Brown syndrome

strabismus disorder

1. CASE PRESENTATION Alireza gholizade

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3. differential diagnosis inferior oblique paresis monocular elevation deficiency orbital fibrosis syndrome “big mimicker” Brown syndrome “simulated Brown syndrome” (e.g., orbital floor fracture, traumatic tenosynovitis, idiopathic orbital inflammation, metastasis to superior oblique muscle, orbital metastasis, frontal sinus osteoma, s/p blepharoplasty, or blunt orbital trauma) Superior oblique overaction

4. Brown Syndrome Brown syndrome is characterized by an inability to elevate the eye in adduction as a result of either a tight or shortened superior oblique tendon, or a process at the trochlea that limits the movement of the superior oblique tendon in the trochlear opening minimal to no hypotropia in primary position, minimal to no superior oblique overaction, 1928, German ophthalmologist P. A. Jaensch is presented with a child who could not elevate the affected eye in adduction. The case was presented in a medical journal the following year, initially under the disease name “ Superior oblique tendon sheath syndrome ” Harold W. Brown first described this syndrome in 1950 He labeled the disease “ Brown's superior oblique tendon sheath syndrome ” or simply “ Brown's Syndrome

5. The vertical saccade is normal but the eye gets to a sudden stop Brown syndrome is usually associated with an exotropia in upgaze (Y-pattern widening of the palpebral fissure in aDduction The inability to passively elevate the eye in aDduction

6. INCIDENCE Incidence is low – 6 in 2583 ( Croswell & Haldi ) Familial occurrence is rare 2%( Birgit Lorenz , ‎ Michael C. Brodsky ) Usually unilateral but 10% is bilateral

7. This child adopts a head tilt away from the affected eye to compensate for a hypotropia of the right eye

8. This child has adopted a chin-up head posture to compensate for a hypotropia of the left eye.

9. Idiopathic acquired Brown's syndrome is often intermittent and sometimes associated with a "dick" that is felt by the patient in the superior nasal quadrant when the patient looks up and in. The cause of the dick and limited elevation is not known, but it may represent inflammation or an abnormality of fascial tissue araund the superior oblique tendon.

10. orbital fibrosis syndrome It can involve one or both eyes, sometimes in a very asymmetric fashion, and most frequently involves the inferior, medial, superior, and then lateral rectus muscles. It is therefore essential to always properly perform a forced duction test (F.D.T.) on all extraocular muscles ( E.O.M.) , of both eyes, while the patient is under anesthesia.

11. “Monocular elevation deficiency”, this deficit occurs primarily in adduction and abduction, and can mimic Browns in the fact that there is a pronounced limitation of elevation in the paretic eye, as is the case in this child. A difference of this is that in primary gaze, patients often have a ptosis of the eye, and may adopt a chin-up head posture to compensate for the ptosis.

12. Inferior oblique paresis Patients with a “True” inferior oblique paresis generally present with the following symptoms, which differentiate it from Browns: A limitation of elevation in adduction, with a large vertical deviation in primary position, usually more than 10 PD. A marked superior oblique overaction An evident A-Pattern convergence, noticeable in direct upgaze Negative forced ductions test positive Bielschowsky head tilt test, This imbalance is rectified upon tilting her head to the opposite side

13. Io paresis Brown sync.

14. Grading of Severity Mild – Restricted elevation in adduction only with no hypotropia or downshoot in primary or adduction Moderate – restricted elevation and downshoot in adduction and direct elevation with minimal hypotropia in primary position and adduction Severe – restriction of elevation and marked downshoot in adduction and direct elevation. Evident hypotropia in primary position with, but not in all cases, adoption of abnormal head posture.

15. Management Management of Brown syndrome varies widely. Imaging of the orbit ( If the cause of an acquired Brown's syndrome is in question) with special attention to the region of the trochlea adds significantly to the workup of the patient with acquired Brown syndrome. In many cases, acquired Brown's syndrome will spontaneously resolve over several months to even several years. Surgery should only be considered after the patient has been observed for at least 6 months to 1 year

16. A significant proportion of children with Brown syndrome will have improvement of eye motility as they get older. Dawson, Barry, and Lee retrospectively reviewed 32 patients with Brown syndrome who were followed between 6 months and 9.5 years, and reported that 75 % of patients had some improvement in their ocular movements without any intervention. Of 6 patients with a “click,” 5 improved Also, as the child becomes older and taller, he/she will look at the parents and other adults at eye level and will not need to as frequently look up, inducing the anomalous eye movements. Most adult patients with persistent Brown syndrome, will generally position themselves and/or arrange their desk/office in such a way to avoid looking in the affected position of gaze, where the deviation is manifest (e.g., a patient with right Brown syndrome, will sit in a position in which he/she would look at others straight ahead or in right gaze).

17. SURGICAL INDICATIONS FOR CONGENITAL if there is a hypodeviation in primary position that causes a significant chin elevation surgery should be reserved for children older than 4 years of age; older children are less likely to develop postoperative Suppression and amblyopia operate on a child under 4 years of age if the hypodeviation is large enough to disrupt fusion Management of congenital Brown's syndrome is based on lengthening the superioroblique tendon. Procedures such as tenotomy and tenectomy release the restriction but are not controlled so muscle is not overacting and, therefore, procedures such as tenotomy or tenectomy often result in a secondary superior oblique paresis

18. superior oblique tendon expander The expander allows for controlled and reversible elongation of the tendon while maintaining the functional integrity of the superior oblique muscle-tendon complex complications of the procedure are rare, but these include extrusion of silicone and scarring of the silicone to the sclera, causing postoperative Iimitation of depression

19. The treatment of inflammatory Brown's syndrome includes a trial of systemic nonsteroidal antiinflammatory agents (e.g., indomethacin 25-50 mg TID) or a local steroid injection in the area of the trochlea.