Superior Orbital Fissure Narrowing and Tumor-Associated Pain in Spheno-orbital Meningiomas

Introduction: Spheno-orbital meningiomas (SOMs) represent a distinct subtype of meningioma characterized by their unique multi-compartmental invasion pattern. Due to their proximity to orbital neurovascular structures, SOMs typically present with ophthalmologically related symptoms. Previous studies have investigated correlations between SOMs and visual manifestations, however the understanding of pain associated with SOMs remains limited. This study aims provide insight into the pathophysiology underlying SOM-related pain through measurements of tumor volume and superior orbital fissure (SOF) narrowing.

Methods: We conducted a retrospective review of medical records to identify patients who had underwent surgical resection for SOMs between 1/2000 and 12/2022. Medical records were reviewed, and data regarding patient demographics, clinical presentation, ophthalmological examination, operative notes, and follow-up were documented. Preoperative computed tomography (CT) and/or magnetic resonance imaging (MRI) scans were analyzed. CT scans were carefully reviewed to assess bony hyperostosis and were obtained with thin-cut sequences to ensure high resolution. The presence of intraosseous tumor involvement was assessed based on the extension of the tumor into the cranial bones. The tumor was partitioned into five distinct segments: intracranial, intraosseous, intraorbital, infratemporal, and intra-temporalis (located within the temporalis muscle). Using the volumetric measurement module, the tumor volume was calculated for each of the five segments in both pre- and postoperative studies. The SOF area was measured. Bony 3-D reconstructions were created from patients’ preoperative CT scans. Using anatomical landmarks, the SOF borders were outlines bilaterally, and the fissure area was measured. To calculate the SOF area narrowing, the healthy side was subtracted from the tumor-affected side. For investigating correlations involving categorical variables, logistic regressions were performed.

Results: The study cohort included 66 patients diagnosed with SOMs. Radiological analysis revealed that 92.4% of the patients (n = 61) had hyperostosis, while intraorbital soft tissue tumor extension was present in 39.4% (n = 26) of cases. Common symptoms on presentation included proptosis in 86.4% of patients (n = 57), decreased visual acuity (VA) in 80.3% (n = 53), and tumor-associated pain in 24.2% (n = 16). Among patients presenting with pain, 87.5% of patients (n = 14) reported improvement postoperatively. There was no significant correlation between the total volume nor the volume of tumor within each compartment and the presence of pain on presentation (p > 0.05). SOF narrowing due to hyperostosis was observed in 36.4% (n = 24) of patients. The median SOF narrowing within patients with identified narrowing was 20 mm² (IQR: 14.8–23.0). Using logistic regression, a significant correlation between the degree of SOF narrowing and the presence of SOM-associated pain on presentation was identified, with an aOR of 1.12 (95% CI: 1.06–1.19, p = 0.001).

Conclusion: Although the pathophysiology of tumor-associated pain is poorly understood, SOF narrowing appears to be a contributing factor in orbital and retro-orbital pain in patients with SOMs. Most patients demonstrate postoperative improvement in SOM-associated pain. Depending on the presenting symptom, we recommend decompression of the SOF in patients with SOM.