Inclusion Criteria:  >18 years Patients included are all adult (>18 years) patients with PNS: Inflammation of the nose and sinuses that is characterised by two or more of the following symptoms (at least one of which must be nasal obstruction or runny nose): Nasal obstruction and nasal congestion Rhinorrhoea (anterior or posterior) Facial pain or pressure Decreased or loss of sense of smell Sneezing and/or nasal pruritus  These symptoms should be associated with :  Endoscopic signs of nasal polyps Diffuse bilateral naso-sinusal opacities on CT or CBCT  Exclusion Criteria:  Decline to participate in the study No one who speaks or understands French History of skull base surgery for tumours History of major head trauma History of cerebral-facial radiotherapy or chemotherapy History of inflammatory or neurodegenerative neurological pathology Systemic disease associated with the presence of sinus polyps (Granulomatosis - with polyangiitis, cystic fibrosis, primary ciliary dyskinesia, immune deficiency) Cancer or haematological disease in progress