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33 Cards in this Set
- Front
- Back
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What are the 5 supranuclear gaze systems?
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1. Fixation
2. Saccadic 3. Pursuit 4. Vergence 5. Non-optic reflex |
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Where is fixation controlled?
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not well known
(maybe parietal) |
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When can fixation be a problem?
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- CNS disorders
- anxiety - drugs |
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What is a saccade?
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A fast, voluntary eye movement
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Where are saccades controlled?
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Contralateral frontal cortex
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What is a clinical problem that commonly affects saccades?
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Middle cerebellar artery stroke
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What do saccades look like clinically?
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Movement between targets on command
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What does fixation look like clinically?
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Maintain fixation on stationary target
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What is pursuit?
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Slow, involuntary eye movements
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Where is pursuit controlled?
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Occipital-parietal cortex
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What does pursuit mean clinically?
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Tracking a slowly moving target
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What does impairment of pursuit look like?
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A "cogwheel" pursuit
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What is vergence?
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Slow, disconjugate eye movements
(focus from far to near) |
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Where is vergence controlled?
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Occipital-parietal to midbrain pretectum
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What is non-optic reflex?
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Slow eye movements that maintain fixation with head movements
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Where is non-optic reflex controlled?
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Vestibular nuclei in the medulla
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What is a clinical method to determine function of non-optic reflex?
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Caloric responses
(cold water in ear, eyes turn opposite, warm water, eyes turn same - COWS) |
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What does III control?
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- superior, medial, inferior, inferior oblique muscles
- levator palpebrae - parasymp to pupil & ciliary ganglion |
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What is ptosis?
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Eyelid drooping
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What is mydriasis?
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Pupil dilation
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What parts of III nucleus cross to the other side?
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Superior rectus
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What parts of III nucleus are midline?
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Edinger-Westphal nucleus (pupils)
Central Caudal Nucleus (lids) |
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What does IV nucleus control?
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Superior oblique muscle
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What does superior oblique do?
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- Depress (adducted eye)
- Intort (abducted eye) |
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What does VI nucleus control?
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Lateral rectus
(abducts eye) |
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Where is the horizontal gaze center?
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PPRF (paramedian pontine reticular formation)
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What is the MLF?
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Medial longitudinal fasciculus
- fibers from VI to III (they cross) |
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What symptoms does internuclear ophthalmoplegia (INO) present with?
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- ipsilateral adduction weakness
- contralateral abduction nystagmus |
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Where is INO generally located?
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MLF
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What is another term for Dorsal Midbrain Syndrome?
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Parinaud's syndrome
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What does it present with?
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- vertical gaze palsy
- lid retraction or ptosis - convergence/retraction nystagmus |
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What is another term for Progressive Supranuclear Palsy (PSP)?
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"Can't look down syndrome"
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What does PSP present with?
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- gradual impairment of supranuclear gaze
- vertical > horizontal - voluntary > pursuit > reflex |
