Brown's syndrome

Question 1

what is brown’s syndrome

Answer 1

Ocular motility defect

Limitation of the affected eye on elevation in adduction
Both actively and passively

Question 2

describe what you will see in a muscle sequelae of a px with brown’s syndrome

Answer 2

• greatest limitation is in up gaze and in adduction
• in pp = px has downward and outward deviation of that eye
• mechanical so only O/A of contralateral SR, inferior field full (i.e. second stage muscle (sequelae)

Question 3

what will the affected eye look like in pp in brown’s syndrome

Answer 3

downward and outward deviation of that eye

Question 4

is brown’s syndrome unilateral or bilateral, and by how much of cases

Answer 4

90% unilateral

Question 5

what 2 cases are equal in brown’s syndrome

Answer 5

RE = LE

Female = male

Question 6

what does congenital and acquired brown’s syndrome have the same of

Answer 6

the same ocular motility defect

Question 7

what do most patients with brown’s syndrome have

Answer 7

most have binocular single vision

Question 8

what varies from one patient to the other with brown’s

Answer 8

Degree of limitation

some patients will gain a AHP to see BSV
the AHP will vary depending on the extent of their OM deficit

Question 9

what are the 4 possible congenital aetiologies of brown’s
first mention the most commonly accepted theory
then mention the 3 other less commonly accepted theories

Answer 9

Most commonly accepted theory:
- Inelastic or short Superior Oblique tendon

Less commonly accepted theories:
- Nodule or swelling of the tendon
SO muscle and tendon are unable to relax to allow the eye to elevate = limitation of that eye
Unlikely to improve over time (stationary variety)

• Thickened trabeculae
  SO tendon and trochlear connected during embryological development by thickened trabeculae which persists rather than remodels and so inhibits passage of tendon through the trochlear
  More plausible it will spontaneously resolve
• Thickened vascular sheath
  Vascular sheath enveloping SO tendon may be thickened thus reducing smooth passage of tendon through the trochlear
  Intermittent variety – idiopathic click

Question 10

what is the acquired aetiologies of brown’s all based on and give 3 possible aetiologies

Answer 10

Secondary changes in previously normal Superior Oblique tendon or tendon-trochlear complex

• Iatrogenic
  Following surgery to strengthen SO (tuck) for SO/4th CN palsy
• Inflammatory
  Rheumatoid arthritis, causes swelling on the tendon
  Stenosing tenosynovitis “trigger thumb” analogy
• Trauma
  Road traffic accidents, ENT surgery, direct trauma e.g. “canine tooth” syndrome from dog bites

Question 11

give 3 reasons why you will want to investigate someone with brown’s syndrome

Answer 11

• Diagnose
• Binocular vision potential
• Plan management
  Cosmetic vs functional outcome

If the BSV that they do have is controlled very well with an AHP and also want to know how big that AHP is e.g. if its a marked chin posture = will need some form of surgery to try and reduce that underlying deviation down for them so its easier for them to control

Question 12

what 3 things may be included in the ‘signs’ of your case history of someone with brown’s syndrome

Answer 12

• Abnormal eye movements: a vertical deviation of the unaffected eye (hypert) affected eye not able to look up
• Strabismus: will notice a squint in pp, but usually when they try to look up, will notice elevation on the other eye
• Abnormal head posture

Question 13

what types of symptoms may a patient with brown’s syndrome complain of

Answer 13

Usually symptom free

Pain / discomfort of affected eye on elevation in adduction

- Tugging around trochlear area
- Vertical diplopia

Question 14

wich type of aetiology of brown’s will cause Pain / discomfort of affected eye on elevation in adduction and why is this

Answer 14

Experienced when they have a nodule of the SO tendon

This causes pain, or a flicking sensation when the eye tries to elevate

Because the nerve tries to go through the nodule itself

Question 15

what 5 tests should be included in your orthoptic report for someone with brown’s syndrome

Answer 15

Abnormal head posture for BSV in moderate / marked case

Vision

Cover test (with and without AHP)

Prism assessment if diplopia in primary position

Ocular motility

Question 16

what will be the AHP for someone with brown’s syndrome and what does it vary with

Answer 16

Chin elevation
Head tilt to affected side
Face turn to unaffected side

varies with the degree of OM deficit the px has

Question 17

when getting a case history from the parent, what will they report of noticing with their child who had brown’s syndrome

Answer 17

usually notice a vertical deviation of the affected eye and will notice the unaffected eye has drifted up

Question 18

how will you carry out your vision test on a patient with brown’s syndrome
what will you find majority of the time
what may you find if the child has a constant manifest squint

Answer 18

• cyclo refraction
• majority have equal vision (as they adopt a AHP)
• amblyopia if constant manifest squint (where they will need relevant patching treatment)

