Prognosis and duration of disabling effects
PD usually starts with mild unilateral involvement but in the majority of people progresses to bilateral disease with increasing difficulty in activities of daily living and self-care.
Symptoms confined to one side are often seen early in the disease course (Hemi-parkinsonism). Eventually in those most severely affected, the person becomes bed or chair bound and unable to move. Many people however remain reasonably active but with increasing restrictions until they die from other causes.
The rate of progression is very variable. Prior to the introduction of levodopa the average life expectancy was 9 years. With current treatment life expectancy has improved but is still slightly less than the normal population.
Staging is as follows:
| Stage | Disabling effect |
|---|---|
Stage 1 |
Unilateral involvement only. |
Stage 2 |
Bilateral involvement without impairment of balance. |
Stage 3 |
Impairment of balance and functional restriction. |
Stage 4 |
Fully developed disease retaining ability to walk and stand unassisted but otherwise markedly incapacitated. |
Stage 5 |
Bed bound or wheelchair bound unless aided. |
PD is a progressive condition and there is likely to be no improvement in mobility and care needs.
In all cases - Indefinite award
All information must be taken into account when considering the duration of disabling effects and the duration of disabling effects must be based on the particular circumstances of the individual claimant.
