Chinook Wind Barosinusitis: An Anatomic Evaluation

Abstract

Background Chinook, or föhn, is a weather phenomenon characterized by a rapid influx of warm, high-pressured winds into a specific location. Pressure changes associated with chinook winds induce facial pain similar to acute sinusitis. The purpose of this study was to determine the relationship between sinonasal anatomy and chinook headaches. Methods Retrospective computed tomography (CT) sinonasal anatomy analysis of 38 patients with chinook headaches and 27 controls (no chinook headaches). The chinook headache status was blinded from the CT reviewer. Forty-one sinonasal anatomy variants, Lund-Mackay status, and sinus size (cm3) were recorded. Results There were three statistically significant sinonasal anatomy differences between patients with and without chinook headaches. The presence of a concha bullosa and sphenoethmoidal cell (Onodi cell) appeared to predispose to chinook headaches (p = 0.004). Chinook headache patients had larger maxillary sinus size (right, p = 0.015, and left, p = 0.002). The Lund-Mackay score was higher in the control patients (p = 0.003) indicating that chronic sinusitis does not play a role in chinook headaches. Conclusion Chinook winds are a common source of facial pain and pressure. This is the first study to show that sinonasal anatomic variations may be a predisposing factor. Anatomic variants may induce facial pain by blocking the natural sinus ostia, thus preventing adequate pressure equilibrium.