Huntington's Disease

Question 1

Which two diseases have a relationship with the Basal Ganglia?

Answer 1

PD and HD

Question 2

What is Huntington’s Disease

Answer 2

A progressive, hereditary (autosomal dominant), neurodegenerative disorder characterized by 
movement abnormalities 
personality disturbances 
decline in cognitive abilities 
dementia

Question 3

Huntington’s Chorea

Answer 3

Brief, purposeless, involuntary and random movement

Question 4

What happens to dopamine and Ach with Huntington’s Disease

Answer 4

You have an increase in dopamine and a decrease in Ach

there is also a decrease in amount of some neurotransmitters

Question 5

Why would HD bring a lot of ethical questions

Answer 5

It is hereditary, if you have the gene you will get it

Almost always a history of a parent with the disease, and a 50% risk in each child of an affected adult

Question 6

What is the onset of HD (2 types)

Answer 6

Adult HD (Sx development between 40-50 yo)
better prognosis, 15-20 years
Juvenile HD (sx before 20 yo)
poorer prognosis, 8-10 years

Question 7

Pathogenogenesis of HD

Answer 7

Predominant findings are
Atrophy of Corpus Striatum of the BG
-Caudate nucleus
-Putamen
-Globus Pallidus

Neuronal degeneration of the temporal & frontal lobes of the cortex

-Brain starts breaking down

Question 8

What happens when the brain starts breaking down

Answer 8

People have a significant cognitive and functional decline

Question 9

Diagnosis of HD

Answer 9

Based on symptoms

You would get genetic testing - if you have the gene you will definitely develop it

CT and MRI only show visible atrophy in the advanced stages

Question 10

What are the clinical manifestations of HD

Answer 10

Early choreic movements may be manifested as restlessness, or may be integrated into normal purposeful movement strategies

Cognitive & emotional manifestation: forgetfulness & slight personality changes

Question 11

What happens in the late stages of HD

Answer 11

In late stage, there is greater inhibition, rather than excitation, of the thalamocortical output, resulting in bradykinesia

All caudate nucleus neurons will have been affected by this time

Question 12

HD patients and risk of falls

Answer 12

Falls risk not as severe as in PD or MS, as the patient may integrate choreiform movements into normal movement patterns

Question 13

What part of the body has more choreic movement

Answer 13

Choreic movements occur more in the UEs & face than in the LEs
↑ during complex motor, intellectual, or emotional tasks

Question 14

What will movement testing in a pt with HD reveal

Answer 14

Movement testing will reveal dysmetria and dysdiadochokinesia

• they test positive but it is not true dysmetria from the cerebellum, it is coming from the excessive movement

Question 15

What will movement testing in a pt with Juvenile HD reveal

Answer 15

In Juvenile HD, the chorea is exhibited briefly if at all, with rigidity being the dominant sx instead

Question 16

What else do you have to watch out for with Juvenile HD

Answer 16

Seizures are also another common sx in juvenile HD

Question 17

How is the muscle strength and tone of someone with HD (early and late stages)

Answer 17

They may appear weak but it is do to poor control and excessive motion

Muscle strength testing may be normal in the early stages, but testing may be difficult due to motor disturbances

Hypotonia may be present initially, but rigidity may be noted accompanying the end stage bradykinesia
-definitely gets worse later one

Question 18

How does movement transform in HD from the early to late stages

Answer 18

too much in the beginning to really stiff later on

Question 19

HD and Vision

Answer 19

Eye movement abnormalities are common 20 motor disturbances affecting ocular & extraocular muscles

Saccadic intrusions – dysmetria of the eyes
Saccades: ability to focus eyes from one target to another
↑ latency & under/over-shooting of the target

↓ gaze fixation or stabilization
↓ smooth pursuit (tracking)

Question 20

Saccadic intrusions are

Answer 20

Dysmetria of the eyes
Saccades: ability to focus eyes from one target to another
↑ latency & under/over-shooting of the target

Question 21

Gait and HD and what is it called

Answer 21

Chorea comes from the Greek word for “dance”

