week 9 - neurodegeneration

Question 1

What other conditions can be mistaken for Parkinson’s?

Answer 1

Essential tremor
Multiple strokes
Alzheimers

Question 2

What are some risk factors for developing PD?

Answer 2

Increasing age
2 times more common in men
More common in white people
Some environmental factors - pesticides
1.4-3.5x more likely to get it of you have relatives with it

Question 3

What are some features of PD?

Answer 3

Gradual worsening of symptoms
Symptoms start on one side of the body

Question 4

What are some symptoms of PD?

Answer 4

Bradykinesia
Tremors
Rigidity

Question 5

What is bradykinesia/akinesia?

Answer 5

This is where your movement slows and you have difficulty in imitating movements.
Affects fine movements

Question 6

What are tremors?

Answer 6

It usually starts on one side.
More seen when the body is at rest

Question 7

What is rigidity?

Answer 7

This is where the patient resists passive movements

Question 8

What happens to your posture when one has PD?

Answer 8

More forward leaning
Loss of arm swing
More unsteady and at risk of falls

Question 9

What are the non-motor symptoms of PD?

Answer 9

Autonomic function disturbances - Impotence, slower bowel motility, orthostatic hypotension (low blood pressure)

Differences in cognition and mood - Depression, apathy, frustration

Sleep disturbances

Fatigue

Question 10

How can one diagnose PD?

Answer 10

First look for the symptoms, see if they start on one side

See whether the patients responds to levodopa (treatment for PD)

EMG - helps to measure tremor frequency

MRI of brain

DaT scan

Question 11

What is a DAT scan?

Answer 11

1. the patient is injected with radioactive substance
2. The substance attaches to the dopamine transporters in the nigrostriatal system in the brain
3. You can then detect the uptake of the radioisotope

Results: results are normal in drug induced PD
Results are abnormal in IPD

Question 12

What are some causes of PD?

Answer 12

1. oxidative damage
2. Environmental toxins
3. Genetic predisposition
4. Accelerated aging

Question 13

What is the pathophysiology of PD?

Answer 13

The patient has a loss of dopaminergic neurones in the substantial nigra - part of basal ganglia

This causes a disruption in signalling between the basal ganglia, the cortex and thalamus which causes all the symptoms of PD

A large decrease of dopamine levels

Question 14

Why do the dopaminergic neurones die?

Answer 14

There are 3 things that cause the neurones to die (apoptosis):

1. Genes that cause a predisposition to PD
2. Pathogenic mechanisms such as oxidative stress and protein aggregation
3. environmental factors such as pesticides and living rural

Question 15

What is protein aggregation in the brain?

Answer 15

Known as Lewy bodies
learn more

Question 16

Why do you get the motor symptoms in PD?

Answer 16

In the brain we have the direct pathway that stimulates movement containing dopaminergic synapses and the indirect pathway which inhibits movement.

In people with PD, you have less activity/stimulation in the direct pathway.
And more activity in the indirect pathway which leads to a loss of movement/rigidity etc

Question 17

Why do you get the NON motor symptoms?

Answer 17

Because of the degeneration of dopaminergic neurones in the mesocortiyal, mesolimbic and tuberoinfundiubular pathways

Question 18

What is Alzheimer’s?

Answer 18

Progressive neurodegenration characterised by amyloid plaques and tangles in the brain.

It is the most commonest cause of dementia

It eventually destroys cognitive function, personality and ability to function as the brain atrophies (wastes away)

Question 19

What are the main symptoms of Alzheimer’s ?

Answer 19

Memory loss
Language deterioration
Confusion
Restlessness
Mood swings
Poor judgement
Impaired mental processing

Most important risk factor is age

Question 20

How can one diagnose Alzheimer’s ?

Answer 20

Mental state examination
Psychological evaluation
CT/MRI scans
Analysis ion the CSF, Tau proteins and abnormal amyloids

Question 21

What is the cause of Alzheimer’s ?

Answer 21

Plaques and tangles in the brain that results from the accumulation of abnormal beta amyloid proteins

The plaques/tangles disrupt neuronal function causing neuronal death

Question 22

So what causes the plaques and tangles in the brain?

Answer 22

1. Genetics
2. Mutations in the amyloid precursor protein
3. The amyloid precursor protein which ids vital for neuronal survival breaks down forming abnormal beta amyloid proteins that clump up to form the plaques
4. The tau protein - These break down into the abnormal beta amyloid plaques when the microtubules in the axon disintegrate

Question 23

What are the environmental factors that can cause Alzheimer’s ?

Answer 23

Head trauma
Vascular factors
Hypertension
NSAIDS

Question 24

What is the only infectious /contagious neurodegenerative disease?

Answer 24

Prion diseases

Question 25

What are the types of Prion diseases?

Answer 25

1. Creutzfeldt - Jacob disease (CJD)
2. German Straussler Scheinker Syndrome
3. Fatal Familial Insomnia