The document discusses congenital and acquired oculomotor nerve palsy, a rare condition predominantly affecting children, with various causes including trauma, inflammation, and genetic factors. It outlines diagnostic approaches, clinical findings, and management strategies, emphasizing the need for imaging and careful examination to prevent complications such as amblyopia. Treatment options include both conservative measures and surgical interventions, tailored to the specific needs and anatomical variations of the patient.

1. Congenital third ( oculomotor )nerve palsy
& Acquired Oculomotor Nerve Palsy

3. Disease Entity ( Paediatric 3red cn palsy )
• Cranial nerve three (CN3) palsies are overall rare in the pediatric population with up
to 50% diagnosed as congenital, followed by trauma, inflammation & vascular
etiologies .
• It may also uncommonly present in the setting of migraine, infection, or neoplasm .
• Although exact mechanisms of congenital CN3 palsy development is unknown, it is
thought to be secondary to damage of the peripheral nerve, frequently during
adverse perinatal events, in most incidences, as opposed to injury or developmental
factors within the brainstem
• ( congenital 3red CN palsy = incidence – 7.6 per 1,00,000 )

4. Diagnosis & history
• Ask about pregnancy & birth history due to the association with birth trauma &
perinatal complications.
• Inquire whether the patient is meeting their developmental milestones or if they are
exhibiting any other neurologic signs or symptoms. Although additional focal
neurologic abnormalities or generalized delays in development have been described
in these patients, their presence may increase concerns of other neurologic
etiologies.
• Determine whether they have signs of oculomotor synkinesis, such as asking the
parents if they notice eye or eyelid movement during feeding.
• Question if they have any family history of strabismus.
• Heritability may suggest other forms of strabismus with known genetic associations.

5. Physical examination
• Visual acuity:
• Careful assessment & documentation is important to assess for amblyopia & should
be performed as appropriate given a patient’s age & maturity.
• Pupils:
• Pupillary involvement allows better localization of lesion, suggesting pathology
involving CN3 or along the sympathetic pathway.
• Although CN3 palsy is more commonly associated with enlargement of the affected
side, smaller pupils have also been reported & is thought to be related to aberrant
regeneration.
• There are also many cases in which the pupil is spared, thus a diagnosis of CN3 palsy
cannot be ruled out based on presence of pupillary involvement.

6. EOM ‘s & External examination
• Complete CN3 palsy results in paralysis of the inferior rectus, inferior oblique, medial
rectus and superior rectus. This would result in inability to adduct, elevate, or
depress the eye. As a result, the unopposed actions of the superior oblique & lateral
rectus may cause the eye to be abducted & depressed.
• Head posturing performed to promote fusion should be noted .

7. External Examination
• Upper eyelid ptosis results from paralysis of the levator muscle, which is also
innervated by CN3. As noted with the extraocular muscles, the patient may present
with complete or partial muscle function leading to variable severity.
• Most important to prevent amblyopia is determining whether the visual axis is
obstructed by the lid.
• For surgical planning, measurements of the patient’s MRD1 & levator function
should be obtained.
• Presence of a Bell’s phenomenon should be evaluated.

9. Diagnostic procedure & additional findings
• Given the potential for an underlying neurologic lesion, it has been recommended
that neuroimaging be obtained in all children who first present with a CN3 palsy.
Discussion with pediatric neurology has also been advised .
• Oculomotor synkinesis:
• Aberrant regeneration of the CN3 has been described in as many patients with CN3
palsy. This presents as synergistic movement of either the lids or extraocular
muscles with jaw movements- usually most apparent while the patient is eating.
This suggests the formation of secondary connections with the ipsilateral the
trigeminal nerve.

10. • Cyclic oculomotor spams:
• Rare cases of cyclical spams involving the oculomotor nerve have been reported
in children with congenital CN3 palsy, thought to be a form of aberrant
regeneration. These patients present with signs of CN3 palsy but with regular,
short bursts of spastic movements causing elevation of the lid, adduction of the
eye, miosis & increased accommodation.