Question 19

how will you carry out a cover test on a patient with brown’s syndrome and why
what results will you find with majority of patients in pp
where will you find these patients to have BSV and what 2 tests will you carry out in this position

Answer 19

• with and without AHP
  with: to make sure/check that everything is absolutely fine and to make sure that they are controlling to a latent deviation
  the moment you put their head straight i.e. without the AHP, they are likely to have a manifest deviation
• Majority are phoric (hypo) in primary position
• BSV in lower field
  Prism fusion range
  Stereoacuity

Question 20

when will you find that you need to do a prism assessment if diplopia in primary position and what will you find and what can you do to correct this in clinic

Answer 20

• found usually in slightly older children ~ 6-7 y/o, who haven’t been diagnosed formally of having brown’s syndrome
• when looking up into elevation with their head straight, px will have diplopia
• in clinic, can alleviate that diplopia with some fresnel prisms

Question 21

describe what you will see with the affected eye when doing OM on a patient who has brown's syndrome in: 
elevation in adduction 
direct elevation 
elevation in abduction
adduction 
abduction 

and 2 other additional observations

Answer 21

elevation in adduction: limitation of eye (is greatest here)

direct elevation: slight limitation

elevation in abduction: full or very slight limitation

adduction: downdrift (this is the side of the gaze of the affected eye)
abduction: normal

will also see:
V pattern on divergence of eyes in elevation
- Abducting action of Inferior Oblique muscles as elevation attempted

Discomfort/pain/click on attempted elevation in adduction
- May show an improvement on repeated testing

Question 22

how will you differentiate brown’s syndrome from a IO palsy

Answer 22

the muscle sequelae of brown’s syndrome will only be limited to the overaction of contralateral Superior Rectus as mechanical
where as IO palsy muscle sequelae will be full as its neurogenic

Question 23

why will you see a V pattern on divergent of eye in elevation in someone with brown’s syndrome

Answer 23

as abducting action of Inferior Oblique muscles as elevation is attempted

Question 24

list 2 ddx of browns syndrome

Answer 24

• Isolated Inferior Oblique Palsy

- Blow-out fracture

Question 25

how can you differentiate browns syndrome from an isolated inferior oblique palsy

Answer 25

Because its RARE!!!! Suspect Browns until proven otherwise

Neurogenic would have full muscle sequalae
Overaction contralateral SR, Overaction ipsilateral IO, underaction Contralateral IR

Question 26

how can you differentiate browns syndrome from a blow out fracture

Answer 26

• Clear history of trauma
• Limitation in elevation, greatest in abduction
• Retraction of globe of up gaze
• Infraorbital nerve anaesthesia

Question 27

why is a conservative treatment mostly chosen to manage someone with browns syndrome
give 3 reasons

Answer 27

• Majority symptom free BSV in PP and lower field
• Slight head posture depending on degree of limitation (nothing needs to be done, something only done is AHP is marked)
• Natural history:
  Limitation may improve over time, if not up-gaze used less as child grows in height therefore anomaly less noticeable

Question 28

what is the non-surgical management for someone with browns syndrome
give 2 reasons why
what is a disadvantage
when is this method only indicted

Answer 28

• Retrobulbar steroid injection
• Reduces inflammation
• Prevent development of fibrous tissue following trauma
• Not substained effect in all cases
• Indication only in patients who would otherwise of had surgery

But as this treatment is down under local anaesthetic, the px cannot be too young

Question 29

give 3 reasons when surgical management for browns syndrome is indicated

Answer 29

• Marked AHP / significant angle in primary position
• Cosmetic problem
• Indication of decompensation of squint (i.e. deviation is significantly reduced with AHP but px cannot control it for too long)

Question 30

list the 4 surgical options

Answer 30

• Weaken Superior Oblique tendon (tenotomy)
• Superior Oblique tendon expander (lengthening procedure)
• Weaken (recess) contralateral Superior Rectus
• Horizontal muscle surgery (not done if have vertical squint)

Question 31

what can the surgery outcome for browns syndrome be

Answer 31

unpredictable as…

results range from no change in limitation in elevation in adduction to a complete SO palsy

Question 32

what is the only aim for surgery in browns syndrome and what must you tell the parent before hand

Answer 32

• surgery is only for the poor cosmetic reasons in pp or to reduce the angle of deviation to control it more easily
• must tell parent that limitation of eye movement will still persist

Question 33

if the parent is mostly noticing the eso and exo deviation in pp and not the hypert/hypot dev in pp, what surgery can you do

Answer 33

either weakening or strengthening treatment of the horizontal muscles only
but only to counteract the horizontal deviation

Question 34

if the parent is mostly noticing the vertical squint, what surgery can you do

Answer 34

surgery on the SO of affected eye or SR of unaffected eye