basal ganglia disease

Question 1

basal ganglia structures

Answer 1

2 subgroups:
Rostral:- 
Striatum 
•	Putamen 
•	Caudate nucleus 
Globus Pallidus 
•	Internal segment 
•	External segment 
Caudal:-
Subthalamic nucleus 
Substantia nigra

Question 2

motor disorders associated with basal ganglia dysfunction

Answer 2

• Parkinson’s disease
• Huntington’s disease
• Dystonia
• Gilles de la Tourette syndrome

Question 3

Psychiatric disorders associated with basal ganglia dysfunction

Answer 3

• Obsessive compulsive disorder

* Attention deficit hyperactivity disorder (ADHD)

Question 4

secondary damage associated with basal ganglia dysfunction

Answer 4

• Cerebral palsy

* Wilson disease

Question 5

function of basal ganglia

Answer 5

facilitation
integration
fine tuning of movements

Question 6

what causes Parkinson’s disease

Answer 6

• increased muscle tone (spasticity), reduced movements
• not enough dopamine in substantia nigra – loss of dopaminergic neurons
• substantia nigra appears ‘faded’ – less dopamine production – less byproduct (black pigment – neuromelanin)
• less dopamine means that the external globus pallidus will not be able to inhibit the subthalamic nucleus meaning it will in turn excite the internal global pallidus resulting in the inhibition of the thalamus and thus a decrease in movement

Question 7

symptoms of Parkinson’s

Answer 7

Brady/Akinesia
•	Problems with doing up buttons, keyboard etc
•	Writing smaller
•	Walking deteriorated: Small steps, dragging one foot etc
Tremor
•	At rest
•	May be on one side only
Rigidity
•	Pain
•	Problems with turning in bed

Question 8

treatment of Parkinson’s

Answer 8

• Drugs mostly aim at correction of dopamine deficit
• L-DOPA
However:
But:
• More and more cells die
• The drugs work shorter and shorter
• The longer on treatment, the more likely are the patients to develop side effects, in particular dyskinesias

Question 9

alternative treatment for PD

Answer 9

deep brain stimulation of the subthalamic nucleus – inhibits the subthalamic nucleus meaning that the thalamus does not get inhibited and can thus excite the cortex resulting in improved movement

Question 10

what causes Huntington’s disease

Answer 10

• decreased muscle tone, overshooting movements

* too little GABA resulting in too much dopamine

Question 11

clinical features of HD

Answer 11

• Chorea
• Dementia/psychiatric illness
• Personality change
• Atrophy of ventricles

Question 12

clinical genetics of HD

Answer 12

• Autosomal dominant

* Fully penetrant

Question 13

treatment of HD

Answer 13

dopamine receptor blockers