Huntington's Disease

Question 1

What region of the brain is most affected by Huntington’s?

Answer 1

striatum

Question 2

How does the volume of the striatum predict motor symptoms?

Answer 2

smaller equals worse symptoms

Question 3

HD epidemiology

Answer 3

average onset: 40 years old
average duration of disease: 18 years

Question 4

What is the symptom triad of HD?

Answer 4

motor
cognitive
behavioral/psychiatric

Question 5

What determines HD clinical diagnosis?

Answer 5

abnormal motor examination

Question 6

abnormal motor examination in HD

Answer 6

chorea: dance-like movements
poor motor coordination
motor slowing

Question 7

psychiatric and cognitive symptoms of HD

Answer 7

occurs prior to motor symptoms in many patients
often causes more morbidity than motor symptoms
agitation/irritability is most common: treated with medication
depression: more related to receiving diagnosis
dementia: planning, initiating, organizing

Question 8

HD disease course

Answer 8

slow progression/deterioration
eventually nursing home placement
death: head trauma/falling, aspiration pneumonia, wasting

Question 9

Are there drugs to slow or prevent HD?

Answer 9

no

Question 10

treatment of HD symptoms

Answer 10

chorea: antipsychotics, benzodiazepines
psychiatric: antidepressants, antipsychotics
cognitive: unclear of drug success

Question 11

genetic cause of HD

Answer 11

HTT gene
caused by too many CAG repeats (>40)
the function of the gene is highly dependent on the number of repeats
long repeats leads to faster onset

Question 12

How are HTT repeats inherited?

Answer 12

commonly parents pass on their exact copy number
rarely males will pass on a much longer repeat

Question 13

Nopoulos Lab theory of HD

Answer 13

HTT could be a gene that was positively selected for brain evolution
HTT is vital to development: KO is fatal
In children with expanded HTT: larger cerebral volumes and higher cognitive skill
HTT creates an accelerated brain trajectory