Browns syndrome

Question 1

Histology

Answer 1

by Brown in 1950 and it is usually unilateral and there are only 10% bilateral cases and these are occasionally reported in females.

Question 2

Cong or Acq

Answer 2

It can be congenital or acquired

Question 3

Frequency

Answer 3

There is an equal frequency in males and females and the RE is more affected than the LE.

Question 4

Features

Answer 4

Restriction of elevation in adduction
Normal or near normal elevation in abduction
Positive forced duction test
Absence of muscle sequlae except o/a contralateral SR

Question 5

Further features

Answer 5

• Downdrift on adduction
• Widening of palpebral fissure on adduction
• V pattern (A also reported)
• Improved movement with ‘click’ on repeated testing
• AHP

Question 6

Youtube summary

Answer 6

https://www.youtube.com/watch?v=jBASYYMhHVA

Question 7

Grading browns

Answer 7

Mild
Mod
Severe

Question 8

Mild browns

Answer 8

Position with limited elevation
PP- no
Adduction- no
Elevation in adduction- yes

Question 9

Moderate browns

Answer 9

Position with limited elevation
PP- no
Adduction- yes
Elevation in adduction- yes

Question 10

Severe browns has limitated elevation where…

Answer 10

EVERYWHERE

Position with limited elevation
PP- yes
Adduction- yes
Elevation in adduction- yes

Question 11

Superior oblique anatomy

Answer 11

https://www.youtube.com/watch?v=f_rb6FMVHPk
at 6:43

Question 12

Aetiology of congenital browns

Answer 12

• Short anterior tendon sheath
• Developmental Anomaly affecting trochlea/superior oblique complex
• Inelastic superior oblique tendon
• Nodule or swelling on the tendon
• LR pulley instability Bhola 2005 (1 case)
• In the CCDD spectrum

Question 13

CCDD disorders

Answer 13

• CFEOM (congenital fibrosis of extraocular muscles)
• 3rd nerve palsy
• 4th nerve palsy
• 6th nerve palsy
• Moebius syndrome
• Duane syndrome
• Brown syndrome
• Ocular synkinesis syndromes
• Horizontal gaze palsy with progressive scoliosis.

Question 14

Is Browns a CCDD

Answer 14

It is linked with a congenital SO palsy and there is a proposed mechanism for Browns and Congenital SO palsy

Question 15

Aetiology in acquired browns

Answer 15

• S.O. tuck
• Injury to trochlea area (less since seat belt law introduced)
• Orbital trauma
• Inflammatory (Elnahry AG, Elnahry GA, 2019)
• Rheumatoid arthritis
• Surgery for blow-out fractures (Ji et al, 2015)
• Comestic blepharoplasty (Wilde et al, 2012)
• Orbital mass (Fard et al, 2011)
• Infection (COVID19, Haliyur et al, 2022; Kızıltunc et al, 2021)

Question 16

VA and AHP in acquired browns

Answer 16

VA
Usually normal unless associated manifest deviation

AHP
Chin elevation, tilt to affected side and turn to unaffected side

Question 17

Further investiagtion of browns

usually binocular in pp

Answer 17

CT
Often binocular in p.p. possible hypophoria/exophoria
May have reduced control become manifest without AHP

Binocular Function
Usually good binocular functions
Test for potential BSV if manifest
Plot field of BSV in older child or adult

Measurement
PCT in p.p.
May measure on versions and elevation
Plot Hess chart (dog ear appearance of affected eye) in older child

Question 18

Differential diagnosis of Browns

Answer 18

IO palsy- muscle sequelae present, A pattern, negative FDT
Double elevator palsy- Elevation limited in all elevated positions , no alphabet pattern, FDT may be negative dependant on aetiology

Question 19

Management

Answer 19

Observe- 75% show spontaneous improvement (Dawson et al 2009)

Surgery: Indicated if decompensating, mkd AHP or poor cosmesis, Results often disappointing

Question 20

Surgical options

Answer 20

SO tendon spacer (expands muscle)
Tenotomy
Recession of contralateral SR

Question 21

Tenotomy

Answer 21

Tenotomy with preservation of intermuscular connective tissue septum
Tenotomy with removal of intermuscular connective tissue septum.

Question 22

Recession of contralateral SR

Answer 22

Reverse S.O. tuck. Operate on horizontal muscles if large horizontal angle. Tendon Splitting Moghadam (2014) Dubinsky-Pertzov et al(2021)
Trochlea reconstruction in acquired Brown’s

Question 23

Steroid injection used to

Answer 23

To reduce inflammatory reaction or prevent fibrosis in trauma
Some success in early onset (Trimble 1988) though not sustained

Question 24

Exaggerated traction test

when done and repeated

Answer 24

Squirrell et al case report in congenital Brown’s.

Performed under GA & steroid injection given following traction test.

Repeated 5months later

Question 25

Summary

Answer 25

• Restriction of elevation in adduction
• No development of muscle sequelae
• Often improve / resolve
• Surgery only if symptomatic
• To do: Read Ansons / Davis 2014 ed: p 545-51