Features

Parkinson's disease is a progressive neurodegenerative condition caused by degeneration of dopaminergic neurons in the substantia nigra. The reduction in dopaminergic output results in a classical triad of features: bradykinesia, tremor and rigidity. The symptoms of Parkinson's disease are characteristically asymmetrical.

Epidemiology

• around twice as common in men
• mean age of diagnosis is 65 years

Bradykinesia

• poverty of movement also seen, sometimes referred to as hypokinesia
• short, shuffling steps with reduced arm swinging
• difficulty in initiating movement

Tremor

• most marked at rest, 3-5 Hz
• worse when stressed or tired, improves with voluntary movement
• typically 'pill-rolling', i.e. in the thumb and index finger

Rigidity

• lead pipe
• cogwheel: due to superimposed tremor

Other characteristic features

• mask-like facies
• flexed posture
• micrographia