Hello! I have been through your question. Related your concern I think you should know that sphenoid sinuses are just behind the skull, above the nasopharynx and just below the pituitary gland and the symptoms of sphenoid sinus disease are also the same with other sinusitis like block nose, mucus discharge, headache, facial pain or sensation of pressure behind cheekbones and nose, in some cases weakened sense of smell ect. Yes of course, you have right that sphenoid sinusitis should not be taken for granted because progressive growth of the infection can cause neurological damage and it is known that of all the sinuses, the sphenoid is one of the most sensitive because of the connection between the sinus and the optic nerve. But, it is a good news that if you treat them with antibiotic like the other sinusitis, the risk of complications decrease a lot. What I suggest for you is to start as soon as possible the treatment with antibiotic ( usually I prescribe amoxicillin or levofloxacin if you aren t allergic) and use of nasal decongestants , saline solution and steam inhalation. I hope my answer help you. I wish you a quick recovery.