W5 - Parkinson’s Disease

Question 1

Define Parkinson’s

Answer 1

A chronic, progressive, neurodegenerative disorder caused by the degeneration of dopamine producing neurons in the substancia nigra of the basal ganglia

Question 2

Risk factors of Parkinson’s

Answer 2

Environmental & genetics factors
Positive associations between Parkinson’s & pesticides
Parkinson’s gene mutation (5%-10%)

Question 3

How is Parkinson’s diagnosised

Answer 3

Post mortem brain exam

Question 4

4 cardinal signs of Parkinson’s

Answer 4

Bradykinesia (slow movement)
Rigidity
Resting tremor
Postural instability

Question 5

Clinical criteria for Parkinson’s

Answer 5

Bradykinesia
Diadodyskinesia
Rigidity
Resting tremor
Postural instability
Response to dopamine
Replacement therapy
MRI scans

Question 6

Secondary Parkinson’s symptoms

Answer 6

Fatigue
Freezing
Festinating gain pattern (shuffling, flexed posture with no heel stride)
Sleep disorders
Dysphagia (swallowing dysfunction)
Anxiety & depression

Question 7

Function of the basal ganglia

Answer 7

Well learned motor skills & movement sequences
Preparation & planning
Initiation & termination
Sequencing & timing
Regulating muscle tone & inhibition of antagonistic movement

Question 8

Name the 5 nuclei of the basal ganglia & say which ones are input & output response

Answer 8

Input
Caudate & putamen (striatum)

Output
Globus pallidus (internal & external)
Subthalamic nuclei
Substantia nigra (pars compacta & pars reticulata)

Question 9

Name the 2 pathways in the basal ganglia

Answer 9

Direct (go) & indirect (stop)

Question 10

Explain the direct pathway

Answer 10

The cortex send excitatory signals to the striatum

The striatum only sends inhibitory signals and can send these signals due to the excited signals sent to it from, the cortex

The striatum sends inhibitory signals to the globus pallidus & substania nigra pars reticulata meaning these cannot send any signals to the thalamus

The STN & GPe release dopamine into the striatum to help the movement of the direct pathways

Due to no inhibition being sent to the thalamus it has more excitatory signals to be sent back to the cortex & produce movement

Question 11

Explain the indirect pathway

Answer 11

Cortex sends excited signals to the striatum & striatum sends inhibitory signals to the GPe

The GPe cannot send the STN any signals

The cortex sends excitiry signals to the STN which then goes to the GPi & SNpr which then send inhibitory signals to the thalamus

The inhibitory signals to the thalamus means less excitatory signals are sent back to the sorted & less movement

Question 12

What does dopamine do to the pathways

Answer 12

Direct = excites
Indirect = inhibits

Question 13

Name some medicine for Parkinson’s

Answer 13

Dopamine replacements = replace lost dopamine & facilitates it crossing over the blood/brain barrier

Dopamine copycats = pergolide

Dopamine protectors = protect current dopamine levels by blocking the enzyme that breaks it down

Question 14

How to treat secondary effects of medication

Answer 14

Deep brain stimulation = decrease symptoms of dyskinesia in prolonged dopamine treatment

Stimulation of the STN = done with electrode input

Question 15

What scale do you use to measure Parkinson’s severity

Answer 15

Modified hoehn & yahr scale (1-5)

Research staging tools = UPDRS

Question 16

How to enhance function in Parkinson’s disease patients

Answer 16

Cueing
Duel tasking
Balance training
Gain re education
Symptoms specific exercises