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Opt 637 CNS Exam 1
Dr Smith Lecture 3
51
Medical
Graduate
09/02/2011

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Cards

Term
How is muscle tone affected in Parkinson's?
Definition
Increased tone or rigidity leading to resistance to passive movement, with ratchet like 'cogwheel' interruptions of passive movement
Term
How is gait and posture affected in Parkinson's?
Definition
difficulty getting out of a bed or chair

Difficult to initiate walking, must lean forward and walk in place to initiate

Gait is small shuffling steps, no arm swing

Gait increases in speed as they walk so they can prevent falling: 'festinating' gait

Unsteadiness on turning and difficulty stopping
Term
How are facial expressions affected by Parkinson's?
Definition
Face becomes relatively immobile, lack of expression
Term
What are early s/sx of Parkinson's dz?
Definition
depression

constipation

impaired smell

insomnia

blepharoclonus (eyelid flutter); often with blepharospasm

Myerson's Sign - glabellar reflex

cognitive decline

Dysphagia and weight loss
Term
What is blepharoclonus?
Definition
fluttering of closed eyelids
Term
What is Myerson's sign?
Definition
If the glabella (top of nose between eyebrows) is tapped, pt is unable to resist blinking
Term
What is a very early sign of Parkinson's dz?
Definition
constipation
Term
Why is a walker not a useful device for Parkinson's dz tx?
Definition
It forms a visual block of the floor, which leads to inability to gauge movement, so they simply choose not to move and risk falling
Term
When can olfactory compromise begin to present if Parkinson's is developing?
Definition
Up to 5 years prior to dx, an early sign
Term
When can depression begin to present as Parkinson's develops?
Definition
3-4 years prior to dx
Term
How does the cognitive decline associated with PD compare to AD?
Definition
PD is milder, less debilitating
Term
What is dysphagia?
Definition
difficulty swallowing
Term
What is a frontal override?
Definition
A conscious decision in the frontal cortex overruling a reflexive action
Term
What must be restored to treat PD?
Definition
balance between dopaminergic and cholinergic influences of GABA
Term
What are drugs that increase dopamine levels in PD?
Definition
levodopa and amantadine
Term
What is the mechanism and use of levodopa?
Definition
dopamine precursor used to increase dopamine levels in PD. Is given w/ carbidopa (Sinemet)
Term
What is the mechanism and use of amantadine?
Definition
Antiviral drug that enhances dopamine synthesis, release, and re-uptake in surviving neurons of PD pt's. Mechanism ultimately unknown. Does not work on all individuals, loses effectiveness over time on pt's it does work on.
Term
What is the dose of Levodopa?
Definition
.5 to 1 g qd (sometimes bid-qid)
Term
What are PD drugs that stimulate dopamine receptors? **edit: this will not be on the test**
Definition
apomorphine

pramipexole

ripinirole

pergolide

bromocriptine
Term
What are drug classes that inhibit DA metabolism for PD tx?
Definition

MAO-B inhibitors

 

COMT inhibitors (Catechol-o-methyltransferase)

 

 

Term
What is entacapone?
Definition

DA metabolism inhibitor (COMT inhibitor), used to treat PD and is now on the market, given in 1 tab q3-8h

 

Is mixed with Sinemet to form Stalevo.

Term
What is tolcapone?
Definition
DA metabolism inhibitor (COMT inhibitor), used to treat PD, given in 100 to 200 mg t.i.d. doses
Term
What are anti-cholinergice drugs used to treat PD?
Definition
hyoscyamine

trihexyphenidyl

biperiden

benztropine
Term
What are ocular SE of anti-cholinergic drugs?
Definition

dry eye

 

lose accommodation

 

pupillary dilation

Term
How can PD related spasms be treated?
Definition
botulinum toxin
Term
What is a thalamotomy?
Definition
production of a lesion the thalamic nuclei by thermal or electrical means. Now largely obsolete due to L-dopa drug classes, but still used some.
Term
What is a pallidotomy?
Definition
surgical destruction of part of the thalamus
Term
What is deep brain stimulation?
Definition
Thalamic stimulation: pacemaker implanted into thalamus to control tremor. Mechanism unknown.
Term
What are 4 future PD tx that are currently being evaluated?
Definition
neuroprotective deactivation of free-radicals

neural tissue transplants from fetal pigs to restore affected area

modification of genetic code of others cells to create dopamine

implantation of human RPE cells (they produce L-dopa)
Term
What is Huntington's dz?
Definition

Destruction of cholinergic and GABA-ergic neurons that leads to excess DA

 

autosomally dominant inheritance

 

s/sx do not appear until adulthood, generally 4th or 5th decade.

Term
What is the mechanism of Huntington's dz?
Definition

loss of cerebral cortex and corpus striatum

 

destruction of cholinergic and GABA-ergic neurons which results in imbalance with excess DA

Term
What is chorea?
Definition
movement disturbance 'dancelike' herky jerky movement. Typical of Huntington's.
Term
What are the precursors of HD related dementia?
Definition
moodiness and irritability --> full blown dementia
Term
How is HD diagnosed?
Definition
positive family history

genetic testing
Term
Is there a cure for HD?
Definition
no
Term
What drugs are used to treat HD symptoms?
Definition
haloperidol for spasmodic movement of limbs and face

tetrabenazine decreases involuntary movements by decreasing DA level
Term
What is myasthenia gravis?
Definition
autoimmune attack of ACh receptors by Ab's that damage postsynaptic muscle membrane
Term
Myasthenia gravis is often comorbid with what disorders?
Definition
SLE

thyroid dysfunction
Term
Myasthenia is more prone in what gender?
Definition
female
Term
When is onset of myasthenia gravis seen?
Definition
Two peak onsets: ~20 yr and then 50-60 yrs
Term
In what dz does bradykinesia sometimes present as a sudden stoppage of all movement?
Definition
Parkinson's dz
Term
Does Parkinson's related tremor induce the 'cogwheel' stepped motion that presents as s/sx of PD?
Definition
No, the stepped motion will be observed even if tremor is not present
Term
What is sinemet?
Definition
A carbidopa/levodopa mix that is used to treat PD.  
Term
What is the advantage of sinemet?
Definition
The carbidopa prevents levodopa induced nausea due to levodopa digestion in the stomach.
Term
What is the #1 Parkinson's drug?
Definition
Sinemet (levodopa/carbidopa mix)
Term
What s/sx are dopamine agonists effective at treating in Parkinson's?
Definition
hypokinesia, but not tremor
Term
What Parkinson's drugs are associated reduced inhibition and impulsive behavior such as gambling, hypersexuality, reckless driving, and shoplifting?
Definition
Some dopamine agonists, in particular pramipexole and ropinirole
Term
What is the most common dopamine agonist used to treat Parkinson's dz?
Definition
Bromocriptine
Term
How do COMT inhibitors increase the effectiveness of administered levodopa?
Definition
The COMT pathway reduces levodopa via 3-O-methyldopa competition, so blocking this pathway results in more levodopa.
Term
What kind of hypersensitivity is myasthenia gravis?
Definition
Either type II (Ab attacks own cells) or Type V (Ab attack of neurotransmitter receptors)
Term
What is Stalevo?
Definition
A mixture of carbidopa, levodopa and entacapone.
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