Parkinson's

Question 1

What is parkinsons?

Answer 1

Degenerative movement disorder caused by a reduction in dopamine in the substantia nigra

Question 2

What is the characteristic triad of symptoms in Parkinson’s disease?

Answer 2

• Rigidity
• Bradykinesia (slow to execute movement)
• Resting tremor

Question 3

What structures make up the basal ganglia?

Answer 3

• Striatum
• Globus pallous (external and internal)
• Substantia nigra
• Subthalamic nucleus

Question 4

Which two structures make up the straitum?

Answer 4

Caudate nucleus and Putamen

Question 5

What does the substantia nigra produce?

Answer 5

Dopamine

Question 6

Which part of the substantia nigra is affected in parkinsons?

Answer 6

Pars Compacta

Question 7

What is the effect of reduced dopamine?

Answer 7

The thalamus is inhibited resulting in reduced movement

Question 8

What can be seen under a microscope when looking at the brain in parkinsons?

Answer 8

Lewy-bodies

Question 9

What are the risk factors associated with Parkinson’s disease?

Answer 9

• Age (increases with age, peak is 55-65)
• Gender (males > females)
• Family history (parkin gene and alpha synuclein gene)
• Being A NON SMOKER
• Environmental factors (eg pesticides or methyl-phenyl tetrahydropyridine (MPTP) in illegal opiates)

Question 10

Whats symptoms can present other than motor symptoms in Parkinsons?

Answer 10

• Anosmia - reduced sense of smell
• Depression / anxiety (common)
• Aches and pains
• REM sleep disorders
• Urinary urgency
• Hypotension and constipation

Question 11

What are some characteristics of the tremor in Parkinson’s disease?

Answer 11

• Worse at rest and often asymmetrical
• Usually most obvious in the hands (pill rolling of the thumb and fingers)
• Improved by voluntary movements and made worse by anxiety
• 4-6 cycles / sec (slower than cerebellar tremor)
• Issue with repetitive hand movements with worsening in rhythm the longer attempted (ONLY IN PARKINSONS)

Question 12

What are the characteristics of rigidity in Parkinsons?

Answer 12

• Limbs resists passive extension throughout movement (cogwheel)
• ## No hypertonia/spasticity

Question 13

Give some examples of bradykinesia/hypokenisia?

Answer 13

Slow to initiate movement and slow, low-amplitude excursions in repetitive actions
- Reduced blink rate
- Monotonous hypophonic speech
- Micrographia - writing smaller
- Difficulty with fine movement (eg buttons)
Gait
- Reduced asymmetrical arm swing
- Narrow gait
- Stooped posture and small steps (simian stoop)
- Problems with balance
- Festinance - shuffling steps, maybe dragging foot with
flexed trunk
Expressionless face (hypomimesis)
- Speech becomes quiet, indistinct and flat
- Drooling of saliva and swallowing difficulty is a late
feature (can lead to aspiration pneumonia as a terminal
event)

Question 14

What investigations would you do in Parkinsons disease?

Answer 14

• Mainly based on examination and history
• Can use response to Levodopa
• MRI head

Question 15

What is the main pharmacological treatment given in Parkinsons?

Answer 15

L-dopa

Question 16

Why is L-Dopa given in parkinsons?

Answer 16

It is the precursor to dopamine and is able to cross the BBB, it then will get converted into dopamine within the brain.

Question 17

Other than L-Dopa what treatments can be given in Parkinsons?

Answer 17

• Dopamine Agonists
• Monoamine Oxidase B (MAO-B) inhibitors
• Catechol-O-methyltransferase (COMT) inhibitors

(last two inhibit enzymes that breakdown dopamine)

Question 18

What surgical treatment can be given in Parkisons?

Answer 18

Surgical ablation of overactive basal ganglia circuits eg subthalamic nuclei