The purpose of this study was to investigate the prevalence of incidental sinonasal diseases on CT scan in Pakistani population presenting with neurological signs and symptoms for brain imaging.

This cross sectional study was conducted in Department of Radiology, Services Institute of Medical Sciences/ Services Hospital, Lahore, between August 2009 and June 2010. All the cases undergoing CT head referred by physicians and neurophysicians presenting with neurological symptoms and signs besides exclusion of the cases of head trauma were included. The study population consisted of 507 patients, including 311 men and 196 women, who were 2-75 years old (mean age, 42 years). Frontal, ethmoid, sphenoid, left and right maxillary sinuses were separately evaluated. The pathological processes included were mucosal thickening, opacification, air-fluid level, retention cysts and polyps.

Out of 507, there were 199 patients (39.25%) in whom sinus pathology was documented. There were no significant gender differences amongst the study population. Most of the patients were adults; pediatric age group consisted 11%. The incidental sinonasal disease was more common in the patients above 30 years of age, with slight predilection toward females (56%). Mucosal thickening was the most common pathology (71.8%); categorization including normal (no mucosal thickening), mucosal thickness of 1 mm (34.6%), 2 mm (24.6%), 3 mm (27.7%), and 4 mm or above (13.1%) was done accordingly. Other abnormalities including sinus opacification (14%), air-fluid level (5.0%), retention cyst (5.5%) and polyp (3.5%) were found uncommon.

The high prevalence of sinonasal disease in general population emphasizes the necessity of clinical correlation, if picked incidentally on cross-sectional brain imaging. Subtle mucosal thickening, in particular to ethmoidal air cells, is a normal variant, most likely due to the physiologic nasal cycle. Incidental findings of paranasal sinus disease without clinical signs and symptoms do not define a diagnosis of sinusitis or a sinonasal disease; adequate clinical information is mandatory prior to starting the treatment. The possible reason of high prevalence of sinonasal disease in Pakistani population could be dust allergy and pollution besides respiratory tract infections and smoking. Future studies are recommended to a larger population to evaluate the significance of these incidental findings.