11. D/D
• Congenital Horner syndrome
• Duane’s syndrome
• Acquired CN3 palsy
• Chronic progressive external ophthalmoplegia

12. Management ( both non surgical & surgical T/t)
• Although usually requiring surgical intervention for binocularity, treatment may
begin with occlusion therapy & glasses for refractive error and/or prism. Botulinum
A toxin has also been trialed with varying success in this population.
• The goal of strabismus surgery is to allow binocular fusion in primary gaze in
addition to reading. Surgery to improve ocular alignment can be complex due to the
involvement of multiple muscles & the possibility of aberrant regeneration.

13. • The most common surgery performed in these patients is a horizontal rectus
recession & resection provided most patients present with exotropia. To aid with
vertical deviations, horizontal muscle transpositions or superior oblique
weakening procedures are the most common procedures employed .

14. Ptosis surgeries ..
• In addition to strabismus surgery, treatment of ptosis associated with a CN3 palsy is
essential to prevent development or progression of amblyopia & to provide the best
chance of binocularity.
• In general, it is recommended to perform strabismus surgeries prior to eyelid surgery for
the best lid position outcomes; this is most important when vertical muscles are
involved as the eyelid position may be altered by vertical muscle surgery.

15. • The two main surgical options for these patients are a frontalis sling or levator
advancement. The selection between the two may be based on multiple factors like
amount of levator function & degree of ptosis.
• A frontalis sling establishes a connection between the frontalis muscle & the upper
tarsal plate, increasing palpebral fissure aperture with brow elevation. This is
recommended in patients with poor levator function, measuring less than 3-4 mm &
severe ptosis.

16. • Common frontalis sling materials are facia lata / silicone, though a wide variety of
other synthetic materials are available.
• Facia lata is harvested from the lateral thigh & thus requires a second procedural
site. It may be autogenous in patients older than three to six years of age, or from
a donation bank .
• Synthetic materials avoid the risk of second site surgery, rejection or theoretic
disease transmission, however, may be lead to an increased rate of recurrent
ptosis. Autogenous fascia lata remains the gold standard.

17. • If greater than 5 mm of levator function is present, levator advancement is
frequently performed. Advancement of the levator to the anterior surface of the
tarsus effectively shortens the aponeurosis & tightens the muscle, strengthening
upper lid opening.
• Sequelae associated with both frontalis sling & levator advancement procedures
include undercorrection or overcorrection, which may require further surgical
interventions. Importantly, lagophthalmos is a frequent complication following
surgery, which can lead to exposure keratopathy. Patients with poor Bell’s
phenomenon are extremely high risk .

18. Surgical follow – up.
• Frequent follow up is recommended while the child is of amblyogenic age to
prevent long-term outcomes. As we explained… that multiple surgeries may be
required in addition to conservative treatments.
• The development of stereopsis is rare with CN3 palsies, though varied results of
visual acuity have been reported with meticulous treatment & early
intervention.

19. • Adult onset or acquired cause of 3red cranial nerve palsy

20. • Acquired oculomotor nerve palsy is an ocular pathology resulting from damage
to third cranial nerve. It can presents in different ways causing somatic
extraocular muscle dysfunction (superior, inferior, medial recti; inferior oblique;
& levator palpebrae superioris) & autonomic (pupillary sphincter & ciliary
muscles )
• Disease entity : Partial & complete 3rd nerve palsy

21. • Clinical findings of acquired third nerve palsy may depend on the affected area of
the oculomotor nerve track.
• Complete 3rd nerve palsy presents with complete ptosis, with the eye positioned
downward & outward with the inability to adduct, infraduct, or supraduct, as well
as dilated pupil with sluggish reaction.
• Partial 3rd nerve palsy may be more common & can present with variable duction
limitation of the affected extraocular muscles with variable degree of ptosis /or
pupillary dysfunction.

