Parkinson's disease

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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

Common.jpg

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.

Risk Factors

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 is the primary treatment for Parkinson's. It is converted into dopamine by the body. However, if it is converted to dopamine in the periphery (out side the brain) it will produce unwanted side effects. Hence, it is given in combination with another agent (dopa decarboxylase inhibitors) to prevent peripheral conversion.

The 2 forms available in the UK are:

1. Sinemet (levodopa & carbidopa aka co-careldopa)

2. Madopar (levodopa & benserazide aka co-beneldopa)

Prognosis