Oculomotor nerve palsy

Oculomotor Nerve Palsy

1. Dr. Mahziba Rahman
MCPS, FCPS
Eye Specialist & Surgeon
Bangladesh Eye Hospital Ltd.

2. 3
rd
cranial nerve
Oculomotor nerve
Entirely motor in function
Supplies –
•All the Extraocular muscles except superior
oblique and lateral rectus
•Levator palpebrae superioris
•Intra 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
•Unpaired Edinger-Westphal nucleus

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

5. Course

6. Course

7. Intracavernous portion of 3
rd
nerve

8. Intraorbital portion of 3
rd
nerve

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

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

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

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

13. continued

14. continued

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

16. Intraorbital causes of 3
rd
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 3
rd
nerve supplied by the vasa nervorum

18. Continued
Type of lesion affecting
Pupillomotor fibers :Surgical
Main trunk : Medical

19. Causes of isolated 3
rd
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 3
rd
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
Age < 50 years CT or MRI, Cerebral angiography
Age > 50 years
Pupil sparing FBS and 2HABF, HbA1c, Lipid profile,
Check BP, CBC with ESR, CRP
Pupil involving FBS and 2HABF, HbA1c, Lipid profile,
Check BP, CBC with ESR, CRP, CT or
MRI, Cerebral angiography

26. Investigations
Hess Chart

27. Treatment
Non-surgical
Treatment of underlying cause
Diplopia – Occlusion patch or prism in involved eye
Monitor children for development of amblyopia

28. Treatment
Surgical
Neurosurgery – Aneurysm or haematoma
Strabismus or ptosis surgery – Not earlier than 6
months from time of onset

29. 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

30. Differential Diagnosis
Myasthenia gravis
Thyroid associated orbitopathy
Chronic progressive external ophthalmoplegia
Idiopathic orbital inflammatory disease

31. Thank
you