The document discusses the oculomotor nerve (cranial nerve 3), which is entirely motor and supplies several extraocular muscles and the levator palpebrae superioris muscle. It has nuclei located in the midbrain and courses from the midbrain to the orbit. Common causes of cranial nerve 3 palsy include vascular issues like diabetes and hypertension, neoplastic lesions, and trauma. Signs of a total cranial nerve 3 palsy include ptosis, limitation of eye movements, and a dilated pupil. Treatment depends on the underlying cause but may involve surgery, patching, or prism correction of double vision.

1. Dr Md Ferdous Islam
FCPS Part 2 Trainee
Dept of Ophthalmology
CMH, Dhaka
3rd Cranial Nerve Palsy

2. 3rd cranial nerve
OCULOMOTOR NERVE
 Entirely motor in function
 Supplies –
o All the Extraocular muscles except
superior
oblique and lateral rectus
o Levator palpebrae superioris
oIntra ocular muscles- Sphincter
pupillae and cilliary muscle

3. Nucleus
Located in midbrain at the level of
superior colliculus, ventral to the
Sylvian aquiduct.
Composed of
 Unpaired levator subnucleus
 Paired superior rectus sub nuclei
 Paired medial rectus, inferior rectus
and inferior oblique subnuclei

4. Course
Can be divided into –
Fascicular
Basilar
Intracavernous
Intraorbital part

5. Course

7. Intracavernous portion of 3rd
nerve

8. Intraorbital portion of 3rd
nerve

9. complex
lesion of 3rd nerve palsy
Vascular occlusion – Diabetes &
Hypertension
Neoplastic lesions – primary
tumour or metastasis
Haemorrhage

10. Major causes of fascicular
lesion of
3rd nerve palsy
 Vascular occlusion – Diabetes &
Hypertension
 Neoplastic lesions – primary tumour or
metastasis
 Haemorrhage
 Demyelination

11. Syndromes of Fascicular
lesion
 Benedikt syndrome- Ipsilateral 3rd nerve palsy
and contralateral extrapyramidal signs
 Weber syndrome- Ipsilateral 3rd nerve palsy and
contralateral hemiparesis
 Nothnagel syndrome- Ipsilateral 3rd nerve palsy
and cerebellar ataxia
 Claude syndrome

12. Major causes of lesion in
Basilar
region
 The 3rd nerve traverses the basilar part
unaccompanied by any other cranial
nerves.
 Isolated 3rd nerve palsies are commonly
basilar.
The important causes are
 Aneurysm
 Head trauma-Extradural or subdural

15. Major causes of
Intracavernous
lesion
 Usually associated with involvement of
4th, 6th nerves & first division of 5th
nerve.
 Diabetes – causes pupil sparing 3rd
nerve palsy
 Pituitary apoplexy
 Others – Aneurysm, Meningeoma,
Carotid-cavernous fistula.

16. Intraorbital causes of 3rd
nerve
palsy
 Trauma
 Vascular
 Neoplasm
 Inflammation

17. Pupillomotor fibers
 Parasympathetic fibers
 Located superficially between the
brainstem and the cavernous sinus
 Blood supply derived from the pial blood
vessels
 Main trunk of 3rd nerve supplied by the
vasa nervorum

19. Causes of isolated 3rd nerve
palsy
 Idiopathic – about 25%
 Vascular – Hypertension & Diabetes
(commonly pupil sparing)
 Aneurysm – posterior communicating
artery at its junction with internal carotid
artery
 Trauma – subdural haematoma with
uncal herniation
 Miscellaneous

20. Clinical features of total 3rd
nerve
palsy
SYMPTOMS
 Drooping of eyelid
 Binocular double vision
 Pain (may be present)

21. SIGNS
 Ptosis
 Abduction of globe
 Intortion of the globe which increases on
attempted down gaze
 Limitation of adduction
 Limitation of elevation
 Limitation of depression
 Dilated pupil with defective accommodation

23. History of Patient
 Onset
 Duration
 Diplopia
 Trauma
 Associated systemic disorders

24. Examination
 Pupillary reactions
 Motility restrictions
 Ptosis
 Other cranial nerves

25. Investigations

26. Investigations

27. Treatment
Non-surgical
 Treatment of underlying cause
 Diplopia – Occlusion patch or prism in
involved eye
 Monitor children for development of amblyopia
Surgical
 Neurosurgery – Aneurysm or haematoma
 Strabismus or ptosis surgery – Not earlier
than 6 months from time of onset

28. Follow-up
 Pupil sparing – Observe daily for 5 days
for pupil involvement
 Recheck every 4 to 6 weeks
 If secondary to ischemia function usually
returns within 3 months

29. Thank
You