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Abstract: An 84-year-old man with a genetically confirmed diagnosis of VEXAS (vacuoles, E1 enzyme, X-linked, autoinflammatory, somatic) syndrome treated with tocilizumab reported with a 3-day history of left eye pain, conjunctival chemosis and injection, and horizontal binocular diplopia. Examination revealed restriction of left eye ductions in all directions with mild unilateral proptosis. MRI of his brain and orbits demonstrated abnormal enhancement of the left posterior sclera and intraorbital optic nerve sheath, without involvement of the extraocular muscles, cavernous sinus, or optic nerve parenchyma. B-scan ultrasonography heralded a positive "T-sign." Empiric treatment with high-dose intravenous methylprednisolone led to rapid clinical improvement. Workup for alternative causes was unremarkable. Oral prednisone dose and tocilizumab ultimately resulted in complete resolution after 4 weeks. The final diagnosis was consistent with orbital inflammatory manifestations of VEXAS syndrome., Competing Interests: The authors report no conflicts of interest., (Copyright © 2024 by North American Neuro-Ophthalmology Society.)

Competing Interests: The authors report no conflicts of interest.

Background: Pituitary adenomas and nonadenomatous lesions in the sellar region may be difficult to distinguish by imaging yet that distinction is critical in guiding management. The nature of the diagnostic errors in this setting has not been well documented., Methods: Two neurosurgeons and 2 neuroradiologists of differing experience levels viewed deidentified MRIs of 18 nonadenomatous sellar lesions and 21 adenomas. They recorded their diagnoses, the imaging features they used to make those diagnoses, and their confidence in making those diagnoses., Results: Among the 18 nonadenoma cases, 11 (61%) were incorrectly diagnosed as adenoma by at least 1 reader, including Rathke cleft cyst, plasmacytoma, aneurysm, craniopharyngioma, chordoma, Langerhans cell histiocytosis, metastasis, and undifferentiated sinonasal carcinoma. Among the 21 adenoma cases, 8 (38%) were incorrectly diagnosed by at least 1 reader as craniopharyngioma, Rathke cleft cyst, sinonasal carcinoma, hemangioblastoma, and pituitary hyperplasia. Incorrect imaging diagnoses were made with high confidence in 13% of readings. Avoidable errors among the nonadenomatous cases occurred when readers failed to appreciate that the lesion was separate from the pituitary gland. Unavoidable errors in those cases occurred when the lesions were so large that the pituitary gland had been obliterated or the imaging features of a nonadenomatous lesion resembled those of a cystic pituitary adenoma. Avoidable errors in misdiagnosis of adenomas as nonadenomas occurred when readers failed to appreciate features highly characteristic of adenomas. An unavoidable error occurred because a cystic adenoma had features correctly associated with craniopharyngioma., Conclusions: Errors in imaging differentiation of pituitary adenoma from nonadenomatous lesions occurred often and sometimes with high confidence among a small sample of neurosurgeons and neuroradiologists. In the misdiagnosis of nonadenomatous lesions as adenomas, errors occurred largely from failure to appreciate a separate pituitary gland, but unavoidable errors occurred when large lesions had obliterated this distinguishing feature. In the misdiagnosis of adenomas as nonadenomatous lesions, avoidable errors occurred because readers failed to recognize imaging features more characteristic of adenomas and because cystic adenomas share features with craniopharyngiomas and Rathke cleft cysts. Awareness of these errors should lead to improved management of sellar lesions., Competing Interests: The authors report no conflicts of interest., (Copyright © 2021 by North American Neuro-Ophthalmology Society.)

Background: Allergic fungal rhinosinusitis (AFRS) is a common condition in which sinusitis develops as an IgE-mediated response to common sinonasal fungal organisms. If that response leads to blockage of sinus ostia, bone expansion and erosion by expansive cysts containing dense inspissated debris may occur with the potential for critical neurovascular compression including damage to the anterior visual pathway., Methods: Review of clinical and imaging features of 2 patients who sustained catastrophic clinical outcomes., Results: The first patient had pansinusitis with massive mucocele-like cysts expanding the sphenoid sinus and cranial base and causing compression of the anterior visual pathway that led to persistent severe vision loss despite extensive sinus surgery. The second patient developed sphenoethmoidal expansion with a marked inflammatory response and presumed conversion to invasive fungal sinusitis that caused anterior visual pathway vision loss, bilateral ocular motor palsies from extension into the cavernous sinuses, and death from a large middle cerebral artery stroke., Conclusions: Although AFRS is most often benign and treatable, it may rarely produce catastrophic outcomes, especially if the sphenoid sinus is involved. Irreversible vision loss may occur from compression, and ocular motor palsies and death from conversion to invasive fungal disease. Close ophthalmologic and imaging monitoring is necessary in patients with expanded sinuses, and prophylactic sinus surgery may be indicated in certain cases.

