Parkinson's Disease

Question 1

Cause of Parkinson’s Disease

Answer 1

Loss of dopaminergic neurones in the substantia nigra pars compacta causing disruption in the cotrio, striatal, pallidomo thalamic tracts.

Symptoms don’t normally develop until there has been a 60-80% loss of dopaminergic neurones.
Clinical diagnosis.

Multi-systems disorder affecting motor, autonomic and neuropsychiatric function

Question 2

Classic Triad of Symptoms of Parkinson’s Disease

Answer 2

• Bradykinesia
• Rigidity
• Asymmetric resting tremor

Question 3

Dopamine Agonists for Parkinson’s Disease

Answer 3

• Pramipexole, Rotigotine, Apomorphine
• Rotigotine and Apomorphine can be used in patients who cannot absorb orally
• Side effects- N&V, hypotension, cognitive impairment

Question 4

Dopamine precursors for Parkinson’s Disease

Answer 4

• Levodopa, Carbidopa
• Should be combined with a dopa decarboxylase to prevent conversion to dopamine prior to crossing the BBB
• Side effects- N&V, orthostatic hypotension, dyskinesias, hallucinations

Question 5

Monoamine oxidase B Inhibitors for Parkinson’s Disease

Answer 5

• Selegiline
• Side effects- headaches, arthralgia, risk of serotonin syndrome

Question 6

Catechol-O-Methyl Transferase Inhibitors for Parkinson’s Disease

Answer 6

• Entacapone
• Side effects- dark urine, increased response to drugs such as adrenaline

Question 7

Risks of abrupt withdrawal of Parkinson’s medication

Answer 7

Parkinsonism Hyperpyrexia Syndrome
- Withdrawal of levodopa
- Like neuroleptic malignant syndrome- fever, rigidity, CV Instability, reduced GCS
- Mortality 20%

Dopamine agonist Withdrawal Syndrome
- Anxiety, N&V, Pain, Postural hypotension

Question 8

Pre-operative consideration for patients with Parkinson’s Disease

Answer 8

• Early involvement of Parkinson’s team- plan for Parkinson’s medications and what to do if patient not tolerating oral medications
• Make first on the list to make drug timings more predictable

Question 9

Intra-operative consideration for patients with Parkinson’s Disease

Answer 9

• Neuraxial where possible but significant tremor or cognitive impairment may make this difficult
• Excessive sweating is common making routine monitoring difficult to apply
• Careful induction as autonomic dysfunction is common
• Ensure full reversal of NMBDs as may mask Parkinson’s symptoms
• Avoid neostigmine as increases secretions
• High prevalence of reflux and GORD therefore low bar for intubation
• Ondansetron and cyclizine are safe anti-emetics
• If patient has a deep brain stimulator then bipolar only and make sure device is turned off

Question 10

Post-operative consideration for patients with Parkinson’s Disease

Answer 10

• Poor cough and swallow- must be sat up and have early chest physio
• Ensure Parkinson’s medications are given and prescribed
• Review from Parkinsons team post-op
• High risk of post-op falls, VTE, aspiration pneumonia
• Increased LOS
• Increased POCD

Question 11

Parenteral Drug Options for patients with Parkinson’s Disease

Answer 11

Apomorphine infusion (subcut)
- Potent, will need admission pre-op for “drug challenge”
- Can cause severe N&V and hypotension
- Start 24-48 hours prior to surgery

Rotigotine (Topical)
- Simple patch but not adequate for patients on high doses of dopamine agonists
- Online conversion calculators are available

Question 12

Common Anaesthetic drugs to avoid in Parkinson’s Disease

Answer 12

• Dopamine antagonists- prochlorperazine, droperidol, metoclopramide, haloperidol
• Caution with atropine- centrally acting anticholinergic can cause confusion, restlessness
• Caution with adrenaline in patient’s taking a COMT inhibitor- COMT inhib prevents breakdown of adrenaline
• Caution with opioids such as remifentanil can lead to increased risk of “wooden chest”

Question 13

Physiological changes in Parkinson’s Disease

Answer 13

Airway
- High risk of laryngeal muscle dyskinesia meaning patients aren’t able to clear secretions easily
- At risk of laryngospasm

Respiratory
- Rigidity can lead to restrictive pulmonary disease
- OSA is common

Cardiovascular
- Arrhythmias are common
- Orthostatic hypotension common- increased risk of intra-operative hypotension

CNS
- Greater risk of post op delirium and hallucinations
- Risk of parkinsonim hyperpyrexia syndrome

GI
- Dysphagia increases aspiration risk
- Drooling is common in advanced parkinsons may need hyoscine/ glycopyrolate pre-op

Renal
- Increased risk of post-op UTI