Headache on the right side behind the eye for 1 week: also drooping right eyelid and pain in the eye when quickly looking down or down towards the nose. History of Brown syndrome OD 4 years ago. Orbits MRI: There is focal swelling, T2 hyperintensity, and hyperenhancement of the right superior rectus muscle posteriorly towards the orbital apex, measuring up to 6 mm in thickness, with mild compression of the optic nerve and proptosis. There is minimal, if any edema or enhancement in the adjacent orbital fat. The other right rectus muscles appear to be intact. The left orbit is unremarkable. Brain MRI: There is no evidence of intracranial hemorrhage, mass, or acute infarct. There is susceptibility effect in the bilateral globi pallidi, which may represent mineralizing. The brain parenchyma otherwise appears unremarkable. There is no abnormal intracranial enhancement. The ventricles and basal cisterns are normal in size and configuration. There is no midline shift or herniation. The major cerebral flow voids are intact. The orbits, skull, and scalp soft tissues are grossly unremarkable. There is mild ethmoid sinus mucosal thickening diffusely and moderate right sphenoid sinus mucosal thickening.Brain MRA: There is no evidence of significant steno-occlusive lesions or cerebral aneurysms.
A lesion affecting the right superior rectus muscle may be infectious or inflammatory in nature and less likely neoplastic, given the relatively acute onset of symptoms. No evidence of associated vascular or intracranial lesions, within the limited of MRA. The paranasal sinus disease suggestive of sinusitis may be potentially related to the orbital lesion or it may be incidental.