Brief pathogenesis of Parkinson's disease?
Degeneration of the dopaminergic pathways in the substantia nigra.
Parkinson's disease is characterised by which 3 clinical features?
Tremor at rest
Definition of rigidity?
Increased resistance to passive movement.
May be increased by asking patient to perform movements with opposite limb
: contralateral synkinesis.
Definition of bradykinesia?
Slowness of voluntary movement and reduced automatic movement.
Early signs of Parkinson's disease?
Impairment of dexerity.
Slight dragging of foot.
Fixed facial expression.
Later signs of Parkinson's disease?
Festinant (shuffling) gait.
Difficulty rising from a sitting position and starting to walk.
Unsteadiness on turning.
Differential diagnoses of Parkinson's disease?
Benign essential tremor-
tremor worse on movement, rare at rest.
SSRIs, amphetamines, B-blockers, anti-psychotics (chlorpromazine).
usually chorea (involuntary movements) is 1st presentation.
Investigations for Parkinson's disease?
CT scan if fail to respond to L-dopa within 12 weeks.
MRI to exclude rare secondary causes such as supratentorial tumours.
Management of Parkinson's diease?
- selgiline, rasagiline.
Oral or transdermal
- Pramipexole. 1st line in younger patients.
most effective symptomatic drug.
What drug needs to be prescribed with Levodopa and why?
A peripheral dopa-decarboxylase inhibitor- Sinemet/Madopa.
Prevents peripheral conversion to dopamine.