22. etiology & risk factors :
• There are many etiologies for oculomotor palsy including vasculopathic process,
trauma, compression (e.g. PCA aneurysm), infiltrative (e.g. leukemia), toxic (e.g.
chemotherapy) etc.
• Risk factors can include Diabetes mellitus, Hypertension,
Vasculitis, Trauma, Infections, Tumor, Aneurysm etc.
• Pathophysiology : To understand the pathophysiology of the oculomotor nerve palsy
it is essential to know its pathway .

25. • The nuclear complex of the third (oculomotor) nerve is situated in the midbrain
at the level of the superior colliculus, ventral to the Sylvian aqueduct .
• It is composed of the following paired and unpaired subnuclei:
• • Levator subnucleus is an unpaired caudal midline structure that innervates
both levator muscles. Lesions confined to this area will therefore give rise to
bilateral ptosis.

26. • Superior rectus subnuclei are paired: each innervates the respective
contralateral superior rectus. A nuclear third nerve palsy will therefore spare the
ipsilateral, and affect the contralateral, superior rectus.

27. • Medial rectus, inferior rectus and inferior oblique subnuclei are paired and
innervate their corresponding ipsilateral muscles. Lesions confined to the nuclear
complex are relatively uncommon. The most frequent causes are vascular
disease, primary tumours and metastases.

28. The fasciculus
• Involvement of the paired medial rectus subnuclei cause a wall-eyed bilateral
internuclear ophthalmoplegia (WEBINO), characterized by exotropia with
defective convergence and adduction. Lesions involving the entire nucleus are
often associated with involvement of the adjacent and caudal fourth nerve
nucleus.

29. • The fasciculus consists of efferent fibres that pass from the third nerve nucleus
through the red nucleus and the medial aspect of the cerebral peduncle. They
then emerge from the midbrain and pass into the interpeduncular space. The
causes of nuclear and fascicular lesions are similar, except that demyelination
may affect the fasciculus.

30. • Benedikt syndrome involves the fasciculus as it passes through the red nucleus
and is characterized by ipsilateral third nerve palsy and contralateral
extrapyramidal signs such as hemitremor.

31. • Weber syndrome involves the fasciculus as it passes through the cerebral
peduncle and is characterized by ipsilateral third nerve palsy and a contralateral
hemiparesis.
• Nothnagel syndrome involves the fasciculus and the superior cerebellar peduncle
and is characterized by ipsilateral third nerve palsy and cerebellar ataxia.
• • Claude syndrome is a combination of Benedikt and Nothnagel syndromes

32. Basilar part
• that leave the midbrain on the medial aspect of the cerebral peduncle, before
coalescing to form the main trunk .
• As the nerve traverses the base of the skull along its subarachnoid course
unaccompanied by any other cranial nerve, an isolated third nerve palsy is
commonly basilar. The following are important causes

33. • Aneurysm of the posterior communicating artery at its junction with the internal
carotid artery. typically presents acutely as a pupil-involving painful third nerve
palsy.
• Head trauma, resulting in extradural or subdural haematoma, may cause a
tentorial pressure cone with downward herniation of the temporal lobe. This
compresses the third nerve as it passes over the tentorial edge , initially causing
irritative miosis followed by mydriasis and complete third nerve palsy

36. • Pupillomotor fibres
• Between the brainstem and the cavernous sinus, the pupillomotor
parasympathetic fibres are located superficially in the superomedial part of the
third nerve . They derive their blood supply from the pial blood vessels, whereas
the main interior trunk of the nerve is supplied by the vasa nervorum.
Involvement or sparing of the pupil is important, as it frequently differentiates a
‘surgical’ from a ‘medical’ lesion:

37. • ‘Surgical’ lesions such as aneurysms, trauma and uncal herniation
characteristically involve the pupil by compressing the pial blood vessels and the
superficially located pupillary fibres.
• ‘Medical’ lesions such as occur in hypertension and diabetes usually spare the
pupil. This is because the microangiopathy associated with medical lesions
involves the vasa nervorum, causing ischaemia of the main trunk of the nerve,
leaving the superficial pupillary fibres intact.

