Movement Disorders Flashcards
what is the aim of pharmacological treatment in parkinson’s?
control symptoms
improve the patients quality of life
what are the risk factors for parkinson’s?
age - elderly
male sex
rural living
what factor can reduce the risk of parkinson’s?
smoking
what are the three clinical hallmarks of parkinson’s?
bradykinesia
rigidity
tremor
what is bradykinesia?
slowness of movement
when is tremor seen in parkinson’s?
usually at rest
what criteria needs to be met for a diagnosis of parkinson’s?
inclusion criteria met
three or more of the supporting criteria present
what is the inclusion criteria for parkinson’s?
bradykinesia and at least one of:
- muscle rigidity
- 4-6Hz rest tremor
- postural instability not due to an alternate primary cause
what are the supporting criteria for a diagnosis of parkinson’s?
unilateral onset rest tremor progressive asymmetric response to L dopa clinical course >10 years
describe the tremor seen in parkinson’s
4-6Hz rest tremor
what is the pathophysiology behind parkinson’s?
loss of dopaminergic neurones from the pars compacta region of the substantia nigra
60% loss is usually when symptoms show
what four types of drugs are used to treat parkinson’s?
levodopa
COMT inhibitors
dopamine agonists
MAO-B innhibitors
what is the mechanism of action of levodopa in parkinson’s?
replaces dopamine
what is the first line treatment for parkinson’s?
levodopa
what is levodopa given in combination with and what are these drugs?
carbidopa or benserazide
dopa decarboxylase inhibitors - stop it forming dopamine until it reaches the brain to reduce side effects
what is sinemet?
a combination of levodopa and a dopa decarboxylase inhibitor given for parkinson’s
aka co-careldopa
what are some acute adverse effects of levodopa use?
N+V
postural hypotension
tachycardia/arrythmias
what anti-emetic is often prescribed for nausea due to levodopa in parkinson’s?
domperidone as it does not cross the BBB
what are some slowly developing adverse effects of levodopa?
motor complications - response fluctuations and dyskinesias
how do COMT inhibitors work for parkinson’s?
preserve levodopa
name a COMT inhibitor
entacapone
how do dopamine agonists work to manage parkinson’s?
mimic dopamine
name three dopamine agonists
pramipexole
ropinirole
rotigotine
how do MAO-B inhibitors work in parkinson’s?
preserve existing dopamine
name two MAO-B inhibitors
rasagiline
selegiline
which drug for parkinson’s carries the highest risk of adverse effects?
dopamine agonists
what are the possible adverse effects of drugs for parkinson’s?
excessive sleepiness
psychosis - hallucinations/delusions
impulse control disorders
what is the drug of choice for drug induced parkinson’s?
central anti-cholinergic drugs
name some examples of central anti-cholinergic drugs
orphenadrine
benzotropine
procyclidine
trihexiphenidyl
when should caution be taken with the use of central anti-cholinergic drugs?
in patients with dementia and BPH
how does drug induced parkinson’s present?
bradykinesia expressionless face slow initiation of movement symmetrical symptoms speech difficulties
how is drug induced parkinson’s managed?
50% of cases reversible when causative drug stopped
what is tardive dyskinesia and what causes this?
delayed drug induced movement disorder
neuroleptic drugs
why is drug induced parkinson’s not treated with levodopa?
receptors are blocked so it would not work
how is neuroleptic induced parkinsonism managed?
procyclidine
what investigation can be used to distinguish parkinsonism from dystonia?
DAT scans
what is a tremor?
a rhythmic sinusoidal oscillation of a body part
name four different types of tremor
essential
drug induced
rest/parkinsonian
orthostatic
what body parts are affected by an essential tremor?
usually upper limbs
head, voice and other body parts less commonly
which tremor type is usually associated with a positive family history of tremor?
essential tremor
what is the frequency of an essential tremor?
6-12 Hz
what can suppress an essential tremor?
alcohol
beta blockers
what type of tremor is an essential tremor?
action or postural
what type of tremor is a drug induced tremor?
action or postural
what body parts are usually affected by a drug induced tremor?
upper limbs
when does a parkinsonian tremor tend to occur?
when the body part is at rest
hence why it is also known as a rest tremor
what body parts are usually affected by a rest tremor?
hands, legs and jaw
what is the frequency of a rest tremor?
4-6Hz
when does an orthostatic tremor occur?
when the patient is standing still
what body parts are affected by an orthostatic tremor?
lower limbs
results in unsteadiness
what is the frequency of an orthostatic tremor?
14-16 Hz
what is it called when myoclonus occurs during movement?
action myoclonus
what is it called when myoclonus is provoked by a stimulus?
stimulus sensitive or reflex myoclonus
what is chorea?
a movement disorder characterised by a continuous and random flow of muscle contractions
what can cause chorea?
genetics drugs vascular infections immune conditions endocrine problems
