basal ganglia and parksinsons

Question 1

What are basal ganglia

Answer 1

• They are deep brain structures

Question 2

WHay are the two subgroups

Answer 2

1. ) Rostral (upper part)

2. ) Caudal (lower part)

Question 3

What makes up the rostral part

Answer 3

T1.) he striatum

• putamen
• caudate nucleus
  2. ) Globus pallidus
• internal segment
• external segment

Question 4

What makes up the caudal part

Answer 4

• Subthalamic nucleus

- substantia nigra

Question 5

Whats caudate nucleus + putamen

Answer 5

= striatum

Question 6

Circuits in the basal ganglia

Answer 6

1. ) Motor circuit
2. ) Limbic circuit
3. ) Oculomotor circuit

Question 7

Illnesses associated with basal ganglia dysfunction

Answer 7

1. ) Motor disorders: Parkinson’s/Huntington’s/Dystonia/Gilles de la Tourette syndrome
2. ) Psychiatric disorders: ADHD/OCD
3. ) Secondary damage: cerebral palsy/Wilson disease

Question 8

What do we see in PD/HD

Answer 8

1. ) PD: increased muscle tone/reduced movements. Not enough dopamine
2. ) HD: decreased muscle tone/overshooting movements. Too much dopamine

Question 9

What is dopamine

Answer 9

It is a hydroxylated amino acid. IT acts as a *something. Check for 10.11
L-Dopa is converted to dopamine by decarboxylation

Question 10

Where is it produced

Answer 10

In the substantia nigra

Question 11

Where does it act

Answer 11

It acts at the terminals of axons

Question 12

Pathology

Answer 12

Lose over 2/3’s of your Dopamergic neurones

Question 13

Whats affected in huntington’s

Answer 13

The striatum is mainly affected: in particular the caudate nucleus

Question 14

In normal

Answer 14

• From striatum: have gaba

- From substantia nigra: dopamine

Question 15

In PD

Answer 15

• Substantia nigra: no dopamine

- less movement

Question 16

In HD

Answer 16

• Striatum: no gaba

- more movement

Question 17

Most important medication

Answer 17

L-Dopa: the naturally occurring precursor drug

Question 18

PD

Answer 18

• Lack of movement is due to the striatum. Dopamine acts as a lubricant so movement inpaired
• the subthalamic nucleus has inhibitory neutrons. These further reduce movement. Dopamine normally acts as a break so there is normally no inhibition of movement

Question 19

In deep brain surgery

Answer 19

• electrodes are placed in the subthalamic nucleus

Question 20

Features of huntington’s disease

Answer 20

• autosomal dominant + fully penetrant

- clinical features: chorea/dementia/personality change

Question 21

Where does HD affect

Answer 21

• affects striatum/cortex

- It is a triplet disease: Huntington’s

Question 22

Medication of HD

Answer 22

• too much dopamine

- hence: dopamine receptor blockers = neuroleptics