VN - Neurodegenerative Disorders - Week 9

Question 1

Parkinsons disease is characterised by the loss of what kind of neurons in what part of the brain?

Answer 1

The loss of dopaminergic neurons in the substantia nigra

Question 2

What is the typical age of onset for parkinsons disease?

Answer 2

> 50, but can be younger

Question 3

What is the inclusion criteria for the diagnosis of probable parkinsons disease (4)?

Answer 3

Bradykinesia
At least one of
-muscular rigidity
-4 to 6Hz rest tremor
-postural instability

Question 4

Define bradykinesia.

Answer 4

Slowness of initiation of voluntary movement with progressive reduction in speed and amplitude of repetitive actions

Question 5

What may postural instability not be caused by for a diagnosis to be confirmed as probable parkinsons disease (4)?

Answer 5

Visual, vestibular, cerebellar, or proprioceptive dysfunction

Question 6

List 8 supportive (prospective) criteria that must be met for a diagnosis to be confirmed as probable parkinsons disease. Note how many of these are required (the minimum).

Answer 6

Unilateral onset
Rest tremor present
Progressive disorder
Persistent asymmetry affecting side of onset most
Excellent response to levodopa
Severe levodopa-induced chorea
Levodopa response for +5 years
Clinical course of +10 years
At least three of these must be met

Question 7

List 3 common presentations of parkinsons disease.

Answer 7

Tremor
Impaired volitional movement
Better-preserved reflexive movements

Question 8

Is there a cure for parkinsons disease?

Answer 8

No

Question 9

Can treatment reverse the continuing loss of DA neurons seen in parkinsons disease?

Answer 9

No

Question 10

What is the first line treatment for parkinsons disease? What about second?

Answer 10

First - MAO-B inhibitor

Second - levodopa/carbidopa

Question 11

Are reflexive saccades affected in parkinsons disease?

Answer 11

Nearly unaffected

Question 12

Are volitional saccades affected in parkinsons disease? Explain.

Answer 12

Their ability to generate them is grossly abnormal

Question 13

Compare initiation of saccades to the accuracy (gain) of volitional saccades with parkinsons disease.

Answer 13

Initiation is more deficient compared to accuracy

Question 14

Is pursuit gain affected in parkinsons disease?

Answer 14

It may or may not be

Question 15

Is the inhibition of unwanted reflexive saccades intact with parkinsons disease? Is this typical for a neurodegenerative disorder?

Answer 15

It is intact

This is unusual

Question 16

Are remembered saccades accurate or inaccurate with parkinsons disease? Explain why.

Answer 16

As they are volitional, they are inaccurate

Question 17

All in all, summarise whether the effects of parkinsons disease on ocular motor control is significant or not.

Answer 17

Relatively modest effects on ocular motor control

Question 18

Describe progressive supranuclear palsy, including its clinical features (4).

Answer 18

A cause of parkinsonism but distinct from parkinsons disease itself
Features are parkinsonism, pseudobulbar signs, dementia, supranuclear vertical gaze palsy

Question 19

List 5 ocular signs of progressive supranuclear palsy and note the percentage of individuals who present with them.

Answer 19

Photophobia
Ocular burning/dryness
Blurred vision
Diplopia
No neurological complaints

Question 20

What do individuals who have progressive supranuclear palsy often complain of, aside from the ocular signs (3)?

Answer 20

Difficulty reading
Watching the ground shake while walking
Seeing food on a plate
-also spillage of food while eating

Question 21

What regions of the brain are involved in progressive supranuclear palsy (4)?

Answer 21

Components of the basal ganglia such as the

• subophthalmic nucleus
• globus pallidum
• substantia nigra
• dentate nucleus

Question 22

Damage to what structure may cause pursuit defects in progressive supranuclear palsy?

Answer 22

Pontine nuclei

Question 23

In the context of neuropathology of progressive supranuclear palsy, what are gaze palsies associated with? What structure does this have significant projections with?

Answer 23

Greater neuron loss in the substantia nigra pars reticulata

Significant projections to the superior colliculus

Question 24

Relating to eye movement dysfunction, what is the hallmark of progressive supranuclear palsy?

Answer 24

Vertical saccade failure

Question 25

Are antisaccades more or less frequent in progressive supranuclear palsy compared to parkinsons disease?

Answer 25

Antisaccade errors are more frequent

Question 26

What is huntington disease characterised by?

Answer 26

Uncontrollable choreoform movements

Question 27

What is the neuropathology of huntington disease?

Answer 27

Gross atrophy of the caudate nucleus and putamen

Marked neuronal loss in the deep layers of the cerebral cortex

Question 28

Is the substantia nigra affected in huntington disease?

Answer 28

Yes

Question 29

List three significant ocular motor aread of the brain that are affected in huntington disease.

Answer 29

Globus pallidus
Substantia nigra
Cerebellum

Question 30

Describe how the clinical presentations of apathy and disinhibited behaviour with alzheimers disease can be seen in an optometric setting.

Answer 30

Corresponding eye movement abnormalities can be seen

• diminished curiosity
• antisaccade errors

Question 31

Would you expect to see deficits in saccades for an alzheimers patient?

Answer 31

Yes

Question 32

What do studies suggest that making uncorrected errors correlates with what? What do these studies suggest is the failure?

Answer 32

Dementia severity

-suggested there is a failure of error-monitoring

Question 33

With neimann-pick type c disease, describe how saccades and slow eye movements are affected.

Answer 33

Saccades are affected before slow eye movements.