Parkinson's disease Flashcards
which neurotransmitter is implicated?
dopamine
which pathway is effected?
nigrostriatal pathway
dopaminergic neurones die in which part of the brain?
the above structure falls under which larger group of structures?
substantia nigra pars compacta
basal ganglia
what is the aetiology?
idiopathic
what is seen on histology?
Lewy bodies in substantia nigra
where does parkinson’s rank in the most common neurodegenerative disorders?
2nd
what is the most common neurodegenerative disorder?
Alzheimer’s
which gene is involved?
LRKK-2 gene
which gender is a RF?
males
the basal ganglia is mainly responsible for what?
movement
basal ganglia enables subconscious control of what property in skeletal muscles?
tone
a person want to move.
Dopamine in the direct pathway does what?
stimulates desired contracting muscle
a person want to move.
dopamine in the indirect pathway does what?
inhibits antagonistic muscle
what are the 4 main movement symptoms?
Bradykinesia
Resting Tremor
Rigidity
Postural instability
what are the non-movement symptoms?
-6
Sleep troubles Depression, anxiety, dementia Constipation Anosmia
why is there tremor and rigidity?
Dopamine & ACh balance is thrown off. ( ↓[dopamine] )
Resting tremor is exacerbated and alleviated by what?
worse when tired
better with movement.
how many types of rigidity are there in Parkinson’s?
name each?
explain each?
2
Cogwheel rigidity - arm passively moves and it stops and starts i.e. clunks.
Lead-pipe rigidity - in lower legs do not move at all, a lot of resistance.
what is the must have symptoms to diagnose PD?
Bradykinesia
what type of diagnosis is this?
which speciality must diagnose?
Clinical Diagnosis
neurologist
Bradykinesia will results in what features in their movement?
-4
shuffling steps
mask face
can not stop abruptly
can not resist a push
what is the main feature of their posture?
hunched over
what Ix can you do to check Da levels in basal ganglia?
SPECT (DaT scan)
why would you do a brain MRI?
exclude other causes
what is the 1st line Mx (nutshell mx)?
Levodopa + Carbidopa
which drug used in Parkinson’s has a side effect of increased psychosis?
why does this SE happen?
Levodopa
↑Dopamine
which drug used in Parkinson’s has a side effect involving your heart?
what is this side effect specifically?
why does this SE happen?
Levodopa
arrhythmias
Levodopa in periphery –> peripheral DOPA decarboxylase converted it to –> dopamine –> epinephrine –> arrhythmias
the two first line drugs for PD are given together.
one of these is used to stop SE of the other.
what is this drug called?
moa of this drug?
does it cross BBB?
Carbidopa
dopa decarboxylase inhibitor
does not cross the BBB
treatment involves doing essentially what to dopamine levels?
↑dopamine
which group of drugs can be used to help with tremor and rigidity?
why does it help?
Antimuscarinic
block ACh, ↓ACh so more in balance with Da
which two enzyme inhibitor drugs can be given 2nd line?
what effect would the two enzymes have if they were not inhibited?
thus, what is effect when you take there two enzyme inhibitors?
MAO-B inhibitor
Catechol-O-methyltransferase inhibitor
breaks down dopamine
↑dopamine
names of MAO-B inhibitor commonly used in Parkinson’s?
-2
what is the suffix of this drug class?
rasagiline or selegiline
giline
names of COMBT inhibitors commonly used in Parkinson’s?
-2
what is the suffix of this drug class?
entacapone, tolcapone
capone
2 e.g. of antimuscarinics commonly used in Parkinson’s?
benztropine, procyclidine
effect of amantadine on Da?
increases it
function of carbidopa?
dopa decarboxylase inhibitor in periphery only
if you do not give carbidopa with levodopa what se can happen?
why?
arrhythmia
Levodopa in periphery > peripheral DOPA decarboxylase converted it to > dopamine > epinephrine > arrhytmia
Da precursor?
levodopa
levodopa + carbidopa combo together is called what?
sinemet
which enzyme converts levodopa to Dopamine?
DOPA decarboxylase
drug class of prochlorperazine?
anti-sickness/ anti-emetic
prochlorperazine commonly to stop what symptoms?
-2
N&V and dizziness
prochlorperazine effect on Da?
thus prochlorperazine effect on Parkinson’s symptoms?
Da antagonist
makes it worse
