Explorations physiques et fonctionnelles des fosses nasales

Abstract

Fibroscopes and optics are commonly used and bring essential data in everyday rhinology practice. But medicolegal and safety concerns impose precise rules about decontamination and sterilization. Plain radiography (Caldwell's and Water's projections) is quick and easy in sinus imaging. Digitization gives higher quality and less radiation exposure. But, here, CTscan is the first choice (at least, frontal and axial sections). Contrast (iodine) is used only to study tumors or inflammatory disease complications. Radiation exposure and cataract hazard are very low. Virtual endoscopy from CTscan must be assessed in clinical practice. In addition to CTscan, MRI is really usefull only to analyse tumoral disease. Acoustic rhinometry is a reliable and non invasive mean to assess the first five centimeters of the nasal fossa anatomy (pre- and post-application of vasoconstrictors). It could become an important way to evaluate nasal obstruction, but establishing "standard values" still needs more scientific work. Nasal peak flow measurement is easy and cheap. It is usefull in clinical practice but keeps barely used. Rhinomanometry, most often anterior than posterior, does not appear so usefull in clinical practice. Mucociliary function can be assessed with more or less complicated clearance measurements (saccharin, stains, isotopes). In vitro ciliary motility study is dedicated to look for ciliary dyskinesia. This kind of study, in vivo, is only experimental. Ultrastructural analysis is primordial in the diagnosis of the primary ciliary dyskinesia syndrome. Nasal cytology gives different results if blowing, whashing, suctioning, printing or scrapping samples are used, because different cellular subcompartments are involved. In practice, only the eosinophil count is currently usefull, particularly in the diagnosis of non allergic rhinitis with eosinophilia syndrome (>10 to 20 % eosinophils in the total leucocyte count). Bacteriological studies show many commensal microorganisms in the nasal fossae. Maxillary sinus puncture keeps the "gold standard", but a sample collected at the middle meatus is reliable in 70-80 % and less invasive. Chronic sinusitis is more polymicrobial with more often anaerobic bacterias. The pathogenic role of fungus in chronic rhinosinusitis is still a debate, despite the frequent presence of fungus in the nasal mucus. Nitrogen oxyde measurements are used in research, but not yet in diagnosis. The response to nasal challenge can be evaluated clinically, or using rhinomenometry, acoustic rhinometry or cytology. Allergen challenge are useful, but higher standardizations are needed for more reliability. Pharmacologic nasal challenges are only used in research. Histological studies are essential to the diagnosis of tumoral or autoimmune diseases, but samples have to be conditionned according to the analysis to perform (eg : immunohistochemestry, molecular biology).