Neurology Flashcards
what is the pathophysiology of parkinsons disease?
Progressive degeneration of the dopaminergic neurons in the substantia nigra
what is the classical symptoms of parkinsons disease?
triad:
tremor - pill rolling
bradykinesia - slow shuffling gait, difficulting initiating movement
rigidity - cogwheel
these symptoms are characteristically asymmetrical
what is the mean age of parkinsons disease diagnosis?
aged 65 years
is parkinsons more common in men or women?
men
what are some additional symptoms of parkinsons beyond the classic triad?
mask like face
flexed posture
depression
fatigue
postural hypotension
poor sleep
drooling of saliva
freezing of gait
constipation
how can you differentiate between parkinsons disease and drug induced parkinsonism?
drug induced - symptoms typically bilateral , more predominant motor symptoms
tremor/rigidity - less common
Management of suspected parkinsonism in general practice?
if suspected - refer urgently as appropriate diagnosis and treatment should not be delayed
If drug induced suspected - can reduce/stop the medication and assess response - but referral still needed and do not delay this whilst waiting for response
what are some common medications that can cause parkinsonism?
antipsychotics - first gen (haloperidol, zuclopenthixol, chlropromazine)
anti-emetics - prochlorperazine, metoclopramide
Other drugs more rarely - Antidepressants, such as selective serotonin reuptake inhibitors (SSRIs).
Calcium-channel blockers.
Cinnarizine.
Amiodarone.
Lithium.
Cholinesterase inhibitors, such as donepezil or memantine.
Sodium valproate.
Methyldopa.
Pethidine
what is the management of confirmed parkinsons in GP?
ensure has review every 6-12 months
refer to MDT as needed
Only alter medication on advice of specialist
what is the DVLA advice for parkinsons disease for group 1 drivers
still able to drive as long as symptoms are well controlled/not interfering with driving, license will be revoked if symptoms poorly controlled or severe
what is the DVLA advice for parkinsons disease for group 2 dirvers?
may drive as long as safe vehicle control is maintained at all times. If the individual’s condition is disabling and/or there is clinically significant variability in motor function, the licence will be refused or revoked.
what is the first line pharmacological management of parkinsons disease for patients whose motor symptoms are affecting their life?
levodopa
what is the first line pharmacological management of parkinsons disease for patients whose motor symptoms are not affecting their life?
Dopamine agonist (non-ergot derived), levodopa or monoamine oxidase B (MAO-B) inhibitor
what are some examples of oral monoamine oxidase inhibitors (MOA-B)?
selegiline
rasagiline
safinamide
how do monoamine oxidase inhibitors work in parkinsons?
monoamine oxidase is an enzyme that breaks down dopamine - monoamine oxidase inhibitors prevent the action of MOA and so increase levels of dopamine
what is the benefit of using a MOA-B?
fewer adverse effects + lower risk of hallucinations
what are some examples of dopamine agonists?
ropinorole
pramipexole
rotigotine patch
what are the benefits of using dopamine agonists?
can be administered as a patch - lower pill burden
how does levopoda work?
Levodopa (L-DOPA) is a dopamine precursor that crosses the blood-brain barrier (unlike dopamine itself).
Once in the brain, it is converted into dopamine by the enzyme DOPA decarboxylase, replenishing dopamine levels in the basal ganglia.
what are the three considerations of levodopa treatment?
1) “wearing off effect” - after prolonged use, can have treatment failure where substantia nigra no longer able to store dopamine
2) “on-off” phenomenon - sudden unpredictable fluctuations in the symptoms
3) dyskinesia - SE of prolonged use for 5-10 years, due to sensitisation of the dopamine receptors
what should always be given alongisde levodopa?
carbidopa - to stop peripheral conversion of dopamine which could lead to nausea and hypotension
what medications are given prior to levodopa to prolong its use?
MOA-B inhibitors or dopamine agonists
what are the SE of MOA-B inhibitors (selegiline, rasagiline)?
insomnia
risk of serotonin syndrome if used with SSRI’s
what are the indicators for MOA-B inhibitors?
monotherapy in mild parkinsons to delay levodopa need
adjunct to levodopa use to reduce wearing off