Objective: A modern imaging review is necessary to further define the anatomic origin of the juvenile nasopharyngeal angiofibroma., Methods: After institutional review board approval, a search from January 1998 to January 2013 yielded 33 male patients (aged 10-23 years) with pathologically proven juvenile nasopharyngeal angiofibroma lesions, as well as pretreatment computed tomography/magnetic resonance imaging. Juvenile nasopharyngeal angiofibroma involvement was assessed in the following regions: sphenopalatine foramen, pterygopalatine fossa, vidian canal, nasopharynx, nasal cavity, sphenoid sinus, choana, pterygomaxillary fissure/masticator space, orbit, and sphenoid bone., Results: The choana and nasopharynx were involved in all 33 patients. In contrast, only 22 lesions involved the pterygopalatine fossa, 24 lesions involved the sphenopalatine foramen, and 28 lesions involved the vidian canal., Conclusions: Our results suggest that the juvenile nasopharyngeal angiofibroma origin is in the region of the choana and nasopharynx rather than the sphenopalatine foramen or pterygopalatine fossa.

Background: The vulnerable brain areas in hypoxic-ischemic encephalopathy (HIE) following systemic hypotension are typically the neocortex, deep cerebral gray nuclei, hippocampus, cerebellum, and the parieto-occipital arterial border zone region. The visual cortex is not commonly recognized as a target in this setting., Methods: Single-institution review from 2007 to 2015 of patients who suffered cortical visual loss as an isolated clinical manifestation following systemic hypotension and whose brain imaging showed abnormalities limited to the occipital lobe., Results: Nine patients met inclusion criteria. Visual loss at outset ranged from hand movements to 20/20, but all patients had homonymous field loss at best. In 1 patient, imaging was initially normal but 4 months later showed encephalomalacia. In 2 patients, imaging was initially subtle enough to be recognized as abnormal only when radiologists were advised that cortical visual loss was present., Conclusions: The occipital lobe may be an isolated target in HIE with cortical visual loss as the only clinical manifestation. Imaging performed in the acute period may appear normal or disclose abnormalities subtle enough to be overlooked. Radiologists informed of the clinical manifestations may be more attune to these abnormalities, which will become more apparent months later when occipital volume loss develops.

Bilateral lateral geniculate nucleus (LGN) injury is a rare cause of vision loss. We describe a patient with pre-eclampsia who developed profound but reversible bilateral vision loss, bilateral serous retinal detachments, and magnetic resonance imaging signs of a variant of posterior reversible encephalopathy syndrome (PRES) that affected both LGNs and spared the retrogeniculate pathways. We provide evidence that the visual loss was not from the chorioretinal lesions but from the LGN lesions. The concurrence of PRES and lesions attributed to choroidal hypoperfusion provides support for the notion that vasoconstriction also underlies the pathogenesis of PRES.

In this pictorial review, we present diverse imaging features of spinal schwannomas with an idea to familiarize spine imagers with the varied spectrum of presentation of these tumors. Different types of spinal schwannomas presented include multiple schwannoma (n = 3), schwannoma with cystic degeneration (n = 3), schwannoma with hemorrhage (n = 2), melanotic schwannoma (n = 1), intraosseous schwannoma (n = 2), schwannoma growing into the foramen transversarium (n = 1), intramedullary schwannoma (n = 1), large or giant schwannoma (n = 1), malignant schwannoma (n = 2), and infarcted schwannoma (n = 1). We present imaging findings in these cases and review their differential diagnosis. Awareness of the uncommon presentations of these seemingly common tumors is important in offering a correct diagnosis.

Purpose: The aim of our study is to describe the hyperintense ring sign on fluid-attenuated inversion recovery (FLAIR) images in patients with dysembryoplastic neuroepithelial tumors (DNET), to discuss the radiopathologic correlation for this appearance, and to determine its role in preoperative diagnosis of DNETs., Materials and Methods: We retrospectively analyzed imaging features in 11 patients with pathological diagnosis of DNET. All patients had undergone surgery for refractory seizures. All had FLAIR imaging sequences performed on a 1.5-T magnetic resonance scanner. Clinical and pathological details in all cases were examined. Twenty-one age matched patients with pathologically confirmed low-grade glioma (n = 11), oligodendroglioma (n = 2), and ganglioglioma (n = 8) in similar locations acted as control cases. Ten patients had follow-up imaging., Results: There were 11 patients with DNET (5 girls and 6 boys). The age of presentation varied from 4 to 18 years (average, 9 years 1 month). Tumors were located in the temporal (n = 5), frontal (n = 4), parietal (n = 1), and occipital (n = 1) lobes. In 9 patients (82% sensitivity), the FLAIR images showed a well-defined hyperintense ring around these tumors, either as a complete or incomplete ring. Among the 21 control cases, the hyperintense ring sign was seen in 2 cases (90% specificity): one with low-grade glioma and one with ganglioglioma. Pathological evaluation of the DNETs suggested the hyperintense ring might correspond to the presence of peripheral loose neuroglial elements. Postoperative imaging showed partial residual ring in 3 patients, all of whom had persistent seizures. One patient had recurrent DNET at second surgery., Conclusion: Magnetic resonance imaging findings of DNET are well described. We describe an additional imaging sign, the hyperintense ring sign on FLAIR images, which is distinct and is fairly sensitive and specific for DNET. We believe this sign is a helpful adjuvant to preoperatively diagnose these tumors. The presence of this ring on postoperative imaging may indicate residual or recurrent tumor.