Post on 07-May-2015
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Neurogenic Conditions
Fourth Nerve (or Superior Oblique) Palsy
Common as both congenital and acquired Can be bilateral or unilateral
Aetiology
Familial defect of nerve or its nucleus, or major brain abnormality
Many unknown Head injury, eg damage to trochlea in upper cut
blow in boxing Diabetes Intracranial tumour
Characteristics
Bielschowsky Head Tilt Test : this differentiates SO palsy from the contralateral SR Palsy
Ocular Posture
Unilateral palsies: affected eye hypertropic and slightly esotropic Excyclotropia likely
» Hypertropia increases on near fixation» Slight V pattern
Bilateral palsies:» Constant V pattern esotropia with hypertropia of the non-fixing
eye
» Extorsion of non-fixing eye in acquired only
AHP
Unilateral: (I) Head tilt to sound side (ii) Face turn to sound side (iii) Chin Depression All are to overcome the vertical diplopia Bilateral: Chin depression
Hess Chart
Field of BSV is displaced upwards (and to affected side in unilateral)
Management
Acquired unilateral palsy = vertical prism Others = surgery 90% of isolated unilateral palsies (except
some traumatic ones) recover spontaneously within 6 months.
Sixth Nerve (Lateral Rectus) Palsy
Common Aetiology
» Birth trauma: instrumentation, increases intracranial pressure presses nerve against the petrous temporal bone
» Childhood: meningitis, otitis media, pneumonia etc» Adult:trauma, demyelinating disease, intracranial space
occupying lesions
» Old Age: CVA
Characteristics
Ocular Posture esotropia on distance fixation with less for near (or only phoria at near)
Crossed fixation and equal VA in congenital bilateral type
AHP
Unilateral = face turn to affected side (esp in distance fixation)
Hess Chart
Field of BSV displaced to unaffected side in unilateral
Management
Prism base out to distance portion of bifocals Botulinium toxin A injection into MR reduces
esotropia to alleviate diplopia and prevents contracture of ipsilateral MR
Occlusion to prevent amblyopia in children Surgery
Related Syndromes to 6th Nerve Palsy
Mobius’ syndrome Congenital. Due to close association of 6th and 7th cranial nerves in the mid-
brain This syndrome is bilateral 6th and 7th nerve palsies, causing loss
of abduction and facial weakness (not necessarily symmetrical) Expressionless face, incomplete lid closure, bilateral loss of
abduction etc
Graderigos Syndrome
LR palsy caused by a middle ear infection which spreads to the petrous bone causing swelling and affecting the 5th (Trigeminal) and 6th nerves
Results in 6th nerve palsy, ipsilateral trigeminal pain of the face, deafness and facial turn to the affected side
This condition is rare since the advent of antibiotics
3rd Nerve Palsy (Ophthalmoplegia)
Mostly unilateral Possible causes: Birth injury, head injury,
diabetes, hypertension, compression by posterior communicating artery aneurysm
Classification
Complete Oculomotor Palsy affects all extra- and intra- ocular muscles.
Divergent strabismus with slight depression, ptosis, mydriasis, loss of pupil action accommodation
Partial Paresis
External ophthalmoplegia (all external ocular muscles only)
Internal ophthalmoplegia (paresis of ciliary muscle and iris sphincter)
Superior division of 3rd Nerve (SR and levator) Inferior division (IR, MR, IO, ciliary muscle and
sphincter Double elevator palsy (SR and IO). Congenital
Single Muscle Paresis (usually congenital)
SR with V pattern exotropia (usually accompanied by ptosis)
MR (very rare) IR (least common)
Cyclic Oculomotor Palsy
intermittant 3rd Nerve Palsy. Rare, ? Cause An acquired SR palsy is generally accompanied by ptosis
since the SR and levator share the superior division of the 3rd nerve and are anatomically in close proximity
Often get accompanying symptoms eg HIA, a tremor of the contalateral limbs (due to involvement of the Red Nucleus = Benedikts’ syndrome, and other diabetic symptoms).
Management
Prisms – limited use (diplopia only present if incomplete ptosis)
Botulinum toxin A – injection into LR can be helpful
Pilocarpine 0.1% to reduce photophobia Surgery
Mechanical Restriction of Ocular Movement
Duane’s Retraction Syndrome
Congenital Bilateral or unilateral – more often affecting
LE Incidence higher in females
Characteristics
One or all of: Limitation of abduction with widening of palpebral aperture Less marked limitation of adduction in the same eye Retraction of globe on adduction with narrowing of
palpebral apertures Poor convergence Face turn to affected side
Classification
TYPE A:Limited abduction, less marked limitation of adduction
TYPE B:Limited abduction but normal adduction TYPE C:Limitation of adduction exceeds
limitation of abduction.Exotropia and face turn
Aetiology
Innervation of the LR by extra branches of the 3rd nerve in place of an absent or atrophic 6th nerve
Simultaneous contraction of MR and LR resulting in retraction
Lack of abduction because lack of 6th nerve innervation Fibrosis of LR results, and hence mechanical
restriction
Management
Treatment of amblyopia and correction of refractive error
Surgery for cosmetic correction of AHP, if necessary.
