Different causes and diverse outcomes of extremely rare septic cavernous sinus thrombosis complicated with internal carotid artery stenosis

Background: Cases of acute sphenoid sinusitis complicated by septic cavernous sinus (CS) thrombosis and internal carotid artery (ICA) stenosis are rarely reported. Different causative pathogens have been reported for this condition. We present two extremely rare and special cases with diverse clinical presentations and outcomes. Case 1 involved a female patient with less extensive sinusitis, but critical ICA occlusion. Case 2 involved a male patient with extensive pansinusitis, meningitis, cerebritis, and vasculitis due to fungal infection, but less stenosis of the ICA lumen. Both patients underwent surgical debridement and received broad-spectrum antibiotics. Additional anti-fungal medication was also administered in Case 2. However, outcomes differed considerably between cases. Discussion: Case 1 recovered with minimal neurological deficits and had Glasgow Outcome Scale (GOS) and modified Rankin Scale (mRS) scores of 5 and 2, respectively; however, the Case 2 had GOS and mRS scores of 3 and 4, respectively. Although rare, septic CS thrombosis with ICA stenosis can lead to unexpected and severe neurological sequelae. Fungal infection can result in catastrophic complications and poorer prognosis. Conclusion: In addition to early detection, aggressive surgical debridement and adequate antimicrobial treatment are crucial to satisfactory outcomes in patients with septic CS thrombosis complicated with ICA stenosis.