This document provides an overview of neuroanatomy as it relates to the ophthalmologist. It discusses the cranial fossae and their boundaries, cranial nerves III-VII, venous sinuses, and cerebrospinal fluid circulation. The oculomotor, trochlear, abducens, trigeminal, facial, and vestibulocochlear cranial nerves and their nuclei and pathways are described in detail.

1. Neuro-anatomy for the
Ophthalmologist
Raed Behbehani, MD, ABO

2. Neuro-anatomy
 Orbits
 Cranial Cavity
 Venous sinus
 Cavernous sinus
 Cranial Nerves

3. Anterior Cranial Fossa
 Anteriorly: Frontal bone.
 Posteriorly: Lesser wing of sphenoid.
 Floor : Orbital plate, cribriform plate.
 Anterior clinoids tentorium.

4. Middle Cranial Fossa
 Floor: “Butterfly shape”.
 Anteriorly: The lesser wings of the sph., ant. Clinoids.
 Posteriorly : Petrous port. Of Temp. bone, dorsum sellae.
 Foramina : SOF, Rotundum, Ovale, Spinosum, Lacerum,

5. Posterior Cranial Fossa
 Roof: Tent.Cerebelli.
 Anteriorly : Petrous part of Temp. bone, Dorsum sellae.

6. CSF Circulation

7. Venous Sinuses

8. Venous sinuses
 Superior SS .
 Inferior SS join the Great vein of Galen 
Straight sinus.
 SSS, straight S, and two transverse S.
frequenly join (confluence of sinuses).
 Straight S Sigimoid S Int Jugular vein.

9. CSF

10. Cavernous sinus
 Intercavernous comunications.
 Tributaries: Sup and Inf Ophthalmic veins,
sup cerebral vein.
 Drainage: Sup and Inf petrosal sinus 
Internial Jugular vein ( direct ) or via
transverse sinus  Int Jug vein.

11. Cavernous sinus

12. Cranial Nerves

13. Oculomotor Nerve
 Nuclei lie at level of sup colliculi.
 Dorsally into the third ventricle.
 Laterally: MLF.
 Through tegmentum and
Red nucleus  medial to
Crus cerebri.

14. Oculomotor Nerve
 Interpeduncular fossa.
 Lateral to PCOM (between PCA above and Post Cerebellar art.
Below).
 Lateral wall of cavernous sinus SOF.

15. Oculomotor nucleus
 MR subnucleus : 3 different masses.
 SR subnuclue : innervates contralateral SR.
 Central caudal nucleus: innervates LPS bilaterrally.
 Visceral subnuclei: anterior median, Edinger-Westphal,
nucleus of Perlia.

16. 3rd Nerve

17. Trochlear Nerve
 Two nuclei in mesencephalon ventral to inferior colliculi.
 Close to caudal end of IIIrd nerve nuclei.
 Only somatic nerve to emerge from the dorsal aspect of the CNS.
 Decussation (anterior medullary velum ).
 Nucleus: anterior to periacqueductal gray matter.

18. Trochlear nerve
 Around the crus cerebri between PCA and Sup cerebell art
(lateral to 3rd nv.) beneath the free edge of the tentorium 
Pierces the dura and enters the lateral wall of the cavernous sinus
beneath the 3rd cranial nerve.

19. Abducens Nerve
 Midpons beneath the facial colliculus.
 Longest course.

20. Abducens Nerve
 Emerges at pontomeduallry junnction.

21. Abducens Nerve
 Pierces the dura early upward on
The clivus.
Vertical  Horizontal direction.
Runs beneath the petroclinoid
(Guber’s) Ligament.
Within the cavernous sinus (lateral
to the ICA).

22. Trigeminal nerve
 Gessarian ganglion : Temporal bone within middle cranial fossa
(Meckel’s cave).
 V1 SOF , V2 FR , V3 FO.

23. Trigeminal nerve
V1Sensory.
V2 carries PS from
The facial (superficial
Petrosal nv.) for
Lacrimation,
V3 Motor and
Sensory.

24. Facial nerve
 Supranuclear neurons : in the frontal lobe
(pre-central gyrus).
 Corticobulbar fibers in the middle of internal
capsule.
 Fibers cross (below MB) cross to innervate
contralateral facial nucleus , some to
ipsilateral.

25. Facial nerve

26. Facial nerve
 Facial colliculus.
 PS component : Superior salivatory nucleus
(Sub-ling., Sub-Mand., Lacrimal gland).
 Nervus intermedius “7 ½ nerve” : carries PS
and sensory input.
 Nucleus Solitarius : Sensory nucleus for
taste.

27. Facial-Motor visceral
 Nervus intermedius (tearing,salivation,taste).

28. Facial Nerve

29. Facial Nerve
 Ventrolateral pons : Facial motor root and 8th
nerve exit togather.
 CPA: Vth, VIIth and VIIIth lie close togather.
 Facial motor root  internal auditory
meatus Fallopian canal.
 At geniculate ganglion: first branch of VII is
Greater superficial petrosal nv.
sphenopalatine ganglion lacrimal gland.

30. Facial Nerve

31. Facial nerve
 In the canal, nerve to stapedius , and chorda
tympani.
 Facial nerve exit through the Stylomastoid
foramen Parotid gland.

32. Facial nerve-Motor

33. Facial nerve