Parkinson's disease

Question 1

Parkinson’s disease - what is it a triad of?

Answer 1

A movement disorder characterised by
1 - resting tremor
2 - rigidity
3 - bradykinesia

Question 2

Pathology of Parkinson’s disease

Answer 2

reduction of dopamine secretion in the substantia nigra - lewy bodies appear in substantia nigra
sometimes genetic mutations

Question 3

Epidemiology - affected age group?

is it rare?

Answer 3

typically starts aged 55-65

second most common neurodegenerative disease after alzheimers

Question 4

Presentation of Parkinson’s disease

Answer 4

Slowly Progressive

• motor function
  i) slow movements (problems initiating movements, reduced arm swing, reduced amplitude of a repetitive movement with time)
  ii) resting tremor (‘Pill rolling’, can be ^ by having them concentrate)
  iii) gait/balance disturbances - small shuffling gait
  iv) cogwheel rigidity

NO WEAKNESS tho

-non motor
autonomic dysfunction (orthostatic hypotension, constipation, urinary problems, sleep disturbance, psychiatric symptoms (visual hallucinations))

Question 5

other features for diagnosis (NICE - step 3)

Answer 5

unilateral onset with persistent asymmetry
70-100% response to L-dopa
hyposmia - cant smell

Question 6

l-dopa - after 5-10 years.. common things to happen

Answer 6

motor fluctuations - on/off stiff/bradykinetic phases - tend to be more off's as dose wears off
axial problems (balance, speech, gait disturbance)

Question 7

parkinson’s disease dementia - 3 features

Answer 7

occurs 1 year + after Parkinson’s diagnosis
1 - presence of parkinson’s in limbs
2 - frequent visual hallucinations
3 - frequent fluctuations in lucidity

Question 8

how is diagnosis made

Answer 8

it is clinical - tests can exclude other things
CT/MRI brain - if L-dopa doesnt do anything

if patient is young - ceruloplasmin levels (wilsons disease) and syphilis

Question 9

management - non medical

Answer 9

parkinson specialist nurses
physiotherapy/exercise
occupational therapy 
SALT
nutritional support

Question 10

management - medical treatments

Answer 10

levodopa
dopamine agonists (pramipexole, ropinirole, rotigotine)
entacapone, tolcapone (catecholamine-O-methyltransferase inhibitors - degrade dopamine)
benztropine - ACh inhibitors
Deep brain stimulation

Question 11

risk factors for parkinsons

Answer 11

pesticide
gene variants (LRRK2)

Question 12

substantia nigra - anatomy

Answer 12

part of of basal ganglia - one each side of mid brain - controls moment- connects to motor cortex

Made of two parts:

1) pars reticulata - receives signals from striatum (=caudate+putamen), then relays message to thalamus via GABA
2) pars compacta - sends message to striatum via dopamine (nigrostriatal pathway) this part is affected in parkinsons

Question 13

dopamine - overview

Answer 13

cant cross blood brain barrier - levodopa (precursor) can. Dopa decarboxylase converts it to dopamine

the drug is given with carbidopa which inhibits dopa decarboxylase which is outside the brain. carbidopa cant cross the blood brain barrier so levodopa can be converted into dopamine in the brain still

Question 14

Parkinson’s and strength

Do they even lift?
Is there a reduction in strength

Answer 14

There is no weakness/loss of strength in Parkinson’s. This is important for differentiating it between things.

That and they cant smell