OCULAR MOTOR NERVE PALSIES

OCULAR MOTOR NERVE PALSIES

Marwan Salah Salman MD.
Third crainal nerve palsy

Symptoms

Binocular horizontal diplopia and ptosis, with or without pain.
Note: Pain does not distinguish between microvascular infarction and compression .
Signs
Critical
1-external ophthalmoplegia
-complete palsy : limitation of ocular movement in all fields of gaze except temporally.
-Incomplete palsy :partial limitation of ocular movement.
-superior division palsy : ptosis and inability to look up .
-inferior division palsy: inability to look nasally or inferiorly.
2-internal ophthalmoplegia
-Pupil –involving : A fixed ,dilated poorly reactive pupil
-Pupil- sparing : pupil not dilated and normally reactive to light
-Relative pupil sparing : pupil partially dilated and sluggishly reactive to light
Others
Exotropia or hypotropia .aberrant regeneration


DDX
1-Myasthenia gravis.
2-Thyroid eye disease .
3-Chronic progressive external ophthalmoplegia
4-Idiopathic orbital inflammatory syndrome .
5-internuclear ophthalmoplegia INO .
6- Skew deviation .
7- parinaude syndrome /dorsal midbrain lesion .
8- GCA (Giant cell arteritis )

Etiology

Pupil involving :
more common : aneurysm ,particularlly posterior communicating artery aneurysm .
-Less common: tumor, trauma, congenital, uncal herniation ,cavernous sinus mass, pituitary apoplexy, orbital diseases, varicella zoster virus ,and leukemia. In children ophthalmoplegic migrain
Pupuil sparing : ischemic microvascular disease , raely cavernous sinus syndrome or GCA
Relative pupil sparing :ischemic microvascular diseases ,less likely compressive
Aberrant regeneration present : trauma , tumor ,aneurysm ,congenital not microvascular

WORK UP

1- History : onset and duration of diplopia, recent pertient medical history ( e.g, diabetes , hypertension , CNS mass , recent infection ) if the patient above 55 years specifically ask about GCA symptoms .
2- Complete ocular examination : check for pupillary involvement ,the direction of motility restriction ( in both eyes ), ptosis a visual field defect by confrntation ,proptosis orbicularis muscle weakness , and eyelid fatigue with sustain upgaze look carefully for signs of aberrant regeneration.
3- Full neurologicall examination : carefully assess the other crainal nerves on both sides .
4- Immediate CNS imaging : to rule out mass /aneurysm is indicated for
A- pupil involving ( relatively or completely involved ) third nerve palsies .
B- pupil sparing in the following group of the patient
- patents less than 50 years of age ( unless there is longstanding diabetes or hypertention)
- Patient with incomplete third nerve palsies ( with sparing of some muscle function ) because this condition may be evolving into a pupil involving third nerve palsy . If imaging not obtained ,closely monitor patients for pupil involvement daily for at least 7 days .
- Patient with additional crainal nerve or neurological abnormalities.
C- children less than 10 years of age ,regardless the state of the pupil .
CT SCAN , MRI , IF clinical suspicion remains high , catheter angiography may be indicated .
5- prompt CNS imaging is required for :
A- all patients in whom aberrant regeneration develops .
B- pupil –sparing third nerve palsy for more than 3 months in duration without improvement .
6- imaging usually not required in complete sparing third nerve palsies that do not fit these criteria especially in patients more than 50 years of age with known vasculopathic risk factors such as DM or HT.
7- Cerebal angiography is indicated for all patients more than 10 years of age with pupil involving third nreve palsies and whose imaging study is negative or shows amass cosistent with aneurysm .
8-CBC with differential in children
9-Edrophnium choride test when myathenia gravis is suspected .
10- for suspected ischemic diseases check blood pressure , fasting blood sugar , glycosylated hemoglobin.
11- immediate ESR , CRP, and platelets if GCA is suspected .


Treatment
1- Treat the underlying abnormality .
2-If the third nerve palsy causing symptomatic diplopia , an occlusion patch or prism may be placed over the involved eye . Patching is usually not perform in children less than 11 years of age because of the risk of amblyopia . Children should be monitored closely for the development of amblyopia in the deviated eye .
3- strabismus surgery may be considered for persistent significant misalignment .

