Parkinson's disease

Definition

• Parkinsonism - this is a set of neurological symptoms which are characteristic of Parkinson's disease but can also be symptoms of other disease.
• Idiopathic Parkinson's disease - a chronic degenerative neurological disease with symptoms of parkinsonism. It is the most common cause of parkinsonian symptoms.

Epidemiology

More common in old age, but quite a common condition in that generation.

Pathophysiology

The dopamine-secreting (or dopaminergic) cells of the substantia nigra in the cerebellum reduce in activity. There's lots of other clever stuff that happens but this has a hypokinetic (reduced movement) effect on almost all movement.

Clinical Features

The main five symptoms helpfully spell the word TRAPS; they are:

• Tremor
• Rigidity
• Akinesia/bradykinesia
• Posture
• Shuffling Gait

These really ought to be present but others include: reduced arm swing; small, shuffling steps; festinant gait (the patient leans forward but does not move feet quickly enough - can lead to falls); kinesia paradoxica (fast movements are easier than slower ones - usually in early Parkinson's).

Investigations

The diagnosis of Parkinson's is done clinically. There's not a great deal to find on investigation.

Management

Levodopa, a form a dopamine, is the primary treatment for Parkinson's. However, in order to reduce side-effects, it is generally given in combination with another agent: Sinemet (carbidopa & levodopa) or Madopar (benserazide & levodopa).