Parkinsonism and Movement Disorders Flashcards
what is role of basal ganglia?
involved in initiation of movements and modulation of movement
they receive input from cerebral cortex, process it and relay it back to cerebral cortex via thalamus
what is the most common neurodegenerative disease?
alzheimers
what is cause of parkinson’s?
it is mostly idiopathic with some link to genetic and environmental factors
what is the pathological hallmark of parkinsons?
sections through brainstem reveal loss of the normally dark pigment in the substantia nigra and locus coeruleus
this pigment loss correlates with dopaminergic cell loss
what is a neurohistological hallmark of PD?
lewy bodies
what are the motor symptoms of PD?
tremor
bradykinesia
rigidity
postural instability
what are the non motor symptoms of PD?
sleep disorders
hallucinations
GI dysfunction
depression
cognitive impairment - dementia
constipation
anosmia
approx 60% loss of dopaminergic neurones results in PD - where are these neurones actually lost from?
pars compacta region of substantia nigra
what are the 2 broad subtypes of PD motor symptoms?
tremor dominant (with absence of other motor symptoms)
non-tremor dominant (such as akinetic-rigid syndrome)
what are essential features for a diagnosis of PD?
bradykinesia (unilateral onset) and one more of:
resting tremor
rigidity (cogwheel or lead-pipe)
postural instability
what are additional motor features which could aid diagnosis of PD?
stooped, fixed posture
dystonic postures
hypomimia ("masked face")
shuffling
short-stepped gait (+/- festination)what are additional non-motor features which could aid diagnosis of PD?
late onset hyposmia depression and anxiety constipation bladder problems pain subtle mental or cognitive impairment
how do you confirm PD diagnosis?
parkinsonism (features)
no alternative explanation
dopamine responsiveness
what should patients not present with?
early-onset bulbar problems, dementia and hallucinations, preferential involvement of lower limb
prominent eye movement disorder
intrusive early autonomic problems
diagnostic tests usually not needed but what could possibly be helpful?
structural brain imaging
SPECT (DaTSCAN) - normal is comma shaped. Period shape = possible PD
do patients with PD have increased life span?
no - decreased
what is risk factors for PD?
advancing age
positive family history (if <40 = probably genetic cause)
male gender
environmental factors (pesticide, head injury, rural living, b blocker use, agricultural occupation, well water drinking)
what environmental factors decrease risk of PD?
tobacco smoking coffee drinking NSAID use CCB use alcohol consumption
what is the most relevant genes in PD?
autosomal dominant = LRRK2
autosomal recessive = PARKIN
what drugs can be used to symptomatically treat PD by enhancing intracerebral dopamine or stimulate dopamine receptors?
levodopa
dopamine agonist
monoamine oxydase type B inhibitors
amantadine (less common)
when should treatment be initiated?
when symptoms cause disability or discomfort
what symptoms respond reliably to dopaminergic treatment early in disease?
bradykinesia and rigidity
tremor is inconsistently responsive to dopamine replacement - what could be more effective?
why reluctant to use these?
anticholinergic agents
trihexyphenidyl
clozapine
nasty side effects
what are side effects of dopamine agonist and levodopa?
nausea
daytime somnolence
oedema
what behaviours associated with dopamine agonist?
impulse control disorders inc pathological gambling
hypersexuality
binge eating
compulsive spending
when should dopamine agonists be avoided?
patients with history of addiction, obsessive-compulsive disorders and impulse personality
why should dopamine agonists not be prescribed in elderly?
because they are also associated with hallucination
especially shouldnt be given in those with cognitive impairment
what drug provides greatest symptomatic benefit?
what is longterm use of this drug associated with?
levodopa
associated with motor complications (dyskinesia and motor fluctuations)
