Parkinsons Flashcards
pathophysiology of Parkinsons disease (PD)
loss of dopaminergic neurons in the substantia nigra pars compacta
triad of symptoms in PD
TEMOR
RIGIDITY
BRADYKINESIA
features of tremor in PD
asymmetrical
worst at rest
usually hands- “pill rolling” tremor
4-6Hz
what improves a tremor in Parkinsons disease
voluntary movement
features of rigidity in PD
increased tone - lead pipe rigidity
rigidity + tremor – cogwheel rigidity
gait seen in PD
shuffling
absent arm swing
flexed trunk
features of bradykinesia in PD
Decreased initiation of movement
Decreased speed of movement
Decreased amplitude of repetitive movements
speech in PD
monotone
quiet
what autonomic dysfunction contributes to instability + falls risk in Parkinsons
Orthostatic hypotension
sleep disorder seen in PD
REM sleep disorder
what is micrographia
small handwriting
- feature of PD
features suggestive of drug induced parkinsons
BILATERAL motor symptoms
rapid onset symptoms
resting tremor uncommon
what imaging modality can differentiate between drug induced parkinsons and parkinsons disease
DaTSCAN
- will show striata dopaminergic neuron loss in parkinsons disease
what class of drugs typically cause drug induced parkinsons
typical antipsychotics
- haloperidol, chlorpromazine
Block dopamine in substantia nigra
1st line treatment in PD where motor symptoms having greatest impact on life
Levodopa + dopa-decarboxylase inhibitor
- carbidopa
- madopar
what is the purpose of prescribing levodopa with a dop-decarboxylase inhibitor
reduces peripheral conversion of levodopa to dopamine
list 5 short term side effects of levodopa
Nausea + vomiting postural hypotension red urine confusion / hallucinations / delusions / vivid dreams daytime drowsiness
what are the main long-term side effects of levodopa
dyskinesia (common -50%)
- involuntary movement
unpredictable ‘on-off’
- leads to bradykinesia
treatment of nausea in PD
Domperidone
which anti-emetic can induce parkinsons
metoclopramide
treatment of daytime sleepiness in Parkinsons
modafinil
treatment of REM sleep disorder in PD
melatonin or clonazepam
1st line treatment in PD if motor symptoms are not impacting quality of life
MAO-B inhibitor
Dopamine agonist
mechanism of action MAO-B inhibitors
block dopamine degradation within cell
rasagiline and selegiline are examples of which class of drug
MAO-B inhibitors
what drug can MAO-B inhibitors not be prescribed with
SSRI
- risk of serotonin syndrome
side effects of rasagiline / selegiline
anticholinergic:
- dry mouth
- blurred vision
- constipation
- urinary retention
- postural hypotension
ropinirole, cabergoline, pramipexole are examples of which class of drug
dopamine agonists
subcut apomorphine is an example of which class of drug
dopamine agonist
side effects of dopamine agonists
fatigue
nausea + vomiting
Impulse control disorders - gambling, sex, eating, shopping
oedema
mechanism of action catechol- O- methyltransferase inhibitors (COMT)
block dopamine + levodopa degradation outside the cell
entacapone and tolcapone are examples of which class of drug
COMT inhibitors
treatment pathway parkinsons disease
1st line motor - L-Dopa + dopa-decarboxylase inhibitor
1st line non-motor - MAOB (rasagiline) or dopamine agonist (ropinirole)
2nd line motor or development of dyskinesia add
- MAOB / dopamine agonist / COMT inhibitor
what drug can be used to treat dyskinesia if other agents have been ineffective
amantadine
- increases dopamine release and reduces reuptake
what drugs can be used to treat tremor in drug-induced parkinsons
antimuscarinics
- procyclidine
what is progressive supranuclear palsy
a parkinsons plus syndrome - features of Parkinsonism +
- vertical gaze palsy
- slurred speech
- falls
- axial involvement
what is multi-system atrophy
a parkinsons plus syndrome
- autonomic dysfunction: postural hypotension, erectile dysfunction, atonic bladder
- cerebellar features
hot cross bun sign
cerebellar + pontine atrophy
- multi-system atrophy
bilateral tremor, worse with movement/arms outstretched
improves with alcohol
essential tremor
treatment essential tremor
propanolol
uncomfortable sensations in lower legs, worse at rest
intense urge to move + movement providing relief
restless leg syndrome
1st line management restless leg syndrome if affecting sleep/functioning
gabapentin / pregabalin
what haematological abnormality is associated with restless leg syndrome
iron deficiency anaemia
