Early symptoms of motor neurone disease are often mild. They may include:
- stumbling due to weakness of the leg muscles
- difficulty holding objects due to weakness of the hand muscles
- slurring of speech or swallowing difficulties due to weakness of the tongue and throat muscles
- cramps and muscle twitching (fasciculation).
For most people with MND the senses of sight, hearing, taste, smell and touch are not affected.
The bladder is not usually directly affected by MND; however, some people experience changes to bladder control. Constipation can occur, especially when people bec ome less mobile or have to change their diet due to swallowing difficulties.
In the past, it was thought that MND only affected the nerve cells controlling the muscles that enable us to move, speak, breathe and swallow. However, approximately 50% of people with MND may experience some change in cognition, language, behaviour and personality. When cognitive and behaviour changes occur in MND, it is because there have been changes in specific areas of the brain called the frontal and temporal lobes. Most people experience relatively mild changes. However, a small proportion (5–15%) will show more significant changes and will receive a diagnosis of ‘motor neurone disease with frontotemporal dementia’ or MND/FTD. Often the symptoms of dementia precede the motor symptoms, sometimes by a number of years.
The effects of motor neurone disease - initial symptoms, rate and pattern of progression, and survival time after diagnosis vary significantly from person to person.