(PM3B) Parkinson's disease

Question 1

What is Parkinson’s disease?

Answer 1

Common + complex neurological disorder

Affects mainly movement

Question 2

What are the types of motor symptoms experienced by those with Parkinson’s disease?

Answer 2

(1) Bradykinesia – slow movement
(2) Muscular rigidity
(3) Rest tremor
(4) Imbalance

Question 3

What is bradykinesia?

Answer 3

Slow movement –associated with Parkinson’s disease

• Reduced armswing + stride length
• Reduced facial reaction
• Soft/ slurred speech
• Smaller handwriting

Question 4

What is muscular rigidity?

Answer 4

Stiffness of limbs

Sometimes associated with pain

Associated with Parkinson’s disease

Question 5

What is a rest tremor?

Answer 5

Tremor in one limb with limb at rest

Tremor with holding posture

Asymmetric tremor

Question 6

What is imbalance?

Answer 6

Loss of balance reflex

Associated with Parkinson’s disease

Question 7

What are some non-motor symptoms of Parkinson’s disease?

Answer 7

(1) Autonomic dysfunction
- Constipation/ temperature intolerance

(2) Sleep disorders
- Insomnia/ sleep attacks or sleep fragmentation

(3) Neuropsychiatric disorders
- Fatigue/ dementia/ depression/ anxiety

(4) Sensory disorders
- Pain/ colour vision deficits/ abnormal sensations

Question 8

What neuropathological difference is there in those with Parkinson’s disease?

Answer 8

Loss of cells in the substantia nigra

Question 9

Why does dopamine have a role in the development of Parkinson’s disease?

Answer 9

Essential for control of movement

Acts as a neurotransmitter in the substantia nigra

Question 10

What are two key pathological hallmarks of Parkinson’s disease?

Answer 10

(1) Loss of (predominantly) dopaminergic neurones in the Substantia nigra
(2) Accumulation of intracellular inclusions (Lewy bodies) comprised of alpha synuclein

Question 11

What molecules comprise Lewy bodies?

Answer 11

Intracellular inclusions

Proteins

Alpha synuclein

Question 12

What percentage of cases of Parkinson’s disease development are considered sporadic?

Answer 12

95%

Question 13

What are some of the causes of Parkinson’s disease?

Answer 13

Unknown

Could be idiopathic or sporadic

95% seem to be sporadic

Some links between pesticide and MPTP exposure (toxins)

Also associated with influenza exposure + repeated head trauma

Question 14

What is an example of a gene that has been linked with Parkinson’s disease?

Answer 14

PINK1/ PARK 2/ PARK 7/ SNCA

Question 15

State a non-pharmacological therapy for Parkinson’s disease.

Answer 15

Surgical intervention

Question 16

State some pharmacological therapies for Parkinson’s disease.

Answer 16

(1) Symptomatic relief – e.g. dopamine

(2) Disease modifying therapies

Question 17

Where does DDC convert L-DOPA?

Answer 17

~90% in intestinal wall

Question 18

How are dopamine pathway treatments effective for Parkinson’s disease?

Answer 18

Ensure majority of L-DOPA enters brain unchanged for conversion to dopamine

Question 19

What is the first line treatment for symptomatic relief of Parkinson’s disease?

Answer 19

Dopamine pathway treatment

L-DOPA

e.g. carbidopa/levodopa (co-careldopa)

Question 20

What symptomatic treatment is also approved for Parkinson’s disease?

Answer 20

Pramipexole

Dopamine-receptor agonist

Question 21

What are some potential side effects of dopamine pathway treatment?

Answer 21

Acute effect – psychosis

Chronic effect –dyskinesia (excess movements)

Question 22

Why is a surgical intervention not possible for most patients with Parkinson’s disease?

Answer 22

Very expensive

Question 23

What is the most common surgical intervention for Parkinson’s disease?

Answer 23

Electrode on globus pallidus + subthalamic nucleus

Regulated by a pulse generator

Question 24

Describe the use of stem cell therapy in Parkinson’s disease.

Answer 24

Replacement of cells in the basal ganglia

Correction of underlying cause of reduced dopamine levels

Often carried out in Sweden

Question 25

Name a therapy which can slow the development of Parkinson’s disease

Answer 25

There are none