Huntington's Disease

Question 1

What is Huntington’s Disease?

Answer 1

Progressive neurodegenerative disorder characterized by involuntary movements (chorea), dementia and progression to severe dependency and death over 15-20 years from first onset of symptoms

Question 2

Who gets Huntington’s?

Answer 2

Autosomal dominant trait

Age dependant penetrance

Question 3

Gene in Huntington’s?

Answer 3

CAG repeats for glutamine
CAG repeat expansion results in production of an abnormal protein with a long string of glutamine residues that is toxic to some cell types within the brain

In normal gene there is around 20 CAG repeats at one position in the gene coding for around 20 glutamine residues

Question 4

Presentation of Huntington’s?

Answer 4

• Involuntary movements
• Dementia
• Progression to severe dependency and death over 15-20 years

Question 5

Late clinical signs of Huntington’s?

Answer 5

Rigidity 
Bradykinesia 
Severe chorea 
Serious wt loss 
Inability to walk 
Inability to speak 
Swallowing problems, danger of choking 
Inability to care for oneself

Question 6

Investigation of Huntington’s?

Answer 6

Genetic testing

MRI: loss of caudate heads

Question 7

What does an MRI of Huntington’s show (long answer)?

Answer 7

Loss of cells from basal ganglia causing flattening of normal convex curve of lateral walls of lateral ventricles

Cells are lost from other brain areas including cerebral cortex

Question 8

Treatment of Huntington’s?

Answer 8

Mood stabilisers
Chorea treatment
HD nurse specialist

Question 9

MRI of Huntington’s shows (short answer)?

Answer 9

Loss of caudate heads

Question 10

Pathogenesis of Huntington’s?

Answer 10

-Caused by pathological expansion of a trinucleotide repeat in the Huntington gene

Question 11

Early signs of Huntington’s?

Answer 11

• Subtle fidgetiness
• Difficulty concentrating
• Memory lapses
• Mood swings
• Clumsiness

Question 12

What are early signs followed by?

Answer 12

• Development of chorea
• Inability to walk
• Difficulties speaking/swallowing
• Bradykinesia
• Dementia
• Ultimately death

Question 13

Prognosis of Huntington’s?

Answer 13

Patients usually die 10-20 years after 1st symptoms onset

1st onset usually 30-40 years

Question 14

Investigations for Huntington’s?

Answer 14

Genetic test

MRI shows loss of caudate heads

Question 15

Management of Huntington’s disease?

Answer 15

• No disease modifying drugs

- Chorea can improve with treatment such as risperidone or sulpride