L5 Parkinson's Disease Flashcards
What is the prevalence of PD?
3% in people over 65 years of age.
How do you usually diagnose PD?
By taking a history and physical examination.
What can PD be described as?
A ‘hardware’ problem. This is where the neurons are dying and causing the problems.
What is an important thing to notice when diagnosing PD?
That all of the symptoms are arising on one side of the body.
What are the three main symptoms of PD?
1) Brady (slowness) or Akinesia (complete absence of movements).
2) Resting tremor.
3) Rigidity. This can cause pain and problems turning over in bed.
What is the pathology of PD?
There is a loss of the melanin-containing dopaminergic neurons found in the substantia nigra. There is also the presence of Lewy bodies.
What can be used to visualise the reduced dopamine supply to the striatum in living patients?
The DaTSCAN. This allows you to visualise the nerve endings that reach out from the substantia nigra to the striatum.
What do treatments of PD aim to achieve?
The treatments are symptomatic and aim to compensate for the loss of dopamine.
What balance must be kept when treating PD patients?
The balance between increasing the availability of dopamine and reducing the acetylcholine activity.
What are four treatments used for PD?
1) L-Dopa. This is turned into dopamine in the brain. It is then stored in synaptic vesicles and released when needed. This is the most powerful drug but has a greater risk of side effects with higher doses.
2) Dopamine agonists. These act directly on the dopamine receptors. These show a reduced risk of dyskinesias in the short-medium term. This is the first line of treatment in younger PD patients (<60 years).
3) COMP/MOA-B Inhibitors. These help to increase the levels of dopamine through the synaptic cleft. These are not very powerful drugs.
4) Anticholinergics. These have many side effects so are not used as much today.
What are the complications of late-stage PD?
1) Wearing off i.e. the medication isn’t working as effectively as before.
2) On-Dyskinesias. This is where, when the drugs are working, you have hyperkinetic and choreiform (repetitive and rapid jerky involuntary movements).
3) Off-Dyskinesias. This is when the drugs don’t work, you get fixed, painful dystonic posturing typically of the feet.
4) Freezing i.e. unpredictable loss of mobility.
What factors should be taken into consideration when decided when treatment for the motor symptoms of PD should start?
- Severity of the motor impairment and quality of life.
- Side effects of the drugs.