Choreiform gait is typified by a wide base of support, with staggering movements

Question 22

Oromotor Impairments and HD

Answer 22

Speech is dysarthric, with some aspects of aphasia

Dysphagia is common, making eating and proper nutritional intake difficult

But cachexia (muscle wasting) is often noted even in the presence of normal intake

Question 23

Sleep Disturbances and HD, when does it happen and what happens

Answer 23

Often seen in later stages

Manifests as insomnia

Potential reversal of sleep patterns (likely related to dementia)

Question 24

Why do sleep disturbances and hallucinations happen later on in HD

(what other disease might you see this and why)

Answer 24

because of the significant increase of dopamine

you would see this if you are over-medicated with PD

Question 25

B/B and HD

Answer 25

``` Incontinence is common, due to Immobility Hyperreflexia Depression Dementia ``` Can lead to UTI or skin breakdown

Question 26

Neuropsychologic and Psychiatric Disturbances with HD

Answer 26

``` Cognitive and intellectual changes Personality & behavioral changes Emotional/behavioral changes Ideomotor apraxia visuospatial deficits depression ```

Question 27

What can be early signs of HD (often subtle)

Answer 27

Neuropsychologic and Psychiatric Disturbances

Question 28

What would cause Cognitive and intellectual changes in HD

Answer 28

Lack of blood flow to the striatum

Question 29

What are some personality & behavioral changes for pts with HD

Answer 29

apathy, blunted affect, irritability, depression, violence or aggression, impulsivity and lability, anxiety, egocentrism, compulsive behaviors leading to addictions (alcoholism, gambling, hypersexuality)

Question 30

With HD Emotional/behavioral changes are often followed by

Answer 30

Intellectual changes Inability to recall stored memory ↓ organizational skills Impaired sequencing

Question 31

Other symptoms caused by the Huntington gene expressed throughout the body, and can cause other abnormalities peripheral to the brain

Answer 31

``` Muscle atrophy Cardiac failure Impaired glucose tolerance Weight loss Osteoporosis Testicular atrophy ```

Question 32

Medical management of HD

Answer 32

No cure; treatment is symptomatic Tetrabenazine – 1st FDA approved drug came out in 2008 for the tx of choreic symptoms Anticonvulsants or antipsychotics are given to block dopamine transmission These drugs also may treat the behavioral deficits Only used if the chorea has reached a point of severity that interferes with normal movement and function

Question 33

What are the side effects of medication for HD

Answer 33

High incidence of medication side effects Acute dystonias -- involuntary sustained muscle contractions Pseudo-Parkinsonism Akasthisia (uncontrollable physical restlessness) Tardive dyskinesia (uncontrollable, involuntary movement of the face, lips and tongue)

Question 34

Procedural Memory and HD

Answer 34

Ideomotor, they have procedural memory but cognitive decline

Question 35

What is Tardive dyskinesia

Answer 35

uncontrollable, involuntary movement of the face, lips and tongue

Question 36

What is Pseudo-Parkinsonism | Akasthisia

Answer 36

Uncontrollable physical restlessness

Question 37

What is Acute dystonias

Answer 37

Involuntary sustained muscle contractions

Question 38

Prognosis of HD

Answer 38

The earlier the onset of sx, the more severe the form of the disease Death usually occurs 15-20 years after onset Long term survival is possible with management of secondary complications

Question 39

For HD death usually occurs 15-20 years after onset, usually due to

Answer 39

Pneumonia (~33%) – due to dysphagia causing aspiration & inability to synchronize respiratory muscles Cardiac disease (~25%) Suicide – 27% attempt it, ~7.3% succeed Physical injuries from falls

Question 40

Death usually occurs 15-20 years after onset, usually due to

Answer 40

usually die from a secondary issue Pneumonia (~33%) – due to dysphagia causing aspiration & inability to synchronize respiratory muscles Cardiac disease (~25%) Suicide – 27% attempt it, ~7.3% succeed Physical injuries from falls