Parkinson's Disease

Question 1

What causes PD?

Answer 1

Degeneration of the dopamine-producing neurons found within the substantia nigra.

Question 2

Name 2 genes associated with PD?

Answer 2

Parkin

Alpha-synuclein

Question 3

Which part of the brain are the substantia nigra found in?

Answer 3

There are 2 of these, found either side of the midbrain.

Question 4

What are the characteristic symptoms of PD?

Answer 4

Tremor (resting)
Rigidity
Akinesia
Postural instability

Remember TRAP!

Question 5

What is the difference in the tremor experienced in cerebellar dysfunction compared with that of PD?

Answer 5

Tremor in PD is at rest, improves with movement.

Tremor in cerebellar dysfunction is an intention tremor (not present at rest).

Question 6

What is meant by rigidity?

Answer 6

Increased muscle tone felt when trying to move limbs passively.

Question 7

What test is used to check for rigidity?

Answer 7

Froment’s manoeuvre.

This initiates the ‘cogwheel’ sign.

Question 8

What is akinesia?

Answer 8

Slowness/absence of voluntary muscle movement.

Question 9

What is the typical gait observed in a PD patient?

Answer 9

Slow gait, with narrow, shuffling steps.

Hesitation initiating movement and a stooped posture.

Question 10

Which test is used to analyse posture and gait in suspected PD?

Answer 10

Pull test.

Question 11

Are most cases of PD idiopathic or genetic?

Answer 11

Idiopathic (95%).

Question 12

What is thought to be a marker of neuronal ill-health?

Answer 12

Presence of Lewy bodies.

Question 13

Is PD the most common neurodegenerative disease?

Answer 13

No, Alzheimer’s disease is - PD is second.

Question 14

What investigation methods are used in the diagnosis of PD?

Answer 14

It is usually a clinical diagnosis, although a DaTSCAN can be helpful (this shows function, not structure).

Response to dopamine therapy will back-up diagnosis.

Question 15

What is a major prevailing factor common in those with PD?

Answer 15

Old age.

Question 16

What non-motor symptoms are linked to PD?

Answer 16

Late-onset hyposmia
Depression/anxiety
Constipation
Bladder issues
Pain
Mild cognitive impairment

Question 17

What are the 4 main types of drug used in PD?

Answer 17

Levodopa
COMT inhibitors
MAO-B inhibitors
Dopamine agonists

Question 18

Which therapy is first-line in PD management?

Answer 18

Levodopa.

Question 19

Why is levodopa an inactive form of dopamine?

Answer 19

To allow it to cross the blood-brain-barrier.

Question 20

What is given alongside levodopa to produce active dopamine?

Answer 20

Carbidopa.

Question 21

In those with levodopa-induced nausea and vomiting, what is given?

Answer 21

Domperidone.

Question 22

What is the role of COMT inhibitors?

Answer 22

Blocks the enzymatic breakdown of levodopa prior to it crossing the blood brain barrier.

Question 23

In PD, dopamine levels are decreased. What other neurotransmitter must be controlled in these patients to stop symptoms?

Answer 23

Acetylcholine.

Question 24

What drugs are given to prevent tremor?

Answer 24

Anticholinergics.

Remember cause dryness.

Question 25

Are treatment methods in PD preventative or do they aim to manage symptoms?

Answer 25

Symptomatic relief only - disease progression inevitable.

Question 26

What are side-effects of dopamine agonists?

Answer 26

Impulsive behaviour Sleepiness Psychosis

Question 27

What drugs can cause drug-induced PD?

Answer 27

Chlorpromazine Metoclopramide Methyldopa Diltiazem

Question 28

What are some long-term complications of dopamine therapy?

Answer 28

Motor fluctuations Non-motor fluctuations Dyskinesia Drug-induced psychosis

Question 29

When are MAO inhibitors used?

Answer 29

In moderate disease only.

Question 30

How does substantia nigra degeneration present?

Answer 30

Loss of characteristic black appearance of the regions.

Question 31

Is muscle weakness a feature of PD?

Answer 31

No. This helps to set it apart from issues with the motor cortex and the corticospinal pathway.

Question 32

Tremor is most commonly seen in which part of the body?

Answer 32

Upper limbs.

Question 33

Is PD a condition characterised by symmetrical disease?

Answer 33

No, patients will have asymmetrical symptoms.

Question 34

What % of PD patients develop Parkinson's dementia?

Answer 34

Around 80%.

Question 35

What is the difference between dementia with lewy bodies and Parkinson's dementia?

Answer 35

Parkinson's dementia will present after a year of PD - DwLB presents earlier.

Question 36

Can PD be drug-induced?

Answer 36

Yes, following a few months of treatment withdrawal, symptoms will improve.

Question 37

Which test is used to induce postural instability in an individual suspected to have PD?

Answer 37

The pull test.

Question 38

Is PD usually symmetrical at point of onset?

Answer 38

No, it is common for PD to begin asymmetrically.