38. Signs
• Profound ptosis due to weakness of the levator muscle so that diplopia may not
be volunteered.
• • Abduction and depression in the primary position (‘down and out’ – due to
unopposed action of the lateral rectus and superior oblique muscles.
• The intact superior oblique muscle also causes intorsion of the eye at rest, which
increases on attempted downgaze

39. • Normal abduction as the lateral rectus is intact .
• • Limited adduction due to medial rectus weakness .
• • Limited elevation due to weakness of the superior rectus and inferior oblique

40. INVESTIGATIONS
• Vascular risk factor assessment similar to that for retinal arterial disease .
Supplementary investigation may be required if a rarer aetiology such as infection
(e.g. syphilis, Lyme disease) or vasculitis (including giant cell arteritis) is
suspected; this may include a lumbar puncture.
• CT angiography should be performed with great urgency if the clinical features
are suspicious of an expanding aneurysm, especially if there is marked pupillary
involvement with milder motility dysfunction and only partial ptosis.

41. • MRI brain and orbits with venography, including specific exclusion of a brainstem
stroke or tumour, cavernous sinus or orbital apex lesion.
• • Conventional cerebral angiography is occasionally indicated.

44. Management
• Management of 3red CN palsy remains the most difficult, incomplete & least
satisfying .
• Investigations :
• 3red CN palsy of acute onset & non pupil sparing should be subjected to through
neuro-ophthalmic evaluation & be investigated with prompt & appropriate neurologic
studies :
• MRI & Carotid angiography : criteria :
• Children < 10yrs age : regardless of state of pupil : if MRI normal , carotid ang. Not
essential .( because less chances of aneurysm )
• Patient > 10 yrs of age with pupil sparing , if MRI normal ,a through medical
evaluation should be conducted .

45. • In patients of vasculopathy age group ( >40yrs) HTN & Atherosclerosis should be
taken care of. Further diabetic mononeuropathy should always be ruled out by
oral glucose tolerance test ( OGT ) in patient with pupil sparing 3red CN palsy.
• All such patients should be observed frequently & if pupil is involved or signs /
symptoms of subarachnoid haemorrhage develops -- angiography is required to
rule out aneurysm .
• Tensilon test : ptosis / diplopia unknown cause : endrophium test is done to rule
out Myasthenia gravis.
• ESR : if patient > 55yrs of age with symptoms of polymyalgia rheumatica , GCA /
temporal arteritis : ESR done / temporal artery biopsy done .

46. Treatment of the cause : conservative t/t
• If surgical cause is found like DM, PCA – aneurysm or myasthenia gravis : the patient
should be referred to neurosurgeon or neurophysician , depending upon indication .
• If no surgical cause found – patient should be managed conservatively followed by
extraocular muscle surgery .
• Conservative treatment :
• Observation : like any other paralytic squint wait & watch for the self recovery should
be done at least for 6-8 months .
• During this period patent should be followed every 6 weeks & at eacg follow up visit ,
following examination should be done .
• Measurent of exotropia & hypotropia with PBCT
• DIPLOPIA charting
• Hess charting

47. • Amblyopia is associated with 3red CN palsy in paediatric patient & must be
treated .
• Alternate patching should be done to prevent amblyopia
• Surgical T/t to raise the ptotic lid is needed urgently in children.
• Complete ptosis is useful in preventing diplopia in visually mature patient
.therefore ptosis surgery should be deferred until after the eyes has been
straightened .
• Alternate patching is required in visually mature patients with incomplete ptosis .
• Opaque contact lens or blurred spectacles can be used as alternative to patching .

