Supranuclear Disorders

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Supranuclear Disorders
2011-11-10 15:16:37
Neurophthalmology Ch7

Neuro Ch7
Show Answers:

  1. What is Pursuit system ?
    area of brain controlled?
    • maintains an object on the fovea while the object moves slowly
    • Ipsilateral parietal lobe
  2. What is Vestibular Ocular Reflex (VOR)? What is the delimna of the VOR system?
    • Holds object steady on while the head moves during a pursuit
    • It doesnt last long and OKN must take up for it.
  3. How does Optokinetic Nystagmus (OKN) work with VOR?
    OKN supplements VOR and holds image steady on fovea during sustained head movement
  4. What does the saccade system function to do?
    Controlled in the brain where?
    • Quick movement to fast for pursuits. Rapidly brings object of interest to the fovea
    • contralateral frontal lobe
  5. What are saccadic intrusions?
    What is the mcc type
    What dz is it found?
    • unwanted eye movements during fixation
    • square wave jerks
    • Progressive supranuclear palsy
  6. Supernuclear control of saccades is initiated from the
    • contralateral Frontal Eye Fields
    • contralateral Superior Colliculus
  7. Supernuclear control of Pursuits is initiated from the
    ipsilateral parieto-occipital-temporal regions
  8. What is the vertical gaze centers?
    Neural intergrator
    • riMLF (rostral interstial nucleus of MLF)
    • midbrain
    • Interstical nucleus of Cajal
  9. What are the horizontal gaze centers?
    Neural integrator
    • Parapontine reticular formation PPRF
    • Location -PONS
    • Medial vestibular nucleus
    • nucleus prepositous hypoglossi accessory nucleus of 7
  10. How do you test the VOR? Describe each.
    • Dolls eye manuever; move head with visual fixation; if catch up saccade then abnl
    • Calorics: irrigate H20 in ear and watch for type of nystagmus base of the temp of H20
  11. Calorics interpretation:
    What is the mnemonic
    If warm water irrigated in right eye, what type of nystagmus
    If cold water irrigated in right eye what type of nystagmus
    • COWS: cold opposite/warm same
    • warm H20- right ear -righting beat nystagmus
    • cold H20- right ear -left beating nystagmus
  12. If patient is comatose which ear does the eye move in caloric testing
    toward the same side with slow phase movement
  13. What is the etiology of Ocular tilt?
    What is the disorder?
    • otolithic organs
    • head tilt
    • ocular rotation
    • skew deviation
  14. In ocular tilt which way is the head tilted and cyclotorsion in respect to the lesion?
    • head tilted towards lower eye away from the higher eye
    • higher eye incyclotorted
  15. How do you differentiate a skew from 4th nerve palsy?
    hypertropia on opposite side of gaze (head tilt)
  16. What is the lateral medullary syndrome of wallenberg?
    • stroke without paralysis
    • Ipsi loss of pain/temp on face
    • ipsi cerebellar ataxia
    • ipsi horner
    • ocular tilt
  17. How do you test VOR suppression?
    • pt fixates on near card while being rotated in a swivel chair.
    • nl eyes maintain fixation on near card during rotation without catch-up saccade.
    • impaired VOR eyes move off the target during rotation
  18. Progressive Supranuclear Palsy (PSP)
    • slow disappearance of all ocular movements
    • vertical gaze affected first aka (Dirty tie syndrome)
    • horizontal pursuits late
  19. Hypermetropic saccades indication dyfx where in the brain.
  20. Congential Ocular motor apraxia
    inability to initiate volitionally saccades; thus, use head thrust to see target
  21. Gaze palsy-which direction is the gaze in respect to the lesion in the following?
    • cerebral-inablitiy to produce contralateral gaze; thus tonic devatiation toward the lesion
    • brainstem-inability to produce move ipsilateral to lesion
    • Pontine-loss of horizontal movements
    • Midbrain-loss of vertical movments
  22. Dorsal Midbrain Syndrome Parinauds features include
    • ccllvs
    • convergence retraction nystagmus ( co-contraction of EOM)
    • convergence insufficency
    • vertical gaze palsy
    • light-near dissociation (middilated pupils with light)
    • lid retraction
    • skew deviation

    increase square wave jerk