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Name 4 cardinal features of PD. What other features are there?

- Tremor (in hand or finger)
- Bradykinesia (it takes longer for a person to complete a movement)
- Rigidity (no smooth movement)
- Postural Instability (balance problems)
But also:
- Freezing
- Flexion (act of bending due to bent limbs)


Define Parkinson's Diseases

A progressive, neurodegenerative (loss of Dopamine neurones in the brain) disease.


Where are dopamine neurones found?

Substantia Nigra (in the midbrain)


What symptoms are involved in Parkinsonism?

Posturial instability


Define idiopathic.

When cause of disease is unknown


Expand on Tremor feature of PD. (7 points)

- Unilateral therefore only affects one side

- Activity dependent/ happens even when resting but more when doing an activity. Essential tremor only occurs with activity.

- Low frequency (4-7HZ) involuntary movement

- Can cause supination or pronation a.k.a pill rolling

- Affects lips, chin, jaw and legs but not the head/neck and voice (unlike essential tremor)

- can get recurring postural tremor

- this is not always a present feature


What symptom is said to be the disabling symptom of PD?



Expand on Bradykinesia feature of PD. (5 points)

What are some other things bradykinesia affects?

- disabling feature of Parkinson's
- can cause micrographia (small, cramped handwriting)
- initially affects fine movements
- due to basal ganglia damage; substantia niagra has lack of dopamine neurones
- difficulties with ADL (activities of daily living) such as getting dressed, eating, putting on clothes

- reduced arm swing
- festination gate (quickening and shortening of normal strides)
- hypomimia (blank face) and reduced blinking
- drooling
- slow monotonous speech, low volume


What types of rigidity are there?

- Muscular stiffness/ pain
- Cog-wheel rigidity
- Lead pipe rigidity
- Froment's manoeuvre


Postural instability includes features such as f_____. The n___ and tr___ are affected when arms are brought forward in front of the body. This occurs early/late in the disease. It is the cause of ___ percent of falls



What is freezing in PD?

- Sudden and transient (< 10 seconds) inability to move
- Not a universal feature (only happens to around 50%)
- can affect legs (mainly), arms and eyelids
- initiated by visual stimuli or anxiety


What are some other motor symptoms of PD?

Primitive reflexes:
- glabellar reflex
- palmomental
- applause sign
Bulbar dysfunction
- sialorrhoea
- dysphagia
- hypophonia
- dysarthria


What are some non motor symptoms of PD?

- constipation
- headaches
- sexual dysfunction
- sleep disorders
- cognitive and behaviour abnormalities: dementia, anxiety, OCD and hallucinations


At what age can you exclude Wilson's disease?

< 40 years


If there is a response to Levodopa, can you diagnose with PD?



Direct pathway - tell me about it

- Striatum releases GABA (inhibitory) neurotransmitter to Globus Pallidus internal.
- NORMALLY the GPi would inhibit the Thalamus and so the thalamus would not be able to activate the motor cortex and so no signal would be sent to muscles; thus NO MOVEMENT.
- Since the striatum releases GABA, this inhibits the activity of GPi and so the thalamus is NOT inhibited.
- Thalamus is free to communicate with motor cortex which can send message to muscle; results in movement.

ANOTHER MECHANISM is present involving the Substantia Nigra.
- SN releases Dopamine which binds to the D1 (excitatory) receptors, which are present in the striatum.
- Now, striatum is excited and can release more GABA to the GPi, leading to more inhibition.
- As a result, thalamus may communicate with motor cortex and can allow for movement.


What is present in the dopaminergic neurons in the susbtantia nigra of a person with PD?

Lewy body