Parkinson's Disease Flashcards
What is PD?
- Degenerative disorder of CNS
- Result of decreased stimulation of motor cortex by basal ganglia
- Chronic & progressive
What does PD cause?
- Decreased speed & amplitude of movement
- Tremor
- Changes in muscle tone & posture
- Inability to perform simultaneous or sequential motor tasks
What is the aetiology of PD?
- Likely induced by environmental factors in people with genetic predisposition
- 2-14 fold increase in incidence in close relatives of people with PD
- 1 in 100 people > 65yo
What are the risk factors of PD?
- Positive family history
- Male
- Exposure to pesticides
- Rural living
- Head injury
- Consumption of well water
What are 4 nuclei that make up the basal ganglia?
- Striatum (caudate & putamen)
- Globus pallidus (internus & externus)
- Subthalamic nuclei
- Substantia nigra
What is the role of the basal ganglia?
- Execution of complex motor tasks
- With SMA run well-learned & predictable movement sequences
- Provision of internal cues for starting/stopping movement sequences
- Involved in aspects of memory & cognitive function
- Loss of motor set
What is the pathophysiology of PD?
- Loss of dopaminergic neurons in substantia nigra
- Causes decreased inhibition of globes pallid us & increased inhibition of thalamus (decreased output)
- Presence of Lewy bodies
- Other neurotransmitters thought to be involved
- Still not well understood
What is clinical diagnosis of PD based on?
- Medical history
- Physical examination
- Improvement with dopaminergic treatment
- Long pre-clinical/symptomatic period (many people are far progressed at diagnosis)
What is used in the medical management of PD?
Levodopa:
- Metabolic precursor to dopamine
- Initially effectively controls motor problems
- Associated with significant side effects (nausea, mood/behavioural issues, orthostatic hypotension)
COMPT inhibitors used to maintain therapeutic doses for longer
What are the long term effects (5-7 yrs) of levodopa (L dopa)?
- Dyskinesia (impairment of voluntary movement, central writhing movement)
- On-off phenomenon (on phase after medication causes peak in motor performance; as medication wears off causes decrease in quality of movement)
What does the surgical management of PD include?
- Pallidotomy (removal of globus pallidus, which removes inhibition of thalamus)
- Deep brain stimulation of globus pallidus internus or sub-thalamic nuclei - shown to improve QOL significantly in advanced PD
What are the primary impairments in PD?
- Bradykinesia (slowness of movement)
- Hypokinesia (decreased amplitude of movement)
- Akinesia (difficulty initiating movement e.g. freezing)
- Tremor (resting, rhythmical, consistent)
- Rigidity (centrally mediated, in both directions)
- Balance impairment
What are the secondary impairments in PD?
- Dyskinesia
- Disuse weakness
- Flexed posture
What are the common activity limitations in PD?
- Turning in bed
- Sitting up from lying
- Standing up
- Reduced speed & balance, freezing & falling during walking/turning in standing
- R&M esp handwriting
What should the assessment of PD include?
- History
- Observation
- Assessment & measurement of impairments/activity limitations
What should be included in the history assessment of PD?
- Time since diagnosis
- Medications (what, when, how long, fluctuations, side effects)
- Movement problems, including falls
- Other problems associated with PD
- Previous/current physio intervention
What should observation assessment of PD include?
- Turning in bed
- Supine to sitting over side of bed
- STS
- Walking
- 360 deg turn in standing
- R&M
What are some of the balance tests used when assessing PD?
- Tandem stance
- Single leg stance
- Functional reach
- Shoulder tug (Pastor’s test)
- Mini Best test