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The first 25 slides, exactly as they appear. The full deck has 65 content slides.
Ophthalmology
Anatomy and Lesions of Oculomotor Trochlear and Abducent N
Built from Khurana — Neuro-Ophthalmology
What’s inside
5 sections · 65 slides
Overview
- Six muscles, three nerves: the big picture
- Why these three nerves are studied together
Oculomotor (Third Cranial) Nerve
The workhorse of eye movement, eyelid and pupil
- Oculomotor nerve: what it controls
- Three functional fibre types inside the nerve
- Where it starts: the oculomotor nuclear complex
- Oculomotor nucleus, its connections and course
- Column of cranial-nerve motor nuclei in the brainstem
- Main motor nucleus: one subnucleus per muscle
- Motor subnuclei of the oculomotor complex
- The Edinger-Westphal nucleus: the pupil controller
- What the nucleus talks to (its connections)
- The journey out: four parts of its course
- Fascicular and basilar segments
- Oculomotor nerve running from midbrain to the orbit
- Intracavernous segment
- Roof of the cavernous sinus with the nerve apertures
- Coronal section of the cavernous sinus
- Intraorbital segment: the final branches
- Nerve arrangement at the superior orbital fissure
- The ciliary ganglion: relay station for the pupil
- Ganglion output: the short ciliary nerves
- Roots and branches of the ciliary ganglion
- Complete third nerve palsy - the signs (part 1)
- Complete third nerve palsy in a patient
- Complete third nerve palsy - the signs (part 2)
- Localizing the lesion: supranuclear and nuclear levels
- Fascicular midbrain syndromes
- Basilar (subarachnoid) lesions
- How an extradural haematoma compresses the third nerve
- Intracavernous and intraorbital lesions
- The pupil rule: surgical vs medical lesions
- Blood supply and the pupil-sparing rule
- Causes of an isolated third nerve palsy
- In an acute painful third nerve palsy, why does an involved (dilated) pupil demand urgent imaging?
Trochlear (Fourth Cranial) Nerve
The thin, crossed nerve for one muscle
- Trochlear nerve: three things that make it unique
- Functional components and nucleus
- Trochlear nucleus in the midbrain
- Connections of the trochlear nucleus
- Course: a long path with a full crossover
- Trochlear nerve running to the superior oblique
- A quirk of its proprioceptive fibres
- Fourth nerve palsy: the clinical picture
- Causes of fourth nerve palsy
Abducent (Sixth Cranial) Nerve
The long, fragile nerve for outward gaze
- Abducent nerve: the basics
- Nucleus: a hub tied to the facial nerve
- Abducent nucleus and its relation to the facial nerve
- Connections of the abducent nucleus
- Course: why it is so vulnerable
- Abducent nerve: pons to lateral rectus
- Sixth nerve palsy: the clinical picture
- Nuclear and fascicular lesions
- Basilar lesions and false localizing sign
- Sixth nerve stretched by raised intracranial pressure
- Intracavernous and intraorbital lesions
Putting It Together
Comparing the three ocular motor nerves
- The three nerves side by side
- One-line summary of each nerve
- Key take-home messages
- References (1/2)
- References (2/2)
- Neuro-Ophthalmology