Diagnosis depends largely on:
- The presence of a specific set of clinical features (using research derived diagnostic criteria, such as the UK Brain Bank criteria) —bradykinesia,rigidity, rest tremor, and postural instability
- The absence of atypical features
- A slow, progressive course
A good response to drug treatment for Parkinson’s disease.
Drug treatment

Parkinson’s disease drug treatment
Diagnosis and pharmacological management of Parkinson’s disease: summary of SIGN guidelines BMJ 2010