Starbismus Fixus
Characteristics Very marked Esotropia Fibrosis and contracture of both MR – hence adduction of both eyes Absence of active and passive horizontal eye movement Face turn to side of fixing eye Rare Presents in infancy Uncertain if fibrosis of MR is a primary condition or secondary to LR
paralysis
Adherence Syndromes
Either: congenital adherence of extra-ocular muscles to each other or to facial tissue or levator
Familial Or: acquired due to infection, trauma or more
surgery (especially strabismus or retinal detachment surgery)
Management; Surgery
Brown’s Syndrome (or Superior Oblique Tendon
Sheath Syndrome)
Develops in infancy, or acquired later through inflammation (eg rheumatoid arthritis) or trauma in the trochlear region.
Mainly unilateral, can be bilateral
Characteristics
Limitation of elevation in adduction Overaction of the contralateral SR but other muscle sequelae do not
develop (therefore no defect in lower field) A or V pattern Typical Hess chart In some acquired cases with repeated attempts to look up and in an
audible ‘click’ is heard and eye suddenly shoots up with overacting IO AHP: tilt to affected side (Not always present) Positive forced duction test (Negative in IO palsy)
Aetiology
Uncertain and variable. Main causes: Short tendon sheath Presence of swelling on SO Tendon
preventing free passage through trochlea
Management
Most spontaneously recover Some surgery for cosmetic correction of
AHP
Blow-Out Fracture
Caused by direct blow to eye through closed lids Wave of pressure causes orbital floor to fracture,
and a portion of orbital tissue may become trapped
This restricts rotation of the globe, particularly up and down
Management
May recover spontaneously within 2 weeks Others require surgery to free trapped tissue
Myogenic Palsies
One in which the weakness of ocular movement is due to a primary problem affecting the muscle itself rather one disrupting the nerve supply or causing mechanical restriction.
Myasthenia Gravis
Comparatively rare disorder of neuromuscular transmission Onset 20-40 years. Characterised by excessive fatiguability of striated muscle, most commonly the
EOMs but may be more generalised. Diplopia and Ptosis are often presenting symptoms, which worsen during the
day. May later progress to a more generalised muscle involvement. The condition generally stabilises and then help may be gained with prisms,
ptosis props or surgery. Can get ptosis and can be confused with 3rd nerve palsy
Orbital Myositis
Inflammatory swelling of one or more of the EOMs.
Self limiting and resolves in about 8 weeks
Rhabdomyosarcoma
Highly malignant tumour of the striated muscle
May produce a strabismus and restriction of ocular movement or acute proptosis
Usually in childhood
Dysthyroid Eye Disease (Ophthalmic Grave’s Disease)
Can occur in hyperthyroidism (thyrotoxicosis) Or hypothyroidism (myxoedema) But is most common in the former Can present as a muscle palsy without exophthalmus Limitation of elevation, but more than one muscle is
affected, in the following sequence swelling of EOM (wet phase) = MYOGENIC fibrosis and secondary muscle contracture, especially of the
IR (dry phase) = RESTRICTIVE
Dysthyroid Eye Disease (Ophthalmic Grave’s Disease)
Other eye signs: proptosis, von Graefe’s sign, lid retraction, decreased blinking chemosis and vertical diplopia
Other symptoms may be:» increased/decreased appetite (depends on whether hyper/hypo)» decrease/increase weight» clammy hands» increased/decreased heart rate» anxiety/lethargy
» Tremor in hyper
Other systemic conditions causing ocular palsies
Diabetes Disease of the small blood vessel network (vaso nervorum) May cause acquired 3rd, 4th or 6th Nerve palsy (Third most
common) Usually spares the pupil (these fibres lie superficially in
Third Nerve and are not supplied by small vessel network as much)
Diplopia
Other symptoms:severe headache, increased thirst,
increased urination, increased appetite,decreased weight,
constipation, boils and skin conditions.
More common in older overweight females.
Diabetes
Other symptoms:» severe headache, » increased thirst, » increased urination, » increased appetite,» decreased weight, » constipation, » boils and skin conditions.
» More common in older overweight females.
Hypertension
Most commonly affects the 6th nerve, mostly in old age
Symptoms: » Headache, » dizziness, » breathlessness, » tinitis
Temporal arteritis (Giant Cell Arteritis)
Inflammatory disease of temporal artery occurring in over 60s Rarely presents as isolated oculomotor nerve palsy Symptoms:
» scalp tenderness,» headache, » prominent temporal arteries, » general malaise
» weight loss
Multiple Sclerosis
Ocular palsy is an early symptom in many patients
Other symptoms: loss of muscle coordination, limb weakness, slurring of speech
THERE ARE MANY CONDITIONS WITH OCULAR PALSY AS ONE OF THE FEATURES. THESE ARE THE MOST COMMON.