Browns Syndrome Flashcards
What did Brown (1950) first find out about with regards to Browns Syndrome?
8 cases restricted elevation in adduction finding that during surgery shortened tendon sheath of superior oblique muscle tendon was found and thus used to be called Superior Oblique Tendon Sheath Syndrome (SOTSS)
The abnormality in most cases involves the superior oblique tendon and/or the trochlear complex.
What is the prevalence rate of Brown’s Syndrome?
Rare - 0.22% of all strabismus up to 10% of cases in vertical strabismus
Who/what does Brown’s Syndrome affect the most?
- Usually unilateral (<10% bilateral)
- RE more commonly affected
- 59% females affected
- Can be congenital or acquired
What is Browns Syndrome?
Superior Oblique + Mechanical Restriction = Restriction of Elevation in Adduction
Tight muscles, limits movement in position of gaze opposite (May be referred to as direct leash)
What do OMs look like between ductions and versions in Browns?
OMs: ductions the same as versions
Retractions may be seen but saccades are normal
What does a Hess Chart look like in Browns?
Hess chart: “squashed” inner and outer fields in area of greatest limitation
What is IOP like in Brown’s Syndrome?
Increases when looking away from limitation
What does the muscle sequelae look like in Brown’s Syndrome?
Only one step (overaction of contralateral synergist)
What does a forced duction test look like in Brown’s Syndrome?
Positive FDT (normally performed before surgery)
What is the purpose of a FDT in Brown’s investigation?
- To differentiate a mechanical from of a non-mechanical cause for the limitation on elevation and differentiates Brown’s syndrome from IO palsy
- To differentiate Brown’s from a tight IR muscle – retropulsion (pushing the globe into the orbit) increases the FDT in Brown’s Syndrome but decreases it if contracture of the IR is present
What is the congenital aetiology of Browns?
Tendon
- Nodule/swelling
- Tight/inelastic
- Short (anterior sheath)
- Congenital fibrosis
Pulley System
- Tight
- Misaligned
Innervation
- Anomalous to SO and IO muscles
- Bifid (muscle split in 2 with another insertion site) sclera insertion of SO
What is Brown’s Syndrome a category of? Disorder-wise
CCDD (Congenital Cranial Dysinnervation Disorder)
What is the systemic aetiology in acquired Browns?
- Dysthyroid disease
- Arthritis
- Lupus
- Sinusitis
- Sjogren Syndrome
What is the ophthalmic aetiology in acquired Browns?
- Blepharoplasty (eyelid lift, is a surgical procedure that removes excess skin and fat from the upper or lower eyelids)
- Glaucoma implant / any implant in superior nasal region
- Orbital floor fracture
- Iatrogenic (following surgery: superior oblique tuck)
- Trochleitis (inflammation of trochlea within the tendon sheath)
- Neoplasms of superior nasal orbit (tumour)
- Trauma
What are some acquired Browns aetiology that aren’t systemic or ophthalmic?
- Cyclic
- Idiopathic
- Inflammation
- Postpartum
- Infection
- Age related degeneration
- Iatrogenic following frontal sinus surgery
What are some features of Browns Syndrome?
- Limitation of elevation in adduction. If restriction of movement is severe, there may also be some limitation of direct elevation and even of elevation in abduction.
- Down-drift of the affected eye on contralateral version, sometimes accompanied by widening of the palpebral fissure.
- o/a of contralateral SR. Other muscle sequelae doesn’t normally develop so there’s no o/a of SO on affected side but o/a of IO on unaffected side is sometimes reported.
- A or V patterns
- Typical Hess chart shows limitation of elevation or no or minimal abnormality in the lower field
Discomfort on attempting elevation in adduction - Improvement in elevation in adduction when repeating testing in that direction. Can get ‘click syndrome’ where you hear a click sound, in some cases this is followed by o/a of ipsilateral IO with restricted movement in downgaze. The ‘click’ can indicate the condition may spontaneously resolve.
- Torsion in upgaze
- Positive FDT
- AHP – head up, head tilt to affected side and head turn to contralateral side. Head up only if syndrome is bilateral and symmetrical. Often Brown’s patients can maintain BSV without AHP.
What does Browns look like in elevation?
Limited elevation in adduction. If restriction of movement is severe, there may also be some limitation of direct elevation and even of elevation in abduction.
What happens in contralateral version in Browns Syndrome?
Down-drift of the affected eye on contralateral version, sometimes accompanied by widening of the palpebral fissure.
