eMedicine Specialties > Ophthalmology > Extraocular Muscles
Brown Syndrome: Differential Diagnoses & Workup
Updated: Dec 3, 2007
- Overview
- Differential Diagnoses & Workup
- Treatment & Medication
- Follow-up
- Multimedia
Differential Diagnoses
Other Problems to Be Considered
The following signs of superior oblique overaction help differentiate it from Brown syndrome (see Table below):
- Mild limitation of elevation in adduction
- No limitation of elevation in abduction
- Common bilateral involvement
- Superior oblique overaction
- A-pattern, lambda-subtype with divergence in downgaze
- Fundal examination reveals intorsion in primary position that increases in downgaze.
- Negative forced ductions test
The following signs occur with inferior oblique paresis, differentiating it from Brown syndrome (see Table below):
- Limitation of elevation in adduction occurs, with a large vertical deviation in primary position, usually more than 10 PD.
- Marked superior oblique overaction
- A-pattern, convergence in upgaze
- Fundal examination reveals intorsion in primary position, which increases in upgaze.
- Positive head-tilt test
- Negative forced ductions test
Double elevator palsy: In Brown syndrome, limitation of elevation in adduction is invariable; yet, this sign is also present in 70% of patients with double elevator palsy. The difference between elevation in adduction versus elevation in abduction differentiates Brown syndrome from double elevator palsy, where elevation is equal to or worse in abduction.
Differential Diagnoses: Clinical Features of Brown Syndrome, Inferior Oblique Paresis, and Superior Oblique Overaction
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Table
| Brown syndrome (inelastic superior oblique muscle-tendon complex) | Primary superior oblique overaction | Inferior oblique paresis | |
| Limitation of elevation in adduction | Usually severe (-3 to -4) | Usually mild | Usually severe (-3 to -4) |
| Limitation of elevation in adduction | Common (mild to moderate) | No | No |
| Bilateral involvement | Rare (5-10%) | Common | Unusual |
| Vertical deviation | None or small (<10 PD) | Bilateral small (<10 PD) | Unilateral large (>10 PD) |
| Superior oblique overaction | None or minimal | Yes, marked | Yes, marked |
| Pattern | None or V-pattern Y-subtype with divergence in upgaze | A-pattern Lambda-subtype with divergence in downward gaze | A-pattern, often convergence in upgaze |
| Fundus torsion | None in primary or downgaze, intorsion in upgaze | Intorsion in primary, increasing in downgaze | Intorsion in primary, increasing in upgaze |
| Head title test | Negative | Negative | Positive |
| Forced ductions | Positive | Negative | Negative |
| Brown syndrome (inelastic superior oblique muscle-tendon complex) | Primary superior oblique overaction | Inferior oblique paresis | |
| Limitation of elevation in adduction | Usually severe (-3 to -4) | Usually mild | Usually severe (-3 to -4) |
| Limitation of elevation in adduction | Common (mild to moderate) | No | No |
| Bilateral involvement | Rare (5-10%) | Common | Unusual |
| Vertical deviation | None or small (<10 PD) | Bilateral small (<10 PD) | Unilateral large (>10 PD) |
| Superior oblique overaction | None or minimal | Yes, marked | Yes, marked |
| Pattern | None or V-pattern Y-subtype with divergence in upgaze | A-pattern Lambda-subtype with divergence in downward gaze | A-pattern, often convergence in upgaze |
| Fundus torsion | None in primary or downgaze, intorsion in upgaze | Intorsion in primary, increasing in downgaze | Intorsion in primary, increasing in upgaze |
| Head title test | Negative | Negative | Positive |
| Forced ductions | Positive | Negative | Negative |
Workup
Laboratory Studies
- No laboratory tests are specifically required in the workup of congenital Brown syndrome.
- In cases of acquired, nontraumatic Brown syndrome, tests to exclude autoimmune diseases, such as lupus, juvenile rheumatoid arthritis (JRA), and rheumatoid arthritis, may need to be ordered.
Imaging Studies
- Consider MRI of the orbit for acquired Brown syndrome, especially if associated with pain, discomfort, signs of inflammation, or an atypical pattern of strabismus.