48. • Botulinum toxin : used in acute phase partial 3red CN palsy .
• This is useful in cases of isolated involvement of MR muscle ., it paralyse the
antagonist LR temporarily .
• Note : Botox should not be injected in SR /LPS : as ptosis can ocure
• vitamin B complex
• Systemic steroids : useful in non specific inflammation like GCA , rheumatological
disorders .

49. surgical T/T
• General principles
• 1. wait & watch : like any other paralytic squint wait at least 6-8 months . Before
performing surgical intervention
• 2. surgery should be undertaken continuously in pt. with complete palsy & good BSV.
Since elevation of the lid & incomplete realignment without useful single binocular
fileds may produce incapacitating diplopia .
• 3. Sx for 3red CN palsy is challenging & outcome should be discussed with the
patient .
• Because associate factors like amblyopia , aberrant regeneration, poor Bells , SO
overaction & LR contracture further complicate the results. It should be explained to
patient or parents that several operations will most likely to be necessary to straight
eyes .

50. Goals of surgery
• 1. TO IMPROVE ALIGNMENT IN PRIMARY GAZE .
• 2. TO PRODUCE OR ENLARGE SOME DEGREE OF BSV
• Surgical procedure :
• It should be done only if the strabismus & diplopia measurement remain stable for
3 months . ( after 6-8 months after paralysis )
• Aim of Sx : is to give alignment in the two important positions , i.e primary &
downgaze

51. • Sx for exotropia : LR recession & MR resection
• In an incomplete palsy : recess- resect procedure should be planned as done for
comitant exotropia
• In complete paralysis : Halveston many others have adviced supramaximal
recession of LR ( 14-16 mm ) & resection of MR (8-14 mm) to align the eye in
primary position . But this has limited success as overtime chronic contracture of
LR & elongation of resected muscle causes exotropic drift again .
• Myectomy of LR muscle : to accomplish a supermaximal weaking effect of
abduction in patient with complete 3red CN palsy .( limitation is result in
exotropia )
• Adjustable sutures diring recess - resect procedure are quite useful in co-
operative patient .

52. • Sx for hypotropia : it includes
• Supraplacement of horizontal recti during recess- resect procedure is preferred
by some surgeon
• SO tenotomy : is preferred by some surgeon over the supraplacement of
horizontal recti.
• IR recession with resection of SR : is used to correct hypotropia with preserved
partial function of vertical recti . ( side effect : most common is anterior segment
ischaemia )
• Faden recession of contralateral verical recti : is also helpful to correct thr vertical
misalignment in primary position / downgaze .

53. • Transposition of SO tendon : if eye remain exotropic 3 months after all this
procedures : in this situation , a further adduction effect can be obtained by
transposition of the insertion of the SO tendon to a point 2 to 3 mm anterior to
the medial side of SR insertion .
• Conditions / indication for SO transposition .
• Acquired 3red CN palsy
• With palsy is complete
• Involved eye is fixing eye
• Maximum recess- resect SX on horizontal recti failed to restore the globe in
primary position

54. • In the case of palsy of superior division of thired nerve : Knapp’s procedure
should be done .
• In case of palsy of inferior division of 3red CN ocure : transposition of LR to the
site of insertion of IR muscle & transposition of SR to MR area combined with
tenotomy of SO to align the eye in primary position should be carried out.
• This helps to correct intorsion & provide a vector force in the direction of palsied
muscle .

55. • Anchoring of the LR to periosteum of lateral orbital wall by non – absorbable .
• 5-0 mersilene suture along with 8-0 mm of MR resection has also been
recommended for the alignment of the globe in primary position

56. • Surgery for ptosis :
• Frontalis sling taking care that the globe is not omly jeopardized because of
impaired or absent Bell’s phenomenon .
• Ptosis should be corrected only to cover half of the cornea with relaxed brow .
• Protecive measures to avoid exposure keratopathy must be taken .

57. •THANK YOU