Progressive Muscular Atrophy (PMA)
What is PMA?
PMA is a condition affecting the lower motor neurones. Lower motor neurones are groups of nerve cells in the spinal cord and brain that manage the muscles in the body. If they are damaged then these nerves will be unable to control the movement of your muscles and the affected muscles will atrophy.
In PMA there is a loss over time of the lower motor neurones, so that muscles grow steadily weaker, causing problems within the body. This then leads to fasciculations (muscle twitches), progressively worsening muscle weakness, and a loss of muscle mass and weight.
- PMA affects about five to seven percent of people with MND.
- More men are affected by PMA than women (the ratio may be as much as 5:1).
- The average age at which PMA manifests is below fifty.
- PMA generally has a longer life expectancy than other types of MND, between five and ten years.
- There is usually not any history of PMA within families of sufferers.
- Occasionally PMA may present when there is a family history of MND.
How is it diagnosed?
As with the other types of MND, PMA can often be tricky to diagnose. Whilst most PMA sufferers do have MND (in its lower motor neurone form), roughly one in three suffer from different disorders associated with the lower motor neurones.
Your doctor will need to review your diagnosis regularly, this is why the early tests are absolutely vital. They help to identify or eliminate any other lower motor neurone disorders which may be confused with or appear alongside PMA.
What are the tests?
Tests you may undergo could include:
- MRI scans to rule out any abnormalities in the brain or spinal cord
- Nerve conduction tests (tiny electrical signals which are used to check the rate at which your nerves transmit messages through your body)
- Electromyography (EMG)
- A blood test may be used to check for other disorders or diseases
What are the symptoms?
PMA symptoms include: muscle weakness, atrophy, fatigue, cramps, fasciculations, muscle twitches and a degradation of your reflexes
Most often PMA begins with loss of strength in one hand, though it can also be in your tongue or a foot. This weakness then moves into more of your muscles as the condition progresses further and the muscles which are attacked shrink and fail. Cramps usually precede the loss of strength and the muscle twitches also manifest early on in the disease.
Because the upper motor neurons are not involved, those suffering from PMA may often not experience the muscular stiffness or the loss of emotional control which Motor Neurone Disease is often characterised by.
As with all types of MND, managing the disease is very personal to the individual patient. The disease progresses at different rates and it largely depends on dealing with issues as they become a problem to the sufferer, minimizing the impact on their day to day life and health.
Equipment might be required in order to help offset leg weakness in the limbs. Communication aids could also be needed. Feeding can be an issue and assistance may be required, for example a feeding tube. Assistive equipment may also be needed to help with breathing as well.
At every stage of the disease, you should consult with your doctors to make sure the treatment and assistance you receive is what is best and right for you.