What does the muscle sequelae look like in Browns Syndrome?
o/a of contralateral SR. Other muscle sequelae doesn’t normally develop so there’s no o/a of SO on affected side but o/a of IO on unaffected side is sometimes reported
What does a Hess Chart look like in Browns Syndrome?
Typical Hess chart shows limitation of elevation or no or minimal abnormality in the lower field
What happens with ‘click syndrome’?
Improvement in elevation in adduction when repeating testing in that direction. Can get ‘click syndrome’ where you hear a click sound, in some cases this is followed by o/a of ipsilateral IO with restricted movement in downgaze. The ‘click’ can indicate the condition may spontaneously resolve
When do Brown’s Syndrome patients get torsion?
In upgaze
What does AHP look like in Browns Syndrome?
AHP – head up, head tilt to affected side and head turn to contralateral side. Head up only if syndrome is bilateral and symmetrical. Often Brown’s patients can maintain BSV without AHP.
What are patients likely to say in case history?
- May present with abnormal eye movements, AHP or manifest deviation
- Adults may report diplopia, pain or discomfort or a ‘clicking’ sound
- Past medical history: may include inflammatory conditions, trauma or previous surgery
What does AHP look like in Browns Syndrome?
Majority of Brown’s have comfortable BSV and can maintain this with head-up AHP (chin elevation) and sometimes a head tilt to affected side and face turn away from affected side. A decompensating deviation is seen from loss of AHP, slow recovery to BSV after dissociation which is often seen after using the CT, loss of BSV and manifest deviation.
What does a deviation in pp look like in Browns?
- Small deviation in primary position (doesn’t match the amount of mechanical restriction).
- Possible hypotropia (manifest) of affected eye depending on severity, latent deviation possible
(Amblyopic risk factor if manifest strabismus present)
What does Dextroversion look like in LE Brown’s?
- Possible downdrift on adduction of affected eye
- Widening palpebral fissures may occur in adduction
What does Dextro-Elevation in the affected eye look like in LE Browns Syndrome?
- Restriction of affected eye (key feature - present in all irrelevant of severity)
- Movement can improve on repeated testing in cases with a “click”
- May see overaction of contralateral SR (muscle sequelae)
What does direct Elevation look like in Brown’s Syndrome?
- Generally slight limitation of affected eye but can be normal movement
- A or V pattern may be present
What does Laevo-Elevation of affected eye look like in LE Brown’s Syndrome?
- Generally normal unless SO very tight; may be a slight limitation
What does Dextro-Version of affected eye and depression look like in LE Brown’s Syndrome?
- Normal movement
What does the grading look like in Brown’s Syndrome?
- Mild
- Moderate
- Severe
Which Brown’s has limited elevation in adduction? Mild, Mod or Severe
All 3
What Brown’s grading has limited direct elevation?
Severe only
What Brown’s grading has limited movement in abduction?
Moderate & Severe
Which Browns grading has a hypotropia during CT?
Severe
Which Browns grading has a downshoot in adduction?
Moderate & Severe (marked in severe!)
What does the Field of BSV look like in Browns?
- Generally BSV present in pp (unless manifest deviation) and lower field
What is ‘Click Syndrome’?
Can be a part of Browns
Spontaneous improvement over long periods of time occurs often in early-onset Brown’s Syndrome. The presence of ‘click syndrome; that’s intermittent is usually associated with a better long-term prognosis. If a click is suspected the it can be detected by placing a finger over the trochlea and asking the patient to look up and inwards. A click can be felt by a sudden movement of the tendon through the trochlea. Need to repeat the procedure over each eye. Sometimes a bilateral click can be felt in patients whose symptoms are unilateral.
How do we test for ‘click syndrome’?
If a click is suspected the it can be detected by placing a finger over the trochlea and asking the patient to look up ad inwards. A click can be felt by a sudden movement of the tendon through the trochlea. Need to repeat the procedure over each eye. Sometimes a bilateral click can be felt in patients whose symptoms are unilateral.
What causes ‘click’ syndrome?
Can be painful (can be associated with inflammatory conditions)
Generally due to nodule or swelling
Due to the tendon catching and releasing as it moves through the trochlea
What should Brown’s be differentiated from?
- Isolated IO palsy. Rare but seen most often in orbital trauma or in association with MG
- MG (Myasthenia gravis, “great mimicker” , also has general variability and fatigue)
- Double elevator palsy. Can be differentiated from double elevator palsy, elevation is equal to or worse in abduction, while in Brown syndrome, elevation is limited in adduction and by the presence of a ptosis. Bell’s may be intact, confirming absence of mechanical restriction of elevation.
