Parkinson's Lecture Flashcards
What is Parkinsons?
- Loss of dopaminergic neurones in substantia nigra of basal ganglia
- = triad of bradykinesia, tremor and rigidity
Cause of loss of dopaminergic neurones in parkinsons
Alpha synuclein misfolds = deposits and forms Lewy bodies
Theories surrounding Parkinsons
- Link to pesticides (farmers?)
- Age genetics and environment interplay
- Start in gut? Constipation occurs before motor symptoms?
How much dopaminergic neruones do you have to lose before becoming symptomatic?
50% - LOTS it is a very slow onset disease
Ways to visualise brain to show parkinsons
DAT scan
* radioactive tracer attaches to dopamine transporters
* These are present on dopaminergic neurones
* Shows presence of these
* Reduced signalling comes from striatum in parkinsons
* Usually asymmetric reduction and eventually symmetric
Manifestations of bradykinesia
- Short shuffling steps
- Reduced arm swing
- Difficulty initiating movement
- When asked to finger tap index and thumb = decreased amplitude and irregular rhythm
Tremor in Parkinsons
- Not present in all - 70%
- Most marked at rest
- Starts unilaterally –> bilaterally
- 3-5Hz
- Pill-rolling between thumb and index finger
- Worse when stressed
- Improves with voluntary movement
rigidity in parkinsons
- Lead pipe
- Cogwheel if tremor present sometimes
- Difficulty turning, transferring and fine motor movement
Other manifestations of Parkinsons
- Hypomimia - loss of facial expression
- Flexed posture
- Micrographia
- Drooling
- Depression - or other psychiatric features
- Anosmia
- REM sleep disorder - acting out dreams
- Fatigue
- Autonomic dysfunction - postural hypotension
What does Parkinsons increase risk of?
Falls
Hip fracture from fall
Osteoporosis - decreased mobility
Tip for examining PD patients
Distract while examining to get them to fully relax to assess tone eg get them to do something with other hand or count back from 20
What can trigger freezing?
Walking through doors
Change of flooring
Scale for assessing severity of Parkinsons
Hoehn and Yahr Scale
Other way of staging severity of Parkinsons
- Early
- Maintenance
- Advanced/complex - PD drugs become less effective, increased doses needed, cognitive changes
- Palliative
Causes of Parkinsonism
- Parkinsons
- Parkinson plus syndromes
- Drugs
- Other - post encephalitis, tumour, vascular
Parkinson plus syndromes
- MSA - multi system atrophy
- PSP - Progressive supranuclear palsy
- CBD - Corticobasal degeneration
- LBD - lewy body dementia
Drugs that can cause Parkinsonism
- Antipsychotics - Haloperidol
- Anti-emetics - Metoclopromide, prochlorperazine
- Lithium
- Methyldopa
What is progressive supranuclear palsy?
- Postural instability and falls
- Impairment of vertical gaze bilaterally (down gaze worse than up)
- Parkinsonism
- Cognitive impairment
- Dysarthria too
Caused by midbrain atrophy - MRI sign is hummingbird
Problem with parkinson plus syndromes
- Poor response to medication
- Poorer prognosis for pt vs parkinsons
- Need to identify
What is multisystem atrophy?
- Severe autonomic dysfunction
- Severe postural hypotension
- Urogenital dysfunction (eg erectile dysfunction, atonic bladder)
What is lewy body dementia?
- Parkinsonism and dementia symptoms occur within 1yr of eachother
- Hallucinations of children and animals
- Contrast - In Parkinsons disease cognitive decline will occur at least 1 yr after motor symptoms
What is corticobasal degeneration?
- Dementia
- Parkinsonism
- Limb apraxia - difficulty with motor planning, can lead to alien limb syndrome when they feel limb is not being moved by them
Diagnosis of Parkinsons
Mainly clinical
If worried about other causes - CT for masses
MRI for PPS
PET
DAT scan
Things to look out for in someone with Parkinsons acute presentation of worsening
- Medication SEs
- Constipation - affects absorption of medication
- Get it on time - campaign for Parkinson meds to be on time
- New medicattions
- Stress/anxiety
- Infections underlying
First line treatment of Parkinsons
- Affecting QOL - Levodopa
- Not affecting QOL - dopamine agonists, levodopa or monoamine oxidase B inhibitors
Revise drugs for parkinsons in lecture given in Yr 2 pharmacology/neuro
:)
Surgical management of PD
Deep brain stimulation - works well if tremor dominant, quite high risk of stroke/death though, done in under 70s, not for cognitive impaired, stays in brain stimulating continiously.
Knocks 10yrs off symptoms
Complications of Parkinsons
- Falls
- On/off
- Freezing gair
- Wearing off medication
- Dyskinesia
- Impulse disorders
- Aspiration pneumonia
Interesting thing about Parkinsons
There is a woman who can smell Parkinsons - theory that increases high molecular weight lipids active could give the smell from skin
