ALS than women. The life expectancy is on
average
from two to five years from the onset of symptoms. ALS usually starts in people over the age of 55.
- Progressive muscular atrophy (PMA) affects about 25% of people with MND. With PMA it is mostly the lower neurones that are affected. Early symptoms
include
weakness and/or clumsiness of the hand. It causes muscle twitching, wasting and weakness. PMA progresses more slowly than
ALS although many people with PMA will go on to develop ALS at a later stage. Most people with PMA live for more than five years.
- Progressive bulbar palsy (PBP) affects 25% of those people with MND. PBP only affects those motor neurones in the head and neck. Early symptoms include
slurred speech or choking on certain foods. This affects the speaking and swallowing mechanisms. People with this syndrome
may laugh and cry
for nor apparent reason- this is because the part of the brainstem that controls the physical expressions of the emotions is affected by the
disease. The life expectancy with PBP is between six months and three years from onset of symptoms.
The motor neurones are a complex system of nerve cells in the brain and spinal cord that control the action of the muscles. With MND, these nerve cells
break down causing the weakening and wasting of muscles.
There are about 5000 people at any one time in the UK with MND. The average age at onset is 50 and the male to female ratio is 1.4:1.