- Orbital blow-out fracture can cause limitation of elevation that’s greatest in abduction with globe retraction when attempting upgaze (sometimes is also in adduction making it difficult to differentiate from Browns).
- Congenital fibrosis of extraocular muscle syndrome (ptosis and restrictions bilaterally of other muscles)
- Adherence Syndrome - following inferior oblique surgery due to adhesions, progressive hypotropia can occur
- Glaucoma drainage surgery - can give ocular motility restrictions similar to Brown’s
- Grave’s Orbitopathy. Oblique muscle involvement in Graves’ orbitopathy is probably underreported; in most cases the 2 conditions can readily be differentiated
- CCDDs such as Duanes (due to PF changes but restrictions in other areas)
- Strabismus fixus / heavy eye - high myopia associated with strabismus and restrictions
How do we measure strength of BSV in Browns?
Deviation in pp should be measured by a PCT and strength of BSV assessed using stereotests, positioned in the lower field if necessary. Binocular function should be investigated if manifest strabismus.
When should we plot a Hess Chart in Brown’s Syndrome?
Once OM’s have been done then a Hess chart should be plotted. This is because, if deferred until later in the exam, the full extent of limited elevation in adduction may not be shown due to the repeating of this movement allowing them to move into this position more so with time.
See slide 27!
How do we differentiate Brown’s Syndrome and IO Palsy by:
- Vertical deviation
- Head posture
- Muscle Sequelae
- Alphabet Pattern
- OMs
- Hess Chart
- FDT
- Vertical deviation
Browns = small or nil
IO = Obvious - Head posture
Browns = often absent or very slight
IO = Present & marked - Muscle Sequelae
Browns = o/a contralateral SR only (only o/a of contralateral synergist)
IO = + contracture ipsilateral SO and u/a contralateral IR (will eventually develop into a full muscle sequelae) - Alphabet Pattern
Browns = V (or A)
IO = A - OMs
Browns = May be painful. Movement may improve on repeated testing
IO = No pain, no improvement - Hess Chart
Browns = Classical mechanical picture with V-pattern
IO = Non-mechanical, show muscle sequelae and A-pattern - FDT
Browns = Limited movement up and in (positive FDT)
IO = Normal (negative)
What are the general management plans in Brown’s Syndrome?
- Observations
- Correction of any refractive error, any amblyopia treated
- Spontaneous improvement can occur in 75% of cases (Dawson et al, 2009) generally around the age of 7 and then full improvement by 12-15 years or spontaneous improvement can occur in adulthood
If spontaneous improvement doesn’t occur children generally look up less as they grow
- Local steroids- in cases with inflammation (oral or injected), some success but may not be continual
- If manifest angle, prisms may help
What non-surgical options do we have for Brown’s Syndrome?
- Majority of patients with Brown’s that’s early onset maintaining symptom-free BSV with a slight AHP. Field of BSV is usually adequate and in the optimum position on depression of gaze. These patients don’t usually need treatment but children should be observed. It may spontaneously improve but, if not, as the child grows the anomaly will be less noticeable as upgaze will be used less.
- Retrotrochlear Steroid Injection
Local steroids can be used in late-onset Brown’s Syndrome to reduce inflammatory reaction or to prevent development of fibrous tissue secondary to trauma.
What surgical options do we have in Browns Syndrome?
Is not predictable, the results may range from no change in elevation in adduction to a SO palsy so operations should be cautious, especially as spontaneous improvement can occur. But where BSV is only maintained with a severe AHP then surgery can be used, diplopia in primary position or decompensation. Shouldn’t use posterior tendon surgery as it can lead to fibrosis and would limit the passage of the tendon through the trochlea in both directions.
What type of surgery is the most effective in Brown’s Syndrome?
- Silicone expander of superior oblique tendon or lengthening procedure (often most successful)
- Can be varied/controlled depending on severity of Brown’s
What other types of surgery are options in Brown’s Syndrome that isn’t Silicone expander of superior oblique tendon or lengthening procedure?
- Tenotomy of superior oblique tendon (weakening, can cause superior oblique palsy)
Superior oblique posterior Tenectomy (weakening) - Freeing any adhesions around trochlear
- Contralateral superior rectus recession
- If SO tuck, reverse this but must be done quickly
- Post op: duction exercises may aid (in elevation in adduction)
