Parkinson's Disease Flashcards
(40 cards)
What is Parkinson’s disease?
- a progressive neurodegenerativve condition
- caused by degeneration of dopaminergic neurones in the substantia nigra
- this is part of the basal ganglia, which has a role in regulation of motor signalling
there is a gradual but progressive fail in the production of dopamine
What is the classic triad of symptoms?
What is significant about these symptoms?
- bradykinesia
- resting tremor
- rigidity
- these symptoms are ASYMMETRICAL with one side being affected more than the other
Who is typically affected by Parkinson’s disease?
- it is twice as common in men
- the mean age of diagnosis is around 65 years
How is the tremor in Parkinson’s disease described?
“pill rolling tremor”
- it looks as though they are rolling a pill between their fingertips and thumb
What is the frequency of the tremor?
4-6 Hz
it occurs 4 to 6 times each second
When is the tremor worse / better?
- the tremor is more pronounced when resting
- it improves during voluntary movement
- it becomes worse when the patient is distracted or stressed / tired
ask the patient to perform a task with the other hand (e.g. mime the motion of painting a fence) will exaggerate the tremor
What is significant about the tremor?
it is unilateral
How is the rigidity in Parkinson’s disease described?
“cogwheel rigidity”
- when passively flexing / extending the arm at the elbow, there is tension in the arm that gives way to movement in small increments (small jerks)
- this is due to the superimposed tremor
this is different to “lead pipe rigidity” in which there is uniform resistance to movement
What is meant by bradykinesia?
- this describes how movements beome smaller and slower
- there are often hesitations / pauses during continued movement
sometimes described as hypokinesia = this is a decrease in amplitude of movement
What symptoms result from the development of bradykinesia?
- handwriting becomes smaller and smaller (micrographia)
- they have a “shuffling gait” as can only take small steps when walking
- difficulty initiating movement (e.g. from standing still to walking)
- difficulty in turning around, having to take many small steps
- hypomimia - reduced facial movements + facial expressions
How is gait changed in Parkinson’s disease?
- they have a “shuffling gait” as they take many small steps
- there is reduced arm swinging
- they also have a stooped posture
What other features can sometimes affect patients with Parkinson’s disease?
- depression
- sleep disturbance / insomnia
- REM sleep behaviour disorder
- anosmia (loss of sense of smell)
- postural instability
- cognitive impairment + memory problems
What are the differences between a Parkinson’s tremor and benign essential tremor?
- BET tends to improve at rest
- it is symmetrical
- it is worse with intentional movement
- it improves with alcohol
What are the 4 main Parkinson’s-plus syndromes?
- multiple system atrophy
- dementia with Lewy Bodies
- progressive supranuclear palsy
- corticobasal degeneration
What is multiple system atrophy?
- the neurones of multiple systems in the brain degenerate
- the degeneration of the basal ganglia results in a Parkinson’s presentation
- the degeneration in other areas leads to autonomic + cerebellar dysfunction
What are the additional symptoms seen in multiple system atrophy?
cerebellar dysfunction:
- ataxia
autonomic dysfunction:
- constipation
- postural hypotension
- abnormal sweating
- sexual dysfunction
What is dementia with Lewy bodies?
- a type of dementia associated with features of Parkinsonism
- it causes progressive cognitive decline
- there is a decline in thinking, reasoning + independent function
What is dementia with Lewy bodies?
- a type of dementia associated with features of Parkinsonism
- it causes progressive cognitive decline
- there is a decline in thinking, reasoning + independent function
What are some of the symptoms associated with Lewy body dementia?
- REM sleep behaviour disorder
- fluctating consciousness
- recurrent visual hallucinations / delusions
- spontaneous changes in attention / alertness
What is REM sleep behaviour disorder?
- a sleep disorder in which the patient physically acts out vivid, unpleasant dreams during REM sleep
- this involves vocal sounds and sudden, often violent arm and leg movements
How can Lewy body dementia be differentiated from isolated Parkinson’s disease?
- cognitive impairment typically occurs before parkinsonism
- both features tend to occur within 1 year of each other
- in PD, the motor symptoms tend to present at least one year before the cognitive symptoms
What is the characteristic pathological feature of Lewy body dementia?
- positive immunohistochemistry staining for alpha-synuclein
- the Lewy bodies within the substantia nigra stain brown
What 2 main features are unique to Lewy body dementia and do not occur in other forms?
- cognition is fluctating - this does not occur in other forms of dementia
- there are early impairments in attention + executive function (in Alzheimer’s there is just memory loss)
What medication must be avoided in Lewy body dementia?
neuroleptics
- patients are very sensitive and may develop irreversible parkinsonism
- the patient will deteriorate rapidly following introduction of an antipsychotic agent
neuroleptics = medications that block dopamine receptors
e.g. haloperidol, olanzapine, clozapine, paliperidone, thioridazine etc.
