Huntington's Disease Flashcards
What is Huntington’s Disease?
It is a genetic, hereditary, progressive neurogenerative disorder caused by a defect in a gene on the short arm of chromosome 4.
Caused by a dominant gene that codes for a large brain protein called huntingtin.
How many people are at risk of having HD in Canada?
1 in 7,000 people.
How many people are at risk of inheriting HD in Canada?
1 in 5,500 people.
How many people are affected by HD in Canada (e.g. spouse, friends, relatives, etc.)?
1 in 1,000 people.
Are men or women more at risk of inheriting HD?
Both have an equal risk.
The onset of HD symptoms occur between what ages?
35-55
Juvenile HD accounts for what percentage of all HD cases?
10%
Is there a cure for HD?
No but there are treatments to reduce severity.
What are some HD management options?
Multidisciplinary caregiving.
Exercise has been shown to help rehabilitate cognitive symptoms of HD.
Physical, occupational, and speech therapy.
How can HD be detected?
There is a genetic test to see if a person carries the mutated Huntingtin gene.
What is Genetic Anticipation?
Process where severity of a disease in future generations is anticipated based on genetic testing.
How can HD be diagnosed?
Symptoms, family history, imaging, and genetic testing.
How does stress impact HD?
It can hasten the onset of the disease.
A positive test result can actually add to the damage of HD.
When do symptoms of HD appear?
Later adulthood.
Why is HD a progressive disease?
Symptoms begin very subtly and eventually progress to more pronounced involuntary movements (Hyperkinetic).
What are the early stages of HD?
Face, trunk, and limbs move involuntarily and rapidly.
Not too noticeable, can be disguised by patient fairly easily.
What occurs as HD progresses?
Muscles begin to contract briefly and rapidly.
Arms and other body parts suddenly jerk.
Movements become uncoordinated, and eventually the whole body is affected.
What are the later stages of HD?
Cognitive changes become pronounced.
Irritability, excitability, impulse control issues.
Changes in interests.
Severe depression, dementia, etc.
Death usually occurs 13 to 15 years post onset of symptoms.
What are the symptoms of HD?
Chorea
Cognitive difficulties, including dementia
Emotional difficulties (e.g. depression, apathy, irritability, personality disorders)
Eventually, the motor and intellectual deterioration become so severe that sufferers are incapable of feeding themselves, controlling their bowels, or recognizing their own children.
What is Chorea?
Abnormal movements (involuntary movements, dystonia, and motor coordination).
The Striatum contains groups of specialized neurons called what?
Medium Spiny Neurons (MSN).
They also contain GABA interneurons
Medium Spiny Neurons are specialized GABAergic cells that represent what rate of the neurons in the human Striatum?
95%.
What are the two types of Medium Spiny Neurons?
Direct (D1) and Indirect (D2)
What do the direct MSN do?
Excite their output structures and promote associated behaviours.
