Parkinson's disease

There has been much recent media interest in Parkinson's disease due to the celebrity status of one of the latest sufferers - American film actor Michael J. Fox

What is it?
Parkinson's disease (shaking palsy) is a slowly progressive disease of the brain, which is characterised by shaking and difficulty with co-ordination, walking and movement, and was first described in England by James Parkinson in 1817.

The disease is associated with damage to the part of the brain that controls muscle movement, and it is usually slowly progressive, affecting one or both sides of the body. It may involve speech difficulties, an overall mental deterioration, dementia and changes to emotional responses. Some people with Parkinson's disease also become severely depressed - although early loss of mental capacities is uncommon.

Who gets it?
Parkinson's disease usually only occurs in adults - it is very rare in children - and in the UK it can affect approximately two out of 1,000 people, but because the disease is not contagious and does not need to be reported, true statistics are not really known.

Sex incidence is about equal, although some reports indicate that it occurs slightly more often in men. Whilst ten per cent of those who are affected are under 45 years at the onset of the disease, it does occasionally occur in younger adults, but it is rare under 30 years of age. Both the incidence and the prevalence increase with age, with the latter rising to one per cent in those over 60. It is one of the most common neurological disorders of the elderly.

The diagnosis has to be made clinically as there is as yet no diagnostic test for Parkinson's disease. Some investigation may be necessary, in certain suspected cases, in order to exclude other causes of 'Parkinsonism' - if there are evident features of the disease.

Interestingly, Parkinson's disease is apparently less common in cigarette smokers.