Clinical and preclinical aspects of Parkinson’s disease

Question 1

What is Parkinson’s disease?

Answer 1

Chronic progressive neurodegenerative disorder including the degeneration of dopaminergic midbrain neurons and formation of Lewy bodies

Question 2

What is the population at risk for Parkinson’s disease?

Answer 2

Old people (>65 years of age)
Males are 2x more affected than woman

Question 3

What are the risk factors for Parkinson’s disease?

Answer 3

• Age (greatest known risk factor) 
• Gender (males 2x more)
• Genetics
• Environmental exposures
Smoking and coffee drinking may be protecting factors but not sure

Question 4

What are the clinical presentations of characteristic motor features for Parkinson’s disease (4 in total)?

Answer 4

• Bradykinesia (decreased bodily movement)
• Rest tremor
• Rigidity
• Postural instability and gait difficulties (turning, starting to walk, etc.)
=> Heterogeneous symtoms

Question 5

What are the clinical presentations of non-motor features for Parkinson’s disease?

Answer 5

• Hyposmia
• Sleep (REM sleep behavior => strong predictor of neurodegeneration) 
• Gastrointestinal tract (constipation)
• Urinary tract (need to piss)
• Dysautonomia
• Cognition
• Anxiety
• Psychiatric symptoms
=> Heterogeneous symtoms

Question 6

How is Parkinson’s disease diagnosed?

Answer 6

Neurological examination and oral history are the most important tools
Additional testing: MRI, PET, blood biochemistry, etc.
Differential diagnosis because many conditions can mimic Parkinson’s disease in the early stage

Question 7

What is DaTSCAN when talking about Parkinson’s disease diagnosis?

Answer 7

It is to introduce a substance that binds to dopamine transporters in the brain and see on imaging how many transporters there is in the brain
In PD patients transporters are very low => this diagnosis can determine when uncertain if a patient is PD or not

Question 8

What is the 3 neuropathologies of Parkinson’s disease?

Answer 8

1. Degeneration of dopaminergic neurons in substantia nigra
2. Secondary dopaminergic denervation of the striatum (involved in motor, cognitive and behavioural circuits)
3. Deposition of Lewy bodies (abnormal cytoplasmic aggregates of alpha-synuclein) in neurons primarily of the brainstem

Question 9

How does the neuropathology in Parkinson’s disease progress?

Answer 9

At the beginning it is confined at the brain stem and the olfactory bulb, then progresses to the cortical regions