Test 1: Huntington's Disease

Question 1

what is huntingtons

Answer 1

genetic

Gene mutation on chromosome 4 - Cytosine, adenine, and guanine repeat more than normal

huntingtin protein is mutated - role in nn cell function

mutation leads to build up of toxic fragments that ultimately cause neuron death

severe neuronal loss specifically in caudate and putamen (basal ganglia)

damage to frontal and temporal lobes as well

Question 2

what happens at the basal ganglia pathway during Huntington’s disease

Answer 2

Initially = disinhibition of indirect D2 pathway (inhibition of inhibition = excitation) ; when inhibited, the thalamus gets excited and leads to excessive movement = chorea

late stage = damage to the direct D1 path that INHIBITS the thalamus and then leads to loss of movement or hypokinesia

Question 3

S&S of HD

Answer 3

personality changes, mood swings, depression (frontal lobe)

forgetfulness and impaired judgement/memory (temporal and frontal)

unsteady gait and involuntary movements

slurred speech, difficulty swallowing, significant weight loss

Question 4

etiology of HD

Answer 4

41000 people in US and 200000 more at risk of inheriting

usually diagnosed middle aged (30-50)

juvenile or late onset are possible (below 20 or above 59)

usually people of western european descent

Question 5

sporadic HD

Answer 5

not inherited

spontaneous mutation

Question 6

describe juvenile HD

Answer 6

different S&S than adult
charactteristics
- stiffness in legs
- clumsiness
- seizures
- other typical HD S&S

more rapid progression (10 year lifespan)

more likely to get juvenile if you develop HD gene from dad

Question 7

diagnostic process of HD

Answer 7

50/50 chance of developing if parent has it

neuro exam and medical hx by neurolgist

hx of yourself and fam

physical exam
- reflex
-balance
-tone
-movement
-gait
- mental status

Question 8

imaging dx for HD

Answer 8

with disease progression

cant see at first

shrinking brain with enlarged ventricles

CT or MRI

Question 9

genetic testing for HD dx

Answer 9

counting CAG repeats in huntingtin gene

36+ repeats = HD

26 or less = negative for HD

Question 10

prognosis of HD

Answer 10

fatal usually due to secondary complications like heart failure and pneumonia

disease progression takes 10-25 years

pts are dependent and require total assist for everything by the end of the disease course

Question 11

medical treatment for HD

Answer 11

no cure
manage of symptoms

behavior/psych probs = medication to manage

weight loss = chorea + constant movement; may have hard time swallowing; need SLP and nutritionist; may consider feeding tube

Question 12

symptom management for HD

Answer 12

movement/balance/gait = PT can treat and work on or slow decline

cognitive = work with OT and SLP to manage

Question 13

early stage of HD

Answer 13

still driving, working, handling money, and walking

subtle S&S
- difficulty coordination
- mild chorea
- difficulty with higher level problem solving
- mild depression/irritability

Question 14

middle stage of HD

Answer 14

no longer able to work, drive, manage money, or chores

need assist for eating, dressing, and personal hygiene

signs of
- weight loss
- falls
- swallowing difficulty
- difficulty sequencing
- difficulty problem solving
- cant prioritize tasks
- more chorea
- impulsive
- suicidal behaviors
- paranoia/hallucinations

Question 15

late stage HD

Answer 15

assist all ADLs

nonverbal and bedridden

severe chorea or replaced with more parkinsonian S&S of severe rigodity and bradykinesia

delirium

global dementia

Question 16

Unified HD rating scale

Answer 16

looks at motor function, cognition, behavior, and functional ability

higher scores are worse

motor assessment looks at:
- eye movement
-dysarthria
- tongue control
- balance
- gait
- coordination
- rigidity in limbs

cognitive
- verbal fluency
-pair numbers and shapes
- stroop test (green word that spells red)

functional
- looks at their ADL/activity level functions