VN - Neurodegenerative Disorders - Week 9 Flashcards
Parkinsons disease is characterised by the loss of what kind of neurons in what part of the brain?
The loss of dopaminergic neurons in the substantia nigra
What is the typical age of onset for parkinsons disease?
> 50, but can be younger
What is the inclusion criteria for the diagnosis of probable parkinsons disease (4)?
Bradykinesia
At least one of
-muscular rigidity
-4 to 6Hz rest tremor
-postural instability
Define bradykinesia.
Slowness of initiation of voluntary movement with progressive reduction in speed and amplitude of repetitive actions
What may postural instability not be caused by for a diagnosis to be confirmed as probable parkinsons disease (4)?
Visual, vestibular, cerebellar, or proprioceptive dysfunction
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).
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
List 3 common presentations of parkinsons disease.
Tremor
Impaired volitional movement
Better-preserved reflexive movements
Is there a cure for parkinsons disease?
No
Can treatment reverse the continuing loss of DA neurons seen in parkinsons disease?
No
What is the first line treatment for parkinsons disease? What about second?
First - MAO-B inhibitor
Second - levodopa/carbidopa
Are reflexive saccades affected in parkinsons disease?
Nearly unaffected
Are volitional saccades affected in parkinsons disease? Explain.
Their ability to generate them is grossly abnormal
Compare initiation of saccades to the accuracy (gain) of volitional saccades with parkinsons disease.
Initiation is more deficient compared to accuracy
Is pursuit gain affected in parkinsons disease?
It may or may not be
Is the inhibition of unwanted reflexive saccades intact with parkinsons disease? Is this typical for a neurodegenerative disorder?
It is intact
This is unusual
Are remembered saccades accurate or inaccurate with parkinsons disease? Explain why.
As they are volitional, they are inaccurate
All in all, summarise whether the effects of parkinsons disease on ocular motor control is significant or not.
Relatively modest effects on ocular motor control
Describe progressive supranuclear palsy, including its clinical features (4).
A cause of parkinsonism but distinct from parkinsons disease itself
Features are parkinsonism, pseudobulbar signs, dementia, supranuclear vertical gaze palsy
List 5 ocular signs of progressive supranuclear palsy and note the percentage of individuals who present with them.
Photophobia
Ocular burning/dryness
Blurred vision
Diplopia
No neurological complaints
What do individuals who have progressive supranuclear palsy often complain of, aside from the ocular signs (3)?
Difficulty reading
Watching the ground shake while walking
Seeing food on a plate
-also spillage of food while eating
What regions of the brain are involved in progressive supranuclear palsy (4)?
Components of the basal ganglia such as the
-subophthalmic nucleus
-globus pallidum
-substantia nigra
-dentate nucleus
Damage to what structure may cause pursuit defects in progressive supranuclear palsy?
Pontine nuclei
In the context of neuropathology of progressive supranuclear palsy, what are gaze palsies associated with? What structure does this have significant projections with?
Greater neuron loss in the substantia nigra pars reticulata
Significant projections to the superior colliculus
Relating to eye movement dysfunction, what is the hallmark of progressive supranuclear palsy?
Vertical saccade failure
Are antisaccades more or less frequent in progressive supranuclear palsy compared to parkinsons disease?
Antisaccade errors are more frequent
What is huntington disease characterised by?
Uncontrollable choreoform movements
What is the neuropathology of huntington disease?
Gross atrophy of the caudate nucleus and putamen
Marked neuronal loss in the deep layers of the cerebral cortex
Is the substantia nigra affected in huntington disease?
Yes
List three significant ocular motor aread of the brain that are affected in huntington disease.
Globus pallidus
Substantia nigra
Cerebellum
Describe how the clinical presentations of apathy and disinhibited behaviour with alzheimers disease can be seen in an optometric setting.
Corresponding eye movement abnormalities can be seen
-diminished curiosity
-antisaccade errors
Would you expect to see deficits in saccades for an alzheimers patient?
Yes
What do studies suggest that making uncorrected errors correlates with what? What do these studies suggest is the failure?
Dementia severity
-suggested there is a failure of error-monitoring
With neimann-pick type c disease, describe how saccades and slow eye movements are affected.
Saccades are affected before slow eye movements.
