Parkinson's disease: features

Parkinson's disease is a progressive neurodegenerative condition caused by degeneration of dopaminergic neurons in the substantia nigra. This results in a classic 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
• 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
• drooling of saliva
• psychiatric features: depression is the most common feature (affects about 40%); dementia, psychosis and sleep disturbances may also occur
• impaired olfaction
• REM sleep behaviour disorder

Drug-induced parkinsonism has slightly different features to Parkinson's disease:

• motor symptoms are generally rapid onset and bilateral
• rigidity and rest tremor are uncommon

Wikipedia