14. Parkinson's Disease

Question 1

What is the pathophysiology of Parkinson’s Disease?

Answer 1

Loss of pigmented dopaminergic neurons in the substantia nigra

Question 2

What system is used to stage Parkinson’s Disease?

Answer 2

Braak staging

Question 3

What parts of the brain does the substantia nigra project to?

Answer 3

Striatum: caudate and putamen

Question 4

What are the causes of Parkinson’s disease?

Answer 4

Idiopathic
Toxins and drugs
Head trauma
Genetic

Question 5

What are the cardinal symptoms of Parkinson’s disease?

Answer 5

Tremor
Bradykinesia
Rigidity
Postural instability

Question 6

Describe the tremor present in Parkinson’s disease

Answer 6

Unilateral ‘pill rolling’
Rapid, present at rest
Increased with anxiety

Question 7

What is bradykinesia?

Answer 7

Slowness of movement
Difficulty initiating tasks or carrying out sequential tasks
Reduced amplitude of movement eg. small handwriting
Rapid fatigue of repetitive movement

Question 8

what are the features of rigidity seen in Parkinson’s?

Answer 8

Increased resistance of relaxed muscles to passive stretch: ‘clasp knife and pin wheel’

Question 9

What are the signs of postural instability in Parkinson’s disease?

Answer 9

Shuffling gait with poor arm swing
Turning ‘en bloc’
Leaning forward

Question 10

What are the other motor symptoms of Parkinson’s disease?

Answer 10

Painful involuntary muscle contractions (dystonia)
Hypomimia (reduced facial expression)
Drooling
Hypophonia
Freezing

Question 11

What are the mental symptoms of Parkinson’s?

Answer 11

Depression
Lack of impulse control and visiospatial difficulty
Sleep disturbance, vivid dreams, hallucinations

Question 12

What are the miscellaneous symptoms of Parkinson’s?

Answer 12

Orthostatic hypotension
Anosmia
Seborrhoeic dermatitis (fungal infection of the face)
Urinary incontinence and constipation
Weight loss, anhidrosis, sexual dysfunction

Question 13

How is a diagnosis of Parkinson’s made?

Answer 13

Clinical

MRI to rule out infarcts, hydrocephalus and Wilson’s disease

Question 14

What is the differential for Parkinson’s disease?

Answer 14

Essential tremor
Vascular Parkinsonism
Drug induced
Parkinson plus syndromes
Thyrotoxicosis

Question 15

When should a parkinson plus syndrome be suspected?

Answer 15

Early signs of showing features of late stage parkinsonism: falls and dementia
Meds are ineffective

Question 16

Name 3 parkinson plus syndromes

Answer 16

Multisystem atrophy
Progressive supranuclear palsy
Corticobulbar degeneration

Question 17

Why is dopamine not given alone?

Answer 17

Causes vomiting and broken down by first pass metabolism

Question 18

What is given with dopamine to reduce breakdown by the liver?

Answer 18

Decarboxylase inhibitor

Question 19

What is the effect of a COMT inhibitor?

Answer 19

Slows down metabolism of dopamine in the brain

Question 20

Name a COMT inhibitor

Answer 20

Entacopone

Question 21

Name a dopamine agonist

Answer 21

Ropinirole

Question 22

Name a MOAB inhibitor

Answer 22

Rasagiline

Question 23

What is the most common prescription for Parkinson’s disease?

Answer 23

Levodopa with benserazide or carbidope (decarboxylase inhibitors)

Question 24

What are motor fluctuations?

Answer 24

Involuntary movements and freezing 2 years after starting drugs due to a reduced response to levodopa

Question 25

How can motor fluctuations be treated?

Answer 25

Add a COMT inhibitor

Question 26

What surgeries can be used in Parkinson’s disease?

Answer 26

Thalamotomy reduces tremor

Pallidotomy reduces cardinal symptoms

Question 27

What is deep brain stimulation?

Answer 27

Resets abnormal firing pattern in the brain

Most common is subthlamic

Question 28

What is a contraindication to deep brain stimulation?

Answer 28

Can’t have psychiatric problems