4b. Huntington (subcortical dementia) Flashcards
1
Q
What are characteristics of Huntington’s disease?
A
- It’s a rare hereditary neurodegenerative dominant disorder.
- We now know exactly where the gene is and on which chromosome, thus we can test for the disease.
- You have 50% change of inheriting the disease.
- There is a really early age of onset (35-45).
2
Q
What are technical details of HD?
A
- In a normal person there are 17-29 CAG repeats on the gene encoding for “huntingtin”.
- In HD patients there are 38+ repeats > it fabrics the wrong protein > it clumps in the basal ganglia > neural loss.
- The more repeats, the younger you will get the first symptoms.
3
Q
What are symptoms of HD? (in 3 domains)
A
- Motor
o Chorea = excessive unwanted movements
o Bradykinesia = slowing of wanted movements - Mood & behavior
o Apathy, irritability, depression, OCD - Cognition
o Cognitive changes eventually are leading to a full-blown dementia
4
Q
What do you see on a MRI scan in HD patients?
A
In the early stages you see atrophy of the basal ganglia
In later stages you can see a global atrophy
5
Q
Explain the ‘dog’ figure in HD.
A
In PD there is too much inhibition of the thalamus, and in HD there is hardly any inhibition leading to too much excitation of the motor cortex of the brain (=dog runs away)
6
Q
Which 5 cognitive domains are mostly impaired in HD?
A
- Executive functioning (one of the first symptoms): attention, visual, inflexibility, disinhibition
- Psychomotor speed: slowness
- Memory: working memory, defective retrieval, but also as in PD recognition is better
- Language: only in later stages when there is also atrophy in the rest of the cortex
- Emotion recognition: diminished recognition of negative emotions
7
Q
What is important to note in a NPA?
A
Hyperkinetic patients (most of the patients) perform significantly better on the cognitive assessment than hypokinetic patients (hardly any movement)