- In some cases, imaging studies may identify pathology in the area of the trochlea, even superior nasal orbital tumors and sinusitis.
More on Brown Syndrome |
| Overview: Brown Syndrome |
 Differential Diagnoses & Workup: Brown Syndrome |
| Treatment & Medication: Brown Syndrome |
| Follow-up: Brown Syndrome |
| Multimedia: Brown Syndrome |
| References |
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References
Brown HW. True and simulated superior oblique tendon sheath syndromes. Doc Ophthalmol. Feb 21 1973;34(1):123-36. [Medline].
Parks MM, Brown M. Superior oblique tendon sheath syndrome of Brown. Am J Ophthalmol. Jan 1975;79(1):82-6. [Medline].
Helveston EM, Merriam WW, Ellis FD, Shellhamer RH, Gosling CG. The trochlea. A study of the anatomy and physiology. Ophthalmology. Feb 1982;89(2):124-33. [Medline].
Wright KW. Brown's syndrome: diagnosis and management. Trans Am Ophthalmol Soc. 1999;97:1023-109. [Medline].
Parks MM. Bilateral superior oblique tenotomy for A-pattern strabismus in patients with fusion (commentary). Binoc Vis. 1988;3:39.
Buckley EG, Flynn JT. Superior oblique recession versus tenotomy: a comparison of surgical results. J Pediatr Ophthalmol Strabismus. May-Jun 1983;20(3):112-7. [Medline].
Clarke MP, Bray LC, Manners T. Superior oblique tendon expansion in the management of superior oblique dysfunction. Br J Ophthalmol. Jul 1995;79(7):661-3. [Medline].
Clarke WN, Noel LP. Brown's syndrome with contralateral inferior oblique overaction: a possible mechanism. Can J Ophthalmol. Aug 1993;28(5):213-6. [Medline].
George JL, Maalouf T, Cordonnier MO, Angioi-Duprez K. [Abnormal eyelid positions in Brown syndrome]. J Fr Ophtalmol. Jun 2004;27(6 Pt 1):579-87. [Medline].
Helveston EM, Birchler C. Superior oblique palsy: subclassification and treatment suggestions. Am Orthopt J. 1982;32:104-110.
Prieto-Diaz J. Posterior tenectomy of the superior oblique. J Pediatr Ophthalmol Strabismus. Sep-Oct 1979;16(5):321-3. [Medline].
Scott AB, Knapp P. Surgical treatment of the superior oblique tendon sheath syndrome. Arch Ophthalmol. Sep 1972;88(3):282-6. [Medline].
Scott WE, Jampolsky AJ, Redmond MR. Superior oblique tenotomy: indications and complications. Int Ophthalmol Clin. 1976;16(3):151-9. [Medline].
Von Noorden GK. Binocular Vision and Ocular Motility. St. Louis: CV Mosby; 1996:437-442.
Wright KW. Color Atlas of Ophthalmic Surgery-Strabismus. Philadelphia, Pa: Lippincott; 1991:201-219.
Wright KW. Superior oblique silicone expander for Brown syndrome and superior oblique overaction. J Pediatr Ophthalmol Strabismus. Mar-Apr 1991;28(2):101-7. [Medline].
Wright KW. Surgical procedure for lengthening the superior oblique tendon. Invest Ophthamol Vis Sci. 1989;30(sup):377.
Wright KW, Min BM, Park C. Comparison of superior oblique tendon expander to superior oblique tenotomy for the management of superior oblique overaction and Brown syndrome. J Pediatr Ophthalmol Strabismus. Mar-Apr 1992;29(2):92-7; discussion 98-9. [Medline].
Wright KW, Silverstein D, Marrone AC, Smith RE. Acquired inflammatory superior oblique tendon sheath syndrome. A clinicopathologic study. Arch Ophthalmol. Nov 1982;100(11):1752-4. [Medline].
Further Reading
Keywords
Brown's syndrome, BS, superior oblique tendon sheath syndrome, true sheath syndrome, simulated sheath syndrome, strabismus, amblyopia
