Brown syndrome (orbit)
Citation, DOI & article data
Brown syndrome refers to a failure of upward gaze while the eye is adducted secondary to an abnormality of the superior oblique tendon sheath complex.
This abnormality is a little counter-intuitive and highlights how the action of the superior oblique is position-dependent and that eye movement is dependent on the coordinated action of multiple muscles.
During abduction, it depresses the eye (down-gaze) whereas in adduction it causes intorsion (inward torsion). However, for the eye to be able to look upwards in adduction, a motion carried out by contraction of the inferior oblique muscle, free motion of the superior oblique tendon complex through the trochlea needs to be able to occur. Thus abnormalities at this level prevent the eye from gazing upwards, restricting its motion 1-3.
MRI is the modality of choice. It may show:
- thickening and enhancement of the left superior oblique tendon sheath and the trochlear sling
- edema-like signal around the same structures
History and etymology
It was first described by Allan Brown in 1950 1.
- 1. Currie S & Goddard T. MR Imaging Features of Acquired Brown Syndrome. AJNR Am J Neuroradiol. 2009;30(9):1778-9. doi:10.3174/ajnr.A1591 - Pubmed
- 2. Michels K, Kurup S, Curran M, Alperin R, De Leon E, Mets-Halgrimson R. A Case of Acquired Brown Syndrome Treated with Adalimumab. J AAPOS. 2020;24(3):167-9. doi:10.1016/j.jaapos.2020.01.003 - Pubmed
- 3. Lang M, Faraji N, Coffey M, Badve C. MRI of Acquired Brown Syndrome: A Report of Two Cases. Radiol Case Rep. 2018;13(1):92-5. doi:10.1016/j.radcr.2017.09.025 - Pubmed