Parkinson's Disease

Question 1

Define Parkinson’s disease

Answer 1

Neurodegenerative disorder of the dopaminergic neurones of the substantia nigra

Question 2

What are the causes/risk factors of Parkinson’s disease?

Answer 2

Idiopathic – ?environmental toxins and oxidative stress
Secondary
• Neuroepileptic therapy e.g. for schizophrenia
• Vascular insults
• MPTP toxin
• Post-encephalitis
• Repeated head injury e.g. boxing

Question 3

What are the signs and symptoms of Parkinson’s disease?

Answer 3

• Bradykinesia
• Pill-rolling tremor (4-6Hz) at rest
• Lead-pipe rigidity (superimposed
tremor -> cogwheeling)
• Stooped shuffling gait with
reduced arm swing
• Freezing/difficulty initiating
movement e.g. getting out of
chair/bed
• Postural instability -> frequent
falls
• Glabellar tap
• Micrographia
• Expressionless hypomimic face
• Hypophonia
• Impaired olfaction
• Sialorrhea
• Constipation (autonomic
dysfunction)
• Insomnia
• Mental slowness
• Depression

Question 4

What investigations are carried out for Parkinson’s disease

Answer 4

• Diagnosis is clinical.
• Levodopa trial - timed walking and clinical assessment after levodopa may be informative. Anti-emetic (domperidone) may be needed.
• Blood - serum caeruloplasmin (excludes Wilson’s disease in young onset).
• CT or MRI brain - useful for excluding other causes of gait decline (e.g. hydrocephalus, vascular disease). May also indicate underlying cause.
• Dopamine transporter scintigraphy (DAT-scan) - reduction in striatum and putamen. May be necessary for distinguishing from essential tremor.