Basal Ganglia Disease - Parkinson 01.03.23

Question 1

What are the two subgroups of the basal ganglia in the rostral (upper part)?

Answer 1

• Striatum: Putamen, Caudate nucleus
• Globus pallidus: Internal and external segment

Question 2

What are two structures in the caudal (lower part) of the basal ganglia?

Answer 2

• Subthalamic nucleus
• Substantia nigra

Question 3

Where does the caudate nucleus run?

Answer 3

• Along the wall of the lateral ventricles
• Then the putamen is lateral to the caudate nucleus

Question 4

Where are the red nucleus and substantia nigra located?

Answer 4

• The substantia nigra is in the mesencephalon
• The red nucleus is above the substantia nigra

Question 5

Give three circuits the basal ganglia is involved in

Answer 5

• Motor circuit
• Limbic circuit
• Oculomotor circuit

Question 6

What motor disorders are associated with Basal Ganglia dysfunction?

Answer 6

• Parkinson’s disease
• Huntington’s disease
• Dystonia

Question 7

What psychiatric disorders are associated with Basal Ganglia dysfunction?

Answer 7

• Obsessive compulsive disorder
• Attention Deficit Hyperactivity Disorder (ADHD)

Question 8

What disorders are associated with Basal Ganglia dysfunction due to secondary damage?

Answer 8

• Cerebral Palsy
• Wilson disease

Question 9

What is Parkinson’s disease in terms of dopamine?

Answer 9

• Not enough dopamine (because nerve cells in substantia nigra are lost which produce dopamine)
• Increased muscle tone (rigid)
• Reduced movements

Question 10

What is Huntington’s disease in terms of dopamine?

Answer 10

• Too much dopamine
• Decreased muscle tone (floppy)
• Overshooting movements

Question 11

How is dopamine made?

Answer 11

Tyrosine (amino acid)
Into L-DOPA
Into dopamine

Question 12

What happens to the substantia nigra in Parkinson’s?

Answer 12

There is a loss of nerve cells and the nerve cells in this part of the brain are responsible for producing dopamine

Question 13

How is the caudate nucleus affected with Huntington’s disease?

Answer 13

ADD
- It grows in size

Question 14

How does lack of GABA cause Huntington’s?

Answer 14

GABA is an inhibitory neurotransmitter and if striatum is affected and doesn’t produce GABA then there is an increase in dopamine and therefore an increase in movement

Question 15

What are the three symptoms of PD?

Answer 15

1. Brady/Akinesia: problems doing up buttons, writing smaller (slowness in movement)
2. Tremor
3. Rigidity: pain

Question 16

What is the drug treatment of PD?

Answer 16

• Mostly aim to correct dopamine deficit
• The longer on treatment, the more likely patients are to develop side effects e.g. dyskinesias (involuntary, erratic movements)

Question 17

What is the DBS treatment for Parkinson’s?

Answer 17

DBS: Deep Brain Stimulation
It is connected to one or two fine wires that are inserted into specific areas of your brain. When the pulse generator is switched on, the electrodes deliver high frequency stimulation to the targeted area. This stimulation changes some of the electrical signals in the brain that cause the symptoms of Parkinson’s

Question 18

What are the clinical features of HD?

Answer 18

• Chorea (sudden, unintended jerky movements)
• Dementia
• Personality change

Question 19

What are the clinical genetics of HD?

Answer 19

• Autosomal dominant
• Fully penetrant