Parkinson's disease Flashcards
What is the classic triad of signs with parkinsonism?
Tremor
Rigidity
Bradykinesia/hypokinesia
Is parkinsonism the same as Parkinson’s disease?
No
There are multiple causes of parkinsonism, of which Parkinson’s disease is only one
Is the tremor of parkinsonism worse with action or at rest?
At rest
Is the tremor of parkinsonism faster or slower than a cerebellar tremor?
Slower
4-6 Hz
What is the characteristic tremor that those with parkinsonism display?
‘Pill-rolling’ movement of thumb over fingers
How does the gait change in parkinsonism?
Reduced arm swinging
Festinance (short, shuffling steps with flexed trunk as if forever a step behind one’s centre of gravity)
Freezing at obstacles and doors
Describe the bradykinesia associated with parkinsonism
Slowness of movement initiation with progressive reduction in speed and amplitude of repetitive actions
Paucity of movement (expressionless face, decreased blink rate, scanning speech, micrographia)
What are some causes of parkinsonism?
Idiopathic
Parkinson’s-plus syndromes (PSP, SA, CBD, lewy-body dementia)
Trauma (pugilistic encephalopathy)
Drug induced (prochlorperazine, neuroleptics, metoclopramide)
What is the definition of Parkinson’s disease?
Sbradykinesia/hypokinesia bradykinesiaen dromedaryhypokinesia plus at least one of rest tremor, postural instability without other cause, or muscular rigidity
What is the pathophysiology of Parkinson’s disease?
Degeneration of dopamine rich neurons in the substantial night pars compact causing decreased striated dopamine levels
What is thought to be the reason for the degeneration seen in Parkinson’s disease?
Thought to be related to mitochondrial DNA dysfunction
What are some non-motor features of Parkinson’s disease?
Anosmia, depression, dementia, REM behavioural sleep disorder, L-Dopa side effects
What is the mean age of onset of Parkinson’s disease?
65 years
What is the key decision in the management of Parkinson’s disease and why?
When to start L-Dopa administration
Because of end-of-dose wearing off, and dopamine-induced dyskinesias
Over what timeframe will patients develop dopamine-induced dyskinesias?
5-10 years
When should you start a patient on L-Dopa?
Over the age of 80
Or when Parkinson’s disease interferes with ADLs
What alternative treatments can you use in Parkinson’s disease to delay the use of L-Dopa?
Dopamine agonists and MAO-B inhibitors
What surgical options are available in the treatment of Parkinson’s disease?
DBS (deep brain stimulation) in the substantia nigra
When is DBS used in Parkinson’s disease?
When a patient is dopamine responsive but remains poorly controlled
Dopamine agonists can be used to delay commencement of a Parkinson’s patient on L-Dopa, but which agonists are currently used?
Ropinirole and pramipexole
Apomorphine is a potent DA used subcut for end-of-dose effects but ulceration at injection-site can be severe
What MAO-B inhibitors can be used as an alternative to dopamine agonists in early Parkinson’s disease?
rasagiline
Selegiline
What are some side effects of MAO-B inhibitors?
Postural hypotension
AF
Why are the dopamine agonists bromocriptine and cabergoline no longer used in the treatment of Parkinson’s disease?
Because they may cause cardiac valvulopathies and serosal fibrosis
What is a future drup therapy for Parkinson’s disease?
Istradefylline
An adenosine A2A receptor blocker, potentiates response to L-Dopa allowing lower doses
