parkinsons Flashcards
(25 cards)
causes of parkinsonism
drug induced
Wilsons disease
post encephalitis
toxins - CO, MPTP
PSP + multisystem atrophy
what drugs can cause parkinsonism
antipsychotics
metoclopramide - antiemetic
parkinsons pathophys
degeneration of dopaminergic neurons in the substantia nigra
(brain not making enough dopamine)
are symptoms in parkinsons disease symmetrical or asymmetrical?
ASYMMETRICAL !!
triad
- bradykinesia
- tremor
- rigidity
brady kinesia in parkinsons
poverty of movement
short, shuffling steps, reduced arm swinging
difficulty in initiating movement
tremor in parkinsons disease
most marked at rest
3-5Hz
improves with voluntary movement
pillrolling - between thumb + index
rigidity in parkinsons
lead pipe
cogwheel - due to superimposed tremor
other characteristics of parkinsons
mask-like face
flexed posture
drooling
REM sleep behaviour disrder
psych = depression, dementia, psychosis
autonomic dysfunction = postural hypotension
how do symptoms vary in drug indiced parkinsonism
motor symptoms are more rapid onset + BILATERAL
rigidity and rest tremor uncommon
diagnosing parkinsons
clinical !
if uncertainty -> consider SPECT
pathological findings in parkinsons
discolouration of the substantia nigra due to loss of pigmented nerve cells
( usually brown strip )
in which patients is levodopa most effective
where motor sx affecting quality of life
- improves motor sx + activities of daily living
why can impulse control disorders be assoc with parkinsons
due to dopamine agonist therapy
too much dopamine drives impulses
mx of orthotatic hypotension in parkinsons
med review looking at causes
if sx persist -> midodrine
mx of drooling of saliva in parkinsons
glycopyrronium bromide
common adverse effects of levodopa
dry mouth
anorexia
palpitations
postural hypotension
psychosis
what is levodopa nearly always given with? why?
decarboxylase inhibitor (carbidopa or beserazide)
-> prevents peripheral metabolism of levodopa to dopamine outside of the brain, hence reduce side effects
end-of-dose weaning off in parkinsons
symptoms often worsen towards the end of dosage interval
-> results in decline of motor activity
on-off phenomenon in parkinsons
large variation in motor performance;
- normal function during the “on” period
- weakness + restricted mobility during “off”
what can happen when levodopa dose peaks
dyskineasia = involuntary writhing movements
- dystonia
- chorea
- athetosis
how to stop levodopa / what happens when no oral route
can NOT be acutely stopped
cant take orally = dopamine agonist patch as rescue medication to prevent acute dystonia
adverse effects of dopamine receptor agonists
impulse control disorders
excessive daytime somonlence
more likely than levodopa to cause hallucinations in older patients
examples of dopamine receptor agonists
bromocriptine, cabergoline
- can causes pulmonary, retroperitoneal + cardiac fibrosis
–> echo, ESR, creatinine, CXR prior to tx
drug that would be used to treat drug induced parkinsons rather than idiopathic
antimuscarinics - block cholinergic receptors
help tremor + rigidity
= procyclidine, benzotropine
