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The first 25 slides, exactly as they appear. The full deck has 76 content slides.
Ophthalmology
Supranuclear Control and Disorders of Ocular Motility
Built from Khurana — Neuro-Ophthalmology
What’s inside
8 sections · 76 slides
Overview
- What this topic covers
The Big Picture
What 'supranuclear' means and why it matters
- What does 'supranuclear' mean?
- Two ways to study the same system
Cortical Control Centres
Where in the cortex the eye-movement commands are born
- The two cortical control centres
- The frontal ocular motor area
- How the frontal eye fields steer gaze
- The supranuclear control hierarchy
- One hemisphere drives gaze to the opposite side
- The parieto-occipito-temporal (POT) junction
- What the MT area connects to - and what its damage does
Subcortical Control Centres
The brainstem and cerebellar machinery that executes the commands
- The subcortical (brainstem) control centres
- PPRF - the horizontal gaze centre
- PPRF - how its output moves both eyes together
- riMLF - the vertical gaze centre
- Pathway for downward gaze
- Pathway for upward gaze
- Posterior commissure and Parinaud's syndrome
- The convergence and divergence centre
- The convergence pathway
- The superior colliculus
The Vestibular Apparatus
The inner-ear sensor that stabilises gaze against head movement
- Why we need a vestibular sensor
- The vestibular apparatus of the inner ear
- Semicircular canals - the rotation sensors
- Sacculus and utriculus - the gravity sensors
- The vestibular nerve and how it triggers nystagmus
- Vestibular connections to the eye-movement nuclei
The MLF and the Cerebellum
The connecting cable and the fine-tuner
- The medial longitudinal fasciculus (MLF)
- Four jobs of the MLF
- The MLF links the gaze centres
- What happens when the MLF is damaged
- Functions of the medial longitudinal fasciculus
- The cerebellum - the fine-tuner
The Six Eye-Movement Systems
Six specialised programs sharing one final path
- The six supranuclear eye-movement systems
- Saccades - the fast jumps
- Three cortical pathways that generate saccades
- Brainstem generation of saccades
- Brainstem pathway for horizontal saccades
- Brainstem pathway for vertical saccades
- The pulse-step system - how a saccade is timed
- The pulse-step innervation of a saccade
- Inhibitory burst neurons and pause neurons
- Smooth pursuit - the tracking system
- Vergence movements are slow and disjugate
- Vergence - focusing near versus far
- Three more movement systems
Disorders of Eye Movements
What breaks when the control layer, not the nerve, is damaged
- The anatomy behind the disorders
- The signature of a supranuclear lesion
- The common supranuclear disorders
- Horizontal gaze paralysis: site of lesion
- Where the lesion sits sets the direction of gaze palsy
- Horizontal gaze paralysis - clinical features
- Internuclear ophthalmoplegia (INO)
- Internuclear ophthalmoplegia - the broken link
- INO - clinical features
- Internuclear ophthalmoplegia on gaze testing
- Distinguishing INO from its mimics
- One-and-a-half syndrome
- Brainstem lesion sites and the gaze palsies they cause
- Vertical conjugate gaze paralysis
- Skew deviation
- Cogwheeling
- Ocular dysmetria, ocular flutter and opsoclonus
- Oculomotor apraxia
- Acquired oculomotor apraxia
- Key takeaways
- On right gaze the left eye fails to adduct and the right eye abducts with nystagmus, but convergence is normal. Diagnosis?
- References
- Neuro-Ophthalmology