Parkinson's Disease
Summary
Parkinson's disease is a progressive neurodegenerative disorder characterised by loss of dopaminergic neurons in the substantia nigra. Cardinal motor features are bradykinesia, rigidity, resting tremor, and postural instability. Diagnosis is clinical. Levodopa is the most effective treatment for motor symptoms. Non-motor symptoms (depression, constipation, REM sleep behaviour disorder) are common.
Key Facts
- Definition: Progressive dopaminergic neurodegeneration
- Incidence: 1-2% over 65 years
- Pathognomonic: Bradykinesia + rigidity + resting tremor
- Gold Standard Investigation: Clinical diagnosis (MDS criteria)
- First-line Treatment: Levodopa (most effective); dopamine agonists
- Prognosis: Progressive; life expectancy near-normal with treatment
Clinical Pearls
Bradykinesia Pearl: Essential for diagnosis - slowness AND decrement of movement.
Response Pearl: Excellent levodopa response supports diagnosis.
Non-motor Pearl: Non-motor symptoms may precede motor by years.
- Tremor (resting, pill-rolling)
- Rigidity (lead-pipe, cogwheeling)
- Akinesia/Bradykinesia
- Postural instability
Algorithm
Medical Treatment
| Drug Class | Examples |
|---|---|
| Levodopa | Co-careldopa, co-beneldopa |
| Dopamine agonists | Ropinirole, pramipexole |
| MAO-B inhibitors | Selegiline, rasagiline |
| COMT inhibitors | Entacapone |
Advanced
- Deep brain stimulation (DBS)
- Apomorphine infusion
- Levodopa-carbidopa intestinal gel (Duodopa)
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Postuma RB et al. MDS clinical diagnostic criteria for Parkinson's disease. Mov Disord. 2015;30(12):1591-1601. PMID: 26474316
-
NICE guideline NG71. Parkinson's disease in adults. 2017.
Viva Points
"Parkinson's: bradykinesia + rigidity + tremor. Clinical diagnosis. Levodopa most effective. Don't forget non-motor symptoms."
Last Reviewed: 2026-01-01 | MedVellum Editorial Team