1. Cranial nerve

2. Cranial nerves
They are emerge through foramina or fissures in the cranium and are covered by tubular sheaths derived from the cranial meninges.
There are twelve pairs of cranial nerves, which are numbered I to XII, from rostral to caudal, according to their attachment to the brain and penetration of the cranial dura. Their names reflect their general distribution or function.

3. Olfactory nerve Function: special sense of smell (Olfaction )
The cell bodies of olfactory receptor neurons are located in the roof of the nasal cavity and along the nasal septum and medial wall of the superior nasal concha. 3

4. Olfactory nerve
Anosmia
Hyperosmia
Dysosmia 4

5. causes of unilateral anosmia5

6. Optic nerve Visual pathway
Function: special sense of vision
Its leave the orbit through the optic canal to enter the middle cranial fossa, where it forms the optic chiasm. Here, fibers from the nasal retina join uncrossed fibers from the temporal fibers to form the optic tract (requirement for three- dimensional vision). Thus fibers from the right halves of both retinas form the left optic tract ( right optic tract conveying impulses from the left visual field and vice versa). Most fibers in the optic tracts terminate in the lateral geniculate bodies of the thalamus. From these nuclei, axons are relayed to the visual cortices of the occipital lobes of the brain.

7. Optic nerve Visual pathway
Optic chiasm
Optic tract
Thalamus
Optic radiation
Primary visual cortex (Occipital lobe)

8. Visual field

9. Visual field
Unilateral blindness Optic nerve lesion (prechiasmal)

10. Optic disc optic nerve head
slightly oval approximately micrometers
Clear borders and well defined.
looks like an orange- pink donut with a pale centre
This pale Centre is devoid of neuroretinal tissue and is called the cup
Arteries are brighter red and narrower than veins

11. Papilledema Loss of venous pulsation Loss of optic cup disc swelling
indistinct & elevated disc margins
hemorrhages & exudates around the disc

12. Papilledema Loss of venous pulsation Loss of optic cup disc swelling
indistinct & elevated disc margins
hemorrhages & exudates around the disc

13. Chronic papilledema
Pallor
loss of optic cup
Disc swelling

14. Papilledema (optic disc swelling due to increased ICP)
Idiopathic intracranial hypertension
Cerebral tumor (primary or metastatic)
Hydrocephalus
Intracranial hemorrhage
Intracranial infection
Malignant hypertension
Pre-eclampsia 14

15. Optic disc swelling not due to increased ICP
Papillitis
Papillophlebitis
Central retinal vein occlusion
Diabetic papillopathy
Orbital or optic nerve tumors
Graves’ ophthalmopathy
Pseudopapilledema 15

16. Visual field

17. Optic neuritis Mean age was 32 years 77% were female
Presentation as acute deterioration of vision
92% had ocular pain (especially with eye movements)
35% had optic disc swelling ( mostly the demyelinating was retrobulbar)
Optic disc pallor slowly developed over subsequent months
50% will develop multiple sclerosis after optic neuritis

18. Optic neuritis

19. Optic neuritis viral infection multiple sclerosis Vaccination
meningitis
syphilis 19

20. Optic neuritis
Visual evoked potentials
Positive in 50-80%
MRI

21. Optic neuritis Treatment
high-dose IV methylprednisolone (250 mg every 6 h for3 days)
followed by oral prednisone (1 mg/kg per day for 11 days)
the recovery of visual function occurs more rapidly
makes no difference in final acuity after 6 months

22. Ischemic optic neuropathy
Nonarteritic
(monocular painless, sudden visual loss) 22

23. Arteritic Ischemic optic Neuropathy
Occurs in association with temporal arteritis and polymyalgia rheumatica
age > 75 years
monocular visual loss & headache
Associated symptoms
painful jaw muscle spasms
scalp tenderness
weight loss
fatigue, myalgia
loss of appetite

24. Ischemic optic neuropathy
Arteritic
High (ESR)
Elevated (CRP)
High platelet count (thrombocytosis)
Requires urgent and critical intervention with a very long course of corticosteroids to prevent further damage
Non-treatment leads to bilateral blindness and strokes

25. Optic atrophy 25