Parkinson's Disease

Question 1

What is the definition of Parkinson’s Disease

Answer 1

A neurodegenerative disease of the dopaminergic neurones of the substantia nigra, characterised by: Bradykinesia, Rigidity, Resting tremor and postural instability

Question 2

What is the pathophysiology of Parkinson’s Disease?

Answer 2

Degeneration of dopaminergic neurones projecting from the substantia nigra to the striatum

Patients are only symptomatic after the loss of > 70% of dopaminergic neurones

Question 3

What is the aetiology and risk factors involved with Parkinson’s disease?

Answer 3

1. Sporadic/ Idiopathic Parkinsons: Most common, unknown aetiology however may be related to environmental toxins and oxidative stress
2. Secondary Parkinson’s Disease:
   - Neuroleptic therapy (e.g. for schizophrenia)
   - Vascular insults (e.g. in the basal ganglia)
   - MPTP toxin from cocaine abuse
   - Post-encephalitis
   - Repeated head injury

There are also some familial forms of Parkinsons disease

Question 4

Summarise the epidemiology of Parkinsons disease?

Answer 4

Very COMMON

Prevalence: 1-2% of > 60 yrs

Mean age of onset: 57 yrs

Question 5

What are the presenting symptoms of Parkinsons disease?

Answer 5

INSIDIOUS onset

Resting tremor (mainly in hands)

Stiffness and slowness of movements

Difficulty initiating movements

Frequent falls

Smaller hand writing (micrographia)

Insomnia

Mental slowness (bradyphenia)

Question 6

What are the signs of Parkinsons disease upon physical examination?

Answer 6

• Tremor
• Rigidity
• Gait issues
• Postural instability (Falls easily with little pressure from the back or the front)
• Psychiatric
• Other features seen

Question 7

Describe the typical features of a parkinsonian tremor

Answer 7

• Low frequency
• Pill rolling
• Usually assymetrical
• Improves on movement

Question 8

Decribe the typical features of the gait of someone with parkinsons

Answer 8

• Stooped, shuffling gait
• Small-stepped
• Reduced arm swing
• Difficulty initiating walking

Question 9

What are psychiatric features you can see with someone with Parkinsons?

Answer 9

Depression

Cognitive problems and dementia (in later stages)

Question 10

What are other features you can see with someone with Parkinsons?

Answer 10

Frontalis overactivation (leads to furrowing of the brow)

Hypomimic face

Soft monotonous voice

Impaired olfaction

Tendency to drool

Mild impairment of up-gaze

Question 11

What are the appropriate investigations for someone suspected to have parkinsons?

Answer 11

Normally a clinical diagnosis should be sufficient however the following investigations can also be requested:

• Levodopa trial - Timed walking and clinical assessment after administration of levodopa
• Bloods - Serum caeruloplasmin - rule out Wilson’s disease as a cause of Parkinson’s disease
• CT or MRI Brain - To exclude other causes of gait decline (eg. hydrocephalus)
• Dopamine Transporter Scintigraphy - Reduction present in striatum and putamen