Clinical Outcomes of Severe Rhinosinusitis Complicated with Cavernous Sinus Syndrome

Background: Various diseases involving the cavernous sinus can cause a condition called cavernous sinus syndrome (CSS), which is characterized by ophthalmoplegia or sensory deficits over the face resulting from the compression effect of internal structure. While tumor compression is the most reported cause of CSS, statistical data on CSS caused by infections are limited. Its risk factors, treatment methods, and clinical outcomes are not well-documented. Methods: In this retrospective study, we reviewed the data of patients admitted to a tertiary medical center from 2015 to 2022 with a diagnosis of acute and chronic sinusitis and at least one diagnostic code for CSS symptoms. We manually reviewed whether patients were involved in two or more of the following cranial nerves (CN): CN III, CN IV, CN V, or CN VI, or at least one of these nerves with a neuroimaging-confirmed lesion in the cavernous sinus. Results: Nine patients were diagnosed with rhinosinusitis-related CSS. The most common comorbidity was type 2 diabetes, and the most common clinical manifestations were diplopia and blurred vision. The sphenoid sinus was the most affected sinus. One patient expired due to a severe brain abscess infection without surgery. The remaining patients underwent functional endoscopic sinus surgery, and 50% of the pathology reports indicated fungal infections. Staphylococcus spp. was the most cultured bacteria, and Amoxycillin/Clavulanate was the most used antibiotic. Only four patients had total recovery during the follow-up one year later. Conclusions: CSS is a rare but serious complication of rhinosinusitis. Patients with diabetes and the elderly may be at a higher risk for this complication. Even after treatment, some patients may still have neurological symptoms.