Fourth cranial nerve palsy

Symptoms
Binocular vertical or oblique diplopia , difficult reading , sensation that objects appear tilted, may be asymptomatic .
Critical : deficient inferior movement of an eye when attempting to look down and in .
3 step test isolate a palsy of superior oblique muscle .
Others : hypertropia in primary position increase when looking at the direction of the un involved eye or tilting the head toward ipsilateral shoulder , the patient often maintain ahead tilt to the contralateral shoulder to eliminate diplopia .

DDX

vertical diplopia , hypertropia or both
1- myasthenia gravis
2- Thyroid eye disease
3- idiopathic orbital inflammatory syndrome
4-orbital fracture
5-Skew deviation
6-incomplete third nerve palsy
7-brown syndrome
8- GCA


Etiology
More common : trauma, vascular infarct ( DM AND HT) ,congenital , idiopathic , demyelinating disease.
Rare : tumor , aneurysm , GCA

Work up

1- History : onset and duration of diplopia , misaligned eyes or head tilt since early childhood, trauma , stroke .
2- examine old photograph to determine the head tilt is long standing indicating old or congenital fourth nerve palsy.
3- perform 3 step test .
4- perform double maddox rod test if bilateral fourth nerve palsies are suspected to measure total excyclotorsion .
5- measure vertical fusional amplitude with vertical prism bar to distinguish acongenital form from aquired form
6-edrophonium choride test
7- ct scan for head and orbit for orbital diseases
8- blood pressure measurement , fasting blood sugar , glycosylated hemoglobin. immediate ESR ,CRP and platelet if GCA is suspected
9- MRI for brain
-4CNP accompanied by other crainal nerves or neurological abnormalities.
-all patient less than 45 years of age with no history of significant head trauma , and patients aged 45 to 55 years with no vasculopathic risk factors or trauma

Treatment

1- treat the underlying disorder
2- occlusion patch to relieve symptomatic diplopia
3-prism for small stable hyperdeviation
4- squint surgery for diplopia in primay or readind positionor for significant head tilt .
Defer surgery at least 6 months after the onset of palsy for deviation and because many palsy resolve spontanously .


Symptoms:
Binocular horizontal diplopia , worse for distance than near most prononced in the direction of paretic lateral rectus muscle

Signs

Critical : limitation of abduction with negative forced duction test .
Others : no proptosis
DDX of limited abduction
1- thyroid eye disease
2-myasthenia gravis
3- Idiopathic orbital inflammatory syndrome
4- orbital trauma
5- Duane syndrome
6- Mobius syndrome
7- Convergence spasm
8-Pimary divergence insufficiency
9-GCA

Etiology

Adult
More common : vasculopathic , trauma , idiopathic
Less common : increase intracrainal pressure , cavernous sinus mass , MS, Vasculitis after LP , stroke , meningeal inflammation /infection , GCA .
Children
Benign and self limiting after viral infection or vaccination , trauma , increase intracrainal pressure ( obstructive hydrocephalus ) , pontine glioma , gradenigo syndrome
( petrositis causing 6,7 ,8,5 crainal nerve involvement on the same side associated with complicated otitis media ).


Work up
Adult
1- history of fluctuated symptoms , DM, HT,TED,symptoms of GCA
2- complete neurologic and ophthalmic examination .
Examiation other crainal nerves optic nerve, trigeminal for corneal sensation and optic nerve for papillodemia because increase intracrainal pressure frome any cause can result in unilateral or bilateral six nerve palsies .
3-check blood pressure , fasting blood sugar ,and glycosylated haemoglobine .
4- MRI of brain indicated for the following patients
A- yonger than 45 y if mri negative consider LP)
B-Patient 45-55 y with no vasculopathic risk factors.
C- 6 CNP accompany sever pain or any other neurologic or neurophthalmic signs
D- any history of cancer
E- bilateral 6 CNP
F- Papillodemia is present
5- immediate ESR , CRP and platelet count if GCA is suspected
6- consider RPR,FTA-ABS,lyme titer .

Children

1- history : recent illness or trauma , neurological symptoms , lethargy ,chronic ear infection .
2-complete neurologic and ophthalmic examination.
3-otoscopic examination to rule out complicated otitis media .
4- MRI of the brain in all children


Treatment
1-treate underlying problem revealed by the work –up .
2- occlusion to relieve symptomatic diplopia if patient less than 10 years patch avoided
3- prism in glasses may be fit acutely for temporary relief or for chronic stable deviations.
4- surgery for stable deviation that persists more than 6th months

Done by Omar Abid ALsamrrae

With best wishes