Epidemiology, pathology and genetics

Question 1

Cardinal features

Answer 1

• Resting tremor
• Abnormal posture and gait
• Muscle wasting/Strength
• Distinction between rigidity/bradykinesia and muscle weakness
• Disease progression

Question 2

Core features

Answer 2

1. Slowless of movement
   * Repeated movements get slower and smaller
   * Affects daily activities e.g. washing/dressing
2. Tremor often described as pill rolling
   - present at rest
   - worse with anxiety
3. Rigidity- Velocity independent increased tone
4. Gait- shuffling, stooped, small steps, difficulty in turning

Question 3

Other non motor Sx

Answer 3

1. Pre motor Sx: Constipation, depression, anosmia
2. Others: Dysphagia, drooling, hallucinations, dementia, pain, postural hypotension

Note this is not exhustive

Question 4

Epidemiology- factors that increase risk

Answer 4

• More common as you get older and if you are male
• Hx of traumatic brain injury
• Living in industrial areas (high release of copper, mangenese or lead
• Rural areas- exposure to pestisides
• Excess body weight- shaky evidence
• T2DM
• Low level of Vit D (indicated in many neurological disease)

Question 5

Epidemiology- factors that reduce risk

Answer 5

• Smoking- inverse relationship
• Caffeine
• Moderate activity
• Statins

Question 6

Predictors of mortality

Answer 6

• Atypical: PSP + MSA
• Mild cognitive impairment- PD increases risk of dementia
• Freezing gait
• Hyposmia
• Reduced dopamine in the head of the caudate
• CSF leucocytosis

Question 7

Pathology

Answer 7

• Root cause is unknown
• But physiologically it is a loss of dopaminergic neurones in the substania nigra
• Lewy body can develop but are not diagnostic of parkinsons disease. No correlation shown at present
• Braak staging- distribution of lewy bodies increase as parkinsons disease progresses concentrating in the brainstem/substania nigra but occur in other areas
  *

Question 8

Genetics

Answer 8

• Having a first degree relative increases your risk but 2x but not definitive
• Some genes and some mutations can increase risk.
• Some mutations cause early onset of disease
• Patients with mutations in these genes have a long disease course.

Question 9

Other genetic considerations

Answer 9

• Wilsons disease
• Juvenile huntingtons disease
• Fronto-temporal dementia with parkinsonism
• Neurodegeneration with brain iron accumulation- look for development of atypical features: Bulbar involvement, spacticity, pyramidal signs, dementia, Supranuclear Gaze palsy

These patients tend to be younger and have atypical presentations